Some derivatives showed antimycobacterial activities, especially in biofilm growth conditions. For example, 20–100 µM of HA10Fe2, HA10FeCl, HA10Fe3, HA10Ni2 or HA10Cu2 inhibited Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium marinum biofilm development. HA10Fe2, HA12Fe2 and HA12FeCl could even attack pre-formed Pseudomonas aeruginosa biofilms at higher concentrations (around 300 µM). The phthiocerol dimycocerosate (PDIM)-deficient Mycobacterium tuberculosis H37Ra was more sensitive to the ion complexes of HA compared to other mycobacterial strains. Furthermore, HA10FeCl could increase the susceptibility of Mycobacterium bovis BCG to vancomycin. Proteomic profiles showed that the potential targets of HA10FeCl were mainly related to mycobacterial stress adaptation, involving cell wall lipid biosynthesis, drug resistance and tolerance and siderophore metabolism. This study provides new insights regarding the antimycobacterial activities of HA and their complexes, especially about their potential anti-biofilm activities.Hydroxamic acid (HA) derivatives display antibacterial and antifungal activities. HA with various numbers of carbon atoms (C Mycobacterium tuberculosis. According to the World Health Organization (WHO) Global Tuberculosis Report 2022, globally, in 2021, an estimated 10.6 million people developed active tuberculosis and 1.58 million died from tuberculosis  and [4Fe-4S] ferredoxins, [1Fe-0S] rubredoxin, the ortholog RubB from M. tuberculosis, which is involved in redox homeostasis, also participated in the electron transfer, notably during the oxidative stress process [M. bovis BCG by decreasing CYP124 production and up-regulating rubredoxin for adaptation to the stress H10FeCl treatment condition.In this study, our compounds were evaluated to target three mycobacterial strains: membrane  but alsomembrane ,31. The  process ,33,34. CppsA-E and pks15/1, among others, like Pks12, Pks18, TesA, DrrB, Pks6, PpgK, ClpS and Mmpl7 [pks1 also correlates with other gene expressions, like the expression of fadD22, Rv2949c, lppX, fadD29, pks6 and pks12 [pks12) in the genome of M. tuberculosis H37Rv encodes probable polyketide synthase needed to produce fatty acids, probably involved in the synthesis of phthiocerol, the diol required for DIM synthesis [M. tuberculosis) could catalyze the reduction of phthiodiolone and phenolphthiodiolone to yield phthiocerol and phenolphthicerol in M. tuberculosis [pks12 and BCG_2973, were significantly up-regulated, further indicating that HA10FeCl could affect the virulent PDIM/PGL biosynthesis. As is well known, the virulent mycobacterial cell wall lipids PDIM and PGL were considered potential targets for antituberculosis drug development. The phenolphthiocerol (phthiocerol) moiety biosynthesis of PGL (PDIM) requires several type I polyketide synthases (PKS) encoded by nd Mmpl7 ,38,39,40nd pks12 . The larrculosis . The propstS3-pstC2-pstA1, regulated by the two-component regulatory system (2CRS) SenX3-RegX3 in M. tuberculosis during phosphate depletion and nutrient starvation [M. tuberculosis.Additionally, the phosphate-specific transport operon arvation  and potearvation ,44, is u2+ uptake [M. bovis BCG, suggesting either their lower expression compared with the control or their loss due to a defected outer membrane, i.e., by a reduced amount of PDIM.Furthermore, the membrane protein PE15, which is a PE/PPE protein and essential for efficient Ca+ uptake , and theM. tuberculosis strain than on the other two strains in stressful conditions. Their mechanisms of action still need to be further investigated, among others, by AFM-IR. Indeed, the proteomic data and synergistic activity of the H10FeCl compound suggest that it could affect the integrity of the mycobacterial cell wall.In summary, out of HA and its Fe(II/III), Ni(II), Cu(II) and Zn(II) complexes evaluated for their antimycobacterial activity, the most promising growth inhibitors were some Fe(III), Cu(II) and Zn(II) complexes , which exhibited the highest antibacterial activity against pathogenic mycobacteria. Fe complexes showed stronger inhibitory effects on the PDIM-deficient


Setaria italica (L.) P. Beauv) can respond to abiotic stress through a highly complex polygene regulatory network, in which the SiCYP450 family is also involved. Although the CYP450 superfamily has been systematically studied in a few species, the research on the CYP450 superfamily in foxtail millet has not been completed. In this study, three hundred and thirty-one SiCYP450 genes were identified in the foxtail millet genome by bioinformatics methods, which were divided into four groups, including forty-six subgroups. One hundred and sixteen genes were distributed in thirty-three tandem duplicated gene clusters. Chromosome mapping showed that SiCYP450 was distributed on seven chromosomes. In the SiCYP450 family of foxtail millet, 20 conserved motifs were identified. Cis-acting elements in the promoter region of SiCYP450 genes showed that hormone response elements were found in all SiCYP450 genes. Of the three hundred and thirty-one SiCYP450 genes, nine genes were colinear with the Arabidopsis thaliana genes. Two hundred SiCYP450 genes were colinear with the Setaria viridis genes, including two hundred and forty-five gene duplication events. The expression profiles of SiCYP450 genes in different organs and developmental stages showed that SiCYP450 was preferentially expressed in specific tissues, and many tissue-specific genes were identified, such as SiCYP75B6, SiCYP96A7, SiCYP71A55, SiCYP71A61, and SiCYP71A62 in the root, SiCYP78A1 and SiCYP94D9 in leaves, and SiCYP78A6 in the ear. The RT-PCR data showed that SiCYP450 could respond to abiotic stresses, ABA, and herbicides in foxtail millet. Among them, the expression levels of SiCYP709B4, SiCYP71A11, SiCYP71A14, SiCYP78A1, SiCYP94C3, and SiCYP94C4 were significantly increased under the treatment of mesotrione, florasulam, nicosulfuron, fluroxypyr, and sethoxydim, indicating that the same gene might respond to multiple herbicides. The results of this study will help reveal the biological functions of the SiCYP450 family in development regulation and stress response and provide a basis for molecular breeding of foxtail millet.The cytochrome P450 monooxygenases (CYP450) are the largest enzyme family in plant metabolism and widely involved in the biosynthesis of primary and secondary metabolites. Foxtail millet ( The cytochrome P450 monooxygenases  are heme proteins widely distributed in animals and plants , and theArabidopsis thaliana [Populus trichocarpa [Since the first plant CYP450 was found in cotton in 1969 [thaliana , 1285 inchocarpa , etc. NoIn the primary amino acid sequence of CYP450s, only a few domains are highly conserved: the proline-rich membrane hinge, the sequence surrounding the cysteine which is the axial ligand to the heme, the I-helix (AGxD/ET) involved in oxygen binding, and the E-R-R triad consisting of the Glu and Arg of the K-helix consensus sequence (KETLR) and the Arg in the “PERF” consensus sequence . Among tCYP78A9 in Arabidopsis led to large, seedless fruits [japonica rice led to larger embryos [Arabidopsis CYP715 plays a key regulatory role in flower maturation, petal expansion, and volatile release [OsCYP707A7 in rice resulted in increased abscisic acid (ABA) content and antioxidant enzyme activity, thereby enhancing drought tolerance in rice [AtCYP709B3 in Arabidopsis resulted in delayed germination under NaCl treatment and enhanced salt tolerance [TaCYP81D5 enhanced salt tolerance by enhancing ROS signal transduction and scavenging [ent-kaurene oxidase activity with a mixed substrate that might be involved in the biosynthesis of maize gibberellin (GA) [CYP450 genes encode CYP71, CYP72, CYP73, CYP81, and CYP749 proteins. They are responsible for acetyl-CoA carboxylase (ACCase) (sethoxydim), acetolactate synthase (ALS) (nicosulfuron), photosystem II (PSII) (florasulam), hydroxyphenyl pyruvate dioxygenase (HPPD) (mesotrione), and synthetic auxin herbicide (fluroxypyr) metabolic resistance [Arabidopsis CYP76C1, CYP76C2, and CYP76C4 were capable of metabolizing herbicides monoterpene phenol and phenylurea [CYP450s, as one of the largest enzyme protein families, play a vital role in plant development and physiological processes. For example, overexpression of s fruits , and los embryos . Arabido release . CYP450s in rice . Loss-ofolerance . Wheat Tavenging . The CYPavenging , and CYPavenging . CYP701Alin (GA) . In addisistance ,30,31,32enylurea , and CYPenylurea  Barley Cenylurea .4 photosynthesis and functional gene discovery of Gramineae due to its outstanding characteristics such as a small genome, self-pollination, multiple single-spike seed setting, and easy use in the laboratory, therefore it will become a hot crop for functional gene research in plants in the future [SiCYP450 gene family in foxtail millet has mainly been studied by using the methods of genomics and bioinformatics. The physicochemical properties, chromosomal distribution, gene structure, conserved motifs, and cis-acting elements of the SiCYP450 proteins were analyzed. The gene expression of the SiCYP450 gene family was analyzed after various treatments, including three abiotic stresses , ABA, and five herbicides . The results will help to further explore the function of SiCYP450s in foxtail millet and develop improved varieties.Foxtail millet is an ancient crop that originated in China, with a history of domestication and cultivation of more than 10,000 years. It has such outstanding advantages as resistance to dry climates, poor soil quality, and high efficiency of photosynthesis. At the same time, foxtail millet is rapidly developing into a model plant for Ce future ,35,36. ASiCYP450 genes were identified in foxtail millet. The evolutionary relationship analysis was based on the 331 identified CYP450 genes of Setaria italica and those of Arabidopsis thaliana . Each group was further divided into several subgroups except CYP5X. CYP5X only has one subgroup (CYP51G), and there were only four genes  in the CYP51G group. There were 26 subgroups in the CYP7X group, and the subgroup CYP71A had the most genes with 94 genes. The CYP8X and CYP9X groups had nine and ten subgroups, respectively. In total, there were 46 subgroups in four groups of SiCYP450 genes. CYP71 was the largest family of A-type in foxtail millet (107 genes), while foxtail millet CYP72 was the largest family of non-A-type with 16 members  were not distributed on any of those nine chromosomes , II , and V . The minimum number, 23, was on chromosome I. Both chromosomes III and VIII had the same number, 31, of SiCYP450 genes.To understand the distribution of omosomes . MoreoveSiCYP450 gene tandem duplication pairs, which corresponded to 116 genes , and only seven genes comprised not less than nine exons . SiCYP97B1 consisted of up to 14 exons. Overall, the gene structure of SiCYP450 was relatively simple. The gene structure in the four groups did not show obvious regularity.Based on the data of gene annotation, a gene structure map was produced . The numSiCYP450 gene family. Motif 10 and motif 14 were composed of 11 and 15 amino acid sites, respectively, and contained multiple conserved sites. There were only fifty SiCYP450 genes containing motif 11, including forty-five genes in the CYP7X group, one gene in the SiCYP89A subgroup, three genes in the SiCYP96A subgroup, and one gene in the SiCYP97B subgroup. The motifs of different subfamilies were different. There were more members in the CYP71A subgroup, and motif 16 was found in 88 CYP71A protein sequences, but there was no motif 16 in the CYP709B, CYP710A, CYP711A, CYP714A, CYP715A, CYP716A, CYP72A, CYP721A, CYP722A, CYP724A, CYP734A, CYP74B, CYP77B, CYP78A, and CYP79C subgroups of the CYP7X group. Motif 2, motif 3, and motif 8 were found in all CYP9X protein sequences. In CYP5X and CYP8X classes, there were multiple identical motifs.To examine the characteristic regions of SiCYP450 proteins, twenty motifs were analyzed using the MEME database, and a conserved motif of SiCYP450 protein was produced . The resSiCYP450 gene family as a promoter sequence, and the PlantCARE database was used for cis-acting element analysis , salt (200 mM NaCl), low-temperature stress (4 °C), 100 μM ABA, and herbicide  treatments using RT-PCR , which are divided into 47 families, while rice, wheat, and maize have 45, 45, and 43 CYP450 families, respectively [SiCYP450 genes in foxtail millet  [SiCYP450 genes were colinear with Setaria viridis genes, including 245 gene duplication events, indicating that Setaria italica and Setaria viridis genes have a close genetic relationship.In recent years, researchers have continuously