Extracellular vesicles (EVs), are membrane-bound vesicles that have many advantages over traditional nanocarriers for drug and gene delivery. Evidence from recent studies indicate that EVs have therapeutic capability with chemical or biological modification. Tumor-derived exosomes (TEXs) were used as a new type of antigens or tumor vaccines in anti-tumor immunotherapy. With superior characteristics, modified EVs were applied to loaded and delivered synthetic drugs, silencing RNA, and microRNA for treatment. Different surface functionalization strategies have been proposed to improve the therapeutic functions of EVs. Appropriately modified EVs for disease intervention provide new avenues for effective clinical treatment strategies. Therefore, this review aimed at elucidating the therapeutic functions of EVs to generate new ideas for treatment and to unlock their hidden potential in translational medicine. Cancer is a global human health problem that is associated with severe pain and heavy economic burdens to patients and their families In guidelines released by the ISEV, depending on their biogenesis and generation pathways, EVs can be broadly classified into three subpopulations: exosomes , microvesicles MVs, 200-1000 nm), and apoptotic bodies  00 nm, anExosomal liposome structures allow the loading of various drugs, which enhances drug delivery to specific targets. EVs, as carriers, can transport their cargos to particularly intracellular locations in a target-specific manner across the plasma membrane. As natural nucleic acid and protein carriers, they have been used as vectors for targeted delivery of these molecules Evidence from recent studies indicate that EVs have therapeutic potential in tumors Immunotherapy has shown promising prospects in the treatment of cancers, and EVs are currently applied in tumor immunotherapy. EVs have several advantages and appear to be a highlight of new pattern for cancer immunotherapy at present in vivo, and results from clinical trials on EVs have been feasible. A novel DEX vaccine with antigens and matured with either the TLR-3 ligand induced robust activation of melanoma-specific CD8(+) T cells and the recruitment of cytotoxic CD8(+) T cells, NK and NK-T cells to the tumor site, resulted in significantly reduced tumor growth and enhanced survival Surface engineered EVs can actively participate in tumor immunotherapy. CD47, a "don't eat me" signal, limits the ability of macrophages to engulf tumor cells by binding to SIRPα Exploitation of EVs in anti-tumor research has gained momentum in recent years, and many studies have evaluated EVs -related antitumor effects. Compared with EVs, delivery of drug formulations such as liposomes et al. modified exosomes with a GE11 peptide that specifically binds to epidermal growth factor receptor (EGFR) and was loaded with let-7a miRNA, a regulator that reduced cell division and altered the cell cycle in vivo and in vitroin vitro and in vivo. Natural compounds such as anthocyanins (Anthos) found in berries are limited by low permeability and oral bioavailability. Munagala et al. delivered exosomes loaded with anthocyanins from raw milk to mice with lung cancer et al. tried to further their zebrafish studies pass through loading siRNA in the exosomes The most common treatments for malignant tumors are chemotherapy, radiation surgery, or combination therapy. Cancer targeted therapy is an emerging treatment approach in anti-tumor therapy. However, the success of targeted therapy requires a drug delivery carrier with low immunogenicity and low toxicity. Doxorubicin (DOX) was loaded into exosomes through electroporation, and delivered to breast cancer tumor cells by engineered exosomes leading to effective targeting in vivoet al. found that miR-199a-3p-Exo suppressed c-Met expression, a direct target of miR-199a-3p, leading to the inhibition of cell proliferation and invasion Donor cells have also been engineered to isolate qualified exosomes that contain the gene or drug of interest in vivo studies have also been conducted with satisfactory results. Introduction of T7-exo and antisense miRNA oligonucleotides against miR-21 (AMO-21) via tail vein effectively introduced AMO-21 into the brain and reduced Mir-21 levels in glioblastoma in rats Some in vivo imaging and tracking of EVs. Although EVs have been shown to be useful in vitro anticancer drug carriers, this is not the case in vivo given their non-specific toxicity and off-target effects similar to those observed in conventional chemical drugs The composition of EVs can be modified at the cellular level. EVs from various biological sources can be modified after isolation when cell-derived exosomes are unable to meet the requirements. While preserving the membrane integrity of exosomes, functional fluorescent tags To further increase the functions of EVs, different surface engineering strategies have been explored, which can be roughly divided into three main approaches: physical, chemical, and biological approaches.et al. hybridized macrophage-derived exosomes with liposomes through freeze-thaw method which allowed membrane fusion to form hybrid immune exosomes for doxorubicin treatment of breast cancer in vivo, and its plasma retention time was extended by 18 h providing strong therapeutic effects. A biomimetic nanostructure (BNS) with a multimodal imaging system was designed to coat polymer nanoparticles with natural killer cell membrane (NKM), near-infrared ray (NIR) fluorescent dye and Gadolinium (Gd) conjugated magnetic resonance imaging (MRI) contrast agent in vitro and in vivo tracking In this approach, physical approaches such as ultrasonic treatment, extrusion, and freeze-thaw are used to temporarily destroy lipid structures. Once the structures are removed, the vesicles spontaneously re-assemble into their natural structure. Sagar et al. combined metabolic markers of newly synthesized proteins or polysaccharides/glycoproteins from secreting exosomal cells with chemically active azido groups, modified and functionalized exosomes through bioorthogonal click conjugation Chemical approaches for surface functionalization involve direct use of chemical reagents to anchor functional parts to the surface of exosomes. The transmembrane protein portion of phospholipids or amine/carboxylate on surface of exosomes can be directly functionalized with various functional groups. Alternatively, functional phospholipids obtained from exosomes can be added to exosomes by simple incubation using a hydrophobic insertion strategy. Firstly, lipid functionalization of exosomes sealed with maleimide is achieved via the hydrophobic insertion strategy. A hydrophobic insertion strategy in which maleimide-terminated DSPE-PEG-Mal is used as a labeling probe, which is labeled with fluorescent dye containing maleimide for monitoring of cell communication et al. reported that carboxyamidotriazole orotate (CTO) targets tumor exosomes promoted IL-8 expression and cell adhesion of endothelial cells (ECs). Therefore, CTO inhibits the effects of these exosomes on ECs-chronic myelogenous leukaemia (CML) interaction and the migration of ECs, suppresses angiogenesis induced by exosomes et al. linked a rather sophisticated polypeptide composed of two single chain variable fragment (scFv) antibodies targeting CD3 and EGFR on top of the domain of human platelet-derived growth factor (PDGFR) Studies show that different surface functionalization strategies can enhance targeting of exosomes by adding targeted peptides or ligands to EV surfaces. Expression of a well-characterized exosomal membrane protein (Lamp2b) on engineered exosome DCs fused to αv integrin-specific iRGD peptide has been reported to promote tumor targeting The extraction, isolation, and identification of tumor cell-derived EVs can be used to elucidate the mechanisms underlying tumor progression and provide potential therapeutic targets for cancer patients. Secondly, EVs can be loaded in different antitumor drugs to treat cancer. Lastly, with increasing interest in tumor immunotherapy, EV immunomodulatory properties mainly include regulating antigen presentation, immune surveillance, and immune activation. It is likely that a new approach to tumor immunotherapy will be revealed through an in-depth study of the molecular mechanisms underlying the interaction between EVs and immune cells.As intermediates of intercellular communication, EVs have heterogeneous and pleiotropic physiological and pathological roles. However, many issues still need to be addressed before its clinical application. Due to tissue and cell specificity, not all tissues and cells express these so-called EV markers. Therefore, further investigation into how to identify EVs is a significant goal for future research. Isolation of purification specific EVs is limited by technical limitations, and specific EVs by the availability of suitable biomarkers as well as expensive techniques. It is necessary that we develop standard and highly efficient methods for EV isolation, purification, characterization, and manipulation that allow these vesicles to be successfully applied in the clinic.In the field of nanofabrication, EVs have been widely applied in the diagnosis and treatment of tumors, but the clinical application of exosomes still faces arduous challenges. EVs play important roles in the tumor microenvironment, tumor and non-tumor tissue. Considering their good biocompatibility, tumor targeting and low immunogenicity, EVs have been proven to be potential drug carriers. However, the complex characteristics of exosomes are not thoroughly understood, it is important to comprehensively define the many subtypes of exosomes. Although there are many challenges in the costs, technical challenges, and lack of suitable biomarkers for EVs isolation and purification, more classification and loading mechanisms of exosomes can be exploited in further research to develop efficient exosome-based drug delivery systems. Moreover, EVs have shown great promise in tumor targeting, tumor immunotherapy and inhibition of tumor metastasis. In the future, in-depth research is needed to develop effective tools for efficient drug loading, targeted modification, and studying the mechanisms that drive tumor development and response to drugs. Such efforts will also generate new ideas for the diagnosis and treatment of tumors.


