Renal cell carcinoma (RCC) is one of the most common malignant tumors with a poor response to radiotherapy and chemotherapy. The advent of molecular targeted drugs has initiated great breakthroughs in the treatment of RCC. However, drug resistance to targeted drugs has become an urgent problem. Various studies across the decades have confirmed the involvement of circular RNAs (circRNAs) in multiple pathophysiological processes and its abnormal expression in many malignant tumors. This review speculated that circRNAs can provide a new solution to drug resistance in RCC and perhaps be used as essential markers for the early diagnosis and prognosis of RCC. Through the analysis and discussion of relevant recent research, this review explored the relationship of circRNAs to and their regulatory mechanisms in drug resistance in RCC. The results indicate an association between the expression of circRNAs and the development of RCC, as well as the involvement of circRNAs in drug resistance in RCC. Renal cell carcinoma (RCC) is one of the most common malignant tumors , 2 that CircRNAS are formed by the reverse shearing of precursor RNAs from end to end, which creates a very stable ring structure , 9]. CirSince the discovery of circRNAs, many studies have shown their close association with the biological behavior of tumors. The relationship between circRNAs and RCC has also been confirmed by several studies involving RNA sequencing, which has revealed abnormal circRNA expression in many tumor tissues . CircRNAStudies have also demonstrated that the expression of circRNAs, such as circ PUM1, circRNA ZNF609, circPTCH1, circPCNXL2, circRNA_001287, and circRNA SCARB1, significantly changes in RCC , circRNAs mostly perform their normal biological functions through circRNA–miRNA–mRNA regulation networks. miRNA are considered essential in a variety of biological processes in the body and important factors affecting the normal functioning of cells, including participation in the generation and progression of diseases –54. CircYan et al.  analyzedFOX2 through miR-296-5P. Li et al. [The circSNX6/miR-1184/GPCPD1 axis plays a crucial role in regulating intracellular LPA levels and sunitinib resistance in RCC. Specifically, Huang et al.  found thi et al.  reportedi et al. . The invCircRNAs can regulate cellular physiological and pathological processes through ceRNA mechanisms and by binding to RBPs and RNA polymerase. Furthermore, ribosomes can translate some circRNAs and encode peptides to enable them to perform regulatory functions. Zhang et al.  identifiA potential mechanism of chemoresistance or targeted drug resistance in tumor cells may be the cytoprotective functions of autophagy. Furthermore, circRNAs are variously expressed in response to cisplatin, suggesting their involvement in the pathophysiology of cisplatin-induced nephrotoxicity . A studyThe tumor angiogenesis theory proposed by Folkman in the twentieth century pointed out that tumor angiogenesis is an essential process of tumor growth , 71. CurThe development of molecular targeted drugs has dramatically improved the therapeutic outcomes for RCC. Still, increasing resistance to targeted drugs has become an urgent problem. Drug resistance is a complex process, and the activation of multiple pro-angiogenic pathways may be associated with TKI resistance. This review discussed the role of circRNAs in the mechanism of drug resistance in RCC. CircRNAs were once thought to be the product of RNA mishearing . HoweverIn conclusion, current studies suggest that circRNAs play a crucial role in mediating drug resistance in RCC. CircRNAs enhance RCC’s resistance to sunitinib and gemcitabine primarily through ceRNA mechanisms. Further studies are required to elucidate further the involvement and mechanisms of circRNAs in drug resistance in RCC. The research and discussion on the involvement of circRNAs in the mechanism of anti-tumor drug resistance provides new insights on developing strategies to overcome drug resistance in clinical practice, as well as on developing more effective treatments for RCC.


Obesity is a popular metabolic disorder triggered by excessive caloric consumption with a concomitant reduction in the expenditure of energy where it constitutes a gross health challenge threatening people all over the globe . UnfortuShin et al. explained the effect of fermentation by lactic acid bacteria on ginsenosides identified in Panax notoginseng (PN), a traditional herbal medicine, and their efficacy to alleviate obesity a high-fat diet (HFD)-fed mouse model. Results illustrated that upon fermentation with Lactobacillus plantarum, the fermented PN extract displayed an altered ginsenoside profile with a considerable increase in lactate level that ultimately reflected in the obvious reduction in the food and calorie intake in contrast to unfermented extract via acting on multiple signaling pathways incorporated in appetite and energy consumption. Both the unfermented and fermented extracts modulated the gut microbial composition but they showed obvious differences in the relative abundances gut microbiota. The fermented extract showed a significant elevation in the relative abundance of Akkermansia, Bacteroidetes, Coprococus, Dehalobacterium, Erysipelotrichaceae and Parpabacteroides meanwhile Erysipelotrichi, Allobaculum and Erysipelotrichale were considerably low. Besides, the relative abundance of Lactococcus was higher in the fermented extract while the unfermented extract displayed higher level of Bacteroides relative to HFD group that ultimately reflected that the differences in the ginsenosides profile in Panax notoginseng as well as the gut microbial composition greatly contributed to the anti-obesity properties of the fermented extract.In accordance with this concept, the study conducted by Mytilus edulis hydrolysate in the amelioration of lipopolysaccharide-galactosamine acute liver injury  and its consequent systemic inflammatory responses was discussed by Starikova et al.Mytilus edulis hydrolysate effectively protected mice versus LPS/D-GalN-triggered acute liver injury resulting in 100% survival rate upon constant administration of small doses of the drug in a subcutaneous pattern. The drug efficiently reduced Vascular Cell Adhesion Molecule-1 (VCAM-1), Interleukin-6 (IL-6) production in activated Human Umbilical Vein Endothelial Cells (HUVECs) in vitro with concomitant elevation in Nitric Oxide (NO) formation by HUVECs. However, it reduced Nitric Oxide Synthase (iNOS) expression as well as NO generation in murine peritoneal lavage cells. Furthermore, the ability of the extract to improve the endothelium barrier function and to decrease vascular permeability was evidenced in vitro via Electrical Cell-substrate impedance Sensor (ECIS) and in vivo using Miles assay which further consolidated the concept of adopting Mytilus edulis hydrolysate in case of endothelial dysfunction and uncontrolled inflammation.In addition, the role of Li et al. deliberated the role of glycyrrhizin, commonly known metabolites from Liquorice, as a promising drug in the alleviation of colon cancer cachexia. Cancer cachexia is considered as multifactorial symptom characterized by weight loss in addition to muscle wasting, resulted by many causes comprising decreased food intake, metabolic variation featured by, excessive catabolism and accompanied by inflammation  leaf extract in the amelioration of acetic acid–induced chronic gastric ulcer and the gastroprotective activity of its major flavonoid, quercetin 3-O-α-L-arabinopyranosyl-(1→2)-O-α-L-rhamnopyranoside, Bp1 versus gastric lesions caused by indomethacin and ethanol and in vivo was highlighted by De Araújo et al. The extract effectively enhances the curing of gastric mucosa with considerable decrease in the ulceration index accompanied by enhancement of the antioxidant potential manifested by a pronounced elevation glutathione (GSH) levels and significant reduction in the levels of superoxide dismutase malondialdehyde (MDA). Concerning the anti-inflammatory markers, the extract significantly reduced the levels of tumor necrosis factor-α, interleukin-1β, and myeloperoxidase (MPO) whereas the levels of interleukin 10 were increased in the extract treated animals that is further evidenced by the cytoprotective effect detected by the histological analyzes. Significant amelioration was observed in the antioxidant and anti-inflammatory markers as well as the gastric lesions triggered by caused by indomethacin and ethanol upon treatment of the animals with 5 mg/kg of Bp1. However, the administration of the total extract displayed better results that undoubtedly relied upon the synergistic effect of all metabolites prevailing in the extract.Furthermore, the effectiveness of Palla et al. evaluated the effectiveness of many polyherbal combinations to reduce the severity of metabolic syndrome. After clearing all the collected data obtained by electronic search from any duplications, a total of 41 studies were found 24 of which were conducted in animal models meanwhile 15 were performed as clinical trials related to metabolic syndrome. SPICE  and SPIDER  models were used to evaluate clinical trials. The potential polyherbal combinations together with validation of the animal studies via systematic qualitative and quantitative analyses was stressed and provided a future direction to implement further research to prohibit and management of metabolic syndrome by polyherbal combinations.Additionally, a systematic review conducted by In conclusion, this research topic consolidates the fact that the natural products can act as an everlasting mine offering new drug entities serving as drug leads for pharmaceutical industries combating obesity and chronic inflammation that are highly welcomed by many people all over the globe.


