Understanding the role of PD-L1/PD1 pathway blockade and autophagy in cancer therapy

Biomarker development for PD-(L)1 axis inhibition: a consensus view from the SITC Biomarkers Committee

Therapies targeting the programmed cell death protein-1/programmed death-ligand 1 (PD-L1) (abbreviated as PD-(L)1) axis are a significant advancement in the treatment of many tumor types. However, many patients receiving these agents fail to respond or have an initial response followed by cancer progression. For these patients, while subsequent immunotherapies that either target a different axis of immune biology or non-immune combination therapies are reasonable treatment options, the lack of predictive biomarkers to follow-on agents is impeding progress in the field. This review summarizes the current knowledge of mechanisms driving resistance to PD-(L)1 therapies, the state of biomarker development along this axis, and inherent challenges in future biomarker development for these immunotherapies. Innovation in the development and application of novel biomarkers and patient selection strategies for PD-(L)1 agents is required to accelerate the delivery of effective treatments to the patients most likely to respond.

Autophagy in cancer immunotherapy: Perspective on immune evasion and cell death interactions

Both the innate and adaptive immune systems work together to produce immunity. Cancer immunotherapy is a novel approach to tumor suppression that has arisen in response to the ineffectiveness of traditional treatments like radiation and chemotherapy. On the other hand, immune evasion can diminish immunotherapy's efficacy. There has been a lot of focus in recent years on autophagy and other underlying mechanisms that impact the possibility of cancer immunotherapy. The primary feature of autophagy is the synthesis of autophagosomes, which engulf cytoplasmic components and destroy them by lysosomal degradation. The planned cell death mechanism known as autophagy can have opposite effects on carcinogenesis, either increasing or decreasing it. It is autophagy's job to maintain the balance and proper functioning of immune cells like B cells, T cells, and others. In addition, autophagy controls whether macrophages adopt the immunomodulatory M1 or M2 phenotype. The ability of autophagy to control the innate and adaptive immune systems is noteworthy. Interleukins and chemokines are immunological checkpoint chemicals that autophagy regulates. Reducing antigen presentation to induce immunological tolerance is another mechanism by which autophagy promotes cancer survival. Therefore, targeting autophagy is of importance for enhancing potential of cancer immunotherapy.

Process Development of a Macrocyclic Peptide Inhibitor of PD-L1

This article outlines the process development leading to the manufacture of 800 g of BMS-986189, a macrocyclic peptide active pharmaceutical ingredient. Multiple N-methylated unnatural amino acids posed challenges to manufacturing due to the lability of the peptide to cleavage during global side chain deprotection and precipitation steps. These issues were exacerbated upon scale-up, resulting in severe yield loss and necessitating careful impurity identification, understanding the root cause of impurity formation, and process optimization to deliver a scalable synthesis. A systematic study of macrocyclization with its dependence on concentration and pH is presented. In addition, a side chain protected peptide synthesis is discussed where the macrocyclic protected peptide is extremely labile to hydrolysis. A computational study explains the root cause of the increased lability of macrocyclic peptide over linear peptide to hydrolysis. A process solution involving the use of labile protecting groups is discussed. Overall, the article highlights the advancements achieved to enable scalable synthesis of an unusually labile macrocyclic peptide by solid-phase peptide synthesis. The sustainability metric indicates the final preparative chromatography drives a significant fraction of a high process mass intensity (PMI).

Immune checkpoints between epithelial-mesenchymal transition and autophagy: A conflicting triangle

Inhibitory immune checkpoint (ICP) molecules are pivotal in inhibiting innate and acquired antitumor immune responses, a mechanism frequently exploited by cancer cells to evade host immunity. These evasion strategies contribute to the complexity of cancer progression and therapeutic resistance. For this reason, ICP molecules have become targets for antitumor drugs, particularly monoclonal antibodies, collectively referred to as immune checkpoint inhibitors (ICI), that counteract such cancer-associated immune suppression and restore antitumor immune responses. Over the last decade, however, it has become clear that tumor cell-associated ICPs can also induce tumor cell-intrinsic effects, in particular epithelial-mesenchymal transition (EMT) and macroautophagy (hereafter autophagy). Both of these processes have profound implications for cancer metastasis and drug responsiveness. This article reviews the positive or negative cross-talk that tumor cell-associated ICPs undergo with autophagy and EMT. We discuss that tumor cell-associated ICPs are upregulated in response to the same stimuli that induce EMT. Moreover, ICPs themselves, when overexpressed, become an EMT-inducing stimulus. As regards the cross-talk with autophagy, ICPs have been shown to either stimulate or inhibit autophagy, while autophagy itself can either up- or downregulate the expression of ICPs. This dynamic equilibrium also extends to the autophagy-apoptosis axis, further emphasizing the complexities of cellular responses. Eventually, we delve into the intricate balance between autophagy and apoptosis, elucidating its role in the broader interplay of cellular dynamics influenced by ICPs. In the final part of this article, we speculate about the driving forces underlying the contradictory outcomes of the reciprocal, inhibitory, or stimulatory effects between ICPs, EMT, and autophagy. A conclusive identification of these driving forces may allow to achieve improved antitumor effects when using combinations of ICIs and compounds acting on EMT and/or autophagy. Prospectively, this may translate into increased and/or broadened therapeutic efficacy compared to what is currently achieved with ICI-based clinical protocols.