With the ever-growing number of cancer deaths worldwide, researchers have been working hard to identify the key reasons behind the failure of cancer therapies so the efficacy of those therapies may be improved. Based on extensive research activities and observations done by researchers, chemoresistance has been identified as a major contributor to the drastic number of deaths among cancer patients. Several factors have been linked to formation of chemoresistance, such as chemotherapy drug efflux, immunosuppression, and epithelial-mesenchymal transition (EMT). Lately, increasing evidence has shed light on the role of extracellular vesicles (EVs) in the regulation of chemoresistance. However, there is limited research into the possibility that inhibiting EV release or uptake in cancer cells may curb chemoresistance, allowing chemotherapy drugs to target cancer cells without restriction. Prominent inhibitors of EV uptake and release in cancer cells have been compiled and contrasted in this review. This is in the hope of sparking greater interest in the field of EV-mediated chemoresistance, as well as to provide an overview of the field for fundamental and clinical research communities, particularly in the field of cancer resistance research. In-depth studies of EV-mediated chemoresistance and EV inhibitors in cancer cells would spur significant improvement in cancer treatments which are currently available. Chemoresistance, a state of cancer cells wherein chemotherapy drugs are ineffective against cancer progression, is a major challenge in cancer treatment. It accounts for more than 90% of deaths in patients with metastatic tumors . ChemoreThis review will compile major drug inhibitors targeting specific mechanisms in the release and uptake of both exosomes and microvesicles (MVs) from cancer cells. Existing literature regarding the effectiveness of these inhibitors, as well as the possible difficulties in using them, will be analyzed. This is with the aim of emphasizing the potential of using EV inhibitors to target chemoresistance in cancer therapies.Extracellular vesicles are small, lipid bilayer-enclosed particles secreted from all types of cells for intercellular communication and the removal of cellular wastes; in cancer cells, they mediate chemoresistance  as well Exosomes are formed via the fusion of MVBs with the plasma membrane; MVBs result from the inward budding of endosomal membranes . MVBs arMicrovesicles form via budding directly from the plasma membrane. The transport of molecular constituents of MVs toward the plasma membrane as well as the rearrangement of membrane lipids and actin cytoskeletal components are integral to this process . SeveralPast research  has showThere are various mechanisms by which EVs confer chemoresistance from chemoresistant cancer cells to chemosensitive cells. These mechanisms have been summarized in MicroRNAs, small single-stranded non-coding RNAs about 19–25 nucleotides long, contribute to the development of chemoresistance by influencing genes relating to drug resistance, cell survival and proliferation, cell cycle, apoptosis, stress tolerance and immunity . MiRNAs Extracellular vesicles may additionally contribute to producing a chemoresistive tumor microenvironment . miRNA iIn investigations into EV-mediated chemoresistance, treatment of cancer cell lines with EV-inhibiting drugs may serve two functions: to confirm that EVs contribute to chemoresistance, or to test whether EV inhibition is a suitable strategy to complement treatment with chemotherapy drugs. Although clear links have been established regarding the contribution of EVs to chemoresistance, scientific understanding of the precise mechanisms associated remain primitive and requires more investigation. EV inhibitors which bind to certain proteins or deregulate genes implicated in inducing chemoresistance may be used to clarify the roles those proteins or genes play in chemoresistance. An EV-related strategy against chemoresistance which holds promise includes inhibiting the biogenesis, release or uptake of EVs by cancer cells. Another approach of extracting tumor-derived EVs out from the tumor microenvironment using specific markers for those EVs has also been proposed , but thiTo encourage further investigation, 33 inhibitors have been assessed according to the pathways of EV secretion or uptake which they primarily target. These pathways, as well as their corresponding inhibitors, have been summarized in The 33 inhibitors discussed may be broadly categorized as inhibitors of lipid-related pathways, cytoskeletal organization, other miscellaneous pathways of EV release and endocytosis. These four classifications have been selected based on the specific mechanisms targeted by each inhibitor.Various lipid-related mechanisms are associated with the release of EVs from cancer cells. These mechanisms primarily involve the conversion of sphingomyelin to ceramide by sphingomyelinases, PS translocation by protein kinases, and cholesterol synthesis. Ceramides play roles in causing the curvature of membranes prior to the formation of MVBs or release of MVs; PS translocation is a necessary step for MVs to be released; and cholesterol influences the formation of MVBs and MVs . Thus, iSuch inhibitors include imipramine, GW4869, cambinol, and spiroepoxide as depicted in nSMase2 inhibitors block ceramide-mediated exosome biogenesis. GW4869 is a frequently used inhibitor which targets nSMase2 to prevent the ceramide-modulated inward budding of MVBs and the subsequent release of exosomes from MVBs . GW4869 These include bisindolylmaleimide-I and d-pantethine. Bisindolylmaleimide-I, an inhibitor targeting the ATP-binding site of various protein kinase C isoforms, hinders the release of calcium and the externalization of PS, which are known steps in the mechanism driving the release of MVs . Stratto+ channel of an ABC transporter participating in the release of MVs (Inhibitors targeting ATP-binding cassette (ABC) transporters include glyburide (glibenclamide) and indomethacin. Glyburide, a drug for diabetes, inhibits the ATP-sensitive Ke of MVs . Glyburie of MVs . Since ce of MVs  and its e of MVs . This exe of MVs . Prior te of MVs . The appe of MVs . Althouge of MVs , b, but Simvastatin, a HMG-CoA reductase inhibitor, prevents the synthesis of cholesterol; since cholesterol is an integral constituent in endosomal membranes, this reduced exosome secretion in epithelial cells and monocytes by 40% . HoweverProteins which participate in cytoskeletal organization are targets for various inhibitors since they are vital for EV release as well as endocytic processes. These proteins may specifically interact with actin; or they may have broad effects on cytoskeleton organization, in which case they are classified as cytoskeleton-related proteins. The targeting of EV release via these pathways may reduce the transfer of vesicular content between cancer cells and limit the transmission of chemoresistance .Cytochalasin D is a fungal toxin which binds to actin filament edges, preventing actin polymerization . Actin pCalpeptin is currently the most well-characterized calpain inhibitor. Calpains are cytosolic proteases and their activated forms participate in cellular activities including cell cycle progression, cell motility and cytoskeleton remodeling . CalpainChloramidine (Cl-amidine) is a calcium chelator which irreversibly binds to peptidylarginine deiminase (PAD), consequently causing post-translational protein deimination. PAD-modulated deimination of actin in the cytoskeleton is needed in order for MVs to form . KosgodaAnother inhibitor, NSC23766, acts on Rac1, a Rho GTPase which is involved in cytoskeletal remodeling . In cancY27632 is a competitive inhibitor of ROCK1 and ROCK2, cytoskeleton-interacting members of the ROCK family . Y27632 Extracellular vesicles are released using many other mechanisms such as those involving protein kinases, calcium channels and other molecules, as well as the ESCRT-dependent pathway . These tThese may include Y27632 (described in section “Inhibitors Targeting Other Cytoskeleton-Related Proteins”), U0126, imatinib, and dasatinib. U0126 specifically and non-competitively inhibits MEK 1 and MEK 2, mitogen-activated protein kinase kinase (MAPKK) protein kinases , which pImatinib and dasatinib, medications for leukemia, both inhibit ATP-binding sites of the catalytic sites of bcr-abl tyrosine kinase enzymes . PhosphoThese include manumycin A, tipifarnib, and sulphisoxazole. Manumycin A and tipifarnib both diminish levels of exosome production primarily by targeting Ras farnesyltransferase enzymes, hence inhibiting their activation in order for Ras/Raf/ERK1/2 signaling to proceed, which is part of the ESCRT-dependent pathway of exosome biogenesis . HoweverSulphisoxazole are antibacterial drugs which, by targeting endothelin receptor type A (a G-protein coupled receptor), demonstrates inhibitory activity on components within or relating to the ESCRT-dependent pathway such as ALIX and VPS4B (which aids in ILV formation) as well as some RABs . It was Cannabidiol and SMR peptides are recently discovered to be able to inhibit EV release. Cannabidiol, a phytocannabinoid, has been discovered to inhibit EV release from HEPG2 as well as MDA-MB-231 and PC3 cell lines . Its effin vitro and in vivo (in vitro study using CT26 (mouse colon carcinoma), EL4 (mouse lymphoma) and H23 (human lung adenocarcinoma) cell lines showed that DMA reduced exosome release as per analysis of the culture medium  and dimethyl amiloride (DMA)  inhibit exosome release by altering intracellular calcium levels . Calcium in vivo . An in ve medium . In vivoPathways of clathrin-dependent and CIE may be targeted by EV inhibitors to prevent the uptake of EVs by cancer cells . If EV uChoosing the appropriate inhibitor to investigate a specific endocytic pathway can be challenging as they may be unspecific or toxic for different cell lines. Inhibitors of CDE include dynasore and ikarugamycin (IKA) as well as older inhibitors such as chlorpromazine, potassium depletion and hypertonic sucrose . While pDynasore and IKA are more recent inhibitors. Dynasore is a widely used CDE inhibitor which has been thoroughly characterized. But like the other CDE inhibitors, dynasore too may have non-specific effects. Dynasore non-competitively inhibits GTPase activity of the dynamin proteins dynamin1, dynamin2 and Drp1  in just seconds. Dynamin proteins are necessary for a late step of CDE which involves the production of a clathrin-coated endocytic vesicle (as indicated in v–arc and pplloBngag–fes kinases (Caveolin-mediated endocytosis (CavME) inhibitors include genistein and methyl-β-cyclodextrin (MβCD) as well as heparin. Genistein is a highly specific, dose-dependent inhibitor of tyrosine kinases such as the EGF receptor kinase, and pp60 kinases . It disr kinases . Geniste kinases . Meanwhi kinases . However kinases . In the  kinases . MβCD is kinases .2+ compared to medium consisting Ca2+  coreceptors for the uptake of exosomes when HSPGs are present . An examing Ca2+ . It was ing Ca2+ .