The mucosal surfaces that form the boundary between the external environment and the underlying tissue are protected by a mucus barrier. Mucin glycoproteins, both secreted and cell surface mucins, are the major components of the barrier. They can exclude pathogens and toxins while hosting the commensal bacteria. In this review, we highlight the dynamic function of the mucins and mucus during infection, how this mucosal barrier is regulated, and how pathogens have evolved mechanisms to evade this defence system. The mucus layer, which coats surfaces exposed to the external environment, is a physicochemical barrier that permits the permeation of nutrients and immune factors and excludes toxins and pathogens. Despite being a dynamic, highly organised arm of the innate immune system, the mucus barrier has largely been underappreciated in infectious diseases. Mucins form the critical structural component of the mucosal barrier . O-Glycovia proteases, after binding to a pathogen as part of a defence mechanism  that is proline-, threonine-, and serine-rich region and heavily O-glycosylated. O-Glycosylation is the key element responsible for the hydrophilic character of the secreted mucins and allows expansion and extension of the core. The individual mucin subunits can then form dimers ric form , while Mric form . Glycosyric form .Ex vivo measurements using fluorescent probes have shown that large molecules such as pathogens cannot pass through, while smaller molecules like antimicrobial peptides can easily penetrate the mucus gel  to deliver the effector proteins  to the cytoplasm of the host cell  and, conhia coli , Shigellflexneri , Salmonelmonella , Vibrio olyticus , and H. . pylori .Pseudomonas aeruginosa respiratory infection, as −/−Muc1 mice are more susceptible to infection in a repetitive Pseudomonas infection model  as early as 1 day after oral gavage with H. pylori compared with WT mice   , suggest (MAV-1) . MUC1 hain vitro .Muc3 (the murine orthologue of human MUC17) and Muc13 are two of the most abundant cell surface mucins in the normal intestinal tract. Interestingly, Muc3 may play a role in wound healing in acute chemical-induced [dextran sodium sulphate (DSS)] colitis: intrarectal administration of recombinant cysteine-rich domains of Muc3 accelerated cell migration and reduced apoptosis in the distal colon . Corrobo−/−Muc5ac mice have higher H. pylori colonisation densities compared with WT animals at 16 weeks post-infection, along with a significant reduction in gastric Tnfα and Il-17a (H. pylori-infected −/−Muc5ac mice had significantly lowered gastric corpus mucous metaplasia at 16 weeks post-infection (wpi) and 32 wpi compared with WT mice. Our work has shown that de novo intestinal goblet cell expression of Muc5ac in the intestine is critical in the protection against Trichuris nematode. Muc5ac but not Muc2 reduced nematode ATP levels and was responsible for the expulsion of the nematode. These studies demonstrate a protective role for Muc5ac in inhibiting pathogen-associated inflammatory pathology. Significantly greater inflammation and fibrosis by bleomycin were developed in −/−Muc5ac lungs compared to WT animals  pathogen related to diarrheagenic A/E. coli  as an integral part of the immune response. This will help us address the fundamental gaps in our knowledge, including understanding the mucin structure; its function in health, disease, and during infection; the crosstalk between mucin and microbes; identifying factors that drive changes in mucin O-glycosylation; and the rheological properties of the mucus gel.YS and SH wrote the review and edited the review. SH conceived the idea of the review.YHS is supported by the Mater Foundation and a National Health and Medical Research Council Project Grant (APP116414), GESA Mostyn Family Grant, and GESA Project Grant.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


There are wide-spread fears and expectations about radiotherapy in people referred to it that are not only unrealistic  but also lead to poorer compliance with doctors and poorer satisfaction with treatment .The aim was to reveal relationship between different aspects of subjective perception of radiotherapy in patients and their well-being.34 patients first referred to radiotherapy, 23-70 years old  filled modified version of Beliefs about Medication Questionnaire including items about radiotherapy , Satisfaction With Life Scale , Scale of Positive And Negative Experience .Six scales were revealed by factor analysis in the structure of beliefs about radiotherapy : confidence in the effectiveness of radiation therapy, subjective need for it, lack of understanding of it, concern and general negative attitudes towards radiotherapy, doubts about the effectiveness of radiation therapy. Elder patients reported higher need for radiotherapy but also higher concerns about it (r=.35-.37). Concerns about radiotherapy were related to lower satisfaction with life and positive emotions (r=-.44 - -.34) while subjective need of radiotherapy was related to higher health anxiety (r=.71) and lower positive emotions (r=-.41).Subjective concerns of patients regarding radiotherapy are related to poorer well-being and could be addressed in psychotherapy.


Tissue biopsies will be analyzed to explore perineural tissue remodeling in correlation with intraoperatively measured nerve compression pressure. Effect size on symptoms including pain intensity, light touch threshold, static and moving two-point discrimination, target muscle force, and nerve conduction velocity will be quantified 3, 6, and 12 months postoperatively, and compared (1) to the preoperative values and (2) to the contralateral lower extremity that continues non-operative management. Clinical significance: Targeted surgical release may alleviate mechanical strain on entrapped lower extremity nerves and thereby potentially improve pain and sensory dysfunction in a subset of patients suffering from diabetic neuropathy. This trial aims to shed light on these patients that potentially benefit from screening for lower extremity nerve entrapment, as typical symptoms of entrapment might be erroneously attributed to neuropathy only, thereby preventing adequate treatment.Background: Nerve entrapment has been hypothesized to contribute to the multicausal etiology of axonopathy in sensorimotor diabetic neuropathy. Targeted surgical decompression reduces external strain on the affected nerve and, therefore, may alleviate symptoms, including pain and sensory dysfunction. However, its therapeutic value in this cohort remains unclear. Aim: Quantifying the treatment effect of targeted lower extremity nerve decompression in patients with preexisting painful sensorimotor diabetic neuropathy and nerve entrapment on pain intensity, sensory function, motor function, and neural signal conduction. Study design: This prospective, controlled trial studies 40 patients suffering from bilateral therapy-refractory, painful ( Nowadays, 1 in 11 adults, or about 463 million people worldwide, are estimated to suffer from diabetes, a number that has more than tripled over the past 2 decades [The progressive neurodegeneration in diabetic neuropathy occurs in a length-dependent fashion and primarily affects sensory and autonomic axons of the peripheral nervous system . This caBeyond these mechanisms, previous work indicated that progressive intra- and extraneural fibrotic tissue remodeling ,16,17,18In advanced diabetes, intraneural capillary dysfunction and consequently impaired oxygen extraction, combined with phenotypic alterations in mitochondrial biology in diabetic neurons, result in reduced adaptability to fluctuating energy demand and, thus, may cause exhaustion of the ATP supply in distal axonal components . ChronicTherapeutic options are limited for this debilitating disease. In the United States, all clinical trials that aimed to prevent disease progression of diabetic neuropathy have failed so far . ModifyiThe primary objective of this trial is quantifying the treatment effect size of unilateral surgical release of the tibial nerve in the tarsal tunnel and/or the common peroneal nerve below the muscle fasciae in the proximal lower leg  on pain Secondary objectives are quantifying the treatment effect on target muscle force and fatigability, as well as the incidence of diabetic ulcers in the skin area supplied by the decompressed nerve. Furthermore, tissue biopsies from the perineural fat and overlying compressive fascia are analyzed to explore perineural tissue remodeling in correlation with intraoperatively measured tissue pressures in nerve constriction sites.Trial registration: German Clinical Trials Register (DRKS); DRKS-ID: DRKS00021151.n = 20 participants suffer from therapy-refractory pain with intensities of 5 and greater on the visual analogue scale (VAS), and another n = 20 participants suffer from therapy-refractory hypoesthesia, predominantly localized in the skin areas supplied by the potentially entrapped peripheral nerves.A total of 40 type 1 and type 2 diabetic patients (age 18–90 years) suffering from diabetic sensorimotor neuropathy and showing clinical signs of compression of the tibial nerve in the tarsal tunnel and/or the common peroneal nerve below the muscle fasciae in the proximal lower leg on both lower extremities are included in this trial. Of those, Age 18–90 years;Type 2 or type 1 diabetes mellitus diagnosed according to the guidelines of the German Diabetes Association .Detailed eligibility criteria for participating in this trial are as follows:-Neuropathy Deficit Score > 5 points;-Neuropathy Deficit Score 3–5 points + Neuropathy Symptom Score > 4 points.Diabetic sensorimotor polyneuropathy of both lower extremities :-NeuropAnd-Predominant focal (pain) symptoms in the innervation area of the nerve distal to the compression site;-Hoffman–Tinel’s sign over the compression site;-Characteristic electrodiagnostic findings of compression e.g., local conduction block;-Characteristic findings of compression in the MR-neurography, e.g., local T2 weighted hyperintensity of the nerve within the compression site.Clinical evidence of bilateral local nerve compression of the tibial nerve in the tarsal tunnel and/or the common peroneal nerve under the muscle fascia of the peroneus longus muscle:AndBilateral, therapy-refractory pain in the area supplied by the potentially entrapped nerve under conventional, guideline-compliant analgesic therapy (VAS >5);Bilateral hypesthesia in the area supplied by the potentially entrapped nerve defined as a tactile perception threshold greater than 6 g but less than 60 g.Exclusion criteria are as follows:HbA1c in the blood plasma > 8.5% ;Reduced ability to give consent and/or legal capacity ;Contraindications to