isolated new CYP450 families and genes from plants, and the constructed CYP450 database covers animals, plants, fungi, and other organisms, including 66 plants such as d barley . The Araectively . In thisl millet . Systemi07 genes , which wSiCYP450 genes. SiCYP450 family genes varied from 0 to 13, while 0 to 14 in rice [PCY450s in foxtail millet show high gene structure diversity. A total of one hundred and thirty-seven (41.38%) SiCYP450 genes with one intron accounted for the largest proportion, followed by sixty-three (19.03%) and forty-seven (14.2%) genes, possessing zero and two introns. The conserved motifs of SiCYP450 proteins in foxtail millet were analyzed to explore the similarity and diversity of motif compositions. A total of 20 distinct motifs, named motifs 1–20, were detected using the MEME online program  required the involvement of CYP450s, including CYP500A, CYP90B, CYP90C, CYP90D, CYP724B, etc. ,42. AtCYelopment . In our iCYP98A1 . The exp tissues . It seemCYP450 genes have been reported to be involved in stress response. Wheat TaCYP81D2, TaCYP81D3, TaCYP81D1, and TaCYP81D5 expressions were up-regulated under salt stress [CYP707A1, CYP707A3, and CYP707A4 in Arabidopsis was higher, while CYP707A2 was less expressed [Arabidopsis AtCYP709B3 was up-regulated after 24 h of salt stress treatment [SiCYP450 genes, 13, 12, 13, and 14 SiCYP450 genes could be induced and expressed by osmotic stress, salt stress, low-temperature stress, and ABA, respectively, indicating that they have important biological functions in responding to different stresses. More importantly, the expressions of SiCYP709B4, SiCYP71A11, SiCYP71A14, SiCYP721A1, SiCYP76G7, SiCYP76G15, SiCYP88A2, SiCYP89A20, SiCYP94C3, SiCYP94C4, SiCYP97B1, and SiCYP98A1 could be induced by osmotic stress, salt stress, low-temperature stress, and ABA and they showed overlapping expression characteristics, which indicated their functional pleiotropic effects in different abiotic stresses and ABA. In order to further demonstrate transcription regulation, cis-acting sequence analysis showed that the genes of SiCYP721A1, SiCYP88A2, SiCYP89A20, SiCYP94C3, SiCYP97B1, and SiCYP98A1 all contained abiotic stress response elements such as drought, low-temperature, and abscisic acid response elements  has been reported to be capable of metabolizing a variety of herbicides, including ALS-, HPPD-, protoporphyrinogen oxidase-, and PSII-inhibiting and synthetic auxin herbicides [SiCYP450 genes in herbicide metabolic resistance, and has potential application value for further research on CYP450 genes in the production of a variety of herbicide-resistant crops.CYP450s have been the center of herbicide metabolism research due to their ability to confer crop selectivity and weed resistance . The disrbicides . In addirbicides  and soybrbicides  were alsrbicides . This strbicides . This stSiCYP450 genes, and the P450 domain sequence (PF00067) was downloaded from the Pfam database . The Setaria italica genome data were downloaded from the NCBI database . The National Center for Biotechnology Information conserved domain database  was used to detect P450 domains which were then mapped to the conserved domain. A phylogenetic tree was constructed using MEGA 7 software  by the neighbor-joining method (bootstraps = 1000). Arabidopsis P450 protein sequences were downloaded from the TAIR database . Physicochemical properties and subcellular localizations were predicted using ExPASy-ProParam  and the CELLO , respectively.HMMER 3.0 software  was used to identify Setaria italica genome annotation information using TBtools [http://meme-suite.org/tools/meme, accessed on 9 June 2022). Chromosomal positions of SiCYP450 genes were analyzed by TBtools, and MCScanX was used to detect colinear regions between SiCYP450 genes, as well as colinear blocks of SiCYP450 genes with Setaria viridis and Arabidopsis thaliana genes. The Setaria viridis genome data were downloaded from the NCBI database . The Arabidopsis thaliana genome data were downloaded from the TAIR database . The upstream 2.0 kb DNA sequences of SiCYP450 genes were submitted to the PlantCARE database  to predict cis-regulatory elements. All the above were visualized using TBtools [The gene structure map was produced, and an intron–exon map was compiled based on the  TBtools . The pro TBtools .SiCYP450 genes in different tissues such as roots, stems, and leaves were extracted from the Multi-omics Database for Setaria italica , and the expression heat maps of SiCYP450 genes were drawn by TBtools software .The FPKM values of v/v) for five minutes, and rinsed with distilled water. Then, the seeds were germinated in a box with a temperature of 26 °C, relative humidity of 65%, and a day/night cycle of 16 h/8 h. Two days later, the germinated seedlings were transferred into black plastic pots filled with half-strength Hoagland solution for further cultivation. For osmotic stress, salt stress, and ABA treatments, 12-day-old seedlings were treated with 1/2 Hoagland solution containing 20% PEG 6000, 200 mM NaCl, and 100 µM ABA, respectively. For low-temperature stress treatment, the 12-day-old seedlings were placed in a low-temperature (4 °C) incubator to develop. For herbicide treatments, the 12-day-old seedlings were sprayed with 150 g ha−1 mesotrione, 4.5 g ha−1 florasulam, 60 g ha−1 nicosulfuron, 210 g ha−1 fluroxypyr, and 187.5 g ha−1 sethoxydim by a spray tower. The seedlings in 1/2 Hoagland solution without treatment at 26 °C were regarded as controls. The leaves of the seedlings were sampled at 0 h, 3 h, 6 h, 12 h, 24 h, 48 h, and 72 h after 20% PEG 6000, 200 mM NaCl, 100 µM ABA, low-temperature (4 °C), and the five herbicide treatments. All samples were immediately frozen in liquid nitrogen and stored in a −80 °C refrigerator.Foxtail millet variety Jingu 21 was utilized in the experiment. The seeds were sterilized in 75% ethanol (SiActin (SETIT_026509mg) was used as an internal standard, and the expression levels of each gene were calculated by the 2−∆∆Ct method [SiCYP450 expression was constructed by TBtools, the expression value was standardized by log2. Three biological replicates were conducted for the transcript profiles of genes. Each independent experiment was repeated at least three times.The RNA was isolated from leaves using a TRIzol kit . The quality of RNA samples was verified by agarose gel electrophoresis . Then, tt method . The hea2 in RT-PCR analysis. The figures were generated using the GraphPad Prism 7 , TBtools , and Adobe Illustrator 2019 software .The data were first analyzed using Microsoft Office Excel 2016. The expression value was standardized by logcis-acting elements, and gene expression pattern, which provide essential characteristics for the SiCYP450 genes of foxtail millet. We identified three hundred and thirty-one SiCYP450 genes in the foxtail millet genome, which were classified into four groups, including forty-six subgroups. Analysis of gene duplication events indicated that a large number of segmental duplication events and tandem duplications occurred during the expansion of the SiCYP450 family. The expression profile analyses of SiCYP450 genes showed that most of the SiCYP450 genes were highly expressed in roots and leaves. The RT-PCR analysis of 14 SiCYP450 genes from different subfamilies confirmed that the SiCYP450 genes extensively participated in abiotic stress, ABA, and herbicide responses, including response to drought, salt, low-temperature, and five herbicides containing mesotrione, florasulam, nicosulfuron, fluroxypyr, and sethoxydim. In summary, our work was the first to include genomic analysis of the SiCYP450 family in foxtail millet. These results provide valuable information for studying the development and stress physiology of Gramineous crops and a prospect for genetic improvement.In this study, the SiCYP450 family of foxtail millet was first summarized, including phylogeny, physical and chemical properties of the proteins, gene structure, chromosomal localization, duplicated events,


Graphene quantum dots (GQDs), as 0D graphene nanomaterials, have aroused increasing interest in chemiresistive gas sensors owing to their remarkable physicochemical properties and tunable electronic structures. Research on GQDs has been booming over the past decades, and a number of excellent review articles have been provided on various other sensing principles of GQDs, such as fluorescence-based ion-sensing, bio-sensing, bio-imaging, and electrochemical, photoelectrochemical, and electrochemiluminescence sensing, and therapeutic, energy and catalysis applications. However, so far, there is no single review article on the application of GQDs in the field of chemiresistive gas sensing. This is our primary inspiration for writing this review, with a focus on the chemiresistive gas sensors reported using GQD-based composites. In this review, the various synthesized strategies of GQDs and its composites, gas sensing enhancement mechanisms, and the resulting sensing characteristics are presented. Finally, the current challenges and future prospects of GQDs in the abovementioned application filed have been discussed for the more rational design of advanced GQDs-based gas-sensing materials and innovative gas sensors with novel functionalities. Currently, with the vigorous development of the Internet of Things (IoTs), gas sensing technology has received a lot of attention in various fields ,2,3, incThe sensing materials utilized in the fabrication of chemiresistive gas sensors mainly consist of semiconducting metal oxide nanostructures (SMONs) ,26,27,28Carbon-based nanomaterials have been at the forefront of materials science for the past few decades, which as sensitizers can effectively improve the sensitivity of gas sensors or reduce their operating temperature ,58,59,60Graphene quantum dots (GQDs), as a 0D nanomaterial, have distinct graphene lattices, characterized by atomic thin graphite planes , and lateral dimensions typically < 10 nm ,72. Unli3), hydrogen sulfide (H2S), isopropanol, methanol, trimethylamine, acetic acid gas, benzene, dimethyl methylphosphonate (DMMP) gas, nitrogen dioxide (NO2), and nitric oxide (NO). However, the number of chemiresistive gas sensors reported using GQDs and their composites is still limited. In this paper, the recent advances in GQDs-based chemiresistive gas sensors have been comprehensively summarized from the aspects of the synthesized strategies of GQDs and their composites, gas sensing enhancement mechanisms, and the resulting sensing characteristics. Finally, a summary and future perspectives are proposed on the rational design of advanced gas sensing materials based on GQDs and innovative gas sensors with novel functionalities.There have been many excellent reviews on GQDs in fluorescence-based ion sensing, biosensing, bioimaging, and electrochemistry, photo-electrochemistry and electrochemiluminescence sensing, as well as therapeutic, energy, and catalysis applications ,94,95,96Material synthesis is the main and critical method before materials are used in specific applications. The effective synthetic strategies of GQDs and their composites, giving them specific properties, shape, size, surface characteristic, and inner structure, opens an efficient pathway to develop a high-performance gas sensor. The properties and distribution of GQDs and their composites have been shown to vary depending on their synthesis methods, reaction conditions, as well as the precursor materials used . In thisIn general, GQDs could be synthesized through top-down and bottom-up approaches  59,72,9,95,124. 