+/H+ exchangers (5-(N-ethyl-N-isopropyl)amirolide (EIPA) is one chemical derivative of amiloride which has been regularly used to inhibit macropinocytosis. EIPA lowers sub-membranous pH by targeting Nachangers , and likchangers . While Echangers . Imipramchangers .The challenges in using EV-inhibiting drugs to tackle chemoresistance relate to the efficacy, specificity and toxicity of inhibitors; lack of knowledge regarding the precise mechanism of several inhibitors; and adapting functional and potent inhibitor drugs for clinical use. These challenges are further complicated by still-evolving knowledge regarding EV-related pathways.First, many EV inhibitors vary in their efficacy (between different cell lines and cell types) and their specificity. In a clinical setting, this could lead to difficulty in choosing an appropriately efficacious inhibitor for treatment. Some EV inhibitors may be so specific as to target a single protein involved in EV biogenesis or uptake such as indomethacin which targets ABCA3; but some may have a wide range of targets with varying downstream effects, such as manumycin A which may target Ras farnesyltransferase and nSMase2 enzymes. Some EV inhibitors may target both exosomes and MVs , whereas others  may target the exocytosis of only one subtype of EV. Some EV inhibitors may even target pathways of EV release as well as those of EV uptake, since those pathways may share similar mechanisms, for instance cytochalasin D, MβCD and simvastatin. A particular inhibitor may inhibit the release of certain EV populations but promote the release of others. For example, GW4869 inhibits exosome release but was reported to stimulate MV release in breast adenocarcinoma SKBR3 cells .Many EV inhibitors do not completely inhibit EV release or uptake when used independently. This is usually because the activity of each EV-related pathway contributes only a proportion of total EV secretion or release, and most inhibitor drugs do not inhibit all the pathways of EV release or EV uptake with equal efficacy. All EVs secreted by a cell may have been the result of various EV release pathways, and all EVs taken up by a cell may have been ingested by any endocytosis or macropinocytosis pathway. For example, a study by In clinical settings, the prospect of using two EV inhibitors together with chemotherapy is bound to raise questions regarding managing the side effects of this treatment approach. The relative cytotoxicity of different EV inhibitors to different cell lines may also raise hurdles in research as cytotoxic effects may distort experimental results. EV inhibitors may be toxic at the same concentration found to be optimum for EV inhibition, especially after prolonged incubation. One example of such an inhibitor is IKA, which already reduces cell viability within an hour of treatment and impairs the morphologies of cells and cell organelles under prolonged incubation . AnotherWhile there may not be a perfect inhibitor yet, the pursuit to discover fast-acting inhibitors which have specific, reversible and minimally toxic effects should continue . For thein vitro conditions using various cancer cell lines. However, DMA was assessed in a pre-clinical study by in vivo. In vivo, DMA reduced exosome release into the bloodstream of mice carrying tumors (At this stage, most drug inhibitors of EV release or uptake have only been tested in the context of chemoresistance under g tumors . Combinag tumors . These rAlternatively, EVs may be targeted using a genetic approach. For example, knockdown of the nSMase2 gene suppressed EV release and inhibited angiogenesis and metastasis in a xenograft mouse model of breast cancer . HoweverRather than targeting EV biogenesis or uptake, EVs may also be removed from the circulation. In another study, antibodies to CD9 and CD63, glycoprotein receptors present on the surface of EVs, were used to deplete EVs in a xenograft mouse model of breast cancer . The stuExtracellular vesicle inhibition, control of EV-related gene expression and hemofiltration of EVs all prevent or reduce intercellular communication between cancer cells. When these methods are combined with chemotherapy, they can be expected to result in the repression of EV-mediated mechanisms of chemoresistance such as EMT . ChemoreClinical progresses in targeting EV-mediated chemoresistance are slowed by gaps in knowledge regarding the roles of EVs in mechanisms of chemoresistance. Considering this, investigations into existing drugs which inhibit the release or uptake of EVs may yield discoveries regarding their suitability for use in cancer treatments. Their suitability for use may be defined in terms of their efficacy and toxicity when used alongside chemotherapy drugs. Further research into novel methods to target EV-mediated intercellular communication between cancer cells may aid in planning anticancer therapies while minimizing side effects.Exosomes and MVs contribute significantly to chemoresistance in many cancer cell lines via mechanisms such as the transfer of miRNAs, which activate anti-apoptotic signaling and DDR, and by enhancing other processes such as chemotherapy drug efflux, immunosuppression, alteration of cytosolic pH and EMT. Hence, the inhibition of EV release and uptake could be a promising companion treatment to enhance the efficacy of chemotherapy drugs. Since both exosomes and MVs can be released and taken up by cancer cells via multiple pathways, and since those pathways involve diverse and specific mechanisms, there are many possible targets for the inhibition of EV release and uptake. Such targets may include proteins, transporters, protein kinases and enzymes involved in lipid-related pathways of EV release, cytoskeletal organization, the ESCRT-dependent pathway of EV release, clathrin-dependent and clathrin-independent endocytosis (summarized in in vivo and in vitro conditions; in the case of DMA, this has already been proven using a mouse model. Yet, this strategy requires much investigation as preclinical studies of chemoresistance using EV inhibitors are limited. Pathways related to EV biogenesis, release and uptake mechanisms have yet to be thoroughly explained, and the mechanisms of existing EV inhibitors must be studied further, especially for the use of inhibitors in combination to fully block all avenues of EV production or uptake. More efficacious EV-inhibiting drugs must be developed before they can be implemented in a clinical setting. Further investigation into EV release and uptake pathways is required in order to fully describe the mechanisms involved, and to develop more advanced EV inhibitors capable of targeting those specific mechanisms to counteract chemoresistance. This is vital in advancing the effectiveness of anticancer treatments.Extracellular vesicle inhibitors may have the capacity to sensitize chemoresistant cells under both RH performed searching, analyzed data, and wrote the manuscript. NK, B-HG, and W-LL contributed to the conceptual idea, reviewed the drafts, supervised the writing process, and provided important information for the completion of this manuscript. LM and ZF reviewed the drafts and refined the manuscript. All the authors revised and approved the final version of the manuscript.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.


Incidence of lymphogranuloma venereum increased in England during 2018–2019, after a period of decline. Our retrospective analysis of national surveillance data identified a rapid increase in diagnoses among HIV-negative men who have sex with men. These findings indicate a need for sustained surveillance and targeted public health action. Chlamydia trachomatis infection. In high-income countries, LGV is concentrated among gay, bisexual, and other men who have sex with men (MSM) (Lymphogranuloma venereum (LGV) is an invasive form of >16 years of age) MSM in England who visited sexual health service (SHS) sites during January 1, 2015–December 31, 2019. We obtained data from the Genitourinary Medicine Clinic Activity Dataset Sexually Transmitted Infection (STI) Surveillance System, which has recorded LGV diagnoses, obtained through multiplex reverse transcription PCR (https://www.stata.com).We conducted a retrospective analysis of adult (https://www.gov.uk/government/publications/hiv-and-sti-data-sharing-policy).Public Health England collects pseudonymized, electronic data on all STI tests and diagnoses from all commissioned SHS sites in England  were not available. Inclusion of behavioral covariates in routine STI surveillance in England is underway and will be examined in future iterations of these analyses. Second, the risk among some groups, such as those not born in the United Kingdom, could be overestimated because of differing patterns of healthcare access and barriers to access.In summary, we report a steep increase in the number of LGV diagnoses identified in SHS sites after a period of decline, which indicates the need for sustained surveillance and public health action. Our findings indicate that the epidemiology of LGV has changed, and an increased number of diagnoses are occurring among MSM who are HIV-negative or with unknown HIV status, highlighting the need to integrate health promotion and increase LGV testing within HIV prevention delivery. In addition, increased LGV risk among MSM born in LAC and in countries in Europe that are outside the United Kingdom indicates the need for increased accessibility of health promotion materials and wider engagement with these communities.