lower extremity surgery;Contraindications for electrodiagnostics, such as implanted cardiac pacemaker/defibrillator;-Other diseases of the peripheral or central nervous system not mentioned under “Inclusion criteria”;-Moderate or severe peripheral arterial disease ;-Dermatological conditions of the lower extremities.Diseases that potentially confound the outcomes of interest, in particular:AndPatients with diabetic sensorimotor neuropathy of both lower extremities and signs of bilateral tibial nerve and/or peroneal nerve entrapment undergo unilateral decompression of the entrapped nerve(s) A–H by anA tourniquet is used to improve intraoperative visibility. Decompression of the tibial nerve in the tarsal tunnel is conducted through an 8–10 cm long skin incision on the inner malleolus A. The taThe common peroneal nerve is decompressed through a 5–7 cm long skin incision around the fibular head and neck D,E. The Intraoperatively, tissue biopsies are harvested from (1) the tarsal ligament, (2) the fascia of the peroneus longus muscle, and (3) the perineurial tissue of the decompressed nerves(s) for subsequent analysis. A meticulous bipolar hemostasis is carried out with subsequent multi-layered skin closure using surgical sutures.The surgery is performed as an inpatient procedure, using postoperative compressive dressings, daily wound care, and a slightly elevated position of the operated limb for 48 h post-surgery to reduce postoperative swelling and risk of hematoma.Participants are asked to quantify pain intensity using the numeric rating scale (NRS) in the skin areas supplied by the entrapped peripheral nerves in each lower extremity, preoperatively as well as 3, 6, and 12 months postoperatively.Participants undergo sensory testing in the skin areas supplied by the tibial and peroneal nerves  in both The tactile sensory threshold describes the lowest detectable light touch stimulus. For this trial, it is assessed according to the protocol of the German Research Association for Neuropathic Pain (DFNS)  using a Two-point discrimination describes the ability to recognize two stimuli as two individual stimuli (and not one stimulus) when they are simultaneously applied in close proximity. Static and dynamic two-point discrimination are assessed in a participant-blinded fashion using a two-point esthesiometer  according to the protocol of Dellon and Mackinnon . The estAdditionally, participants undergo standardized quantitative sensory testing (QST) on both lower extremities according to the protocol of the German Research Network on Neuropathic Pain (DFNS)  preoperaMaximum isometric muscle strength and fatigability of movements that involve the target muscles of the entrapped tibial and peroneal nerves are assessed in both lower extremities preoperatively, as well as 3 and 12 months postoperatively.To assess for a potential therapeutic effect of surgical decompression of the tibial nerve in the tarsal tunnel, the maximum isometric muscle strength of great toe flexion is measured using a handheld dynamometer . The peroneal nerve’s target muscles are assessed using the maximum isometric muscle strength of great toe extension.The dynamometer is placed perpendicular to the direction of the force vector and the application points of the dynamometer are standardized using anatomical landmarks. The patient is then instructed to perform the movement to be tested and to maximally press against the force absorbing plate of the dynamometer for a period of five seconds while avoiding explosive movements. The examiner stabilizes the limb proximal to the limb segment to be tested. Three repeat tests are then carried out with approximately 30 s rest in-between. The maximum isometric force mean and the peak values are documented .Muscle fatigability and coordination are assessed using the one-legged toe stand test. Participants perform a repeated concentric–eccentric muscle contraction of the plantar flexors in a one-legged stand ,39. The ®, Viasys Healthcare GmbH, Höchberg, Germany).Nerve conduction velocity of the tibial and peroneal nerves over the respective nerve compression site are quantified preoperatively and 6 to 12 months postoperatively for both lower extremities using adhesive surface electrodes and a CE-certified neurophysiology device  1118 diabetes-specific biobank, part of the tissue bank of the National Center for Tumor Diseases (NCT). Collectively, these CRC 1118 biosamples will be analyzed for glucose metabolism pathologies, metabolic pathway regulation, characterization of cellular senescence, inflammation, and fibrosis to decipher the chronic tissue remodeling processes that potentially underlie nerve compression in this cohort.Following initial recruitment, the inclusion and exclusion criteria are applied, and written consent is acquired from each participant. Then, participants undergo a standardized clinical exam and history taking to assess pain intensity, sensory dysfunction, motor function, and to detect neuropathic ulcerations in the skin innervation area of the tibial and/or peroneal nerve in both legs with subsequent electrodiagnostic testing. Nerve decompression surgery is performed, and in-person follow-up exams are scheduled 3 and 12 months post-surgery to repeat the standardized preoperative assessments . Six monn = 20 is required for painful and painless participants, respectively, to achieve a power of > 0.8 at a significance level of 5% with an expected drop-out rate of 20%.Sample size calculation is based on effect sizes achieved in previous clinical studies ,41,42. BPatients potentially suitable for this trial are primarily recruited through diabetic outpatient clinics of the University of Heidelberg, as well as through the peripheral nerve clinic at the BG trauma center, Ludwigshafen, University of Heidelberg.The selection of the extremity to be operated on is made after inclusion in the study and completion of the pre-operative tests based on the patient’s preference. A randomized selection of the extremity that undergoes surgery was considered unethical given the often-asymmetrical pain distribution among both legs in our patient population.Outcomes are assessed through a blinded examiner. The wounds/scars in the operated limb and the corresponding area of the contralateral extremity will be covered by a third person immediately before examination.The collected data will be pseudonymized using case report forms with a unique participant number. Before publication and during statistical analysis the data will be completely anonymized. All collected data are analyzed using descriptive statistics , and, if necessary, confidence intervals), and graphic methods to characterize distributions. Because intervention and control group measurements are obtained from one subject and are collected in serial measurements over time, the data are analyzed as matched samples using signed-rank tests to address the following hypotheses.A reduced pain intensity in the innervation area of the nerve distal to the decompression site 3, 6, and 12 months postoperatively, compared to the preoperative pain intensity and compared to an intraindividual non-decompressed control .A reduced analgesics consumption 3, 6, and 12 months postoperatively, compared to the preoperative baseline.Improved sensation  in the innervation area of the nerve distal to the decompression site 3 and 12 months postoperatively compared to the preoperative situation and compared to an intra-individual, non-decompressed control .Increased isometric muscle strength in target muscles supplied by muscle branches arising from the decompressed nerve distal to the decompression site, 3 and 12 months postoperatively, compared to the preoperative situation and compared to an intra-individual, non-decompressed control An increase in nerve conduction velocity across the decompression site 3 and 12 months postoperatively compared to the preoperative situation and compared to an intra-subject non-decompressed control .A lower prevalence of neuropathic ulcerations in the innervated skin area of the nerve distal to the decompression site compared to an intra-individual, non-decompressed control  in the 12-month postoperative follow-up period.The targeted surgical release of a mechanically compressed nerve in diabetic, sensorimotor polyneuropathy results in the following:This trial aims to investigate a potential treatment effect of surgical nerve release in patients with diabetic neuropathy and lower extremity nerve entrapment on pain and sensory function. Secondary outcomes of interests are nerve conduction velocity, motor function, and prevalence of diabetic ulcerations.Another objective of this study is to generate hypotheses on currently unknown aspects of the pathophysiology of nerve compression in diabetic sensorimotor polyneuropathy. Here, we focus on the chronically progressive tissue remodeling processes at the compression site by analyzing intraoperatively harvested tissue biopsies, and introduce, for the first time, tissue pressure measurements at the site of compression. The hypotheses generated from this trial will be addressed in subsequent studies in a confirmatory manner.The currently available clinical studies on therapeutic nerve decompression in this cohort are limited by two essential aspects. First, a heterogeneous study collective with multiple compression and varying decompression sites of different nerves in the lower extremities were included ,43,44,45This trial aims for increased internal and external validity through a homogeneous patient collective and by using a standardized intervention with a standardized postoperative assessment of predefined target criteria. These data, together with intraoperative compression pressure measurements and morphological analysis of perineural tissue remodeling, may help to give insight into the potential role of nerve entrapment in patients with symptomatic diabetic neuropathy. However, it must be emphasized that surgical release may not address any underlying metabolic–toxic aspects of this disease but solely alleviates mechanical strain on entrapped neuropathic nerves. Due to the invasiveness of this procedure, and the risk of poor wound healing in diabetics, eligible patients need to be selected with great care. Partaking in the interdisciplinary management of patients with diabetic neuropathy, experienced nerve surgeons may help to allocate this treatment perspective responsibly to those likely to benefit from this intervention.This trial aims to provide evidence on whether selected patients suffering from diabetic neuropathy with unusual distribution of pain or sensory dysfunction may benefit from referral to experienced nerve surgeons to reliably identify and address any potential nerve entrapment.