MicroRNA-561-3p indirectly regulates the PD-L1 expression by targeting ZEB1, HIF1A, and MYC genes in breast cancer

Globally, breast cancer is the second most common cause of cancer-related deaths among women. In breast cancer, microRNAs (miRNAs) are essential for both the initiation and development of tumors. It has been suggested that the tumor suppressor microRNA-561-3p (miR-561-3p) is crucial in arresting the growth of cancer cells. Further research is necessary to fully understand the role and molecular mechanism of miR-561 in human BC. The aim of this study was to investigate the inhibitory effect of miR-561-3p on ZEB1, HIF1A, and MYC expression as oncogenes that have the most impact on PD-L1 overexpression and cellular processes such as proliferation, apoptosis, and cell cycle in breast cancer (BC) cell lines. The expression of ZEB1, HIF1A, and MYC genes and miR-561-3p were measured in BC clinical samples and cell lines via qRT-PCR. The luciferase assay, MTT, Annexin-PI staining, and cell cycle experiments were used to assess the effect of miR-561-3p on candidate gene expression, proliferation, apoptosis, and cell cycle progression. Flow cytometry was used to investigate the effects of miR-561 on PD-L1 suppression in the BC cell line. The luciferase assay showed that miRNA-561-3p targets the 3'-UTRs of ZEB1, HIF1A and MYC genes significantly. In BC tissues, the qRT-PCR results demonstrated that miR-561-3p expression was downregulated and the expression of ZEB1, HIF1A and MYC genes was up-regulated. It was shown that overexpression of miR-561-3p decreased PD-L1 expression and BC cell proliferation, and induced apoptosis and cell cycle arrest through downregulation of candidate oncogenes. Furthermore, inhibition of candidate genes by miR-561-3p reduced PD-L1 at both mRNA and protein levels. Our research investigated the impact of miR-561-3p on the expression of ZEB1, HIF1A and MYC in breast cancer cells for the first time. Our findings may help clarify the role of miR-561-3p in PD-L1 regulation and point to this miR as a potential biomarker and novel therapeutic target for cancer immunotherapy.

Autophagy as a Target for Non-Immune Intrinsic Functions of Programmed Cell Death-Ligand 1 in Cancer

Autophagy is a catabolic process that is essential to the maintenance of homeostasis through the cellular recycling of damaged organelles or misfolded proteins, which sustains energy balance. Additionally, autophagy plays a dual role in modulating the development and progression of cancer and inducing a survival strategy in tumoral cells. Programmed cell death-ligand 1 (PD-L1) modulates the immune response and is responsible for maintaining self-tolerance. Because tumor cells exploit the PD-L1-PD-1 interaction to subvert the immune response, immunotherapy has been developed based on the use of PD-L1-blocking antibodies. Recent evidence has suggested a bidirectional regulation between autophagy and PD-L1 molecule expression in tumor cells. Moreover, the research into the intrinsic properties of PD-L1 has highlighted new functions that are advantageous to tumor cells. The relationship between autophagy and PD-L1 is complex and still not fully understood; its effects can be context-dependent and might differ between tumoral cells. This review refines our understanding of the non-immune intrinsic functions of PD-L1 and its potential influence on autophagy, how these could allow the survival of tumor cells, and what this means for the efficacy of anti-PD-L1 therapeutic strategies.

Study on the allosteric activation mechanism of SHP2 via elastic network models and neural relational inference molecular dynamics simulation

As a ubiquitous protein tyrosine phosphatase, SHP2 is involved in PD-1/PD-L1 mediated tumor immune escape and undergoes substantial conformational changes. Therefore, it is considered an ideal target for tumor intervention. However, the allosteric mechanisms of SHP2 binding PD-1 intracellular ITIM/ITSM phosphopeptides remain unclear, which greatly hinders the development of novel structure-based anticancer allosteric inhibitors. In this work, the open and closed structural models of SHP2 are first constructed based on this knowledge; next their motion modes are investigated via elastic network models such as the Gaussian network model (GNM), anisotropic network model (ANM) and adaptive anisotropic network model (aANM); and finally, a possible allosteric signaling pathway is proposed using a neural relational inference molecular dynamics (NRI-MD) simulation embedded with an artificial intelligence (AI) strategy. In GNM and ANM, the N-SH2, C-SH2 and PTP domains all exhibit distinct dynamics partitions, and the N-SH2/C-SH2 regions show a rigid rotation relative to PTP. According to a series of intermediate snapshots given by aANM, N-SH2 is first identified with pY223 specifically, inducing a D'E-loop to change from β-sheets to random coils, and then, C-SH2 serves as a fulcrum to drive N-SH2 to rotate 110° completely away from the original active sites of PTP. Finally, a possible allosteric signaling-transfer path for SHP2, namely R220-R138-T108-R32, is proposed based on NRI-MD sampling. This work provides a possible allosteric mechanism of SHP2, which is helpful for the following design of novel allosteric inhibitors and is expected to be used in clinical synergies with PD-1 monoclonal antibody.