The development of rational approaches to restore immune tolerance requires an iterative approach that builds on past success and utilizes new mechanistic insights into immune-mediated pathologies. This article will review concepts that have evolved from the clinical trial experience of the Immune Tolerance Network, with an emphasis on lessons learned from the innovative mechanistic studies conducted for these trials and new strategies under development for induction of tolerance. The mission of the Immune Tolerance Network (ITN) is to advance the development of immune tolerance strategies in autoimmunity, allergy, and transplantation by conducting high-quality clinical trials with emerging therapeutic agents. Integrated mechanism-based research is a critical component of these trials that provide new insights into the success or failure of the intervention, as well as further understanding of disease pathogenesis. These results in turn provide the building blocks for further clinical trials and the design of new treatment strategies and incremental advancement towards the tolerance goal.Central to the ITN’s mission is the concept of immunologic tolerance. While specific clinical definitions of tolerance vary across the immune mediated diseases, they all center on differentiating permanent or prolonged improvements in disease that represent a significant clinical benefit over the expected natural history of disease or the standard of care. Conceptual parallels are illustrated in However, at a molecular level, immunologic tolerance represents prolonged or permanent modulation of aberrant immune responses towards a homeostatic state. Immune self-tolerance normally occurs in T and B lymphocytes by central and peripheral mechanisms, reviewed previously . Centralwww.immunetolerance.org.In disease conditions, immunologic tolerance can in theory be re-established through a variety of mechanisms which may expand or augment regulatory cells  and suppress effector responses  that in tandem act to restore immune homeostasis and disease quiescence. In this review, we provide an overview of ITN successes, challenges, and new strategies to achieve immune tolerance in the fields of allergy, autoimmune disease, and solid organ transplantation. Immunological memory is a hallmark of successful immune responses, and is essential for pathogen surveillance and extinction. It is also a formidable barrier to successful immune tolerance induction. The challenge of reversing pathogenic immune responses in individuals with autoimmune disease and allergy requires not only directed therapy against immune effector cells, but also prevention of recurrent memory responses when therapy is discontinued. This concept also plays a role in transplantation, both through initial heterologous memory and subsequently in dealing with the robust alloimmune response. Innate immune activation, memory, and self-perpetuating inflammatory cascades must be restrained, allowing tissue repair to occur. Therefore, a major focus of immune tolerance strategies is to retain and expand regulatory immune mechanisms, thereby exploiting homeostatic pathways that are intrinsic to a healthy balance of immune effector and regulatory compartments.interrupting effector mechanisms, restraining innate activation, and boosting regulation is the central dogma of successful immune tolerance therapy, illustrated in This combination of interrupting/restraining/boosting’ therapeutic dogma without creating an unacceptable level of danger. Selective targets within the adaptive immune system may involve specific subsets of T or B cells, or even antigen-specific receptors and signaling pathways; and selectivity in a broader sense may target a limited set of cytokine, chemokine, or activation pathways without global immunosuppression. Rapid development over the last two decades of novel immune therapeutic agents that meet these types of selectivity requirements has enabled the design of clinical trials with aspirations for achieving immune tolerance. Although transplantation, allergy, and autoimmune diseases have many distinct characteristics, conducting such trials within the ITN provides an opportunity to study immune mechanisms and concepts across clinical disciplines while evaluating safety, therapeutic durability, and homeostatic immune reconstitution.Underlying these efforts to rebalance immune effector and regulatory responses is the recognition that drastic immune suppression is accompanied by significant safety concerns, notably infectious and neoplastic risk, as well as life-long drug administration. Consequently, the targets of immune tolerance therapy need to be selective, addressing the ITN’s ‘Desensitization strategies have been a mainstay of allergy therapy for many years, for many types of environmental allergens, including hymenoptera venom and aeroallergens such as pollens, dust mites, and animal dander. On this background of clinical experience showing that allergen specificity of an allergic response that can often be modulated by controlled antigen exposure, the ITN has designed several clinical trials intended to achieve durable, long-lasting allergen desensitization, i.e. tolerance.IgE-mediated peanut allergy typically develops in the first two years of life and for the majority affected, the disease persists into adulthood. Sensitization to peanut may involve cutaneous and enteral pathways that lead to production of TH2 cytokines and antigen-specific IgE. The Learning Early about Peanut Allergy (LEAP) trial demonstrated that early oral exposure to peanut prevented the development of peanut allergy in atopic infants including those who had already developed sensitization to peanut . Nearly MALT1) gene  gene . MALT1 etivation . The assmponents . This immponents . Peanut Observations in another ITN study, the Oral Immunotherapy for Induction of Tolerance and Desensitization in Peanut-Allergic Children (IMPACT) trial, further emphasize this point. IMPACT was a randomized double-blind placebo controlled trial of peanut oral immunotherapy (OIT) in peanut allergic children ages 12-48 months. Successful desensitization at the end of OIT and persistent desensitization after 6 months of withholding OIT was associated with lower baseline peanut specific IgE, particularly in children below the age of 3 years  have been implicated in the development of asthma and allergic disease . In the o peanut . In the o peanut . In addio peanut . Taken tIn older individuals, with established allergic responses and mature immunological memory, a strategy to alter the allergenic immune program associated with TH2 T cell immunobiology is an alternative approach. To this end, the ITN GRADUATE trial, which is currently underway NCT04502966), combines dupilumab (anti-IL4R) and sublingual grass desensitization to induce durable tolerance. This study builds on the previous ITN GRASS trial comparing desensitization to grass pollen between the sublingual and subcutaneous routes 66, combi, or otheHematopoietic chimerism has been utilized to induce tolerance of kidney allografts in animals and humans, based on the foundational discovery that dizygotic cattle twins exhibit stable red cell chimerism and mutually accept skin grafts , 36. A pvia the CD28 and CD40 pathways plays a critical role in GC interactions between Tfh cells and B cells , anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, type 1 diabetes, and psoriasis, have documented robust changes in immune cell compartments in association with T or B cell targeting, but clinical responses are often transient. Therefore, different ITN trials have been designed to evaluate agents for selective immune depletion, immune modulation, and immune regulation, with combinations of those agents when feasible to assess synergistic mechanisms of action. A few examples that illustrate key concepts are discussed below.via thymic reactivation (Although over a dozen disease-modifying agents have been approved by the FDA for the treatment of multiple sclerosis (MS), some patients with this disease are resistant or refractory to treatment and continue to relapse and accumulate disability. In treatment-resistant relapsing MS, an immune “reset” can be accomplished with immunoablation followed by autologous hematopoietic stem cell transplant (AHSCT). In this procedure, the pathogenic immune repertoire is eliminated with interruption of autoimmune destruction of myelin in the central nervous system. Clinical trials, including the HALT-MS trial conducted by the ITN, demonstrated high efficacy in aggressive treatment-resistant relapsing MS , 52–54. tivation , rebalantivation –59, and tivation . In the tivation . To conftivation .Depletion of specific effector cell populations without the global changes induced by AHSCT are also effective, although with inconsistency in the durability of response. In ANCA-associated vasculitis, ANCA do not appear to cause disease by forming immune complexes or directly binding to tissues. Instead, these autoantibodies are suspected to bind neutrophils, resulting in hyperactivation of neutrophils and formation of neutrophil extracellular traps, which in turn results in vascular damage. The Rituximab for ANCA-associated Vasculitis (RAVE) trial treated patients with severe active granulomatosis with polyangiitis and microscopic polyangiitis with rituximab (anti-CD20), with the goal of depleting antibody-secreting B cells and promoting sustained disease control . In thisDespite an abundance of evidence supporting a critical role for B cells in the pathogenesis of SLE, rituximab-induced B cell depletion has failed in randomized, controlled trials to show clinical efficacy in both non-renal SLE and lupus nephritis , 65. OneSimilar to the rationale for transplantation studies noted above, plasma cell targeting is an attractive option for some antibody-mediated autoimmune diseases. Elimination of plasma cells could be beneficial for the treatment of antibody mediated diseases such as antiphospholipid syndrome (APS), a systemic autoimmune disease characterized by thrombotic and obstetric manifestations in individuals with potentially pathogenic antiphospholipid antibodies . StandarEOMES, a transcription factor and marker of T-cell exhaustion, as a correlate of changes in insulin secretion , alefacept (LFA3-Ig), and anti-thymocyte globulin (ATG) in type 1 diabetes (T1D) are particularly informative. Teplizumab is a monoclonal anti-CD3 antibody, investigated by the ITN for over a decade in several clinical trials. In the ITN AbATE study, treatment with teplizumab delayed the loss of residual insulin secretion in patients with type 1 diabetes in a subset of subjects, with some maintaining insulin secretory function for several years . Teplizuecretion –18. Moreecretion .The costimulatory CD2 cell surface molecule is most prominently expressed on CD4 T effector memory (Tem) cells and naïve CD8 . CD4 T rFailure to retain regulatory T cell function may explain the disappointing outcomes in several trials using CD28 costimulatory blockade as a therapeutic tolerance strategy. Abatacept (CTLA4-Ig) is a fusion protein consisting of the extracellular domain of the CTLA4 ligand for CD80/86 coupled to a modified Fc portion of human immunoglobulin G (IgG). It acts by preventing CD80/CD86 on APCs from binding to CD28 on T cells, thereby inhibiting T cell activation and function, and serving as an effective treatment option in adult rheumatoid arthritis and juvenile idiopathic arthritis. ITN trials with abatacept in multiple sclerosis, lupus nephritis, and psoriasis, however, did not demonstrate clinical benefit for induction or maintenance of tolerance , 24, 26.Successful treatment interventions in transplantation, allergy, and autoimmune disease rarely allow for discontinuation of therapy and result in sustained and selective immune tolerance. However, they do occur, and in the context of clinical trials, they provide an opportunity to identify specific therapeutic targets, or combinations of targets, capable of restoring homeostatic immunity. Notably, minimization or extended drug holidays from immunosuppressive therapy also provide clinical benefit, even without achieving the ideal goal of permanent immune tolerance. Ongoing maintenance intervention may be required, for example a small dose of oral peanut  to maintain a non-allergic state in an individual who had previously undergone successful desensitization to that allergen.interrupting effector mechanisms, restraining innate activation, and boosting regulation. These objectives can be met through targeting of different cells and pathways in different diseases, whether B cell, plasma cell, T effector, T regulatory, cytokine or other non-lymphocytic effector mechanisms. Early intervention, and mechanism-based stratification of individuals for optimal targeting of particular immune pathways, are likely to improve success rates. Combining antigen exposure in allergic disease and transplantation with selective immunomodulation, and using initial induction strategies in autoimmunity followed by regulatory enhancement, are promising conduits for improving clinical outcomes. In the examples summarized in this article, we have learned that early intervention in the form of antigen introduction can be successful in preventing and treating peanut allergy. In autoimmune disease, immunomodulatory agents targeting T cells and inducing exhaustion pathways can delay clinical disease onset and improve the effector/regulatory T cell balance in T1D, while targeting B cells improves outcomes in ANCA-associated vasculitis. For other autoimmune diseases resistant to B cell depletion or costimulatory blockade, targeting alternative costimulatory pathways and antibody-producing plasma cells in tandem, for example, and combination strategies interrupting key hubs in the adaptive and innate immune response may be required to restore immune tolerance and tissue homeostasis. In solid organ transplantation, success has been partially achieved with an immune reset via hematopoietic chimerism, but other strategies including cell-based therapies and molecularly targeted agents are under investigation. Eliminating unwanted immune responses in allergy, autoimmunity, and transplantation and restoring a healthy balance of regulatory and effector immune elements is a formidable goal. Nevertheless, improved understanding of the complexities of the immune system provide opportunities that continue to provide a foundation for future tolerance-inducing strategies and success.Looking across multiple clinical trials and different clinical disciplines in ITN studies, shared patterns emerge that emphasize the need for a combination of All authors contributed to the article and approved the submitted version.The work of the authors was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number UM1AI109565.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.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.