As editors, we are very proud to present this Research Topic. It was really gratifying to review all the accepted reviews and research articles published in this Research Topic. In this editorial, we want first to thank all the reviewers who helped us with this task and to introduce our topic, and briefly summarize the contributing articles.Our Research Topic focuses on developmental genes and their involvement in normal and disease development. Key processes essential for normal embryonic development include cellular proliferation, migration, and differentiation, all of which are regulated by crucial signaling pathways whose dysregulation often leads to developmental defects and severe pathologies.Hu et al. reviewed the potential roles of genetic variants in thousand and one (TAO) kinases, which are major contributors to several neurodevelopmental disorders (NDDs). In this review the authors summarize the potential roles of the TAO kinases based on the development of neurodevelopmental disorders. The group focused on biochemical and structural analyses, by presenting the genetic data from clinical investigations. Furthermore, the group also discuss the mechanistic link between neuropathology, the mutations of TAO kinases, and behavioral impairment in NDDs.Regarding unregulated signaling pathways in pathologies, tweety gene family. This family was very well-reviewed by Nalamalapu et al. in a review published in 2021, covering tweety gene family evolution, structure, expression during adulthood and development, cellular and biochemical functions, and their role in human disorders .Another gene family known to play important roles in the development of several pathologies is the Telias and Ben-Yosef investigated the effects of Wnt/β-catenin signaling on neuronal differentiation using the glycogen synthase kinase-3β inhibitor CHIR99021, to upregulate Wnt β-catenin signaling and the tankyrase-1/2 inhibitor XAV939 to downregulate it. The authors found that Wnt-agonism promoted induction of neural differentiation, while also reducing cell proliferation and survival. This effect was not synergistic with those of pro-neural growth factors during long-term neuronal differentiation. Conversely, antagonism of Wnt by XAV939 consistently prevented neuronal progression of hNPCs. The paper nicely illustrates how these two drugs can be used to manipulate cell fate and how self-renewing hNPCs can be used as reliable human in vitro drug-screening platforms.The canonical Wnt/β-catenin pathway is an important regulator of cell fate during embryo development and adult neurogenesis. Therefore, the pharmacological manipulation of this pathway is widely used and of broad interest. Using stable human neural precursor cell (hNPC) lines derived from embryonic stem cells, Lim et al. in this Research Topic studied the role of serine-threonine kinase WNK3 (With No Lysine [K]), in GABAergic signaling during maturation of prenatal hippocampal neurons. Their study provides the first evidence that WNK3 plays a crucial role in maintaining the polarity of GABAergic signaling, neuron morphology, intrinsic excitability, and synaptic excitation in mature hippocampal neurons in either a KCC2-dependent or independent manner. The authors demonstrate that WNK3 deficiency induces EGABA hyperpolarization, indicating an increase in GABA inhibitory response in mature neurons, through the upregulation of KCC2 activity. In addition, WNK3 deficiency in mature neurons led to altered neuron morphology consistent with the shift of GABAergic inhibitory response upon upregulation of KCC2 activity. The group concluded that WNK3 possibly affects neuronal somatic and synaptic properties by modulating KCC2 activity, resulting in abnormal activity patterns that may underlie psychiatric and neurological disorders.Another research paper from Akbari et al. studied the role of the dysfunction of regulatory T cells (Tregs) affecting the etiology of autism spectrum disorders (ASD). As specific Tregs are known to be regulated by a group of long non-coding RNAs (lncRNAs), in this study the authors compared the expression of five lncRNAs implicated in Treg regulation in blood samples from ASD cases and controls. These lncRNAs were FOXP3 regulating long intergenic non-coding RNA (FLICR), MAF transcriptional regulator RNA (MAFTRR), NEST (IFNG-AS1), RNA component of mitochondrial RNA processing endoribonuclease (RMRP), and Th2 cytokine locus control region (TH2-LCR). The group concluded that their study supports dysregulation of Treg-related lncRNAs in patients with ASD and suggests these lncRNAs could be used as peripheral markers for ASD.As the immune system also plays a crucial role in several disorders, Xu et al. recently identified five-novel heterozygous ARFGEF1 variants implicated in neurodevelopmental disorders. It is already known that mono-allelic loss-of-function variants in ARFGEF1 caused a developmental delay, intellectual disability, and epilepsy, of varying clinical severity. The group demonstrated that variants in this gene affected males more severely than females in terms of acquiring neurodevelopmental disorders. This study broadens the genotypic spectrum of ARFGEF1-related neurodevelopmental disorder using data from a local Chigene database, identifying five novels heterozygous (likely) pathogenic variants. The group provide further evidence of the pathogenicity of ARGEF1 haploinsufficiency in male patients and examine the likelihood of digenic inheritance in female patients.Zheng et al. studied the role of a dominant genetic rare disease caused by the mutation in the USP7 gene (*602519) on chromosome 16p13.2 in Hao-fountain syndrome (HAFOUS) neurodevelopmental syndrome. The group identified three variants, including one frameshift variant (c.247_250delGAGT) and two missense variants  that have not been previously reported. The predominant clinical manifestations in affected individuals were developmental disability/intellectual disability (DD/ID), abnormal behavior, language impairment, and abnormal brain magnetic resonance imaging ; some also had facial abnormalities, a small percentage had genitourinary abnormalities.Finally, Taken together, this collection of papers provides a useful and interesting summary of how disruptions to a number of important developmental regulatory genes can lead to neurodevelopmental disorders.All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.JOM's research is supported by the Simons Initiative for the Developing Brain (SFARI 529085).Author TCLSS was employed by Centogene GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


This review paper considers the consequences of modulating tubular reabsorption proximal to the macula densa by sodium–glucose co-transporter 2 (SGLT2) inhibitors, acetazolamide, and furosemide in states of glomerular hyperfiltration. SGLT2 inhibitors improve renal function in early and advanced diabetic nephropathy by decreasing the glomerular filtration rate (GFR), presumably by activating the tubuloglomerular feedback (TGF) mechanism. Central in this paper is that the renoprotective effects of SGLT2 inhibitors in diabetic nephropathy can only be partially explained by TGF activation, and there are alternative explanations. The sustained activation of TGF leans on two prerequisites: no or only partial adaptation should occur in reabsorption proximal to macula densa, and no or only partial adaptation should occur in the TGF response. The main proximal tubular and loop of Henle sodium transporters are sodium–hydrogen exchanger 3 (NHE3), SGLT2, and the Na-K-2Cl co-transporter (NKCC2). SGLT2 inhibitors, acetazolamide, and furosemide are the most important compounds; inhibiting these transporters would decrease sodium reabsorption upstream of the macula densa and increase TGF activity. This could directly or indirectly affect TGF responsiveness, which could oppose sustained TGF activation. Only SGLT2 inhibitors can sustainably activate the TGF as there is only partial compensation in tubular reabsorption and TGF response. SGLT2 inhibitors have been shown to preserve GFR in both early and advanced diabetic nephropathy. Other than for early diabetic nephropathy, a solid physiological basis for these effects in advanced nephropathy is lacking. In addition, TGF has hardly been studied in humans, and therefore this role of TGF remains elusive. This review also considers alternative explanations for the renoprotective effects of SGLT2 inhibitors in diabetic patients such as the enhancement of microvascular network function. Furthermore, combination use of SGLT2 inhibitors and angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs). in diabetes can decrease inflammatory pathways, improve renal oxygenation, and delay the progression of diabetic nephropathy. Recent studies strongly support that sodium–glucose co-transporter type 2 (SGLT2) inhibitors decrease cardiovascular risk ,2. In adSGLT2 inhibitor, acetazolamide, and furosemide are compounds that can increase macula densa delivery and activate the TGF response, and can possibly decrease hyperfiltration. However, SGLT2 inhibitors seem to be the prototype of drugs to increase macula densa solute delivery and activate TGF response sustainably without changing TGF responsiveness. In contrast, furosemide and acetazolamide have characteristics that possibly fail to meet the prerequisites and prevent sustained increases in TGF activation. Besides the effect of single drugs, we will explore the effect of SGLT2 inhibitors in the real-life context of multiple medications for the treatment of diabetes mellitus and cardiovascular disease. An example would be the combined use of SGLT2 inhibitors and angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs). These latter drugs would supposedly decrease TGF responsiveness, yet the large clinical trials showing the beneficial effects of SGLT2 inhibitors on renal function were performed in study populations where ACEi and ARB use was highly prevalent .Another aspect of this is that while SGLT2 inhibitors were originally reported to specifically diminish the diabetic hyperfiltration of early diabetic nephropathy before anatomical injury to the glomerulus, they also exert preventative properties in more advanced diabetic nephropathy with segmental or global glomerulosclerosis. We will review the proximal tubular reabsorption and TGF dynamics in early versus more advanced diabetic nephropathy. Taken together, given what we know about SGLT2 inhibitors, TGF activation might be a component of the beneficial renal effects of SGLT2 inhibitors in diabetic nephropathy, but other mechanisms are likely and will be discussed.Kidneys stabilize RBF , GFR, and PGC in parallel in response to fluctuations in blood pressure by adjustments in afferent arteriolar resistance by employing two mechanisms: the rapid myogenic response (MR) and the slower TGF. This autoregulation process stabilizes renal function and protects the glomeruli from injury . MR is a universal response in all microvascular beds: a rise in wall tension, generally due to an increase in blood pressure, results in arteriolar vasoconstriction to stabilize tissue perfusion ,12,13,14MR and TGF interact synergistically ,21. It wAs mentioned in the introduction, compounds that decrease solute reabsorption upstream of the macula densa can sustainably increase macula densa delivery. However, partial compensation in reabsorption in segments proximal to the macula densa or resetting or saturation of the TGF system could offset this initial response. The overall thought is depicted in The reabsorption of sodium together with other solutes such as glucose, amino acids, chloride, and bicarbonate in the proximal tubule and loop of Henle ultimately determines the solute concentrations of fluid reaching the macula densa and the activation of TGF. In this section, we will further discuss the main sodium transporters in this context—NHE3, SGLT2, and the Na-K-2Cl co-transporter, NKCC2—and how they are regulated.The three isoforms of the sodium–hydrogen exchanger  in the proximal tubule and descending and ascending loop of Henle ,24 are mNHE3 is regulated by several stimulatory and inhibitory hormones at transcriptional and post-translational levels, including changes in protein phosphorylation and trafficking . InsulinUnder physiological conditions, the sodium–glucose co-transporters (SGLTs) SGLT1 and SGLT2 in the proximal tubule reabsorb almost all of the filtered glucose . This isSGLT2 is upregulated at the transcriptional and post-translational level by ANG II, insulin, and hepatocyte nuclear factor (HNF-1α) ,40. The In the loop of Henle, 25–30% of filtered Na-Cl is reabsorbed via NKCC2 across the apical membrane of the water impermeable thick ascending limb (TAL) ,44. NineSeveral hormones modulate the NaCl reabsorption in TAL by regulating NKCC2 activity. NKCC2 is stimulated at the post-translational level mainly via increasing intracellular cyclic adenosine monophosphate (cAMP) levels by stimulatory hormones such as vasopressin, PTH, and calcitonin. cAMP enhances NKCC2 activity by stimulation insertion into the cell membrane and presumably also by phosphorylation . The stiIn the early phase of diabetic nephropathy, proximal tubular reabsorption is increased, resulting in decreased solute delivery to the macula densa and deactivation of the TGF response , hyperfiIn diabetes mellitus, the glomerular-filtered load of glucose is increased. Nephrons become hypertrophied and SGLT2 expression increases in the proximal tubule . IncreasIn advanced diabetic nephropathy, nephrons can display at least three different phenotypes: intact nephrons, segmentally sclerosed nephrons, and globally sclerosed nephrons. The intact, often hypertrophied nephrons might display enhanced reabsorption due to the same mechanisms as in early diabetes. Increased ANG II levels and the increased activity of SGLT2 transporters will contribute to deactivation of the TGF and cause hyperfiltration. Additionally, some