Ferroptosis, autophagy, tumor and immunity

Ferroptosis was first proposed in 2012, a new form of cell death. Autophagy plays a crucial role in cell clearance and maintaining homeostasis. Autophagy is involved in the initial step of ferroptosis under the action of histone elements such as NCOA4, RAB7A, and BECN1. Ferroptosis and autophagy are involved in tumor progression, treatment, and drug resistance in the tumor microenvironment. In this review, we described the mechanisms of ferroptosis, autophagy, and tumor and immunotherapy, respectively, and emphasized the relationship between autophagy-related ferroptosis and tumor.

Programmed death-ligand 1 expression and overall survival in Thai patients with gastric cancer

Programmed death-ligand 1 (PD-L1) expression has now been implicated in gastric cancer (GC). This study was conducted to determine the impact of clinicopathological characteristics on PD-L1 expression and its association with survival in GC patients receiving standard-of-care. In total, 268 GC patients receiving upfront surgery were enrolled at Chiang Mai University Hospital. PD-L1 expression was assayed by immunohistochemistry staining using the Dako 22C3 pharmDx. The rates of PD-L1 positivity by combined positive score (CPS) at a cutoff value of 1 and 5 were 22% and 7%. PD-L1 positivity was significantly higher in patients younger than 55 than those older than 55 (32.6% vs. 16.5%, p = 0.003; 11.6% vs. 4.4%, p = 0.027). PD-L1 positivity was observed more frequently in GC with metastases than without (25.2% vs. 17.1%, p = 0.112; 7.2% vs. 6.7%, p = 0.673). Patients with PD-L1 positive had a significantly shorter median overall survival than those with PD-L1 negative (32.7 vs. 41.6 months, p = 0.042, 27.6 vs. 40.8 months, p = 0.038). In conclusion, PD-L1 expression has been associated with young age, short survival, and metastases, although unrelated to the tumor stage. For GC patients, PD-L1 testing is recommended, especially among young patients with metastases.

UVRAG Promotes Tumor Progression through Regulating SP1 in Colorectal Cancer

Colorectal cancer (CRC) is the third most common type of cancer. The ultraviolet radiation resistance-associated gene (UVRAG) plays a role in autophagy and has been implicated in tumor progression and prognosis. However, the role of UVRAG expression in CRC has remained elusive. In this study, the prognosis was analyzed via immunohistochemistry, and the genetic changes were compared between the high UVRAG expression group and the low UVRAG expression group using RNA sequencing (RNA-seq) and single-cell RNA-seq (scRNA-seq) data, and genetic changes were then identified by in vitro experiments. It was found that UVRAG could enhance tumor migration, drug resistance, and CC motif chemokine ligand 2 (CCL2) expression to recruit macrophages by upregulating SP1 expression, resulting in poor prognosis of CRC patients. In addition, UVRAG could upregulate the expression of programmed death-ligand 1 (PD-L1). In summary, the relationship between UVRAG expression and the prognosis of CRC patients as well as the potential mechanisms in CRC were explored, providing evidence for the treatment of CRC.

Immunotherapy of thymic epithelial tumors: molecular understandings and clinical perspectives

Immunotherapy has emerged to play a rapidly expanding role in the treatment of cancers. Currently, many clinical trials of therapeutic agents are on ongoing with majority of immune checkpoint inhibitors (ICIs) especially programmed death receptor 1 (PD-1) and its ligand 1 (PD-L1) inhibitors. PD-1 and PD-L1, two main immune checkpoints, are expressed at high levels in thymic epithelial tumors (TETs) and could be predictors of the progression and immunotherapeutic efficacy of TETs. However, despite inspiring efficacy reported in clinical trials and clinical practice, significantly higher incidence of immune-related adverse events (irAEs) than other tumors bring challenges to the administration of ICIs in TETs. To develop safe and effective immunotherapeutic patterns in TETs, understanding the clinical properties of patients, the cellular and molecular mechanisms of immunotherapy and irAEs occurrence are crucial. In this review, the progress of both basic and clinical research on immune checkpoints in TETs, the evidence of therapeutic efficacy and irAEs based on PD-1 /PD-L1 inhibitors in TETs treatment are discussed. Additionally, we highlighted the possible mechanisms underlying irAEs, prevention and management strategies, the insufficiency of current research and some worthy research insights. High PD-1/PD-L1 expression in TETs provides a rationale for ICI use. Completed clinical trials have shown an encouraging efficacy of ICIs, despite the high rate of irAEs. A deeper mechanism understanding at molecular level how ICIs function in TETs and why irAEs occur will help maximize the immunotherapeutic efficacy while minimizing irAEs risks in TET treatment to improve patient prognosis.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease’s origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a “double-edged sword” in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