2SO4, NaNO3, and KMnO4 or similar reagents ..3 molecuuctivity . Before CC-DFTB) c–e. The Therefore, modifying GQDs through edge functionalization is a promising method for obtaining high-performance gas sensors with high selectivity for the desired target gases. However, to further improve sensing properties, GQDs have been used as a modifier/composite with metals and metal oxides. Therefore, in order to further clarify this point, the gas-sensitive mechanism of GQDs based composites is introduced in the next section 2−, O− and O2− at different working temperatures (see Equations (1)–(4)) .,41.2−, OAmong the reported gas sensors based on GQDs, many reports have shown that modifying GQDs on the surface of metal oxides or polymers can improve gas sensitivity by forming heterojunctions at the interface between metal oxides/polymers and GQDs. GQDs act as an electronic medium at the interface heterojunction and provide a large number of active sites for the composite. Active sites allow chemically adsorbed oxygen to react with target gas molecules, further enhancing the gas sensitivity of the composites . TherefoThe formation of heterojunctions plays an important role in improving gas sensing performance, which results in the redistribution of charge carriers at the interface, reducing the enthalpy and activation energy required to adsorb target gas molecules . At p-n g) and Fermi level (EF) of GQDs and metal oxides are calculated using ultraviolet–visible diffuse reflectance spectroscopy, linear potential scanning, and ultraviolet photoelectron spectroscopy (UPS) ..g) and F2 is higher than that of original SnO2, confirming that N-GQDs/SnO2 surface adsorbed more oxygen ions, which makes the electron depletion layer thicker and may have higher fundamental resistance than original SnO2. The interconnected graphene network promotes rapid electron transfer, and N-GQDs also facilitate rapid charge transfer, which increases the affinity between nanoporous TiO2 nanospheres and carbon-based scaffolds, and promotes the formation of p-n heterojunctions, thus improving the sensing performance of composite materials . L. L2 thinx/GQDs-modified TiO2 nanocomposite thin films synthesized in situ on the sensor device are treated by water vapor hydrothermal treatment and oxygen plasma. As a function of oxygen–plasma treatment, the sensing behavior of PtOx/GQDs/TiO2 on oxygen-functionalized VOCs changes reversibly from p-type to n-type, and the sensing performance of these gas sensors on aromatic VOCs always presents p-type 2/rGO/GQDoflowers j–l 105]2/rGO/GQD3, not only does the de-doping process occur, but also PANI nanoparticles can gradually change from a conductive state to an insulating state, resulting in an increased resistance 2 for detat 60 °C . Moreoveat 60 °C ,117. Aftat 60 °C ,117. The3 (AL) is a promising gas-sensitive material with large specific surface area, abundant reactive oxygen lattice, good thermal stability, controllable structure, and strong reducibility, but its working temperature is high ..2 quantung gases c–e. The  sensors f. Therefospheres . At 260 t 312 °C g,h. In appb H2S) i–l. Co,NIsopropanol is a widely used solvent and an intermediate in pharmaceutical, pesticide, and electronic industries. When exposed to concentrations exceeding 400 ppm, it is extremely harmful to the human body, and can cause dizziness, vomiting, swelling, and internal bleeding . Therefo2 thin films, an efficient and convenient sensing system was established by in situ synthesis on the sensing device with water vapor hydrothermal treatment at 120 °C for VOCs detection at room temperature [2 heterojunctions. Compared with the pristine TiO2 thin film, GQDs/TiO2 obtained a more ordered nanostructure, smaller crystal size, and larger surface area, making it an ideal candidate for preparing highly sensitive gas sensors. Especially for isopropanol vapor, GQDs/TiO2 sensing films showed highly sensitive, fast, and reversible response. The best sensing performance was obtained at 1.6 wt% GQDs, with a response value of 13.8 for isopropanol at 50 ppm, and the response/recovery time of approximately 18/11 s at room temperature )  is a hazardous gas with a pungent, fishy, ammoniacal odor, which can cause a series of health problems such as headache, eye irritation, breathing difficulty, pulmonary edema, nausea, and irritation of the upper respiratory system once a certain amount of TMA is inhaled . The maxone step . The infon (15)) a,b. SmalWhen handling silicone sealers, acetic acid vapor may corrode workers’ teeth . The con3 p-p heterojunctions were synthesized using microwave chemical method [3 was well matched, which promoted the separation of electron–hole pairs and enhanced the carrier transport ability. Ag, as a good catalyst, could promote the oxidation of benzene to CO2 and H2O in gas sensitive reactions. In addition, Ag-LaFeO3 was modified by benzene molecular imprinting to optimize selectivity of B-GQDs/Ag-LaFeO3 (B/APPH), which could specifically recognize benzene during detection. The molar ratios of benzene template to Ag-LaFeO3 were 3:10, 4:10, 5:10, and 6:10. The gas sensing performance of Ag-LaFeO3 and B/APPH was compared. Ag-LaFeO3 had a response of 18.5 for benzene and less than 5 for other interfering molecules at the optimal operating temperature of 125 °C. After adding 1.00% B-GQDs, the optimal operating temperature was reduced to 65 °C, and B/APPH had high response (17.5), good selectivity, repeatability, and accuracy, which could detect benzene as low as 1 ppm  could increase the risk of leukemia and cancer, especially for vulnerable population groups . Moreovel method . The banas 1 ppm c–f. The Sarin gas is one of the deadliest and most famous chemical warfare agents (CWAs). In the field of public safety and military affairs, it is very important to detect CAWs such as sarin in time . However2) is a poisonous gas with a pungent smell that came from vehicle exhausts, fossil fuel burning, and industrial production activities [2 will not only cause acid rain and have serious negative effects on water, land, and artificial ecosystems, but also lead to photochemical haze on the ground, which can cause great harm to the environment and human health [2 concentrations. The available NO2 sensors developed using GQDs-based composites are shown below.Nitrogen dioxide , faster recovery speed, better stability, and repeatability. At room temperature, it could effectively identify trace levels of NO2 as low as 10 ppm, and the sensitivity of GQDs/SiNW array did not decrease even after two weeks of storage in the air. Therefore, the GQDs/SiNW array could serve as a framework for further specific modification to expand the sensing range.Li et al.  proposed2 quantum dot heterostructures were prepared using a facile wet chemical method. Within the entire temperature range of 25 °C to 250 °C, the heterostructure had a higher response to 100 ppb NO2, which was superior to the original SnO2, pure GQDs/SnO2, and graphene-based gas-sensors [2 showed enhanced response (gR/aR = 292) and shorter response/recovery time (180/81 s) to 100 ppb NO2 gas at 150 °C. As the temperature was reduced to 50 °C, the response value increased to 4336, while the temperature increased to 200 °C, the response of original SnO2 only increased to 6 /3DOM In2O3, N-GQDs/3DOM In2O3 exhibited higher NO2 sensing performance, characterized by fast response and recovery, high response, low detection limit, good selectivity and repeatability, long-term stability, and low operating temperature. When NO2 concentration was 1 ppm, N-GQDs/3DOM In2O3 showed a maximum response value of 81.7, which was approximately 5.8 times that of the original 3DOM In2O3 at 100 °C (Equations (17) and (18)).N-GQDs/3DOM In studied . Compare2O3, the optimal operating temperature of N-GQDs/3DOM In2O3 was reduced from 160 to 100 °C. At optimal operating temperature, the response/recovery times of N-GQDs/3DOM In2O3 were about 95 and 36 s, respectively. In addition, the optimized N-GQDs/3DOM In2O3 sensor for NO2 response had low detection limit of 100 ppb, excellent selectivity, and good long-term stability without significant fluctuations in response within 60 days  and (18)). The interfacial heterojunction between N-GQDs and ZnO expanded resistance modulation, and the doping of highly active N atoms enhanced the electron transfer from ZnO to N-GQDs and the adsorption of NO2 molecules.N-GQDs/ZnO were successfully synthesized using the hydrothermal method . The gas2 hierarchical hollow cube consisting of ultrathin mesoporous nanosheets uniformly modified by N-GQDs were successfully prepared [2 nanosheets, but also generate large quantities of mesopores on nanosheets. Its stable gas adsorption and diffusion channels, large specific surface area, and rich nanoscale grain boundaries were conducive to improving the sensing performance of NO2. In addition, the construction and N doping of 0D/3D N-GQDs/SnO2 could greatly increase the spatial charge modulation depth and NO2 adsorption active sites of composites, thus improving the NO2 sensing properties (Equations (17) and (18)). The optimized N-GQDs/SnO2 sensor had excellent detection capabilities for low concentration NO2 (100 ppb) (gR/aR = 25.3) and showed improved response to 1 ppm NO2 (gR/aR = 417), which was about 2.2 times that of pure SnO2 at 130 °C. In addition, the optimized N-GQDs/SnO2 sensor had rapid response/recovery speed (59/33 s), good selectivity, repeatability, and long-term stability for NO2 gas at low operating temperature (130 °C)  a–e.2, anchored by GQDs on the surface of MPc nanofibers via π-π stacking, a charge transfer conjugate was formed, and a gas sensor based on MPc/GQDs was obtained [2 was significantly enhanced, which was much better than their individual response to NO2 at room temperature. The incorporation of GQDs greatly improved the conductivity of phthalocyanine fibers, resulting in a faster CoPc/GQDs response. The response value of CoPc/GQDs to 50 ppm NO2 within 100 s was 15.8 times that of CoPc  and GQDs for NOobtained . Under a of CoPc f,g. In a of CoPc h,i. The 3O4-rGOQD-naphthalene-2-SO3H) was prepared by a five-step method. Fe3O4  with different weight percentages was used as NO2 gas sensors, which had high sensitivity, reversibility, and selectivity [2 was chosen for exploring the efficiency of Fe3O4-rGOQD-naphthalene-2-SO3H as a NO2 sensor at 20% humidity and room temperature. Fe3O4-rGOQD-naphthalene-2-SO3H with 15% loading of rGOQD-naphthalene-2-SO3H showed the best response while the concentration of NO2 was 10 ppm. When NO2 concentration increased from 2.5 to 50 ppm, the sensitivity of the optimal Fe3O4-rGOQD-naphthalene-2-SO3H increased from 65 to 130. The Fe3O4-rGOQD-naphthalene-2-SO3H sensor could spontaneously recover to their initial states by flowing N2 gas without thermal assistance or chemical reaction, and the response/recovery time was 25/97 s. The results showed that the Fe3O4-rGOQD-naphthalene-2-SO3H exhibited improved responsiveness, detection range, and optimum temperature compared to other works. The relatively high surface area and unique electronic properties of Fe3O4-rGOQD-naphthalene-2-SO3H improved its application as a gas sensor compared to pure Fe3O4, demonstrating that chemical modification of rGO with sulfonic acid and creation of quantum dots on the surface of rGO is an effective way to improve the performance of rGO for gas-sensing applications.A novel magnetic graft reduction of 2-naphthalenesulfonic to GOQDs ).An alternating stacking 3D structure based on MoSperature . The int2 nanoplate hybrid structure was demonstrated [2 used in the form of {001} crystal planes exhibited the shape of rectangular nanoplate, exhibiting high reactivity in adsorbing reactive oxygen species. The precursor was graphitized by hydrothermal treatment and N-GQDs layers were grown on TiO2 nanoplates. The introduction of N-GQDs on TiO2 surface significantly improved the efficiency of gas and carrier exchange, charge carrier separation and transport, and oxygen vacancy, and finally improved the sensing performance (Equations (20) and (21)). At room temperature, the TiO2/N-GQDs hybrid sensor had a 12.0% response to 100 ppm NO, which was 4.8 times that of the original TiO2 nanoplates. In addition, the sensing performance of TiO2/N-GQDs sensor driven by UV light was 2.6 times higher than that without UV irradiation. Under UV (λ = 365 nm) irradiation at room temperature, the response of the hybrid structure increased to 31.1% when NO was 100 ppm  is a type of exhaust gas mainly produced by the burning of fossil fuels in automobiles and factories, which has adverse effects on the environment and human health . It playnstrated . TiO2 us 100 ppm a,b. On tectively c,d. Unde(1)The excellent electronic mobility, high specific surface area, minute size, surface functionalization, and doping with heteroatoms of GQDs enables better driving force for gas diffusion, more oxygen active sites for the interaction, and easily introduced into other functional materials to form high-quality composite materials, which can remarkably enhance the sensing performance.(2)According to the reported literature on GQDs-based chemiresistive gas sensors, the addition of GQDs can effectively decrease the operating temperature of the sensors. 87.5% of the sensors can achieve the excellent sensing performance below 150 °C, and almost 80% can work below 100 °C or at room temperature, showing enormous application potential.(3)The formation of heterojunctions between GQDs and metals, metal oxides, MPc, polymers, metal sulfides, and SiNW results in the redistribution of carriers at the interface, reducing the enthalpy and activation energy needed for adsorbing target gas molecules, thereby improving transduction between internal grains.