Cancer cachexia is a common condition in many cancer patients, particularly those with advanced disease. Cancer cachexia patients are generally less tolerant to chemotherapies and radiotherapies, largely limiting their treatment options. While the search for treatments of this condition are ongoing, standards for the efficacy of treatments have yet to be developed. Current diagnostic criteria for cancer cachexia are primarily based on loss of body mass and muscle function. However, these criteria are rather limiting, and in time, when weight loss is noticeable, it may be too late for treatment. Consequently, biomarkers for cancer cachexia would be valuable adjuncts to current diagnostic criteria, and for assessing potential treatments. Using high throughput methods such as “omics approaches”, a plethora of potential biomarkers have been identified. This article reviews and summarizes current studies of biomarkers for cancer cachexia. Cancer cachexia is a wasting condition, mainly characterized by loss of muscle and adipose tissue. This condition severely limits the quality of life and use of cancer therapies. Cancer cachexia is mainly associated with cancers caused by solid tumors and may affect up to 80% of patients with late-stage cancer, and be responsible for more than 20% of cancer-related deaths . DespiteCurrent meaningful endpoints for cancer cachexia studies are divided into gravimetric and functional endpoints. A gravimetric endpoint is simply based on the change of muscle mass or lean body mass (LBM), while a functional endpoint is evaluated by a change in physical function such as improved stair climbing power and hand grip strength . In the A biomarker-based evaluation system for cancer cachexia could solve these issues as biomarkers are a more objective and reliable diagnostic tool than functional assessment. Several potential biomarkers have so far been identified including some cachexia-inducing factors ,10, pro-Many cachexia-inducing factors such as activin A (ActA) , myostatZinc-α2-glycoprotein (ZAG) is a lipid mobilizing factor that can be secreted by both tumors and host tissues. Enhanced ZAG production was observed in adipose tissue from cachectic mice and patients ,37. A fuFibroblast growth factor 21 (FGF21), a hormone regulating several metabolic pathways, is associated with brown adipose tissue (BAT) activity in humans ,42, althParathyroid Hormone release Peptide (PTHrP) was shown to promote browning of fat in a cancer cachexia mouse model . In miceTo identify blood-based biomarkers for cancer cachexia induced by all types of cancer, a study was performed to profile plasma cytokines and mRNA in blood, which included patients with breast, upper gastrointestinal, lung, hepatobiliary, pancreatic, prostate, colorectal, head and neck cancers . ElevateOverall, despite extensive studies on the mechanisms of cachexia-inducing factors, more studies are required to investigate their utility as biomarkers for cancer cachexia . AdditioMany inflammatory cytokines are important players in cancer cachexia and can be released by both host tissues and tumors. Upregulation of these cytokines have been observed in several preclinical cancer cachexia models ,21,55. CAmong all the inflammatory cytokines related to cancer, IL-6 is one of the more promising biomarkers for cachexia. Circulating IL-6 levels showed positive correlation to both survival and lean body mass in patients with advanced lung cancer ,59. IL-6Monocyte chemoattractant protein-1 (MCP-1) is a factor that recruits inflammatory cells during infection . Mice wiC-reactive protein (CRP) is a plasma protein that serves as an indicator for inflammation . IncreasCollectively, evidence shows the potential of inflammatory cytokines as biomarkers for cancer cachexia, however, none of these are elevated in cachectic patients across multiple types of cancer . FurtherMechanisms of muscle wasting in cancer cachexia have been widely studied over the past decade. Increased protein degradation and decreased protein synthesis are considered as the main causes of muscle loss during cancer cachexia. Molecular mechanisms of muscle atrophy in cancer cachexia have been reviewed by Wei et al. . From a Collagen is one of the main components of the extracellular matrix of skeletal muscle and is degraded during muscle atrophy ,81. As c2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) β and tyrosine kinase with immunoglobulin-like and EGF-like domains 1 (TIE1) were also positively associated with weight loss in upper gastrointestinal cancer patients [Some biomarkers may remain in the muscle itself and are not released into circulation. For example, β-dystroglycan was shown to be increased in skeletal muscle of cachectic patients with upper gastrointestinal cancer . Muscle patients . HoweverLoss of adipose tissue is another common symptom observed in cancer cachexia. The adipose tissue plays a vital role even in cancer with a relatively low cachexia rate . BrowninIn a study investigating lipid profiles of cancer cachexia, increased circulating levels of sphingolipids were found in different preclinical models and cachectic patients with gastrointestinal cancers . SpecifiMicroRNAs are a class of small non-coding RNA of about 17–22 nucleotides in length, which have been found in a wide range of biological processes. The main role of microRNAs is to regulate gene expression. There is a growing body of evidence detailing the emerging role of microRNAs and other non-coding RNAs in cancer cachexia, which is reviewed by Santo et al. . Many ofMicroRNA-21 is one of the well-studied oncogenic microRNAs that targets several tumor suppressor genes . ExpressAnother similar study demonstrated that circulating microRNA-203 levels were upregulated in cachectic patients with colorectal cancer . ElevateA study measuring circulating microRNA-130a levels in head and neck cancer patients found that low microRNA-130a was associated with high circulating TNF-α levels, and patients with low circulating microRNA-130a expression had a higher risk of weight loss . NutritiMore comprehensive studies may identify other potential non-coding RNAs that may be used as a diagnostic tool for cancer cachexia. One of the most attractive characteristics of these non-coding RNAs is that they are generally secreted into circulation via microvesicles such as exosomes, ensuring stability during the processing of blood samples.There are several other factors that are also differentially expressed in cachectic patients compared to weight stable controls . A studyTissue inhibitor of metalloproteinases-1 (TIMP-1) is involved in tumorigenesis , cancer Enterobacteriaceae levels were increased, while a reduction of lachnospiraceae and ruminococcaceae were found in C26 cancer cachexia model [Although many promising biomarkers for cancer cachexia have been identified, none are yet approved for clinical use. Some potential biomarkers were shown to be adequate indicators of cachexia induced by some cancers, but not consistent across a range of cancer types. Consequently, multiple biomarkers may be required to predict and monitor progression of this condition in the general cancer population. A recent study found expression profiles of 12 cachexia-inducing factors correlate with the prevalence of cachexia and weight loss in different cancer types . Cancersia model ,112. SucInterestingly, recent studies have shown that body composition changes, especially muscle alteration, differ by gender in cancer patients ,114. AnoAlthough utilization of these biomarkers provides potential diagnosis of cancer cachexia, many of these could also be promising targets for treating this condition . As imprAs many of the studies referred to in this review were aimed at finding a correlation of biomarker levels with cancer cachexia, it is not surprising that there were discrepancies in cut-off values, even in cachexia found in the same type of cancer. Clear and reliable cut-off values are usually required for using biomarkers as diagnostic tools in the clinic. Hence, biomarkers with large variations between the cachectic and non-cachectic state are preferred. Although levels of some biomarker candidates showed statistical differences in cachectic and non-cachectic states, clear cut-off values could not be determined, as absolute differences or fold changes in these values were not prominent enough.Another major concern is that none of these studies investigated the feasibility of using biomarkers to differentiate cancer cachexia from sarcopenia and anorexia, all conditions that cause muscle wasting and weight loss that can be found in patients with late-stage cancers. Since the treatments for these conditions are quite distinct, the biomarkers for cachexia should differentiate between these conditions. In this respect, tumor-derived biomarkers are preferred to biomarkers released by peripheral tissues, as their levels should not be affected by conditions such as sarcopenia and anorexia. Most factors investigated so far can be secreted from both tumor and host tissues, making it difficult to ascertain whether they are related to one cause of weight loss or another. Another approach may be the development of positive-negative diagnostic panels that can differentiate between cachexia, sarcopenia, and anorexia.Detection methods for any potential biomarker should also be reliable and preferably subject to automation. Most circulating biomarkers are measured by enzyme-linked immunosorbent assay (ELISA). Accuracy and sensitivity of an ELISA are largely dependent on the specificity and concentration of antibodies used for the assay. In contrast, nucleic acid-based detection methods are more specific, sensitive, and cheaper than most protein-based methods. Hence, nucleic acid biomarkers are promising in this regard. Currently, most nucleic acid biomarkers are detected by qRT-PCR, which gives relative readings and requires controls for every test. In comparison, digital PCR is able to provide an absolute and ultrasensitive quantification of nucleic acid , which iIn summary, there are no approved clinical biomarkers for cancer cachexia. This is currently a major impasse in the diagnosis and treatment of this condition, as cancer patients with increased muscle and fat loss have a definitively poor prognosis and do not tolerate conventional chemotherapeutic intervention. The ability to screen cancer patients with a panel of biomarkers (that cover a range of cancer types) that are upregulated in cachexia will allow clinicians to tailor treatment for the patient . Althoug