nephrons can become segmentally sclerosed, which can result in decreased filtration, decreased macula densa delivery, and the deactivation of TGF. In these partially sclerosed nephrons, GFR might or might not be increased based on the extent of glomerular sclerosis. If there is an adequate glomerular surface, GFR would increase. Otherwise, GFR would remain low.Finally, some nephrons are globally sclerosed and there is no filtration and TGF activity. This would contribute to an overall decrease in GFR. These globally sclerosed nephrons no longer consume oxygen. As further explained below, such nephrons can also disturb microvascular network dynamics in two ways. First, they can cause anatomical disruption. Second, they disrupt the oxygenation of nearby intact nephrons, which can result in decreased solute reabsorption, increased macula densa solute delivery, the activation of TGF, and a decrease in SNGFR in nearby intact nephrons.Additionally, volume expansion in advanced diabetic nephropathy might affect macula densa delivery and the TGF system. Volume expansion decreases ANGII levels . This woIn summary, in early diabetic nephropathy, the solute concentration of fluid reaching the macula densa decreases and TGF is deactivated, which would result in hyperfiltration. In advanced diabetic nephropathy, the changes in reabsorption and the TGF response are difficult to predict due to segmental or global glomerulosclerosis and potential volume expansion . Clinically, SGLT2 inhibitors have been shown to be effective in reducing cardiovascular events and in preventing CKD progression in mild, but also more advanced, diabetic as well as non-diabetic CKD ,2,67. SGNevertheless, SGLT2 inhibitors can sustainably increase the solute concentration of fluid reaching the macula densa, and lead to a sustained TGF activation, afferent arteriolar vasoconstriction, and a decline in SNGFR and whole-kidney GFR. However, in the only available study on this subject, the sustained response was 50% of the acute response ,5,6. Besides the different phases of diabetic and non-diabetic CKD, an area of great uncertainty is whether other concomitant treatments could offset the beneficial effects of SGLT2 inhibitors. An example is ACE inhibitor therapy. It has been documented by us ,74 and oThe available literature about the mechanistic aspects of the positive effects of SGLT2 inhibitors in early diabetic nephropathy is based on a relatively small number of studies in rats and mice supporting the idea that these compounds increase the solute concentration of fluid reaching the macula densa sustainably and activate TGF sustainably, reducing hyperfiltration and thereby preserving renal function. The literature is lacking a solid basis for how SGLT2 inhibitors exert their actions in more advanced diabetic and non-diabetic CKD. In addition, TGF is difficult to assess and has hardly been studied in humans, and whether TGF is the central mediator of positive effects of SGLT2 inhibitors in human diabetic and non-diabetic CKD patients remains elusive. Acetazolamide reduces proximal tubular reabsorption by inhibiting bicarbonate reabsorption via decreasing carbonic anhydrase activity and NHE3 . This inFurosemide reduces sodium reabsorption in the thick ascending limb of the loop of Henle by inhibiting NKCC2, which would initially increase the solute concentration of fluid reaching the macula densa. While this can be compensated by increasing the solute reabsorption in the proximal tubule due to the activation of renin-angiotensin system (RAS) and the sympathetic nervous system, furosemide can increase the solute concentration of fluid reaching the macula densa sustainably . That saAlthough the data in the literature are sparse, there are other explanations for the positive effects of SGLT2 inhibitors in diabetic nephropathy. SGLT2 inhibitors could enhance the network function among nephrons by activating the TGF system. In addition, the combination use of SGLT2 inhibitors and ARBs/ACEi can reduce fibrosis, inflammatory pathways, and glomerular injury in diabetes and thereby preserve renal function. Furthermore, SGLT2 inhibitors and ARBs/ACEi decrease tubular reabsorption. This reduces oxygen demand and renal hypoxia, which are known cause of fibrosis and microvascular injury .Recognition of the complexity of the kidney’s microvascular physiology and anatomy has altered the idea that each nephron is responsible for its own autoregulation. We and others have suggested that nephrovascular units (NVUs), which consist of a nephron and its afferent and efferent arteriole, communicate with each other in a network, and explain renal autoregulation and perfusion in the kidneys better . TGF genMoreover, TGF-generated oscillations can be transmitted to upstream vascular branch points through endothelial gap junctions formed by connexin proteins (mainly connexin 40) . This upAnother explanation for the beneficial effects of SGLT2 inhibitors could be the combined use of SGLT2 inhibitors and ACEi or ARBs in diabetic patients. Increased luminal glucose by SGLT2 inhibitors inhibits urate transporter 1, which would increase uric acid excretion substantially. This in turn would reduce reactive oxygen species (ROS), inflammation, and renal damage induced by uric acid . SGLT2 iIn summary, two prerequisites are necessary to make a compound effective to sustainably activate the TGF system and sustainably alter renal hemodynamics. First, macula densa delivery should increase sustainably without any significant compensation in reabsorption in the segments upstream of the macula densa. Second, no compensation should occur in the TGF response. SGLT2 inhibitors seem to be an example of compounds that can activate the TGF system sustainably, which is one of the explanations for the positive effects of SGLT2 inhibitors in advanced diabetic nephropathy, as they decrease glomerular hyperfiltration by sustainably activating the TGF system. Moreover, SGLT2 inhibitors can enhance network dynamics among NVUs and decrease ROS, which can delay the progression of diabetic nephropathy. Finally, in diabetic patients, the combination use of SGLT2 inhibitors and ARBs/ACEi could contribute to the enhancement of renal hemodynamics. However, many questions remain regarding the exact mechanism of action of SGLT2 inhibitors.


Diabetes is a continuously growing global concern affecting >10% of adults, which may be mitigated by modifiable lifestyle factors. Consumption of nuts and their inclusion in dietary patterns has been associated with a range of beneficial health outcomes. Diabetes guidelines recommend dietary patterns that incorporate nuts; however, specific recommendations related to nuts have been limited. This review considers the epidemiological and clinical evidence to date for the role of nut consumption as a dietary strategy for the prevention and management of type 2 diabetes (T2D) and related complications. Findings suggest nut consumption may have a potential role in the prevention and management of T2D, with mechanistic studies assessing nuts and individual nut-related nutritional constituents supporting this possibility. However, limited definitive evidence is available to date, and future studies are needed to elucidate better the impact of nuts on the prevention and management of T2D. Type 2 diabetes is one of the most globally challenging and prevalent metabolic disorders affecting an estimated 1 in 10 adults (10.5% of adults worldwide)  implied in oxidant reactions and inflammation . Some ofNuts may modulate the expression of genes related to glucose metabolism through the mediatory effect of nutrients on microRNAs (miRNAs), defined as small non-coding RNAs with 20 to 25 nucleotides that post-transcriptionally and negatively regulate gene expression.In the EPIRDERM Study, seven human circulating miRNAs were selected for analysis, that are considered widely related to glucose metabolism, insulin resistance status, prediabetes status, and biomarkers of T2D. The miRNA expression data showed that of the seven miRNAs studied, after pistachio intervention, circulating miRNA-192 and 375 expressions were significantly lower than in the control phase . FurtherSimilarly, in another trial involving 10 healthy women, 8 weeks of following a PUFA-enriched  normocaloric diet resulted in significant modifications to several common miRNAs . SpecifiNutritional metabolomics is an emergent approach to obtaining deeper insights into diet–disease association that holds great promise in improving our understanding of the biological effects of nutritional factors and may help to identify potential novel markers of dietary intake and disease risk . To dateMetabolomics has been used as an agnostic machine learning approach to identify plasma metabolites associated with walnut consumption using data from the PREvención con DIeta MEDiterránea (PREDIMED) study . A metabThere are several strengths and limitations of the available evidence. Strengths, in general, include the relatively long follow-up duration of multiple years observed in the epidemiological studies and data from various countries allowing for potential generalizability of the findings. However, the cross-sectional and prospective cohort studies are limited by the inability to determine causation. A cross-sectional study design is also limited by the lack of ability to assess a temporal relationship between the exposure and the outcome. Additionally, most studies included in this review tended to obtain intake data via food frequency questionnaires (FFQs). FFQs have inherent weaknesses as they are subject to possible measurement error and recall bias . FurtherWhile evidence from both acute and chronic RCTs in individuals with diabetes suggests nut consumption may improve glycemic control via reductions in fasting glucose and HbA1c, the effect still needs to be confirmed by updated SRMAs studying individuals with and without diabetes separately and without mixing interventions of whole nuts with nut oils or other extracts from nuts. It would also be useful to better understand which foods should be replaced with nuts in the diet for the most beneficial impact, as the current trials vary in this regard—some prescribe proportional reductions to all foods, and some suggest replacing for carbohydrate- or saturated fat-rich foods. In contrast, others provide no specific instructions on food replacement. Glycemic control assessment methods are also limited, and there is a lack of direct evidence from clamp studies or from Bergman´s minimal model, which may provide a greater understanding of metabolic regulation . MoreoveIn addition to the limitations to the currently available evidence, there are also a few potential barriers to nut consumption, such as nut-related allergies, cost, dental or swallowing issues, especially in older adults, and lack of knowledge of health benefits by health professionals . This, iFuture research is needed to better elucidate the impact of nuts on the prevention and management of T2D. Given the current research limitations and limited epidemiological and clinical trial evidence available, there are several lines of research that could provide greater insight and better inform diabetes dietary guidelines.Further investigation via prospective cohorts assessing the impact of nuts on diabetes incidence and pooled cohort analyses needs to be undertaken. Pooling data from currently conducted prospective cohorts may provide a relatively cost-effective and informative real-world way to explore the possible role of nuts in diabetes prevention and complications. Additionally, more studies in individuals with T2D are needed to demonstrate the impact of nuts on glycemic control . To determine a possible causal effect, conducting larger and longer RCTs (such as a multicentre RCT) evaluating markers of glycemic control as primary endpoints is needed in order to expand current knowledge to assess the effect of nuts on diabetes prevention in high-risk participants. Acutely, insulin sensitivity analysis testing the effect of nut consumption, such as replacing carbohydrates, using the Bergman Minimal Model of glucose regulation and clamps would aid in increasing the strength of available evidence.Further explorations related to metabolomic and metagenomic signatures of nut consumption in clinical trials and assessing the association in long-term cohort studies of diabetes incidence and complications would additionally provide greater insights into a potential diet (nut)–disease (diabetes) association. Then a range of mechanistic molecular biological studies may be justified when a clear phenomenon, such as reduced insulin resistance and improved diabetes control, has been established.Of the limited evidence currently available, overall findings suggest higher nut consumption may have beneficial effects on diabetes prevention and management. In particular, some but not all large cohort studies have found that higher consumption of total nuts, walnuts, and peanuts was significantly associated with a lower risk of T2D. Moreover, inclusion of nuts in the diets of individuals may have a beneficial effect on glycemic control and lower the risk of cardiovascular disease and mortality in those with T2D. In individuals with T2D, specifically, acute studies have demonstrated reductions in postprandial glucose levels, and long-term trials have indicated modest positive effects on blood glucose control, as shown by reductions in HbA1c and fasting blood glucose. Mechanistic pathways provide further promise for the potential role nut consumption may have in diabetes prevention and management. Despite all the potential diabetes-related health benefits nuts may pose, current evidence is not definitive, and there remains much opportunity for future research to address present weaknesses and limited data in this field to provide more conclusive evidence on the role of nuts in the prevention and management of diabetes.