(4)The morphology of sensing materials also plays an important role in the improvement of gas sensing properties. It can expand the specific surface area of the materials, provide more active reaction sites, favorable adsorption, and diffusion channels, so that the analytes can be quickly adsorbed and desorbed.Obviously, the development of chemiresistive gas sensors based on GQDs and their composites has become one of the research directions in various applications, including environmental monitoring, healthcare and safety. This paper reviews the research progress in gas sensors based on GQDs in recent years, including synthesis strategies of GQDs and their composites, the influence of surface and intrinsic sensing properties of GQDs, heterojunctions, morphologies, doping/de-doping and swelling process of polymers on the improvement of gas sensing properties, as well as the sensing characteristics arising therefrom. The gas sensing key points of chemiresistive gas sensors based on GQDs are summarized as follows:(1)One of the key challenges is the exploration of synthetic strategies of novel GQDs with specific properties. The shape, size, surface characteristic, and inner structure have significant impacts on the gas sensing performance. Currently, the relatively single precursors used for the synthesis of GQDs as chemiresistive gas-sensing materials and the low purity of the desired GQDs limit the improvement of gas-sensing performance, thereby limiting their applicability in real-life applications.(2)The gas-sensitive mechanisms of GQDs-based nanocomposites with different sizes and morphologies are introduced to explain their sensing characteristics. However, there is no clear explanation as to why the same GQDs based composites with similar precursors, size, morphologies, and heterojunctions exhibit significantly different sensing characteristics. Therefore, the development of in situ characterization technologies and theories of sensing mechanisms are necessary.Although remarkable progress has been made in developing novel chemiresistive gas sensors based on GQDs, the number of chemiresistive gas sensors using GQDs and its composites remains limited. There are still many challenges and issues in achieving high response, quick response/recovery speed, excellent selectivity, and long-term stability:To sum up, it is still a great challenge to rationally design advanced GQDs-based sensing materials with excellent sensing characteristics because of the limitations on clearer sensing mechanisms and improved synthesis methods. It is believed that this review will provide a forward-looking direction for researchers and stimulate new ideas to elevate the research of chemiresistive gas sensors to a new level.


Among the many PLK1 targets are members of the FOX family of transcription factors (FOX TFs), including FOXM1, FOXO1, FOXO3, and FOXK1. FOXM1 and FOXK1 have critical oncogenic roles in cancer through their antagonism of apoptotic signals and their promotion of cell proliferation, metastasis, angiogenesis, and therapeutic resistance. In contrast, FOXO1 and FOXO3 have been identified to have broad functions in maintaining cellular homeostasis. In this review, we discuss PLK1-mediated regulation of FOX TFs, highlighting the effects of PLK1 on the activity and stability of these proteins. In addition, we review the prognostic and clinical significance of these proteins in human cancers and, more importantly, the different approaches that have been used to disrupt PLK1 and FOX TF-mediated signaling networks. Furthermore, we discuss the therapeutic potential of targeting PLK1-regulated FOX TFs in human cancers.Polo-like kinase 1 (PLK1) is a serine/threonine kinase with more than 600 phosphorylation substrates through which it regulates many biological processes, including mitosis, apoptosis, metabolism, RNA processing, vesicle transport, and G C. elegans, mice, and humans -P/X, with a strong selection for serine at the −1 position and a weaker selection for proline at the +1 position . To gene1 and S-phases, PLK1 levels are low. However, as cells enter the G2/M phase, PLK1 levels dramatically increase before a rapid turnover at the onset of anaphase [PLK1 transcription, protein turnover, and cyclin-dependent kinase (CDK)-regulated activation mediates this dramatic fluctuation in PLK1 expression and activity.As a result of its broad functions, PLK1 expression and activity are tightly regulated and vary dramatically during progression through the cell cycle ,43. In GPLK1 contains multiple regulatory elements, including a putative SP1 element, a CCAAT box, and cell cycle-dependent element, and cell cycle genes homology region (CDE-CHR) sequences [PLK1 is predominately mediated by the activity of E2F complexes [PLK1 expression. Previous reports have indicated that FOXM1 directly binds to the CHR consensus sequence, thus promoting cell cycle-dependent PLK1 expression [PLK1, thereby upregulating its expression [PLK1.The promoter region of equences ,45. Cellomplexes . Howeverpression ,48. FKHRpression . These dInitially, PLK1 adopts an inactive conformation in which the PBD binds to the KD, masking a nuclear localization sequence (NLS), enforcing PLK1 cytoplasmic localization, and reducing substrate interactions . PLK1 isPLK1 turnover is mediated by ubiquitination and requires the presence of a D-box-like motif, R-K-P-L-T-V-L-N-K, in which the residues R337 and L340 are essential for proteasomal-mediated degradation of PLK1 . During In humans, FOX TFs encompass a diverse family of approximately 50 TFs divided into 19 subfamilies (FOXA through FOXS) ,58. ThesThe transcriptional activity of FOX TFs regulates a broad range of developmental processes, and alterations in a single FOX TF frequently cause severe phenotypes or embryonic lethality . As a reFOXM1 was initially identified in mitotic HeLa cells and named MPM2-reactive phosphopeptide 2 (MPP2) due to its reactivity with the mitotic phosphoprotein antibody, MPM2 ,68. FollFOXM1, differential gene expression analysis of FOXM1-null cells reconstituted with individual isoforms revealed both overlapping and unique target genes of FOXM1 isoforms [FOXM1 consists of an N-terminal repressor domain (NRD), a conserved forkhead DBD, and a C-terminal transactivation domain (TAD) encoded by a gene containing 10 exons. Alternative splicing of exons Va and VIIa, alternatively referred to as A1 and A2, respectively, gives rise to three isoforms, FOXM1a, FOXM1b, and FOXM1c . When exisoforms .Initial efforts identified FOXM1 as having key roles during development and cell cycle regulation. Investigation of FOXM1 in human cancers has expanded its known functions to include the promotion of proliferation, EMT, invasion, angiogenesis, and cancer stem cell (CSC) phenotypes.FOXM1 was initially identified using knockout mice, revealing that Foxm1-null mice exhibited greater than 90% embryonic lethality. Surviving mice had severe hepatic and cardiac hypoplasia-induced defects as well as significant polyploidy [Foxm1-depleted mouse embryonic fibroblasts revealed G2 delays, chromosomal mis-segregations, compromised spindle assembly checkpoints, and cytokinesis defects [Cip1, and p27Kip1, within the nucleus due to reduced expression of SCF ubiquitin ligase complex components [The essential nature of lyploidy ,76,77. C defects . Early i defects . FOXM1 dmponents .Foxm1 overexpression in mice resulted in the formation of a significantly greater number of tumors that were larger, had increased proliferation, and had greater DNA complements than wild-type (WT) mice [MMP-2 upregulation [VEGF [Foxm1 resulted in decreased expression of Vegf-A [VEGF promoter, thereby reducing VEGF gene expression [In cancer, FOXM1 is a key regulator of several cancer-promoting phenotypes. Ubiquitous WT) mice . In vitrWT) mice . AdditioWT) mice . SimilarWT) mice ,83. In ggulation ,85. In Tgulation ,83. FOXMgulation ,86. In son [VEGF . Similarf Vegf-A . In breapression .Accumulating evidence indicates that reactivation of embryonic and pluripotency pathways in a subpopulation of tumor cells, CSCs, results in a stemness phenotype that enhances therapeutic resistance and cancer recurrence . A growiAdditionally, FOXM1 has been identified as promoting therapeutic resistance in multiple treatment modalities across various cancers, including pancreatic, glioblastoma, and breast cancers . In addiFOXM1 is tightly regulated at the transcriptional and post-transcriptional levels, as well as post-translationally through both protein-to-protein interactions and PTMs regulating localization, activity, and turnover of FOXM1 . In this1, FOXM1 protein levels are low, and FOXM1 is generally inactive due to repressive inter- and intra-protein interactions [During Gractions ,95. Initractions ,97,98,99ractions ,95.2/M, the FOXM1-PLK1 interaction results in subsequent PLK1-mediated phosphorylation at S715 and S724, thus increasing FOXM1 target gene transactivation [As previously noted, priming phosphorylation events by CDKs provide binding sites that are recognized by the PLK1 PBD to facilitate PLK1–substrate interactions. T596 and S678 have been identified as key FOXM1b residues that must be phosphorylated by CDK1 for PLK1 binding . Occurritivation . PLK1-detivation . As PLK1tivation ,42. A fotivation . PLK1-metivation . Taken tThe FOXO subfamily that includes FOXO1, FOXO3a, FOXO4, and FOXO6 is the most evolutionarily divergent clade of FOX TFs . These TFOXO1 and FOXO3 encode the proteins of 655 and 673 amino acids, respectively, which contain four major functional regions: a FOX-DBD, a NLS, a nuclear export signal (NES), and a C-terminal TAD , DAPK1, and BNIP3L [cyclins D1 and D2 while upregulating the expression of cyclin G2 and tripling the half-life of KIP1p27, thereby causing G1 arrest [KIP1p27 and GADD45, resulting in cell cycle arrest [cyclin B1 and CDCA3 while upregulating the expression of cyclin G2, which contributes to cell cycle arrest. FOXO3 has been identified to downregulate key S-phase genes cyclin A2, CDC45L, and MCM3 [The FOXO family plays key roles in apoptosis and cell cycle arrest ,109. Intand FasL . Overexpd BNIP3L . In addi1 arrest ,113. In e arrest . Additioand MCM3 .FOXO proteins have been identified as playing key roles in maintaining cellular homeostasis through their regulation of metabolism and oxidative stress. FOXOs regulate several genes essential for glucose and lipid metabolism; however, FOXO1 and FOXO3 appear to have distinct but related functions in which FOXO1 has a greater role in mediating insulin responses, while FOXO3 regulates metabolic flux to maintain redox homeostasis ,117. AddOCT4, SOX2, NANOG, and KLF4 [In addition, FOXO proteins have been identified as playing important roles in preserving the cellular homeostasis required for the maintenance of stem cell populations. The loss of FOXO proteins in NSC and hematopoietic stem cell populations has been identified as resulting in reduced self-renewal and population collapse due to increased oxidative stress ,120. In and KLF4 . Findingand KLF4 ,122.FOXO1 knockdown has been reported to result in enhanced proliferation, motility, and invasive potential, as well as increased EMT-related gene expression in HCC, NSCLC, and PCa cell lines [Erg overexpression was insufficient to cause pathology; however, when combined with Foxo1 knockout, more than 50% of mice exhibited high-grade prostatic intraepithelial neoplasms [FOXO3 knockdown resulted in increased mobility, an effect that is reversible with simultaneous TWIST1 knockdown [FOXO proteins are generally considered to be tumor suppressors due to their negative regulation of cell cycle progression, positive regulation of apoptosis, and their role in cancer-related metabolic dysregulation ,123. FOXll lines ,124,125.eoplasms . Tumor-seoplasms ,129,130.nockdown . Additionockdown . Howevernockdown . Accumulnockdown ,134.In addition to transcriptional and post-transcriptional regulation, FOXO proteins are subject to numerous PTMs regulating their expression, localization, and activity . Their lDrosophila identified polo [2/M. Interestingly, PLK1 acts as the priming kinase by phosphorylating S218 and S329 to create docking sites to facilitate subsequent phosphorylation at S75 [2/M delay, which enables the normal execution of the cell cycle program [An RNAi screen of kinases and phosphatases with regulatory effects upon dFoxO in ied polo . An inven at S75 . Charact program . These dTandem affinity purification and mass spectrometry performed by Bucur et al. identified FOXO3 as a novel PLK1 interaction partner. The PLK1/FOXO3 interaction is mediated by a fragment containing residues 219–270, which includes part of the FOX-DBD and the NLS . FurtherThe FOXK subfamily has