Synergic Induction of Autophagic Cell Death in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) has poor prognosis, high mortality rate and lack of effective therapy. A synergic combination of PD-L1 antibody together with cell death promoting substances like deacetylase inhibitors (DACi) and multi-kinase inhibitors (MKI) could sensitize ATC cells and promote decay by autophagic cell death. The PD-L1-inhibitor atezolizumab synergized with panobinostat (DACi) and sorafenib (MKI) leading to significant reduction of the viability, measured by real time luminescence, of three different patient-derived primary ATC cells, of C643 cells and follicular epithelial thyroid cells too. Solo administration of these compounds caused a significant over-expression of autophagy transcripts; meanwhile autophagy proteins were almost not detectable after the single administration of panobinostat, thus supporting a massive autophagy degradation process. Instead, the administration of atezolizumab caused an accumulation of autophagy proteins and the cleavage of the active caspases 8 and 3. Interestingly, only panobinostat and atezolizumab were able to exacerbate the autophagy process by increasing the synthesis, the maturation and final fusion with the lysosomes of the autophagosome vesicles. Despite ATC cells could be sensitized by atezolizumab via the cleavage of the caspases, no reduction of cell proliferation or promotion of cell death was observed. The apoptosis assay evidenced the ability of panobinostat alone and in combination with atezolizumab to induce the phosphatidil serine exposure (early apoptosis) and further the secondary necrosis. Instead, sorafenib was only able to cause necrosis. The increase of caspases activity induced by atezolizumab, the apoptosis and autophagy processes promoted by panobinostat synergize thus promoting cell death in well-established and primary anaplastic thyroid cancer cells. The combined therapy could represent a future clinical application for the treatment of such lethal and untreatable solid cancer.

Exploiting Autophagy-Dependent Neoantigen Presentation in Tumor Microenvironment

Autophagy constitutes a well-known homeostatic and catabolic process that is responsible for degradation and recycling of cellular components. It is a key regulatory mechanism for several cellular functions, whereas its dysregulation is associated with tumorigenesis, tumor-stroma interactions and resistance to cancer therapy. A growing body of evidence has proven that autophagy affects the tumor microenvironment, while it is also considered a key factor for function of several immune cells, such as APCs, T-cells, and macrophages. Moreover, it is implicated in presentation of neo-antigens of tumor cells in both MHC-I and MHC-II in dendritic cells (DCs) in functional activity of immune cells by creating T-cell memory, as well as in cross-presentation of neo-antigens for MHC-I presentation and the internalization process. Currently, autophagy has a crucial role in immunotherapy. Emergence of cancer immunotherapy has already shown some remarkable results, having changed therapeutic strategy in clinical practice for several cancer types. Despite these promising long-term responses, several patients seem to lack the ability to respond to immune checkpoint inhibitors. Thus, autophagy through neo-antigen presentation is a potential target in order to strengthen or attenuate the effects of immunotherapy against different types of cancer. This review will shed light on the recent advances and future directions of autophagy-dependent neo-antigen presentation and consequently its role in immunotherapy for malignant tumors.

Systems biology of autophagy in leishmanial infection and its diverse role in precision medicine

Autophagy is a contentious issue in leishmaniasis and is emerging as a promising therapeutic regimen. Published research on the impact of autophagic regulation on Leishmania survival is inconclusive, despite numerous pieces of evidence that Leishmania spp. triggers autophagy in a variety of cell types. The mechanistic approach is poorly understood in the Leishmania parasite as autophagy is significant in both Leishmania and the host. Herein, this review discusses the autophagy proteins that are being investigated as potential therapeutic targets, the connection between autophagy and lipid metabolism, and microRNAs that regulate autophagy and lipid metabolism. It also highlights the use of systems biology to develop novel autophagy-dependent therapeutics for leishmaniasis by utilizing artificial intelligence (AI), machine learning (ML), mathematical modeling, network analysis, and other computational methods. Additionally, we have shown many databases for autophagy and metabolism in Leishmania parasites that suggest potential therapeutic targets for intricate signaling in the autophagy system. In a nutshell, the detailed understanding of the dynamics of autophagy in conjunction with lipids and miRNAs unfolds larger dimensions for future research.