Glioblastoma (GBM) is a highly invasive primary brain tumor in adults with a 5-year survival rate of less than 10%. Conventional radiotherapy with photons, along with concurrent and adjuvant temozolomide, is the mainstay for treatment of GBM although no significant improvement in survival rates has been observed over the last 20 years. Inherent factors such as tumor hypoxia, radioresistant GBM stem cells, and upregulated DNA damage response mechanisms are well established as contributing to treatment resistance and tumor recurrence. While it is understandable that efforts have focused on targeting these factors to overcome this phenotype, there have also been striking advances in precision radiotherapy techniques, including proton beam therapy and carbon ion radiotherapy (CIRT). These enable higher doses of radiation to be delivered precisely to the tumor, while minimizing doses to surrounding normal tissues and organs at risk. These alternative radiotherapy techniques also benefit from increased biological effectiveness, particularly in the case of CIRT. Although not researched extensively to date, combining these new radiation modalities with radio-enhancing agents may be particularly effective in improving outcomes for patients with GBM. Median survival is, therefore, poor at 12–15 months, and only 5%–7% of patients survive beyond 5 years.5 No effective treatment strategy has yet been established for recurrent or progressive disease, but current options include surgery, re-irradiation, systemic therapies, and palliative care.6Glioblastoma (GBM and WHO grade 4) is the most common primary brain tumor in adults with an annual worldwide incidence of ~170 000 cases.6-methylguanine-DNA methyltransferase (MGMT) promoter, which can predict response to treatment as well as overall prognosis. Epigenetic silencing of the MGMT promoter suppresses transcriptional expression of the protein, which normally functions to remove O6-alkyl groups from guanine bases in DNA thus counteracting the effects of alkylating agents, such as TMZ. Therefore, patients whose tumors exhibit methylated MGMT promoters have a better prognosis and respond relatively well to TMZ in combination with radiotherapy, compared to unmethylated patients who derive no benefit from this treatment modality.7Prognostic factors for patients with GBM include the Karnofsky Performance Score and the extent of resection of the tumor tissue. Complete surgical excision is not possible because of the invasive and diffuse nature of GBMs. However, surgical removal of ~70%–98% of tumor tissue, when possible, is associated with improved prognosis, although bulky residual tumors can negatively influence prognosis. An important molecular biomarker in GBM is the methylation status of the OThe aim of this review is to provide an overview of the key biological factors and processes known to influence the efficacy of radiotherapy as a treatment for GBM. We then cover some of the strategies being explored to enhance the sensitivity of GBM to radiotherapy, particularly through targeting the cellular DNA damage response (DDR). Finally, we discuss the potential for other types of radiotherapy, including proton beam and carbon ion therapy (PBT and CIRT) to optimize treatment and ultimately improve outcomes.8 DDR signaling responses are controlled by the protein kinases ataxia telangiectasia-mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR), which activate cell cycle arrest through the checkpoint kinases CHK2 and CHK1, respectively. Other key enzymes involved in DNA repair include the DNA-dependent protein kinase (DNA-PK), which coordinates NHEJ, and the DNA strand break binding protein poly (ADP-ribose) polymerase 1 (PARP1) involved predominantly in SSB repair but also in a sub-pathway of NHEJ.The DDR is involved in the maintenance of genome integrity and stability by correcting damaged DNA . In mamm9 Several DDR proteins, including ATM, ATR, CHK1, PARP1, and RAD51 are upregulated in GBM stem-like cells (GSCs) and enzyme activation appears to be primed even in unirradiated cells, leading to enhanced repair and radioresistance.10 Inhibiting RAD51, a key factor in the HR pathway, has been demonstrated to increase apoptosis, decrease cell survival, and delay the repair of IR-induced DNA damage in GSCs.11 In GBM, mutations in the mismatch repair (MMR) genes are implicated in TMZ resistance. However, a CRISPR-Cas9 screen in patient-derived GBM cells identified that the core members of the mismatch repair (MMR) pathway, MLH1, MSH2, MSH6, and PMS2 were enriched in TMZ resistant cells, after 3 weeks of treatment with TMZ.12 Such findings emphasize that alterations in the DDR play a key role in the resistance of GBM to current treatments.Research has reported that GBM cells demonstrate enhanced G2/M checkpoint activation and DNA repair in response to IR, both of which counteract the cytotoxic effects of the treatment. + stem cells are evident in recurrent tumor samples after treatment with high-dose radiotherapy.13 Stem cell markers including CXCL12, CD133, SOX2, OLIG2, NANOG, aldehyde dehydrogenase 1 (ALDH), NESTIN, and Integrin α6 have been shown to be expressed in GSCs.14 Expression of the transcription factor forkhead box M1 (FoxM1) is associated with radioresistance and maintenance of GSCs via increased expression of SOX2, the master regulator for maintaining stem cells in an undifferentiated state. Moreover, overexpression of SOX2 has been associated with increased clonogenic survival and induces a GSC-like phenotype in tumor cells. Inhibiting FoxM1 in combination with IR was shown to reduce SOX2 expression and impair tumor growth in GBM xenograft models, suggesting that the FoxM1-SOX2 pathway is involved in the radiation response of GBM.15 Knockdown of the NOTCH1 transmembrane signaling receptor has also been reported to increase the radiosensitivity of GSCs,16 while decreasing the adaptive response of GBM xenografts in hypoxia.17The presence of Glioblastoma Stem Cells (GSCs) that have the capacity to self-renew and differentiate into multi-lineages has been implicated in the propensity of GBM to recur after treatment, and hence in the poor patient outcomes observed. DNA repair pathways are predominantly activated in GSCs and increased levels of CD13318 Hypoxia, defined as a reduction in tissue oxygen levels (<1%–2% O2), is associated with tumor aggressiveness, poor patient survival, and radiotherapy resistance in GBM.19 As well as causing radioresistance directly, the presence of hypoxia in GBM promotes invasion and metastasis of tumor cells into the surrounding brain tissue to evade the hypoxic tumor microenvironment.20In vitro studies using GBM cell lines have demonstrated that reducing the oxygen concentration to 9% was sufficient to stimulate tumor cell migration, induce hypoxia-related genes and cause therapy resistance.21 Tumor cells adapt to hypoxia by upregulating neovascularisation, or growth of new blood vessels, to ensure an adequate supply of oxygen and nutrients to the rapidly proliferating tumor. However, this creates a more hypoxic environment because the new blood vessels formed are leaky, small, and blocked, which further leads to blood flow disturbances and prevents immune cell infiltration. The presence of tumor hypoxia also reduces the efficacy of chemotherapeutic agents by preventing drugs from reaching and targeting hypoxic areas of tumors. The acidic pH in the hypoxic tumor microenvironment can also inactivate certain pH-sensitive agents. All these favor the emergence of therapy-resistant, aggressive and metastatic clones.22 Furthermore, formation of new blood vessels leads to tumor permeation and formation of micrometastasis.23 Levels of the transcription factor hypoxia-inducible factor 1α (HIF-1α) are also related to radiation effects on the tumor microenvironment. HIF-1α can initiate an adaptive response to IR through upregulation of vascular endothelial growth factor (VEGF), which promotes survival of endothelial cells.24 This has led to several studies assessing the efficacy of combining antiangiogenic agents with IR to promote the radiosensitivity of endothelial cells. Bevacizumab (Avastin), a monoclonal VEGF antibody was evaluated in 2 large phases III trials (LB-05 and EORTC 26101) but reported no significant benefit of adding this agent to standard GBM treatment. Despite seeing no survival advantage, bevacizumab was approved for the treatment of recurrent GBM in the United States and other countries.25 The NCT05284643 trial has recently been initiated to investigate the efficacy of spectroscopic magnetic resonance imaging, in combination with proton and Avastin in GBM patients.In GBM, the partial pressure of oxygen has been reported to be around 13mmHG.26 Exposure of CD133 + GSCs to IR was found to activate autophagy, whereas inhibition of autophagy using the autophagic inhibitor bafilomycin A1, caused radiosensitization and decreased the ability of GSCs to form neurospheres.27 Cathepsin D is a class of cysteine proteases that demonstrates a positive correlation with autophagic markers such as LC3A and LC3B in GBM. Overexpression of cathepsin D has been associated with radioresistance and poor survival of GBM patients, and inhibiting cathepsin D by small interfering RNA (siRNA) or by the inhibitor pepstatin-A was found to suppress autophagy and sensitize GBM cells to IR.28 These data point to the involvement of autophagy in the radioresistant phenotype of GBM.Autophagy refers to the lysosomal-mediated degradation of unwanted and nonessential cellular components, and has been recognized as a survival mechanism that cells use to adapt to hostile environments including hypoxia and in response to IR. GBM cells have been reported to employ autophagy to reutilize unwanted or damaged proteins to aid in the progressive growth of the tumor.29 and purine overexpression has also been associated with poor patient prognosis.30 Inhibiting purine synthesis using mycophenolic acid (MPA) was found to sensitize GBM cells and neurospheres to IR through delays in DSB