Alcohol and cannabis are the most commonly used substances during adolescence and are typically initiated during this sensitive neurodevelopmental period. The aim of this review is to provide a comprehensive overview of the most recent literature focused on understanding how these substances affect the developing brain.Articles included in this review were identified by entering 30 search terms focused on substance use, adolescence, and neurodevelopment into MEDLINE, Embase, PsycINFO, ProQuest Central, and Web of Science. Studies were eligible for inclusion if they longitudinally examined the effect of adolescent alcohol and/or cannabis use on structural or functional outcomes in 50 or more participants.More than 700 articles were captured by the search, and 43 longitudinal studies met inclusion criteria, including 18 studies focused on alcohol use, 13 on cannabis use, and 12 on alcohol and cannabis co-use.Existing studies suggest heavy alcohol and cannabis use during adolescence are related to small to moderate disruptions in brain structure and function, as well as neurocognitive impairment. The effects of alcohol use include widespread decreases in gray matter volume and cortical thickness across time; slowed white matter growth and poorer integrity; disrupted network efficiency; and poorer impulse and attentional control, learning, memory, visuospatial processing, and psychomotor speed. The severity of some effects is dependent on dose. Heavy to very heavy cannabis use is associated with decreased subcortical volume and increased frontoparietal cortical thickness, disrupted functional development, and decreased executive functioning and IQ compared to non-using controls. Overall, co-use findings suggest more pronounced effects related to alcohol use than to cannabis use. Several limitations exist in the literature. Sample sizes are relatively small and demographically homogenous, with significant heterogeneity in substance use patterns and methodologies across studies. More research is needed to clarify how substance dosing and interactions between substances, as well as sociodemographic and environmental factors, affect outcomes. Larger longitudinal studies, already underway, will help clarify the relationship between brain development and substance use. Adolescence is marked by significant social, emotional, cognitive, and physical changes, as individuals transition from childhood to adulthood. Although the exact definition of adolescence tends to vary, recent findings regarding adolescent development and growth include individuals between the ages of 10 and 24.13Emerging research supports the notion that substance use disorders are developmental problems that begin during adolescence and have negative consequences on individuals throughout the life span.19Given the high rates of alcohol and cannabis use during adolescence, coupled with the significant neural maturation occurring during this period, it is critical to understand how alcohol and cannabis use affect adolescent brain development. Although other reviews exist on these topics, they have limitations. Specifically, existing reviews exclusively focus on alcohol,Articles included in this review were identified via literature searches using MEDLINE, Embase, PsycINFO, ProQuest Central, and Web of Science, conducted on February 19, 2021. To capture the effects of alcohol and/or cannabis use on neural and cognitive development during adolescence, search terms included: (1) alcohol, cannabis, marijuana; (2) adolescen*, teenage*, young people, youth, emerging adult, young adult, college student; and (3) neuroimag*, neuroscience, PET scan, brain imag*, spectroscop*, magnetic resonance imag*, fMRI, sMRI, magnetic resonance spectroscopy, electroencephalogram, diffusion tensor imag*, structural imag*, functiona imag*, neuropsychological test, cogniti*, verbal working memory, episodic memory, visuospatial working memory, verbal fluency test, executive function*. In keeping with previous reviews,More than 700 articles were captured by the search; and 43 longitudinal studies met inclusion criteria, including 18 studies focused on alcohol use, 13 on cannabis use, and 12 on alcohol and cannabis co-use. The effects of alcohol and cannabis use on ongoing adolescent neurodevelopment are described, portioned by brain structure , brain function , and neuropsychological effects . Information on levels and typologies of alcohol and cannabis use see , age, anWhere applicable, sex-specific findings are reported. Studies focused on alcohol effects are summarized first, followed by cannabis, then co-use studies. Two consortium-sized studies have examined the effect of substance use on the developing brain, including IMAGENA number of longitudinal structural magnetic resonance imaging (MRI) studies have explored changes in brain volume and cortical thickness that occur across time following alcohol or cannabis use during adolescence. Several studies have delineated the post-substance use effects on brain structure by comparing youth who have and have not consumed alcohol or cannabis, and some have explored the relationship between levels of use and structural effects.n = 548), 22% of youth were drinking moderately and 18% were drinking heavily.32Among 483 NCANDA participants , a portion of youth initiated moderate (13%) or heavy (13%) drinking by the 2-year follow-up assessment.N = 55 to N = 134; 64% to 95% of the samples were White).33The alcohol effects observed in the NCANDA sample are consistent with three smaller longitudinal studies of adolescents with a mean age of 15 to 18 at baseline  was not associated with gray matter volume between ages 14 and 19 when controlling for sociodemographic, puberty, and substance-related confounding factors.n = 706) indicated that greater consumption  who initiated use during middle adolescence.Examination of adolescents engaging in heavy and frequent cannabis and alcohol co-use  found that heavy co-use was associated with a global reduction in cortical thinning  compared to controls, with frontal and parietal lobes being most consistently affected.Diffusion tensor imaging studies measure the microstructural integrity of white matter by mapping the diffusion pattern of water molecules.In a study utilizing 4 years of NCANDA data, a whole-brain FA analysis of 451 adolescents was conducted.N = 54, 74% White) and compared older adolescents engaging in concurrent binge drinking and heavy cannabis use to those engaging in binge drinking only or no substance use.Two studies from the same research group assessed youth who reported alcohol and cannabis co-use, and together they found limited evidence to suggest cannabis is neurotoxic to white matter integrity.Heavy alcohol use during late adolescence is associated with accelerated widespread decreases in gray matter volume and cortical thickness throughout frontal, parietal, temporal, and cerebellar regions. Additionally, attenuated white matter growth and poorer white matter integrity throughout widespread regions have been observed among heavy drinkers, with greater disruptions from consumption during middle to late adolescence than during young adulthood.Heavy cannabis use may be associated with a differentiated neural pattern than alcohol use alone. Cannabis use is associated with macrostructural consequences only, including reduced expansion of the hippocampal region and increased cortical thickness in the frontal and parietal lobes. Early evidence suggests that disruptions in macrostructural development due to cannabis use do not recede over the short term; however, further research on the recoverability of substance-related macrostructural effects is required. New evidence also highlights the importance of studying sex and sex hormones when investigating the effects of alcohol and cannabis use on the adolescent brain;Longitudinal studies have measured resting-state functional connectivity and neural response to cognitive tasks across time to examine the effect of alcohol and cannabis use on brain function.N = 92).N = 526).Limited evidence is currently available on the specific effects of alcohol use on functional neurodevelopment. A 4-year study examined the effect of low-level alcohol consumption during middle to late adolescence on neural response to cognitive control tasks (n = 76).n = 502). In a younger sample of adolescents ages 12 to 15 , the initiation of occasional cannabis use was associated with decreased activity in the cuneus during visuospatial working memory compared to controls; however, there were no changes to cognitive scores.51The effect of prolonged and heavy cannabis use on functional neurodevelopment was examined in four studies. Leveraging the IMAGEN data set, prolonged occasional to regular cannabis use from ages 14 to 19 was associated with relative declines in neural reactivity to angry faces across time when compared to substance-naïve matched controls  as well as heavier use during adolescence may alter the rate of neurotypical functional development in brain regions important for cognitive control. Some neural recovery may be possible after abstinence; however, months or years may be required for complete recovery of functional connectivity from heavy cannabis use. Preliminary evidence underscores that cognitive control and sensation-seeking behaviors could be an important target in prevention and treatment of substance use in adolescents, given the moderating roles on neurofunctional effects. Further research is required to determine the relative effects of alcohol and cannabis consumption on functional neurodevelopment and whether neural recovery occurs following reductions in use.Neuropsychological tests enable tracking of cognitive skills over time to uncover the effect of alcohol and cannabis use on cognitive development. The following sections summarize the reported effects by neuropsychological domain.Executive functions refer to a range of top-down mental processes that enable an individual to hold concentration and attention. There are three core executive functions, including inhibition, working memory, and cognitive flexibility.Similarly, most studies examining young adults have not found detrimental effects of alcohol use on executive functioning development. A 4-year study followed 155 young adults every 22 months from age 18. Individuals who reported consistent binge drinking throughout the entire study showed no disadvantage for decision-making ability when compared to non–binge-drinking controls, who consumed four drinks per week on average.As described above, studies that focused on the impact of alcohol use have not reported an effect of occasional cannabis use on executive functioning maturation throughout adolescence and young