only recently begun to gain significant research interest, following the recognition of its important roles in human cancers ,140. TheFOXK1 results in two isoforms with differing lengths, FOXK1a and FOXK1b [The FOXK1 protein contains a FOX-DBD and a forkhead-association (FHA) domain, which mediates phospho-dependent protein-to-protein interactions . In addid FOXK1b . To dated FOXK1b .Characterization of FOXK1 has identified its functions in multiple cancer hallmarks, including proliferation, metastasis, angiogenesis, and apoptosis, as well as its roles in metabolism .MMP-9, and directly repressed the expression of p21. In gastric cancer cells, a TGF-β-induced increase in proliferation, migration, EMT, and metastatic potential was found to be dependent upon the upregulation of FOXK1 by c-jun. In vivo, FOXK1 overexpression increased tumor volume, microvessel density, and metastasis [An investigation of the functions of FOXK1 in human cancers revealed that it promoted proliferation, EMT, invasion, and metastasis across multiple human cancers, including glioma, ovarian cancer, gastric cancer, and CRC . In gliotastasis . Interestastasis .Additionally, FOXK1 has been identified as a key effector of AKT-mTOR signaling cascades and, in response to metabolic signals, regulates the expression of genes related to biosynthetic, metabolic, autophagic, and stress-response pathways ,152,153.FOXK1 localization, transcriptional activity, and stability are predominantly regulated through phosphorylation . Phospho2/M. Further studies revealed that FOXK1 interacts with JLP via the FOXK1 FHA domain binding to the previously identified residue, T351, on JLP. PLK1 also directly interacts with the FOXK1 DBD to form a JLP-FOXK1-PLK1 complex. Interestingly, the knockdown of JLP with shRNA resulted in increased FOXK1 stability [There is emerging evidence suggesting that PLK1 plays a role in regulating FOXK1 activity. Ramkumar and colleagues reported that PLK1 phosphorylates the scaffold protein JLP at T351, creating a PLK1-binding site and enabling further C-terminal phosphorylation of JLP by PLK1, which then facilitates the recruitment of FOXK1 and FOXK2 to JLP during Gtability . RamkumaEvidence suggests that FOXC2 may be a PLK1 substrate. In breast CSCs, FOXC2 regulates the expression of key cell cycle genes and, notably, has an evolutionarily conserved putative PLK1 site at S125 . FurtherPLK1 expression and histopathologic grading in numerous human cancers, including ovarian, prostate, and gastric cancers [PLK1 was significantly overexpressed in 18 of 19 analyzed human cancers, with the magnitude of PLK1 overexpression ranging from 2-fold to more than 20-fold [PLK1 expression in 25 different cancer types, revealing a negative association between PLK1 expression and overall survival in 10 cancer types, including breast invasive carcinoma, lung adenocarcinoma, and pancreatic ductal adenocarcinoma [PLK1 expression in 7 cancer types [The clinical significance of PLK1 has been recognized since the early 2000s. Studies of patient tumor samples have revealed a positive association between  cancers ,159,160. cancers ,162,163. 20-fold . FurtherPlk1 overexpression demonstrated that Plk1 dysregulation induced chromosomal instability and compromised cell cycle checkpoints by impairing p53 activity, leading to spontaneous tumor formation [KrasG12D/Tp53fl/fl-driven lung adenocarcinoma (LUAD) mouse model, the addition of Plk1 overexpression enhanced tumor burden and accelerated tumor formation through Ret upregulation, resulting in greater MAPK and PI3K signaling [FOXM1. Due to the importance of these proteins, further investigation is warranted.While significant evidence indicates a connection between PLK1 and human cancer, recent reports have provided conclusive evidence of the in vivo oncogenic effects of PLK1. A genetically engineered mouse model evaluating the effects of global ormation . In a Krignaling . These mignaling ,18. Seveignaling ,167,168,ignaling . As suchFOXM1 expression was the most frequently associated gene with adverse prognostic significance across the entire data set [In addition to PLK1, FOXM1 has also been identified as having significant prognostic value. A meta-analysis conducted by Li and colleagues analyzed 23 publications, including nearly 3000 patients across 14 different cancer types, and found that FOXM1 overexpression was associated with reduced overall survival at 3, 5, and 10 years and a more advanced TMN stage . An effodata set .In NSCLC and bladder cancers, lower FOXO1 expression was observed in tumor tissues compared to normal tissues ,172. FurOf note, there is also evidence of prognostic significance for FOXO1 fusion proteins, mainly in tumors harboring PAX3-FOXO1 fusions. The PAX3-FOXO1 fusion protein arises from a commonly observed genetic abnormality of alveolar rhabdomyosarcoma (aRMS) that results from the fusion of the DBD of PAX3 and the TAD of FOXO1. A study of patient outcomes revealed that the PAX3-FOXO1 fusion protein (present in 55% of study patients) was associated with greater invasiveness and worse patient outcomes than fusion-negative patients or those harboring the PAX7-FOXO1 fusion protein (present in 22% of study patients) .In urothelial cancers, FOXO3 expression is downregulated in invasive cases and is negatively associated with both disease-free survival and overall survival . In anotStudies in ovarian cancer have shown that FOXK1 is overexpressed and positively associated with poorer patient prognosis . SimilarOwing to the critical role of PLK1 in human cancers, there has been significant interest in developing PLK1 inhibitors since the early 2000s. Initial efforts to develop inhibitors targeted the PLK1 ATP-binding pocket within the kinase domain; however, following the recognition of the limitations in this approach, more recent efforts have shifted focus to targeting the PBD.To date, several ATP-competitive inhibitors of PLK1 have been explored for clinical application. These agents and their respective stages of clinical development have been explored in detail by Novais and colleagues . HoweverAlternative approaches for PLK1 inhibition have sought to disrupt PLK1–substrate interactions with inhibitors binding to the PLK1 PBD. The first molecule leveraging this approach, called Poloxin, was reported by Reindl and colleagues in 2008, and was found to induce mitotic arrest and mitosis in HeLa cells . However50 values and 140- and 300-fold specificity over the PBDs of PLK2 and PLK3, respectively [50 and specificity represent significant improvements over the micromolar and <100-fold selectivity of other PBD targeting agents [Recently, there have been attempts to specifically disrupt protein–protein interactions with agents targeting the shallow binding pockets on the surface of proteins. Novel approaches to develop high-affinity agents targeting PLK1 have explored agents targeting both the binding pocket and cryptic pockets . Hymel and colleagues had leveraged this approach to develop several novel macrocyclic peptide mimetics with high affinity for the PLK1 PBD . Charactectively . Both thg agents ,184,185.Another therapeutic approach being explored is proteolysis-targeting chimeras (PROTACs), which bring a protein of interest (POI) and an E3 ubiquitin ligase in proximity. This proximity is created by combining moieties with an affinity for the POI and the E3 ligase via a linker, which results in POI degradation following ubiquitination ,188. Mu The toxicities arising from off-target effects of inhibitors and modest effects as monotherapy agents have limited the clinical benefit of targeting PLK1 . HoweverDue to the significant role played by FOXM1 in many human cancers, disruption of FOXM1 signaling could be an effective anti-cancer treatment strategy . The difIncreased expression of FOXO1-regulated pro-apoptotic proteins may have synergistic potential with other drugs. Building upon previous reports that PLK1 phosphorylation of FOXO1 promotes nuclear exclusion and degradation, Gheghiani et al. sought to determine if disrupting the PLK1-mediated inactivation of FOXO1 had therapeutic potential. The PLK1 inhibitor, BI 2536, was used in combination with the microtubule poison nocodazole across a range of concentrations. Low-dose combinations of BI 2536 and nocodazole proved to be cytotoxic to advanced PCa cells, while not significantly impacting normal prostate epithelial cells. The minimal effect on normal prostate epithelial cells suggests that such a combination has the potential to minimize side effects . These rPLK1 expression is associated with poor event-free survival and low overall survival [Seeking therapeutic interventions targeting PAX3/7-FOXO1 fusion proteins, Thalhammer et al. conducted a kinome-directed siRNA and small-molecule inhibitor screen and identified PLK1 as a regulator of PAX3-FOXO1. Xenograft models of aRMS treated with the PLK1 inhibitor, BI 2536, showed decreased expression of PAX3-FOXO1 target genes and eventually led to a complete tumor regression. Clinically, there is a strong correlation between PLK1 and PAX3-FOXO1 target gene expression, and high survival . These rTo date, there are no FOXK1 inhibitors reported; however, the current understanding of this protein warrants further characterization of its regulation, which may lead to novel targeted therapies.Recent advances in drug design and delivery methods offer novel avenues for the exploration of targeted killing of cancer cells. Continued development of peptide-derived small molecules with a high affinity for target proteins, combined with our growing understanding of cryptic pockets and 3D structures, offers the potential to develop molecules with high affinity for PLK1 and FOX TFs. The optimization of these molecules around the phospho-motifs generated, or targeted, by PLK1 may enable greater specificity for neoplastic cells within which these proteins are dysregulated. Additionally, the integration of these molecules into PROTAC or DUBTAC backbones offers the potential for targeted manipulation of PLK1 and FOX TF stability. While these molecules may demonstrate potency as single agents, clinical investigation has demonstrated that combination therapies offer greater potential. As such, combinations of these proposed drugs and existing therapies must be explored for synergistic combinations.Mounting evidence supports the crucial functions of PLK1 in all phases of the cell cycle and beyond. Unsurprisingly, its multi-faceted oncogenic roles across many types of human cancers continue to be uncovered. These functions are mediated by PLK1, which alters the stability, localization, and activity of hundreds of proteins, including numerous TFs, among which are FOX TFs. Both PLK1 and FOX TFs have been shown to play significant roles in human cancers, and PLK1 has been identified as an important regulator of FOX TFs, making these signaling axes promising candidates for targeted therapies .Alternations in PLK1-FOX TF signaling in human cancers can be used to explore novel diagnostic and prognostic markers and inform effective therapeutic regimens. For example, the phosphorylation status of T210 in PLK1, S715 and S724 in FOXM1b, or S75 in FOXO1 could provide valuable information regarding the activity of these proteins and dysregulation of associated signaling pathways. Further characterization of PLK1-FOXO3, PLK1-FOXK1, and PLK1-FOXC2 pathways may reveal additional information for diagnostic and prognostic biomarker panel development. Recent advances in liquid biopsy approaches, particularly those employing CTCs, circulating tumor DNA (ctDNA), and, most recently, exosomes, would allow minimally invasive evaluation of the activation status of these proteins ,200. In Further development of PLK1 PBD-specific inhibitors and PLK1-targeted PROTACs, combined with advances in drug delivery, would allow specific targeting of PLK1 in tumors, which would restrain the proliferative, invasive, and stem cell phenotypes promoted by FOXM1 and enhance the pro-apoptotic functions of FOXOs. The combination of anti-PLK1 agents with other treatment modalities, such as FOXM1-targeting vaccines, is likely to significantly improve therapeutic efficacy. Further investigation of the regulatory role of PLK1 on FOXK1 and FOXC2 may reveal novel PLK1-FOX TF signaling cascades and previously unappreciated targets for cancer treatments. In addition, emerging technologies, such as high-throughput screenings to identify synergistic targets and next-generation sequencing integrating clinicopathologic factors to develop predictive models for patient stratification, could offer opportunities for maximizing the effectiveness of PLK1/FOX TF-targeted therapeutic strategies.