repair, whereas nucleoside treatment before IR increased radioresistance. However, interestingly, this study found that depleting pyrimidines using teriflunomide did not radiosensitize or affect the ability of GBM cells to repair IR-induced DSBs, suggesting that only purine metabolites are responsive to IR. High expression of inosine monophosphate dehydrogenase 1 (IMPDH1), which is involved in purine synthesis, has been associated with shorter survival in GBM patients.29 Clinical assessment of mycophenolate mofetil (MMF), the oral prodrug of MPA, in combination with IR is currently being investigated in GBM patients (NCT04477200). In addition to purines, GBM has been observed to have a higher concentration of lipid droplets compared to normal tissues. Inhibiting monoacylglycerol lipase, responsible for converting monoglycerides into fatty acids, was found to inhibit GBM cell proliferation.31GBM cells display alterations in various metabolic pathways that help them adapt to and proliferate in the tumor microenvironment, and to survive after treatment. For example, purine metabolites such as guanylates have been associated with increased DNA repair and therapy resistanceAs described above, the highly radioresistant nature of GBM has been attributed to in part the presence of GSCs that promote both activations of the G2/M checkpoint and efficient DNA repair. Therefore, novel treatments to enhance IR have focused on targets within DDR pathways, but also through particle ions that are less affected by factors such as hypoxia and the tumor microenvironment.32 The radioresistant nature of GSCs has also been attributed to increased basal levels and activation of ATM, and whilst the first generation of ATM inhibitors such as KU60019 were observed to be effective radiosensitizers, they were not capable of crossing the BBB.33 However, the novel oral ATM inhibitor, AZD1390 has demonstrated a 6-7-fold higher brain penetrance than the previous generation of inhibitors such as AZD0156. It has been shown that nanomolar concentrations of AZD1390 were sufficient to inhibit ATM in p53 mutant LN18 GBM cells, and in combination with IR this increased G2 phase cell cycle arrest, apoptosis, and micronucleus formation. Radiation dose enhancement values associated with AZD1390 in p53 mutant LN18 cells and patient-derived xenograft (PDX) models were approximately 3-fold higher than in p53 wild-type models. In an orthotopic lung-brain metastatic model, the combination of AZD1390 and IR significantly decreased tumor volume and increased animal survival compared to IR treatment alone.34 This exciting new agent is currently being evaluated in combination with IR in the treatment of brain cancers, primarily GBM (NCT03423628).ATM is a member of the phosphoinositide 3-kinase (PI3K)-related protein kinase family (PIKKs) and upon sensing DNA damage, ATM is rapidly recruited to sites of DSBs through interaction with the MRE11-RAD50-NBS1 (MRN) complex.35 In GSC models, the ATR-CHK1 pathway is also activated by IR, and inhibition of either ATR or CHK1 was found to increase mitotic catastrophe resulting in radiosensitization.10 Building on these observations, a recent study investigated the efficacy of the ATR kinase inhibitor, berzosertib in GBM cells and was demonstrated to enhance the sensitivity of U87 and U251 cells and a PDX cell line, GBM22 , to TMZ. However, the compound was actively effluxed at the BBB, leading to low free drug concentrations in the brain tissue and in intracranial PDX models. In keeping with this, berzosertib failed to improve survival in PDX-bearing mice when given in combination with TMZ.36 Alternative ATR inhibitors with superior brain penetrance are therefore needed for clinical trials to advance.ATR is of particular interest because it causes apparent desensitization of GBM cells to treatment with TMZ. TMZ is known to activate the ATM-ATR signaling pathway in cells expressing low levels of MGMT protein, and therefore treating MGMT-deficient GBM cells with TMZ has been shown to increase sensitivity to ATR inhibitors. Additionally, siRNA knockdown of ATR increased TMZ-induced GBM cell death and inhibition of CHK1 led to the same response, indicating that the ATR-CHK1 pathway is an attractive therapeutic target in GBM.37 Another study discovered and characterized a novel DNA-PK inhibitor, nedisertib (M3814), and reported its potent radiosensitizing activity in a dose-dependent manner in the DNA-PK proficient MO59K GBM cell line where the enhancement ratio, calculated at 10% survival, ranged between 2.5 and 6. However, no enhanced radiosensitization was observed in the DNA-PK deficient M059J GBM cell line demonstrating the specificity of the drug to its target.38 Although effective in preclinical evaluation, there is a substantial risk that inhibition of DNA-PK catalytic activity will severely exacerbate normal brain toxicity. This is based on the knowledge that leukemia patients with deficiencies in DNA ligase IV, a core component of the NHEJ pathway, encountered fatalities when treated with radiotherapy.39 However, it is unclear whether transient inhibition of DNA-PK would have the same effect, and if this can be combined with radiotherapy to achieve greater tumor control. Nedisertib is currently being trialed clinically in combination with IR and TMZ in GBM patients with newly diagnosed unmethylated MGMT status (NCT04555577). Additionally, the INSIGhT trial is investigating CC-115, the dual inhibitor of DNA-PK and mammalian target of rapamycin, in combination with IR in newly diagnosed patients with unmethylated MGMT (NCT02977780) to assess if targeting these dual pathways will have greater anticancer efficacy.DNA-PK is an important component of the NHEJ repair pathway, which is the dominant DSB repair pathway, particularly in the G1 phase when HR is nonfunctional. Overexpression of DNA-PK in 57.2% gliomas was associated with shorter survival of patients, and the inhibitor KU0060648 has been reported to significantly sensitize U87 and M059K GBM cells to TMZ.40 The PARADIGM and PARADIGM-2 trials are currently investigating the safety and efficacy of olaparib and IR with or without TMZ in newly diagnosed GBM patients based on their MGMT status.41 In preclinical studies, the PARP inhibitor niraparib (45 mg/kg) exhibited better BBB penetration than olaparib and resulted in a 53% tumor growth inhibition compared to 27% with olaparib (75 mg/kg) after 44 days of treatment.42 Additionally, veliparib showed promising results in preclinical evaluation, however, results from the randomized phase II VERTU trial, did not provide any significant benefit  for unmethylated MGMT patients when given in combination with TMZ and radiotherapy.43 Compared to other PARP inhibitors, veliparib has demonstrated to have low potency and low PARP trapping activity. Although the strong PARP trapper talazoparib has shown to sensitize GBM cell lines and orthotropic GBM models to TMZ, it has demonstrated a restricted ability to cross the BBB.44 A phase II trial of talazoparib is currently recruiting recurrent high-grade glioma patients with DDR deficiency to investigate if combining carboplatin and radiation may sensitize tumors to PARP inhibition and increase talazoparib drug penetration across the BBB (NCT04740190).PARP inhibitors block the enzymatic activity of PARP, and some  increase formation of trapped PARP-DNA complexes resulting in unrepaired DNA damage and cell death. PARP inhibitors are known to act as modest radiosensitizers across a broad range of cancer models, including GBM, and are highly potent sensitizers to TMZ, hence they have exciting potential in this disease. The currently available PARP inhibitors have different pharmacokinetic properties with regard to distribution across the BBB. Results from the phase I OPARATIC trial (NCT01390571) in recurrent GBM patients showed that olaparib penetrated all tumor core and tumor margin specimens, even though preclinical studies had shown a lack of penetration of the intact BBB.45 Consequently, WEE1 inhibition in p53-deficient tumor cells induces synthetic lethality.46 Indeed, in U251MG GBM cells it has been observed that genetic knockdown of WEE1 abolished IR and TMZ-induced cell cycle arrest in the G2/M phase, and eradicated brain tumors in mice when given in combination with IR.47 A similar effect was observed with the WEE1 inhibitor PD0166285 which was shown to radiosensitize U87MG, U118MG, U251MG, and U373MG cells, with enhancement ratios ranging from 1.19-1.95. Furthermore, PD0166285 enhanced the ability of IR to eradicate GBM neurospheres, and CD133 positive GBM cells are thought to represent GSCs.47 Of the WEE-1 inhibitors, AZD1775 (adavosertib) has shown increased radiosensitization across the broadest range of cancer models. Despite AZD1775 displaying poor BBB penetration in a GBM xenograft model, a phase 0 trial (NCT02207010) in recurrent GBM showed that unbound AZD1775 reached therapeutic concentrations within the tumor.48 This study also found that the patients treated with 200mg of AZD1775 demonstrated an ~8-fold increase in DNA DSBs, increased cell cycle abrogation, and an ~3-fold increase in apoptosis posttreatment. A phase I trial (NCT01849146) is currently investigating the safety and activity of AZD1775 in combination with TMZ and IR in newly diagnosed and recurrent GBM.WEE1 is a nuclear enzyme that belongs to the Ser/Thr family of protein kinases. It functions as a G2/M checkpoint regulator and controls G2/M progression by phosphorylating and inactivating CDC25. Moreover, cells with mutated TP53 have a dysregulated G1/S cell cycle checkpoint and therefore rely on the G2/M checkpoint to induce cell arrest and repair damaged DNA.Proton beam therapy (PBT), unlike conventional radiotherapy using photons (X-rays), utilizes positively charged proton ions to treat tumors and offers significant dosimetric benefits for some cancer types because of their physical characteristics. Specifically, proton beams exhibit low entrance radiation doses and as the protons lose energy and come to a stop, the