adulthood.64Overall, there is no strong, consistent evidence to indicate that low to heavy alcohol use during adolescence or young adulthood disrupts executive functioning maturation across time. Longitudinal data on cannabis use and executive functioning performance suggest that frequent consumption and greater cumulative use across adolescence may disrupt inhibitory control, working memory , planning, and decision making.Impulsivity is defined as a behavior characterized by little or no forethought, reflection, or consideration of consequences, when compared to actions by individuals with similar skill and knowledge levels. Impulsivity is thought to be related to risk-taking behaviors.Two studies examined the impact of alcohol use on impulse control across adolescence; however, no studies have examined the impact of cannabis use or co-use of these substances. IMAGEN data from 304 young people ages 13 to 14 at baseline found that over a 2-year period, adolescents who reported more than 40 occasions of alcohol use exhibited increases in trait impulsivity, while youth who reported alcohol use on fewer than 10 occasions exhibited decreases in impulsivity.Attentional control has been measured in two longitudinal studies focused on the effects of low to heavy alcohol use; in two studies focused on effects of heavy cannabis use; and in three studies exploring co-use of alcohol and cannabis.The TRAILS study of 2,226 adolescents reported that 4 years of weekly low or heavy alcohol use did not have an effect on sustained attention, when compared to controls who consumed no alcohol.In terms of cannabis-related effects, declines in cannabis use from very heavy to heavy consumption correspond with improvements in attention.Additionally, alcohol and cannabis co-use has been associated with progressive declines in attentional control across time. In a study of 69 adolescents (80% White) observed from ages 13 to 19, the initiation of concurrent use was related to deficits in complex attention compared to substance-naïve counterparts.38In summary, previous studies have identified attentional deficits among heavy drinking males and heavy cannabis users. Initiation of co-use of these substances in adolescence has predicted poorer attention, with graded dose effects observed that may be driven by alcohol use. Early evidence suggests that adolescents may recover from cannabis-related effects following reductions in use. Recoverability from alcohol effects remains unknown.Inextricably linked to adolescent learning and memory development is educational attainment, one of the most critical developmental tasks for youth. Thus, substance-induced deficits are arguably even more impactful for young people than adults. Ten studies included in this review examined the effect of alcohol or cannabis use on learning and memory performance throughout adolescence.n = 1,978), occasional cannabis use was associated with decreased immediate recall compared to young people with long-term abstinence from cannabis use, suggesting recovery may be possible after long-term abstinence.73Alcohol-focused studies have predominantly reported on the impact of heavy binge drinking. A 6-year study of 112 substance-naïve adolescents  found that higher estimated peak blood alcohol concentration over the 3-month period before the follow-up neuroimaging session predicted worse verbal learning and immediate, short- and long-term delayed, and cued recall across time in a dose-dependent manner.N = 73, 78% White).Alcohol and cannabis co-use has been shown to impair learning and memory, with preliminary evidence implicating alcohol as the predominant driver of these effects. The effect of heavy alcohol and cannabis use  on learning and memory trajectories across 10 years was examined during middle to late adolescence.Overall, studies focused on alcohol use during adolescence have observed a disruption in learning and memory development following heavy and binge drinking, with the severity of effects related to levels of consumption. Occasional cannabis use has been shown to have a negative effect on recall but not on learning. Meanwhile, heavy co-use for up to 10 years is related to poor outcomes, which may be driven by the effects of alcohol use rather than cannabis use.Visual processing involves the brain’s analysis and interpretation of visual signals. Seven previously described studies have examined the impact of alcohol and cannabis use on visual processing ability across adolescence, including four alcohol-focused studies and three co-use studies.Initial evidence from the previously described study suggests that low-level alcohol use during adolescence does not have a negative effect on the development of rapid visual processing.67Others studies have found that adolescent engagement in heavy cannabis use and binge drinking over 3 years has resulted in significant declines in visuospatial functioning, with effects driven by alcohol use.Verbal ability refers to the ability to both understand and communicate effectively with words. Comprehension and verbal fluency are considered parts of verbal ability.n = 2,277; cohort 2, n = 1,241) show that the initiation of occasional cannabis use was associated with a decline in verbal ability; however, this finding is not apparent in twins discordant for cannabis use .n = 1,037).Two large cohorts of twins  demonstrated that the initiation of regular cannabis use was not associated with prospective IQ decline in discordant twins for cannabis use.N = 1,037).IQ is a standard measure of an individual’s intelligence level. Four studies included in this review examined the effect of occasional to very heavy cannabis use on IQ across adolescence. Two large cohorts of twins showed that the initiation of occasional cannabis use was associated with a decline in IQ; however, this finding was not apparent in twins discordant for cannabis use,A wealth of longitudinal studies have assessed the effect of adolescent alcohol and cannabis use on neuropsychological development. Based on the current evidence base, heavy alcohol use (including binge drinking) during adolescence disrupts normative developments in impulse and attentional control, learning and memory, visual processing and functioning, and psychomotor speed, with the severity of some effects dependent on dose. In contrast, low to heavy alcohol use during adolescence and young adulthood does not appear to disrupt executive functioning maturation across time. The recoverability of alcohol effects generally remains unknown.Longitudinal data on cannabis use and neuropsychological development are generally lacking. Preliminary evidence suggests that heavy to very heavy use could lead to deteriorated development of executive functions and IQ. Heavy alcohol and cannabis co-use in adolescence has been linked to a range of deficits, including deficits in attentional control, learning and memory, visuospatial functioning, and psychomotor speed. The added effect of co-use versus singular use has not been adequately explored to date, although early evidence suggests that heavy alcohol use may be driving some of these effects.The rapidly expanding literature of prospective, longitudinal studies tracking neurodevelopment and substance use has greatly increased knowledge of the effects of adolescent alcohol and cannabis use on brain structure, function, and cognition. Overall, it is clear that heavy alcohol use during adolescence is associated with neural and cognitive consequences see . AlthougAn important observation from the current review is the need for more diverse samples. The vast majority of existing work has studied White youth from high socioeconomic backgrounds in the United States and Europe, limiting the generalizability of findings. Future studies also should improve racial descriptions of participants. Often studies report on the proportion of White versus non-White youth, with critical details of race and ethnicity representation overlooked. Another consideration likely reducing the generalizability of the current evidence base is the frequently reported eligibility criteria that excludes youth with co-occurring psychological and medical issues. Importantly, this has enabled specific examination of the effect of substance use on neurodevelopment; however, future studies should begin to explore the interactive effects of adolescent substance use and psychopathology on adolescent neurodevelopment. This knowledge will benefit practitioners working with adolescents and inform future initiatives on substance use prevention and mental health.Overwhelmingly, the majority of studies thus far have examined effects related to low-level substance use initiation or heavy, frequent use. Although some studies report dose-dependent effects, greater clarification is needed to determine whether there is a threshold for harmful use that results in neural and cognitive consequences. The magnitude of neurodevelopmental consequences from alcohol and cannabis use is likely to stem from a multitude of other factors including sociodemographic characteristics, early-onset puberty, genetic polymorphisms, prenatal exposures, childhood adversity, and psychopathology, among other important factors, which may be lost in the standard mean group values used in analysis.Given ethical barriers surrounding adolescent substance use, this field of research is reliant on observational human studies, which creates challenges for establishing causality and directionality. This review aims to identify neurobiological and neuropsychological consequences of adolescent alcohol and cannabis use by summarizing prospective, longitudinal studies that repeatedly assess individuals over time as patterns of substance use emerge and escalate. However, many of the included studies used only two neuroimaging or neurocognitive time points, which does not allow for more complex modeling and understanding of developmental trajectories over time. Furthermore, reliably identifying causal mechanisms in observational studies without randomization is difficult, with the primary concern being confounding . The studies synthesized in this review included statistical models with a range of sociodemographic and environmental covariates to address the issue of confounding. However, numerous methods are now available in response to the confounding problem in observational data, such as Granger causal models, structural equation models, Bayesian networks, state-space models, regression discontinuity design, the difference-in-differences approach, and instrumental variable approaches.An additional methodological concern identified in this review is the reliance on youth self-report of substance use. Several studies also used ranges in surveys to capture frequency and quantity of consumption, weakening the ability to explore graded dose effects. Utilization of real-time measures and biological markers can greatly increase the accuracy and reliably of substance use data.Cannabis potency has increased substantially over the past several decades.89In summary, alcohol and cannabis are two of the most commonly used substances during adolescence, which is a critical developmental period associated with significant neurocognitive maturation. Longitudinal neuroimaging and neuropsychological research have helped clarify the effect of substance use on adolescent brain development. Existing studies suggest alcohol and cannabis use during adolescence are related to small to moderate disruptions in brain structure and function, as well as neurocognitive impairment see . Overall92