A. baumannii clinical isolates, other chromosomally mediated elements of resistance that are considered essential are frequently underestimated. Having a wide substrate range, multidrug efflux pumps frequently underlie antibiotic treatment failure. Recognizing and exploiting variations in multidrug efflux pumps and penicillin-binding proteins (PBPs) is an essential approach in new antibiotic drug discovery and engineering to meet the growing challenge of multidrug-resistant Gram-negative bacteria.Although carbapenemases are frequently reported in resistant A. baumannii were analyzed. Nucleotide sequences for the genes studied were queried against a custom database of FASTA sequences using the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) system. The correlation between different variants and carbapenem Minimum Inhibitory Concentrations (MICs) was studied. PROVEAN and I-Mutant predictor suites were used to predict the effect of the studied amino acid substitutions on protein function and protein stability. Both PsiPred and FUpred were used for domain and secondary structure prediction. Phylogenetic reconstruction was performed using SANS serif and then visualized using iTOL and Phandango.A total of 980 whole genome sequences of AdeB codes for an important efflux-pump structural protein. T48V, T584I, and P660Q were important variants identified in the AdeB-predicted multidrug efflux transporter pore domains. These can act as probable targets for designing new efflux-pump inhibitors. Each of AdeC Q239L and AdeS D167N can also act as probable targets for restoring carbapenem susceptibility. Membrane proteins appear to have lower predictive potential than efflux pump-related changes. OprB and OprD changes show a greater effect than OmpA, OmpW, Omp33, and CarO changes on carbapenem susceptibility. Functional and statistical evidence make the variants T636A and S382N at PBP1a good markers for imipenem susceptibility and potential important drug targets that can modify imipenem resistance. In addition, PBP3_370, PBP1a_T636A, and PBP1a_S382N may act as potential drug targets that can be exploited to counteract imipenem resistance.Exhibiting the highest detection rate, A. baumannii, shedding light on their clinical utility as diagnostic markers and treatment modification targets for more focused studies of candidate elements.The study presents a comprehensive epidemiologic and statistical analysis of potential membrane proteins and efflux-pump variants related to carbapenem susceptibility in  A. baumannii has emerged as an important pathogen in critical care settings during the last decades. It is known to be widely involved in diseases such as mechanical ventilator-associated pneumonia, osteomyelitis, peritonitis, endocarditis, septicemia, and meningitis, as well as wound, skin, soft tissue, urinary tract, ear, and eye infections  and burn units  A. baumannii infection  was recognized, a considerable increase in the number of these strains has been documented worldwide  family, and the loss or modifications of outer membrane porins  family-type pump, has three component structures, AdeA, AdeB, and AdeC, which form the inner membrane fusion protein, the transmembrane component, and the Outer Membrane Protein (OMP), respectively. The AdeABC operon found in 80% of clinical isolates is chromosomally encoded and normally regulated by a two-component system, including the sensor kinase gene (AdeS) and its related response regulator gene (AdeR). Overexpression of AdeB has been attributed to mutations in the AdeS and AdeR genes and also to the insertion of ISAba1 into the AdeS gene or upstream from the operon, resulting in multidrug resistance in A. baumannii , multidrug efflux RND transporter permease subunits AdeB (NZ_CP009257.1: c3977672-3974562) and AdeC (NZ_CP009257.1:c3974485-3973088), efflux system response regulator transcription factor AdeR (NZ_CP009257.1:3979005-3979748), two-component sensor histidine kinase AdeS (NZ_CP009257.1:3979780-3980853), multidrug efflux RND transporter periplasmic adaptor subunit AdeF (NZ_CP009257.1:1450871-1452091), multidrug efflux RND transporter permease subunit AdeG (NZ_CP009257.1:1452098-1455277), multidrug efflux RND transporter outer membrane subunit AdeH (NZ_CP009257.1:1455290-1456738), multidrug efflux transcriptional repressor AdeL (NZ_CP009257.1:c1450673-1449643), multidrug efflux RND transporter periplasmic adaptor subunit AdeI (NZ_CP009257.1:1990739-1991989), multidrug efflux RND transporter permease subunit AdeJ (NZ_CP009257.1:1992002-1995178), multidrug efflux RND transporter outer membrane channel subunit AdeK (NZ_CP009257.1:1995178-1996632), and multidrug efflux transcriptional repressor AdeN (NZ_CP009257.1:4265008-4265661).A total of 980 whole genome sequences of mrdA (NCBI Reference Sequence: WP_000809155.1), PBP3 FtsI (NCBI Reference Sequence: WP_000227939.1), PBP6 dacC (GenBank: AEK25710.1), PBP6b D-alanyl-D-alanine carboxypeptidase (NCBI Reference Sequence: WP_000667917.1), PBP7/8 pbpG D-alanyl-D-alanine endopeptidase (NCBI Reference Sequence: WP_001984577.1), and MtgA monofunctional biosynthetic peptidoglycan transglycosylase (NCBI Reference Sequence: WP_000642942.1).tBLASTn was used to search the translated nucleotide database using a protein query sequence for each of the carbapenem-associated resistance proteins, CarO1, CarO2, and CarO3 . tBLASTn was also used to query the outer membrane protein A (GenBank: ATG88079.1), OmpW (NCBI Reference Sequence: WP_004712981.1), Omp33-36 (NCBI Reference Sequence: WP_000733003.1), glucose-selective porin OprB (GenBank: BAP65421.1), OprD outer membrane porin (NCBI Reference Sequence: WP_002059892.1), and a group of penicillin-binding proteins, including PBP1a MrcA membrane carboxypeptidase (NCBI Reference Sequence: WP_000736677.1), PBP1b (NCBI Reference Sequence: WP_000667420.1), PBP2_Genes included in the analysis had >98% sequence identity and >25% query coverage OR > 90% sequence identity and >50% query coverage. The protein BLAST output or the translated protein sequence for each gene locus in each strain was then aligned using the MUSCLE option, following which it was visualized and comprehensively explored for different amino acid substitutions using the MEGA software. Gene variants identified for membrane protein genes were blasted using tBLASTn to blast the variant protein sequences against a custom-built nucleotide database using BV-BRC tools and services , Scopus, and Web of Science core collection using the following search criteria: “carbapenem resistant These measures were evaluated in relation to their genetic background distribution and predicted functional effects to filter out the most probable significant phenotype predictors. PROVEAN , China , South Korea (Seoul), Thailand, Sweden, Germany, Italy, Iraq, Colombia, United Kingdom, Afghanistan, Honduras, Peru, and India. The studied sequences were isolated from different body sources, including sputum, blood, abdominal fluid, tracheal mucosa, tissue, skin, feces, rectum, urine, and wound, and spanned a range of isolation years between 1982 and 2017. They included 423 imipenem-resistant, 557 imipenem-susceptible, 354 meropenem-resistant, and 208 meropenem-susceptible isolates.In this study, we report the distribution of the structural and regulatory genes encoding different efflux pump systems among a large group of studied whole genome sequences of In this study, we examined the molecular epidemiology and the predictive values of different membrane-related elements in relation to carbapenem resistance, including efflux-pump proteins, and we performed a more detailed analysis of the distribution of different variants related to these groups of genes. We aimed to explore the repertoire, predictive capacity, and phylogeny of these studied resistance determinants among a diverse group of clinical isolates.AdeABC is known to be regulated by the AdeRS two-component regulatory system, AdeFGH by the LysR-type transcriptional regulator AdeL, and AdeIJK by the TetR-transcriptional regulator AdeN. Exploring these genes in the current analyzed set of sequences showed that AdeA occurred at the frequency of 94.18%, AdeB at the frequency of 95.61%, AdeC at the frequency of 68.57%, AdeR at the frequency of 92.85%, and AdeS at the frequency of 93.46%.AdeA gene was absent in 55 sequences, with two other sequences not meeting the identification criteria. The AdeB was absent in 30 sequences, with 13 other sequences not meeting the identification criteria. The AdeC was absent in 305 sequences, with three other sequences not meeting the identification criteria. AdeR was absent in 68 sequences, with two other sequences not meeting the identification criteria. The AdeS gene was absent in 62 sequences, with two other sequences not meeting the identification criteria. Both AdeF and AdeG were absent in six sequences, with one other sequence not meeting the identification criteria in both genes, while AdeH was also absent in six sequences, with two other sequences not meeting the identification criteria. The AdeL was absent in six sequences, while both AdeI and AdeN were absent in five sequences. The AdeJ was absent in four sequences, while AdeK was absent in four sequences, with two other sequences not meeting the identification criteria.The The analyzed structural and regulatory variants, related to the three studied efflux pump systems included a total of 117 variants, including the analysis of variants previously reported in the literature shown in  and otheAll 117 variants were analyzed for their significant correlation and predictive capacity toward the carbapenem-susceptibility phenotype, and the results of the group of variants showing a significant outcome are summarized in p-values indicating the significance of both imipenem and meropenem association, as well as the predicted functional effects of