maximum dose is released in a well-defined region known as the Bragg Peak, with no accompanying exit dose. In certain contexts, this allows larger doses of radiation to be administered directly to the tumor than is possible with photons, whilst sparing the associated normal tissues and organs at risk.49 Whilst there is growing awareness that partial brain photon radiotherapy is associated with volume loss in both gray and white matter structures throughout the brain, early reports indicate that these effects are less pronounced after PBT.50 These observations are in keeping with results from a randomized phase III trial which showed a reduced neurocognitive decline in brain tumor patients treated with stereotactic compared with conventional photon radiotherapy.51 Around 40% of patients treated with the standard GBM treatment of radiation plus TMZ develop radiation-induced lymphopenia (RIL), which is adversely associated with disease-specific survival.52 RIL or decreased lymphocyte count is an independent predictor of poor clinical outcome and is associated with higher rates of relapse and infections, reduced response to treatments and decreased efficacy of immunotherapy.53 A phase II randomized trial investigated the effect of proton vs photon radiotherapy (with concomitant TMZ) in 28 and 56 GBM patients, respectively and reported reduced grade III lymphopenia with PBT.54Evidence is accruing to support the concept that the neurocognitive complications of brain irradiation can be alleviated by PBT. Results from a prospective phase II trial indicated that GBM patients who received PBT had a significantly lower number of grade 2 or higher toxicities compared to patients who received intensity-modulated radiotherapy (IMRT).Although there is not yet any clear evidence that PBT improves tumor control and overall survival compared with conventional radiotherapy, in our view the dosimetric advantages of protons have not yet been exploited to the full. In particular, the use of advanced imaging modalities to identify regions at the highest risk of treatment failure in combination with particle radiation (IMPT) may enable meaningful dose escalation, with the potential to improve survival, while sparing normal tissues and reducing neurocognitive complications.8 CDD is defined as 2 or more DNA lesions within one helical turn of the DNA and broadly can be considered as either non-DSB or DSB-containing CDD. This type of damage is considered the most difficult for the cells to repair and therefore contributes greatly to IR-induced cell death. Clinically, the relative biological effectiveness (RBE) of PBT compared to photons is assumed to be 1.1 (10% more effective). However, this is only an approximation and widely variable RBEs have been documented both in vitro and in vivo and depend on a number of biological  and physical  factors.56In the clinical setting, a spread-out Bragg peak is used to irradiate larger tumor volumes, which is achieved by using a combination of beams with differential initial energies . Despite57 This suggested that the DNA damage induced by PBT is different and has slow repair kinetics, although it is noticeable from the data that the GSCs were irradiated with a relatively high dose (10 Gy) that caused significant cell death, so this conclusion is questionable. It was also suggested that PBT exposure in GSCs led to increased reactive oxygen species levels, which enhanced cell death post-IR. These findings support the theory that RBE is enhanced with PBT vs photon radiotherapy in GSCs, although substantial further evidence is required to validate this. Nevertheless, there are several ongoing clinical trials assessing the efficacy of both PBT and CIRT in GBM patients  led to significant reductions in cell survival compared to X-rays, and increased the number of SSB and DSBs several hours post-IR.patients . The NCTin vitro, CIRT was found to be significantly more cytotoxic than photons (RBE = 3.3–3.9), and this effect was further exacerbated in combination with chemotherapeutic drugs, in particular paclitaxel and camptothecin.58 In another study CIRT has also been shown effective in the killing of X-ray resistant GSCs, with average RBE values ranging between 1.87 and 3.44.59 This increase in radiosensitivity of the GSCs was attributed to the failure of the cells to repair the DNA damage induced by CIRT, as reflected by the presence of residual unrepaired DNA DSBs 24 hours posttreatment. In terms of clinical observations, GBM patients have been treated with CIRT both as primary radiotherapy and as re-irradiations of recurrent tumors. CIRT was reportedly well tolerated with minimal toxicity reported.61 A phase I/II study in GBM patients compared the effects of X-rays to a dose equivalent to CIRT, and reported significant increases in survival from 4 to 7 months (low dose), 7 to 19 months (middle dose), and from 14 to 26 months (high dose) respectively.62 These non-randomized data must however be treated with caution. Currently, 13 centers around the world, with a large proportion located in Japan, use CIRT for GBM patients and several clinical trials are assessing its effectiveness (Although carbon ion radiotherapy (CIRT) shows a similar dose distribution profile to PBT, with the majority of the radiation dose being delivered to the target tumor via the Bragg Peak , it benetiveness .64 It was also suggested that there was preferential activation of the microhomology-mediated end joining (MHEJ) pathway over NHEJ in the repair of complex DSBs induced by CIRT in G1 phase cells. However, other studies have reported HR to play a prominent role in the repair of CDD induced by carbon ions, with NHEJ being employed in response to both PBT and CIRT.65 Another study reported that enhanced radiosensitivity to CIRT was more pronounced in cells with NHEJ deficiency, rather than in those with HR deficiency.66As mentioned above, the number of preclinical studies analyzing responses of GBM tumor models to PBT and CIRT is very small. Therefore, strategies leading to optimal radiosensitization of GBM cells with these radiation modalities, such as through targeting the DDR, have not been investigated in any detail. In fact, while the level and complexity of CDD induced by PBT (relatively low-LET) and CIRT (high-LET) are known to be different, the relative importance of the various DDR pathways  that respond to this damage is still subject to debate. In tumor cell types other than GBM, it has been reported that most of the damage induced by CIRT was subjected to end resection, coordinated by CtIP and the MRN exonuclease.67 This evidence was replicated in an in vivo xenograft model, in which inhibiting ATM in combination with PBT was shown to significantly delay tumor growth, and that Bragg peak protons were furthermore highly effective in the killing of HR-defective (BRCA-1 deficient) cells and tumors.67 Such findings suggest that cells may switch between different repair pathways when repairing more complex DSBs induced by high-LET radiations. Additionally, data acquired from our lab using HeLa and head and neck squamous cell carcinoma cells has demonstrated that relatively high-LET PBT generates CDD that triggers a specific cellular DDR response driven by histone H2B ubiquitylation, and that this damage is largely SSB-associated and requires PARP1 for repair.69 Indeed, using both PARP1 siRNA and the PARP inhibitor olaparib, we demonstrated specific radiosensitization of cells following relatively high-LET PBT, but not those irradiated with low-LET PBT at the entrance dose. In contrast, we showed that inhibitors of ATM, ATR, and DNA-PK enhance the sensitivity of head and neck cancer cells to both low-LET PBT and X-rays.70 Therefore, given the increasing use of PBT and CIRT in the clinic, it is possible that different DDR inhibitors should be used as radiosensitizers specifically for GBM in the context of different radiation modalities. It is also clear that substantially more preclinical studies are needed in clinically relevant GBM models if we are to identify the best strategies for prolonged tumor control and future patient benefit.In terms of PBT, it has been shown that U2OS and BT549 cells irradiated at the Bragg peak with a higher RBE upregulate utilization of HR, but interestingly that inhibiting ATM redirected cells to the NHEJ pathway leading to the formation of toxic DSB repair end products.Clinically, treatment of GBM is challenging due to its aggressive and therapy-resistant nature. Radiotherapy is the mainstay of GBM treatment, with chemotherapy options being limited partly by adverse pharmacokinetics. TMZ is the only drug clinically approved as a radiosensitizer but has minimal efficacy in the large subset of tumors in which the MGMT gene promoter is unmethylated. The radioresistant and hypoxic nature of GBM further complicates treatment, as does the molecular and phenotypic heterogeneity of the disease. Preclinical studies have demonstrated that targeting the DDR, particularly in radioresistant GSCs, can enhance the efficacy of conventional photon radiotherapy in tumor cell killing. However, the use of PBT and CIRT in the treatment of GBM are emerging as attractive therapeutic options, with superior dosimetry which may potentially reduce the adverse side effects associated with photon radiation, such as treatment-induced lymphopenia, and improve the overall quality of life. Recent mechanistic studies raise the exciting possibility of combining PBT and CIRT with DDR inhibitors to overcome therapy resistance in GBM, and indicate that different radiation modalities should be paired with specific agents to maximize clinical benefit. As with any novel therapeutic approach in this heterogeneous tumor type, it is highly likely that subsets of patients will derive particular benefits from these new combinations. Biomarkers that enable the selection of patients with responsive tumors are required to maximize the benefits of novel treatments, and these should be identified and validated as part of ongoing research in this field.