Autophagy is an intracellular process in response to stimulus by which damaged organelles, protein aggregates, or invading pathogens, are targeted from autophagic vesicles to lysosomes and then eliminated . AutophaThe role of autophagy in cancer remains highly controversial, and it is likely reliant on the tumor type, the stage of neoplasia, the cellular context, as well as on the metabolic context in which the cells lie. Earliest reports suggested a role of autophagy against tumorigenesis favoring tumor cell death in an apoptotic-dependent or independent way . In thisHence, the possibility to modulate autophagy may represent a useful therapeutic approach to treat different types of cancer. In this regard, a variety of clinical trials based on autophagy modulators are ongoing. For instance, in tumors with enhanced autophagy, which acts as a survival mechanism and chemoresistance, its inhibition can make them more prone to initiate cell death mechanisms. In this sense, there are a variety of examples showing that autophagy inhibitors, as 3-methyl-adenine (3-MA) or hydroxychloroquine (HCQ), when used in combination with anticancer drugs, may sensitize chemoresistant cells, thus leading to cancer cell death . HoweverOn the other hand, recent advances in nanomedicine make it possible to fight cancer with effective therapeutic compounds, removing the obstacles encountered with traditional drugs. Interestingly, nanomaterials have been explored as potent modulators of autophagy through multiple mechanisms and have been exploited as therapeutic agents against cancer . For thiThis Research Topic gathers original research and review papers on novel drugs and nanomaterials in cancer treatment based on autophagy modulation and the related molecular mechanisms of action ranging from basic research to more applied translational and clinical studies. The 17 accepted articles consist of 9 Original Research articles and 8 Reviews or Mini-Reviews, demonstrating that inhibition or enhancement of the autophagy pathway may serve as an effective tool to counteract cancer.in vivo and in vitro, of several natural substances by modulating signaling pathways regulating autophagy in various tumors, thus representing great candidates for further therapeutic applications. Wang et al. showed that Sotetsuflavone, a naturally derived and occurring flavonoid, induced autophagy in lung cancer blocking PI3K/Akt/mTOR signaling pathway in vivo and in vitro, was able to increase the levels of pro-apoptotic markers, as cytochrome C or cleaved-caspase 3, and to reduce the expression of cyclin D1 and CDK4, thus blocking cell cycle in the G0/G1 phases. Tsai et al. reported that 6-Gingerol, a natural phenol found in ginger, inhibits lung cancer cell growth via suppression of USP14 expression and enhances autophagy-dependent ferroptosis, revealing the therapeutic efficacy of 6-Gingerol in A549 and its possible mechanism of action.Some of the research articles published describe the anticancer proprieties, both colleagues showed that honokiol and magnolol, two compounds derived by magnolia bark extract, display therapeutic potential causing cell cycle arrest, induction of caspase 3-dependent apoptosis, and autophagy in high-grade urothelial carcinoma. Chen et al. explored the anti-breast cancer potential of ethanol crude extracts from Brucea javanica seed (BJE). Their data showed that BJE could inhibit breast cancer cell proliferation and induce apoptosis, together with the inhibition of autophagy, as demonstrated by the reduction of several autophagy-related markers and the increase of mTOR phosphorylation. Gao et al. revealed the molecular mechanisms through, which Moracin N (MAN), a secondary metabolite extracted from the leaves of Morus alba L, inhibited cell proliferation and induced apoptosis in lung cancer cells. Interestingly, they found that MAN treatment dysregulated mitochondrial function and enhanced autophagy flux, concomitantly to the inhibition of mTOR signaling pathway in a time- and dose-dependent manner.Natural compounds derived from herbal medicines have been extensively studied for their anticancer proprieties through modulation of signaling pathways leading to tumor cell death in various cancer types. In this context, Wu et Chicote et al. reported that autophagy inhibitor 3-methyladenine displayed cytotoxicity in mouse fibroblasts and correlates with massive DNA damage, suggesting that in growing conditions, autophagy acts as a protective mechanism to diminish the intrinsic cytotoxicity of 3-methyladenine.Defects in autophagy lead to the accumulation of impaired mitochondria, which are a potential source of ROS that lead to DNA damage and genomic instability. In this regard, Zhang et al. showed here that drug-induced platinum accumulation might also interfere with immune cells and, thus, increase the risk of immune toxicity in cancer patients.Recently, it has been shown that platinum compounds exert long-term effects, including autophagy activation in rat B50 neuroblastoma cells . HoweverChen et al. showed that nickel complex NiPT, a proteasomal inhibitor, was able to induce autophagy by dysregulating AMPK/mTOR signaling pathways in both cultured tumor cell lines and cancer cells derived from acute myeloid leukemia human patients. Interestingly, they found that NiPT leads to apoptosis in lung cancer cells if it is concomitantly used together with autophagy inhibitors, suggesting that NiPT-induced autophagy protects cancer cells from death.However, due to their ability to elicit autophagy, metal-based compounds remain attractive agents for anticancer applications. Here, The Research Topic also counts with several well-structured review articles that summarize studies describing novel drugs and nanomaterials in cancer treatment based on autophagy modulation and the related molecular mechanisms.Sharma et al. highlighted that the use of nanoparticles for the delivery of miRNA-34a in cancer cells might inhibit critical autophagy-related pathways, thus sensitizing cancer cells to traditional chemotherapy drugs. On the other side, Condello et al. focused on the most effective liposomal formulations for the simultaneous transport of chemotherapeutics and autophagy inhibitors to control pharmacokinetics and targeting, thus reducing the adverse effects of drugs.In recent years, several nanocarriers have been developed and investigated to improve the solubility, bioavailability, controlled release of therapeutics, and increase their cytotoxic effect on cancer cells. et colleagues focused their attention on the capability of such structures to induce autophagy by inhibiting the Akt/mTOR cascade when administered as monotherapy or in combination with other drugs.Alkylphosphocholine (APC) derivatives represent a novel class of antineoplastic agents that inhibit the serine–threonine kinase Akt, which acts as the primary regulator of cell survival. Berger Liu et al. discussed the advantages of combining agents that induce cytoprotective autophagy with autophagy inhibitors as a cancer therapeutic approach in clinical application. Hence, the exploitation of appropriate autophagy might cooperate with traditional anticancer drugs to overcome drug resistance.The cytoprotective role that autophagy plays under certain conditions during cancer therapy is well assumed, and many studies have been addressed to reduce protective autophagy to overcome drug resistance in the clinical practice. Lin et al. elegantly described the relationship between ferroptosis and autophagy and focused their interest on small molecules inducing ferroptosis, which have been observed to lead to a robust inhibitory effect on tumor growth and enhance the sensitivity to chemotherapeutic drugs. The tripartite motif family of proteins (TRIMs) has emerged as a critical regulator of the autophagy process, and their dysregulation is strongly connected to oncogenesis or cancer progression. The review of Mandell et al. covers how the actions of TRIM proteins intersect with and orchestrate autophagy, thus contributing to cancer progression and the possibility of targeting TRIM-directed autophagy in cancer therapy.Iron-dependent ferroptosis is a type of cell death discovered in recent years, which is driven by lipid peroxidation and, recently, it has been linked with various kinds of diseases, including cancer. Wang et al. highlighted recent advances of several potential anticancer enzymes and the concomitant employment of autophagy modulators with amino acid degrading enzymes as potential cancer therapeutic approaches.Recently, the interest in metabolic therapy for cancer has been renewed, particularly in amino acid deprivation by enzymes. In this context, L-asparaginase was approved for the treatment of acute lymphoblastic leukemia by the U.S. Food and Drug Administration . ImportaLim and Murthy summarized their current understanding of how autophagy drives tumor progression and chemoresistance via immunosuppression and they resumed an increasing set of pharmacologically actionable targets in the autophagy pathway, which may serve for novel cancer immunotherapies.Recent studies have elucidated that autophagy, in addition to lead severe metabolic changes and chemoresistance also plays a role in regulating the immune system, and increasing attention has been focused on the potential applications of autophagy modulation for tumor immunotherapy. In this regard, In conclusion, this collection of Review and Original Research articles critically summarizes the current understanding of how autophagy modulation could be exploited for cancer treatment. We believe that these advances will inspire basic and clinical scientists working in related fields to investigate molecular mechanisms and translational studies further.