these variants, are shown in Those showing a significant correlation to any of the susceptibility phenotypes were further tested for their predicted effect on gene function. The Regarding the distribution of membrane protein genes, Omp33-36 was completely absent in two sequences, while 292 other sequences showed hits below the threshold used for gene identification. Additionally, for OmpA, 52 sequences showed hits below the threshold used for gene identification. Genes identified below the threshold could be disrupted by insertion sequences and could be non-functional. OmpW was completely absent in nine sequences. OprB was absent in 1 sequence, while OprD was completely absent in 4 sequences, with 79 other sequences showing hits below the threshold used for identification. Three protein variants were identified for Omp33-36. These were further analyzed for their relation to carbapenem susceptibility. For OmpA, most studied sequences showed two variants. OmpW sequence appeared to be highly conserved, with V1 being the most frequently occurring variant and another two variants that were observed at a lower frequency. OmpW T18A was observed and further studied. Three variants were observed in OprD, with V2 and V3 being observed in fewer isolates. Two variants were observed in OprB, with V2 being observed in fewer isolates. Substitutions such as OprB F57L, OprB T304A, OprB S360N, and OprB G403S were observed and further analyzed.CarO sequence was identified in 71 sequences, with hits below the threshold used for gene identification. CarO1 showed a significant correlation to imipenem resistance, while CarO3 variants showed a correlation to meropenem resistance, although it was non-significant. Omp33_V2 showed a significant correlation to the imipenem-susceptibility phenotype, while Omp33_V3 showed a significant correlation to the meropenem-susceptibility phenotype. OmpA_V1 showed a significant correlation to imipenem and meropenem resistance, while OmpA_V2 showed a significant correlation to imipenem susceptibility. OprD_V2 showed a significant correlation to meropenem susceptibility, while OprD-V3 showed a significant correlation to imipenem susceptibility. OprB G403S showed a significant correlation to both imipenem and meropenem resistance. OprB N360S showed a significant correlation to imipenem susceptibility, while OprB F57L was significantly correlated to meropenem susceptibility.FASTA sequences of the studied variants are provided in PBPs previously reported in the literature  , AdeB at 60% (45/75), AdeC at 30.6% (23/75), AdeR and AdeS at 54.6% (41/75), and 48% (36/75) of isolates, respectively  but a decreased expression of AdeR (3.3-fold)  of A. baumanii isolates had the AdeA gene and 81.66% (49/60) of isolates had the AdeS gene  and 59/60 (98.3%), respectively  of A. baumannii isolates studied  for AdeB, and 55 (84.6%) for AdeC, while AdeR was detected upstream of the AdeABC operon in 38 (58.4%) of the studied isolates , 63.4 (41/63), and 79.3 (50/63) of isolates, respectively  isolates (86.4%) overexpressed AdeABC, and only 17 out of 81 isolates (21.0%) overexpressed AdeIJK, while no isolate overexpressed the AdeFGH pump system  and 45 (90%) of the 50 studied imipenem-resistant isolates, respectively. Forty-three out of 47 (43/47) AdeB-positive imipenem-resistant A. baumannii (IRAB) carried the AdeRS regulatory system, which was absent in four isolates. Six (12%) isolates of IRAB carried AdeB and AdeE simultaneously. In addition, AdeB and AdeJ showed approximately 4- and 3-fold increases in expression levels in imipenem-resistant isolates as compared to imipenem-susceptible isolates . AdeJ V573M is located near the proximal drug-binding site  for the C-terminal DNA-binding domain for the positions 139-247. I175L and H195Q were mapped on the available 3D structure of AdeR A53V was the only variant identified in the response regulator receiver domain. Mapped on the predicted structure for that domain, this amino acid substitution occurred near the end of the alpha-2 helix. It appears that it is located as a part of the magnesium-binding motif with a role in the phosphorylation of AdeR. Thus, it may be correlated with the expression of the efflux pump AdeABC. ALA 53 forms a polar interaction of 2.2 A with Ile 49  compared to parenteral strains, ΔompA mutants were more susceptible to both imipenem and meropenem when compared to parenteral strains (2–3 fold difference)  and 33-kDa outer membrane proteins has been previously associated with carbapenem resistance in The glucose-selective porin OprB, the outer membrane protein A precursor, and the 33–36 kDa outer membrane proteins were among the major outer membrane proteins downregulated in imipenem culture conditions  showed that the variant occurs at the transpeptidase (TP) domain, whose inactivation was associated with increased B-lactam susceptibility observed in other studies . The cluster showed the co-occurrence of Omp_V1, CarO1, PBP1b_S112P, PBP2_K152Q, PBP6b_S28P, and PBP78_T71A. It is interesting to observe that PBP2_K152Q was only identified in this cluster and showed a significant correlation to both imipenem and meropenem resistance with high specificity  and from Sweden, Thailand, and Germany (2008-2013) (Cluster 5).MtgA_T49P and MtgA_V54I (Cluster 6). Among these, the variants Omp33_V2, PBP1a_S382N, PBP1a_T636A, PBP1b_P764S, PBP3_G523V, and PBP2_V509I occurred only in this cluster across the entire phylogram and were significantly related to carbapenem susceptibility.Another large cluster isolated from Washington (2003–2008) showed the co-occurrence of Omp33_V2, CarO3, PBP1a_S382N, PBP1a_T363A, PBP1b_P764S, PBP1b_S112P, PBP3_G523V, PBP2_V509I, PBP6b_S28P, and PBP78_T71A, in addition to MtgA_T49P, MtgA_V54I, and Omp33_V2 showed a significant correlation to imipenem susceptibility.The variant PBP3_H370Y was only observed across the whole phylogramin in Cluster 7 (shown in blue). It showed a significant correlation to imipenem susceptibility with very high specificity and PPV . IsolateMtgA_F4V were observed almost exclusively in cluster 8 across the entire phylogram. These four variants showed a significant correlation to meropenem susceptibility. Although genetically related, the cluster contained isolates collected from different parts of the USA, China, and India. It also spanned 10 years between 2003 and 2013 and was collected from different types of specimens, including respiratory infection, wound infection, abdominal fluid, blood, and groin, in addition to sterile body sites, which might indicate the more informative and predictive value of these variants.Cluster 8 showed an interesting observation. The four variants Omp33_V3, OprD_V2, OprB_F57L, and Ps. aeruginosa and E. coli than about those in Acinetobacter spp. Most efflux pump systems possess physiological functions related to the homeostasis of the bacterial cell. An improved understanding of these systems, including the comprehension of their regulation and, particularly, of the RND family, can help us decode their natural functions and offer approaches to block or alter these pieces of machinery. It is also obvious that a complex network of regulations directs the efflux capacity of bacteria and that interplay or compensatory mechanisms between efflux systems could exist. It is worth noting that both membrane proteins and efflux-pump gene changes, when compared to other carbapenem-related elements of resistance, were not linked to phenotypic heteroresistance as in the case of other mobile elements , with lower predictive values.The combination of However, other combinations occur together and can be used to predict carbapenem susceptibility.AdeA A391T, AdeB T584I, AdeC S71G, AdeC K235E, AdeC Q239L, AdeR L142I, AdeR V243I, AdeS D167N, AdeG D501N, and AdeL Q262R from efflux-pump variants and Omp33_V2, PBP1a_S382N, PBP1a_T636A, PBP1b_P764S, PBP3_G523V, and PBP2_V509I from membrane-protein variants.The combination of AdeB D642A, AdeB S645T, AdeC S71G, AdeC T106M, AdeC K161S, AdeH R100G, AdeH A289G, and AdeH N388H from efflux-pump variants and Omp33_V3, OprD_V2, OprB_F57L, and MtgA_F4V from membrane-protein variants.The combination of Carbapenem resistance is currently widespread worldwide in ICUs in different parts of the world; however, the currently available rapid diagnostic panels often depend on the detection of carbapenemases to predict carbapenem resistance and usually do not differentiate antibiotic agents from the same antimicrobial class. This approach is apparently lacking and incomplete as it disregards important chromosomal resistance predictors. Based on the results we presented in this study, the identified sets of markers can act as useful diagnostic predictor panels for inclusion in sequence-based diagnostic workflows.The variants identified in this study can act as potential diagnostic markers that can be used to guide the clinical prescription of carbapenems, which would preserve the utility and effectiveness of such an antimicrobial class, especially in high-risk settings. The elements identified can also provide potential valuable targets for designing agents that might restore carbapenem susceptibility.The original contributions presented in the study are included in the article/WN: Conceptualization, Formal analysis, Investigation, Methodology, Resources, Visualization, Writing—original draft, Writing—review and editing, Supervision. NA: Funding acquisition, Investigation, Writing—original draft, Methodology, Resources, Validation. AA: Funding acquisition, Investigation, Writing—original draft, Resources, Validation, Visualization. SZ: Funding acquisition, Investigation, Writing—review and editing, Methodology, Resources, Validation. AE: Writing—original draft, Visualization. HH: Formal analysis, Investigation, Resources, Supervision, Writing—original draft, Writing—review and editing, Validation.