Dostarlimab an Inhibitor of PD-1/PD-L1: A New Paradigm for the Treatment of Cancer

Immunomodulation checkpoints usually adopted by healthy cells by tumors might cause an imbalance between host surveillance and tumor progression. Several tumors are incredibly resistant to standard treatment. The dynamic and long-lasting tumor regressions caused by antibodies targeting the PD-1/PD-L1 checkpoint have suggested a rebalancing of the host-tumor relationship. Checkpoint antibody inhibitors, like anti-PD-1/PD-L1, are unique inhibitors that reduce tumor growth by modulating the interaction between immune cells and tumor cells. These checkpoint inhibitors are swiftly emerging as a highly promising strategy for treating cancer because they produce impressive antitumor responses while having a limited number of adverse effects. Over the past several years, numerous checkpoint antibody inhibitors pointing to PD-1, PDL-1, and CTLA-4 have been available on the market. Despite its enormous success and usefulness, the anti-PD treatment response is restricted to certain kinds of cancer. This restriction can be attributed to the inadequate and diverse PD-1 expression in the tumor (MET) micro-environment. Dostarlimab (TSR-042), a drug that interferes with the PD-1/PD-L1 pathway, eliminates a crucial inhibitory response of an immune system and, as a result, has the potential to cause severe or deadly immune-mediated adverse effects. As cancer immunotherapy, dostarlimab enhances the antitumor immune response of the body.

Autophagy in Cancer Immunotherapy

Autophagy is a stress-induced process that eliminates damaged organelles and dysfunctional cargos in cytoplasm, including unfolded proteins. Autophagy is involved in constructing the immunosuppressive microenvironment during tumor initiation and progression. It appears to be one of the most common processes involved in cancer immunotherapy, playing bidirectional roles in immunotherapy. Accumulating evidence suggests that inducing or inhibiting autophagy contributes to immunotherapy efficacy. Hence, exploring autophagy targets and their modifiers to control autophagy in the tumor microenvironment is an emerging strategy to facilitate cancer immunotherapy. This review summarizes recent studies on the role of autophagy in cancer immunotherapy, as well as the molecular targets of autophagy that could wake up the immune response in the tumor microenvironment, aiming to shed light on its immense potential as a therapeutic target to improve immunotherapy.

The role of autophagy in colorectal cancer: Impact on pathogenesis and implications in therapy

Colorectal cancer (CRC) is considered as a global major cause of cancer death. Surgical resection is the main line of treatment; however, chemo-, radiotherapy and other adjuvant agents are crucial to achieve good outcomes. The tumor microenvironment (TME) is a well-recognized key player in CRC progression, yet the processes linking the cancer cells to its TME are not fully delineated. Autophagy is one of such processes, with a controversial role in the pathogenesis of CRC, with its intricate links to many pathological factors and processes. Autophagy may apparently play conflicting roles in carcinogenesis, but the precise mechanisms determining the overall direction of the process seem to depend on the context. Additionally, it has been established that autophagy has a remarkable effect on the endothelial cells in the TME, the key substrate for angiogenesis that supports tumor metastasis. Favorable response to immunotherapy occurs only in a specific subpopulation of CRC patients, namely the microsatellite instability-high (MSI-H). In view of such limitations of immunotherapy in CRC, modulation of autophagy represents a potential adjuvant strategy to enhance the effect of those relatively safe agents on wider CRC molecular subtypes. In this review, we discussed the molecular control of autophagy in CRC and how autophagy affects different processes and mechanisms that shape the TME. We explored how autophagy contributes to CRC initiation and progression, and how it interacts with tumor immunity, hypoxia, and oxidative stress. The crosstalk between autophagy and the TME in CRC was extensively dissected. Finally, we reported the clinical efforts and challenges in combining autophagy modulators with various cancer-targeted agents to improve CRC patients’ survival and restrain cancer growth.

Everolimus (RAD001) combined with programmed death-1 (PD-1) blockade enhances radiosensitivity of cervical cancer and programmed death-ligand 1 (PD-L1) expression by blocking the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/S6 kinase 1 (S6K1) pathway

Cervical cancer (CC) is the 4^th most prevalent malignancy in females. This study explored the mechanism of everolimus (RAD001) combined with programmed death-1 (PD-1) blockade on radiosensitivity by phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and autophagy in CC cells. Low-radiosensitive CaSki cells were selected as study objects. After RAD001 treatment, PI3K/AKT/mTOR pathway activation, autophagy, migration and invasion abilities, autophagy-related proteins (LC3-I, LC3-II, and p62), and PD-L1 expression in CC cells were detected. After triple treatment of radiotherapy (RT), RAD001, and PD-1 blockade to the CC mouse models, tumor weight and volume were recorded. Ki67 expression, the number of CD8 + T cells, and the ability to produce IFN-γ and TNF-α in tumor tissues were determined. RAD001 promoted autophagy by repressing PI3K/AKT/mTOR pathway, augmented RT-induced apoptosis, and weakened migration and invasion, thereby increasing CC cell radiosensitivity. RAD001 elevated RT-induced PD-L1 level. RT combined with RAD001 and PD-1 blockade intensified the inhibitory effect of RT on tumor growth, reduced the amount of Ki67-positive cells, enhanced radiosensitivity of CC mice, and increased the quantity and killing ability of CD8 + T cells. Briefly, RAD001 combined with PD-1 blockade increases radiosensitivity of CC by impeding the PI3K/AKT/mTOR pathway and potentiating cell autophagy.