Tumorigenesis and tumor development are closely related to the abnormal regulation of ubiquitination. Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), an E3 ubiquitin ligase critical to the ubiquitination process, plays key roles in the regulation of cancer stem cells, as well as tumor cell functions, including cell proliferation, apoptosis, cell cycle regulation, migration, invasion, epithelial–mesenchymal transition (EMT), and tumor drug resistance, by controlling subsequent protein degradation through ubiquitination. NEDD4L primarily functions as a tumor suppressor in several tumors but also plays an oncogenic role in certain tumors. In this review, we comprehensively summarize the relevant signaling pathways of NEDD4L in tumors, the regulatory mechanisms of its upstream regulatory molecules and downstream substrates, and the resulting functional alterations. Overall, therapeutic strategies targeting NEDD4L to treat cancer may be feasible. Ubiquitination, an important post-translational modification of proteins, is involved in the regulation of various physiological functions in organisms . UbiquitBased on differences in the characteristic structural domains of E3s and the mechanism of ubiquitin delivery to target proteins, E3s can be classified into three family types: those containing the Really Interesting New Gene (RING)-finger structural domain, those containing the Homologous to the E6-AP Carboxyl Terminus (HECT) structural domain, and those containing the U-box structural domain . Accordi+ channel (ENaC), which is associated with cardiovascular and kidney disease  related to NEDD4L in tumors have been reported. In our review, we provide an updated scenario of recent studies on the role of NEDD4L in tumors, including non-solid tumors. The upstream molecules of NEDD4L regulate NEDD4L by regulating transcription, phosphorylation, non-coding RNA, etc. NEDD4L regulates downstream substrates through ubiquitination, regulation of transcription, phosphorylation, etc. Here, we describe the upstream regulatory molecules and downstream substrates of NEDD4, focusing on the signaling pathways associated with NEDD4L in tumors, the regulatory mechanisms of upstream regulatory molecules and downstream substrates, and the resulting functional alterations related to cell proliferation, apoptosis, cell cycle, migration, invasion, epithelial–mesenchymal transition (EMT), cancer stem cell behavior, and tumor drug resistance  tissues than in paraneoplastic tissues. Moreover, NEDD4L mRNA expression was downregulated in liver cancer tissues compared to that in paraneoplastic tissues. Notably, NEDD4L was the only NEDD4 family member differentially expressed in renal cell carcinoma compared with levels in normal kidney tissues. Additionally, the transcript levels of NEDD4L were lower in clear-cell renal cell cancer tissues than in normal kidney tissues. Besides, NEDD4L was lower in gastric cancer tissues than in normal gastric tissues. Furthermore, NEDD4L mRNA was downregulated in all tumor stages of colorectal cancer. In addition, a bioinformatics analysis reported that NEDD4L mRNA expression was significantly downregulated in esophageal cancer compared to that in normal esophageal tissue , and low expression was associated with a normal karyotype and with FLT3 and NPM1 mutations. Additionally, low expression positively correlated with complex karyotypes and TP53 mutations, suggesting that aberrant NEDD4L expression is associated with multiple genetic events in AML  shows the association between NEDD4L expression and survival. The samples are grouped according to the median expression of the NEDD4L gene. Kaplan–Meier plot shows that the high NEDD4L RNA expression correlated with longer overall survival (OS) in LUAD, kidney renal clear cell carcinoma, and kidney renal papillary cell carcinoma  , ovarianarcinoma .NEDD4L has been shown to have a broad range of functions in a variety of tumors. Therefore, more studies focus on exploring the mechanisms of the upstream regulators. Relative mechanism includes non-coding RNA, phosphorylation, transcription regulations, etc. .NEDD4L mRNA, resulting in the downregulation of NEDD4L expression at the protein level, ultimately promoting TGF-β-induced EMT in lung cancer cells  , AMP-act protein . JAC4 in protein . These rNEDD4L mRNA, affecting its stability and leading to tumorigenesis  upregulates NEDD4L expression, thereby enhancing β-catenin ubiquitination to inhibit the proliferation, migration, and invasion of LUAD cells . N-Myc dAs an E3 ligase, most functions of NEDD4L were executed by regulating downstream substrates through ubiquitination, regulation of transcription, phosphorylation, etc. . NotablyAs a HECT-type E3 ubiquitin ligase, NEDD4L regulates substrates mainly through ubiquitination. Tumor-associated substrates of NEDD4L have been identified in numerous pathway proteins and membrane receptors.Class IA phosphoinositide 3-kinases (PI3Ks) are lipid kinases that integrate signals from growth factors and hormones and play a major role in PI3K-associated cancer progression . NEDD4L Ubiquitination mediated by NEDD4L also plays a role in regulating its member receptors. CD71, a transferrin receptor, is an important mediator of ferroptosis, and its degradation, mediated by NEDD4L via the ubiquitin–proteasome system, inhibits ferroptosis in breast cancer cells after exposure to ionizing radiation . Cu actiMMP1 and MMP13  refers to the surrounding microenvironment in which tumor cells exist, including surrounding blood vessels, immune cells, fibroblasts, myeloid inflammatory cells, various signaling molecules and extracellular matrix (ECM) . The rolnd INF-γ . NEDD4L nd INF-γ . In breand INF-γ . In addind INF-γ .+, relapsed, and refractory diffuse large B-cell lymphoma  drug technique chooses the RING E3 ligase as a ligand-selective component to target the degradation of non-drug-eligible target proteins with no binding pocket. Furthermore, commitments to incorporate HECT-like E3 ligases into PROTACT drug preparation will regulate additional proteins expression and pathophysiological processes. Thus, we conclude the dual functions and controversial mechanism of NEDD4L to provide more directional references and thinking perspectives for future researches.


The impact of parathyroid hormone-related protein (PTHrP) and parathyroid hormone receptor 1 (PTH1R or PTHR1) on cancer initiation, growth, and metastasis has been extensively documented in a number of in vitro and in vivo studies. Despite these findings, the attempts to target PTHrP/PTH1R signaling in cancer therapy have not produced successful results in the clinical setting. In light of these conflicting data and conclusions, this review seeks to provide a comprehensive examination of the role of PTHrP/PTH1R in cancer progression and metastasis, as well as offer insights for future research efforts in this field.PTHrP exerts its effects by binding to its receptor, PTH1R, a G protein-coupled receptor (GPCR), activating the downstream cAMP signaling pathway. As an autocrine, paracrine, or intracrine factor, PTHrP has been found to stimulate cancer cell proliferation, inhibit apoptosis, and promote tumor-induced osteolysis of bone. Despite these findings, attempts to develop PTHrP and PTH1R as drug targets have not produced successful results in the clinic. Nevertheless, the efficacy of blocking PTHrP and PTH1R has been shown in various types of cancer, suggesting its potential for therapeutic applications. In light of these conflicting data, we conducted a comprehensive review of the studies of PTHrP/PTH1R in cancer progression and metastasis and highlighted the strengths and limitations of targeting PTHrP or PTH1R in cancer therapy. This review also offers our perspectives for future research in this field. PTHrP (parathyroid hormone-related protein) is a protein initially isolated from tumors of patients with humoral hypercalcemia of malignancy (HHM) . AlthougThe association of PTHrP with the syndrome of HHM initially drew attention in the early 1990s . However10,Leu11,D-Trp12)-PTHrP (7–34) amide, having been shown to be effective in clear cell renal carcinoma . Th. Th62]. Both ligand structure–activity relationship and receptor mutagenesis studies have revealed that the N-terminal (1–34) of PTHrP interacts with PTH1R via a two-component mechanism, as illustrated in GPCR signaling and function have long been believed to be exclusively at the cell surface. Since the breakthrough discoveries of nuclear binding sites for their ligands in 1980s, many GPCRs, including PTH1R, have been detected in the cell nuclei ,72,73,74Yet, to date, mechanisms of the nuclear translocation remain poorly understood. Nevertheless, the subcellular trafficking of GPCRs is regulated by members of the Ras superfamily of small GTPases . The nucS–adenylyl cyclase–cAMP–protein kinase A (PKA), the Gαq–phospholipase C (PLC) β–inositol triphosphate–cytoplasmic Ca2+–protein kinase C pathway, the Gα12/13– phospholipase D (PLD)–transforming protein RhoA pathway, and the β-arrestin–extracellular signal-regulated kinase 1/2 (ERK1/2) pathway [0 and RG, respectively. RG-selective ligands, such as PTHrP (1–36), induce transient cAMP responses derived from signaling complexes localized at the plasma membrane, whereas R0-selective ligands, such as PTH (1–34) and M-PTH (1–14) , can induce prolonged cAMP responses that are derived from complexes associated within endosomes [0 and RG selectivity by developing PTH- or PTHrP-specific analogs [PTH1R is the primary receptor for both PTHrP and PTH, while PTH2R is also capable of binding with PTH to activate the downstream signaling. PTH1R activates several signaling pathways, including the Gα pathway ,80  peptide or overexpression of full-length e cancer ,49,50, re cancer , and bree cancer . The mece cancer , giant ce cancer , prostate cancer , pancreae cancer , and kide cancer ,29. In ae cancer . The indp53 and Rb, showed that both primary tumors and metastasis expressed functional PTH1R [Pth1r in primary O.S. cells reduced proliferation, invasion, and the expression of RANKL in vitro and profoundly inhibited O.S. tumor growth, but increased differentiation/mineralization of the O.S. tumor cells in vivo [Pth1h knockdown or p53-deficiency did not affect cell proliferation. However, ablation of PTHrP or CREB induced O.S. cells growth arrest and apoptosis, suggesting that O.S. depends on continuous activation of the PTHrP/PTH1R/PKA pathway [PTHrP mRNA is also detected in human and rat osteogenic sarcoma cell lines, suggesting that PTHrP has an autocrine function in osteosarcoma (O.S.) ,87,88,89al PTH1R ,91,92. G in vivo . In norm pathway ,94. This pathway ,95. Moreover, PTHrP/PTH1R was found to mediate drug resistance in prostate cancer bone metastasis, possibly through facilitating TGFβ type II receptor (TGFBR2) degradation . BlockinOver the past two decades, research has investigated the effects of PTHrP on tumor-induced angiogenesis. Early reports showed that PTHrP inhibits endothelial cell migration and angiogenesis by activating PKA, and inhibiting PKA can reverse the antimigratory and antiangiogenic effects of PTHrP . SimilarThe pleiotropic actions of PTHrP in endothelial cells and stem-like cells for angiogenesis may be due to its different domains and biologically active fragments, but more research is needed to explore this possibility. While most studies have shown that PTHrP promotes cancer cell proliferation, tumor progression, and metastasis, one study found that intermittent PTH (1–34) inhibited breast cancer bone metastasis, consistent with the dose- and time-dependent anabolic and metabolic effects of PTHrP in bone . TherefoPTHrP gene, PTHLH, in a susceptibility locus for both ER+ and ER- breast cancer [Breast cancer clinical studies have generally supported the stimulatory effects of PTHrP in tumor growth and progression ,14,18. Tt cancer . In prost cancer . PTH1R wt cancer  and was t cancer . The higt cancer .However, a prospective study over ten years of 402 breast cancer patients found that PTHrP was expressed in 79% of the primary tumors and was positively associated with decreased bone metastasis and improved survival . NeverthStudies have demonstrated that in the early stage of tumorigenesis, PTHrP expression was associated with better survival rates and decreased metastasis in patients with various types of cancer ,108,109,In addition to directly inhibiting PTHrP or PTH1R, other approaches have been explored in cancers, including targeting upstream regulators of the PTHrP expression. For example, Wnt signaling drives PTHrP expression in highly osteolytic cancer cells, making it a potential therapy for preventing tumor-induced bone destruction and metastatic outgrowth . HoweverIn breast cancer, TGF-β can induce PTHrP secretion by upregulating Gli2 ,116. InhIn contrast, one recent study demonstrated the potential of the downstream effectors of PTHrP. Overexpression of PTHrP (1–139) in breast cancer MCF-7 cells suppressed the expression and downstream signaling of LIFR, a reported breast cancer tumor suppressor and dormancy marker . ConsequOverall, more research is needed to understand the context-dependent downstream signaling pathways and identify novel targets for effective therapies.The roles of PTHrP/PTH1R signaling in cancer progression, metastasis, and tumor dormancy are context-dependent. Both PTHrP and PTH1R have multiple biologically active domains, and their isoforms can localize in the cytoplasm or the nucleus, leading to diversified roles in different cell types. Ligand binding and activation of PTH1R induce various downstream signaling pathways, including cAMP, PKA, PKC, and CREB, which can have different or opposite effects. Moreover, distinct signaling effects can be induced by effectors that control the PTHrP/PTH1R protein degradation and recycling. The response of PTHrP/PTH1R target cells, including cancer cells and different cells in the tumor microenvironments, can differ depending on the stage of disease progression.Neutralizing antibodies, peptide antagonists, and small molecule drugs have been developed against distinct domains or motifs of PTHrP/PTH1R complexes. However, most of these compounds have limited binding affinity and oral stability, resulting in suboptimal efficacy. Nevertheless, these studies provide good starting points for the optimization of novel binding reagents . Recentl