The Comprehensive Analysis Identified an Autophagy Signature for the Prognosis and the Immunotherapy Efficiency Prediction in Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is a fatal malignancy in the world. Growing evidence demonstrated that autophagy-related genes regulated the immune cell infiltration and correlated with the prognosis of LUAD. However, the autophagy-based signature that can predict the prognosis and the efficiency of checkpoint immunotherapy in LUAD patients is yet to be discovered.

Methods

We used conventional autophagy-related genes to screen candidates for signature construction in TCGA cohort and 9 GEO datasets (tumor samples, n=2181; normal samples, n=419). An autophagy-based signature was constructed, its correlation with the prognosis and the immune infiltration of LUAD patients was explored. The prognostic value of the autophagy-based signature was validated in an independent cohort with 70 LUAD patients. Single-cell sequencing data was used to further characterize the various immunological patterns in tumors with different signature levels. Moreover, the predictive value of autophagy-based signature in PD-1 immunotherapy was explored in the IMvigor210 dataset. At last, the protective role of DRAM1 in LUAD was validated by in vitro experiments.

Results

After screening autophagy-related gene candidates, a signature composed by CCR2, ITGB1, and DRAM1 was established with the ATscore in each sample. Further analyses showed that the ATscore was significantly associated with immune cell infiltration and low ATscore indicated poor prognosis. Meanwhile, the prognostic value of ATscore was validated in our independent LUAD cohort. GSEA analyses and single-cell sequencing analyses revealed that ATscore was associated with the immunological status of LUAD tumors, and ATscore could predict the efficacy of PD-1 immunotherapy. Moreover, in vitro experiments demonstrated that the inhibition of DRAM1 suppressed the proliferation and migration capacity of LUAD cells.

Conclusion

Our study identified a new autophagy-based signature that can predict the prognosis of LUAD patients, and this ATscore has potential applicative value in the checkpoint therapy efficiency prediction.

Intracellular pH-mediated induction of apoptosis in HeLa cells by a sulfonamide carbonic anhydrase inhibitor

Carbonic anhydrase IX (CAIX) is a hypoxia-associated transmembrane protein that is critical in the survival of cells. Because CAIX has a key role in pH regulation, its therapeutic effects have been heavily studied by different research laboratories. This study aims to investigate how a synthetic CAIX inhibitor triggers apoptosis in a cancer cell line, HeLa. In this regard, we investigated the effects of the compound I, synthesized as a CAIX inhibitor, on the survival of cancer cells. The compound I inhibited the proliferation of the CAIX+ HeLa cells, kept the cells in G0/G1 phase (74.7%) and altered the cells morphologies (AO/EtBr staining) and the nuclear structure (γ-H2AX staining). CAIX inhibition triggered apoptosis in HeLa cells with a rate of 47.4%. According to the expression of mediator genes (CASP-3, -8, -9, BAX, BCL-2, BECLIN, LC3), the both death pathways were activated in HeLa cells with the inhibition of CAIX with the compound I. The compound I was also determined to affect the genes and proteins that have a critical role in the regulation of apoptotic pathways (pro casp-3, cleaved casp-3, -8, -9, cleaved PARP and CAIX). Furthermore, CAIX inhibition caused changes in pH balance, disruption in organelle integrity of mitochondria, and increase intracellular reactive oxygen level of HeLa cells. Taken together, our findings suggest that CAIX inhibition has a potential in cancer treatment, and the compound I, a CAIX inhibitor, could be a promising therapeutic strategy in the treatment of aggressive tumours.

PD-L1 and PD-L2 Mutations in Pediatric Hodgkin Lymphoma: Do They Have Any Prognostic Significance?

Background: Reed-Sternberg cells can escape from the immune system by enhancement of the expression of PD-L1 and PD-L2. Objectives: The aim of the present study was to investigate the significance PD-L1 and PD-L2 gene mutations in childhood Hodgkin Lymphoma's (HL). Methods: The study included 39 pediatric classical HL cases. PD-L1 and PD-L2 mutations were determined by Sanger sequencing. Clinicopathological parameters were obtained from patients' records. Results: Eight cases (20.5%) showed p.R260C mutations, and three (7.7%) p.R234L in the exome 5 of PD-L1 gene. None of the cases had PD-L2 mutations. p.R260C mutation exhibited a significant relationship with older age and nodular sclerosing (NS) histology and was associated with longer event free survival. Conclusions: Although PD-L1 mutational status did not show statistically significance with well-established prognostic factors, our preliminary data indicate that p.R260C mutation of PD-L1 gene may be associated with longer event free survival in older patients and NS histology in pediatric HL.

Immunotherapy and Systemic Treatment of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinomas (cSCC) represent one of the most diagnosed non-melanoma skin cancers and its incidence is increasing globally. Whereas early stage and low risk cSCC is typically treated with surgery, and in some cases other localized therapeutic modalities, locally advanced or metastatic cSCC is a cause of significant morbidity and mortality that requires a different approach to therapy. Therapeutic attempts at treating advanced cSCC include a multi-disciplinary approach with considerations for surgery, radiation, and systemic therapies. In this review, we will discuss the various systemic therapies that have been trialed for advanced cSCC, beginning with the early cytotoxic and platinum-based agents as well as their corresponding limitations. We will then review the targeted approaches using EGFR inhibitors prior to discussing the more recent immunotherapeutics that have shown good tumor responses in this often-lethal disease.

At the Cutting Edge against Cancer: A Perspective on Immunoproteasome and Immune Checkpoints Modulation as a Potential Therapeutic Intervention

Immunoproteasome is a noncanonical form of proteasome with enzymological properties optimized for the generation of antigenic peptides presented in complex with class I MHC molecules. This enzymatic property makes the modulation of its activity a promising area of research. Nevertheless, immunotherapy has emerged as a front-line treatment of advanced/metastatic tumors providing outstanding improvement of life expectancy, even though not all patients achieve a long-lasting clinical benefit. To enhance the efficacy of the currently available immunotherapies and enable the development of new strategies, a broader knowledge of the dynamics of antigen repertoire processing by cancer cells is needed. Therefore, a better understanding of the role of immunoproteasome in antigen processing and of the therapeutic implication of its modulation is mandatory. Studies on the potential crosstalk between proteasome modulators and immune checkpoint inhibitors could provide novel perspectives and an unexplored treatment option for a variety of cancers.

Advances and Limitations of Antibody Drug Conjugates for Cancer

The popularity of antibody drug conjugates (ADCs) has increased in recent years, mainly due to their unrivalled efficacy and specificity over chemotherapy agents. The success of the ADC is partly based on the stability and successful cleavage of selective linkers for the delivery of the payload. The current research focuses on overcoming intrinsic shortcomings that impact the successful development of ADCs. This review summarizes marketed and recently approved ADCs, compares the features of various linker designs and payloads commonly used for ADC conjugation, and outlines cancer specific ADCs that are currently in late-stage clinical trials for the treatment of cancer. In addition, it addresses the issues surrounding drug resistance and strategies to overcome resistance, the impact of a narrow therapeutic index on treatment outcomes, the impact of drug-antibody ratio (DAR) and hydrophobicity on ADC clearance and protein aggregation.

Unique integrated stress response sensors regulate cancer cell susceptibility when Hsp70 activity is compromised

Molecular chaperones, such as Hsp70, prevent proteotoxicity and maintain homeostasis. This is perhaps most evident in cancer cells, which overexpress Hsp70 and thrive even when harboring high levels of misfolded proteins. To define the response to proteotoxic challenges, we examined adaptive responses in breast cancer cells in the presence of an Hsp70 inhibitor. We discovered that the cells bin into distinct classes based on inhibitor sensitivity. Strikingly, the most resistant cells have higher autophagy levels, and autophagy was maximally activated only in resistant cells upon Hsp70 inhibition. In turn, resistance to compromised Hsp70 function required the integrated stress response transducer, GCN2, which is commonly associated with amino acid starvation. In contrast, sensitive cells succumbed to Hsp70 inhibition by activating PERK. These data reveal an unexpected route through which breast cancer cells adapt to proteotoxic insults and position GCN2 and autophagy as complementary mechanisms to ensure survival when proteostasis is compromised.

Long non-coding RNAs XIST and MALAT1 hijack the PD-L1 regulatory signaling pathway in breast cancer subtypes

Long non-coding RNAs (lncRNAs) have attracted widespread attention as potential biological and pathological regulators. lncRNAs are involved in several biological processes in cancer. Triple negative breast cancer (TNBC) is characterized by strong heterogeneity and aggressiveness. At present, the implication of microRNAs (miRs) and lncRNAs in immunotherapy has been poorly studied. Nevertheless, the blockade of immune checkpoints, particularly that of the programmed cell-death protein-1/programmed cell-death ligand-1 (PD-L1) axis, is considered as a principle approach in breast cancer (BC) therapy. The present study aimed to investigate the interaction between immune-modulatory upstream signaling pathways of the PD-L1 transcript that could enhance personalized targeted therapy. MDA-MB-231 cells were transfected with miR-182-5p mimics followed by RNA extraction and cDNA synthesis using a reverse transcription kit, and the expression levels of the target genes were assessed by reverse transcription-quantitative PCR. Furthermore, the expression levels of target genes were measured in tissues derived from 41 patients with BC, including patients with luminal BC and TNBC, as well as their adjacent lymph nodes. The results revealed that the expression levels of miR-182-5p, PD-L1 and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) were upregulated in MDA-MB-231 cells and BC tissues. However, X-inactive specific transcript (XIST) expression was downregulated in cancer tissues and TNBC cells. Following co-transfection of cells with small interfering RNAs specific for each target gene and miR-182-5p antagomirs, the effect of miR-182-5p was abolished in the presence of lncRNAs. Therefore, the results of the present study indicated that although miR-182-5p exhibited an oncogenic effect, XIST exerted a dominant effect on the regulation of the PD-L1 signaling pathway via the inhibition of the oncogenic function of MALAT1.

Emerging principles of brain immunology and immune checkpoint blockade in brain metastases

Brain metastases are the most common type of brain tumours, harbouring an immune microenvironment that can in principle be targeted via immunotherapy. Elucidating some of the immunological intricacies of brain metastases has opened a therapeutic window to explore the potential of immune checkpoint inhibitors in this globally lethal disease. Multiple lines of evidence suggest that tumour cells hijack the immune regulatory mechanisms in the brain for the benefit of their own survival and progression. Nonetheless, the role of the immune checkpoint in the complex interplays between cancers cells and T cells and in conferring resistance to therapy remains under investigation. Meanwhile, early phase trials with immune checkpoint inhibitors have reported clinical benefit in patients with brain metastases from melanoma and non-small cell lung cancer. In this review, we explore the workings of the immune system in the brain, the immunology of brain metastases, and the current status of immune checkpoint inhibitors in the treatment of brain metastases.

Emerging role of autophagy in anti-tumor immunity: Implications for the modulation of immunotherapy resistance

Immunotherapies such as CAR-T cell transfer and antibody-targeted therapy have produced promising clinical outcomes in patients with advanced and metastatic cancer that are resistant to conventional therapies. However, with increasing use of cancer immunotherapy in clinical treatment, multiple therapy-resistance mechanisms have gradually emerged. The tumor microenvironment (TME), an integral component of cancer, can significantly influence the therapeutic response. Thus, it is worth exploring the potential of TME in modulating therapy resistance, in the hope to devise novel strategies to reinforcing anti-cancer treatments such as immunotherapy. As a crucial recycling process in the complex TME, the role of autophagy in tumor immunity has been increasingly appreciated. Firstly, autophagy in tumor cells can affect their immune response through modulating MHC-I-antigen complexes, thus modulating immunogenic tumor cell death, changing functions of immune cells via secretory autophagy, reducing the NK- and CTL-mediated cell lysis and degradation of immune checkpoint proteins. Secondly, autophagy is critical for the differentiation, maturation and survival of immune cells in the TME and can significantly affect the immune function of these cells, thereby regulating the anti-tumor immune response. Thirdly, alteration of autophagic activity in stromal cells, especially in fibroblasts, can reconstruct the three-dimensional stromal environment and metabolic reprogramming in the TME. A number of studies have demonstrated that optimal induction or inhibition of autophagy may lead to effective therapeutic regimens when combined with immunotherapy. This review discusses the important roles of autophagy in tumor cells, immune cells and stromal cells in the context of tumor immunity, and the potential of combining the autophagy-based therapy with immunotherapy as novel therapeutic approaches against cancer.

Therapy in Advanced Hepatocellular Carcinoma

Treatment of advanced hepatocellular carcinoma (HCC) is challenging. Several randomized clinical trials are investigating the efficacy of systemic therapy, immunotherapy, and locoregional therapy as monotherapy or combined with other modalities in the treatment of HCC. Systemic therapy is the preferred treatment in advanced disease. To date, multiple first-line and second-line agents received Food and Drug Administration approval. For over a decade, sorafenib was the only first-line agent. In May 2020, combination of atezolizumab and bevacizumab has been approved as a first-line systemic regimen. Lenvatinib is another first-line agent that has multikinase activity. Second-line agents include cabozantinib, regorafenib, ramucirumab, and nivolumab. Adoptive cell transfer therapy is a highly specific immunotherapy that has shown antitumor activity against HCC. Oncolytic viruses are genetically modified viruses that infect cancer cells and induce apoptosis. Locoregional therapies such as transarterial chemoembolization and radioembolization have shown a potential benefit in selected patients with advanced HCC. In this review, we aim to summarize the treatment options available for advanced HCC.

Emerging Autophagy Functions Shape the Tumor Microenvironment and Play a Role in Cancer Progression - Implications for Cancer Therapy

The tumor microenvironment (TME) is a complex environment where cancer cells reside and interact with different types of cells, secreted factors, and the extracellular matrix. Additionally, TME is shaped by several processes, such as autophagy. Autophagy has emerged as a conserved intracellular degradation pathway for clearance of damaged organelles or aberrant proteins. With its central role, autophagy maintains the cellular homeostasis and orchestrates stress responses, playing opposite roles in tumorigenesis. During tumor development, autophagy also mediates autophagy-independent functions associated with several hallmarks of cancer, and therefore exerting several effects on tumor suppression and/or tumor promotion mechanisms. Beyond the concept of degradation, new different forms of autophagy have been described as modulators of cancer progression, such as secretory autophagy enabling intercellular communication in the TME by cargo release. In this context, the synthesis of senescence-associated secretory proteins by autophagy lead to a senescent phenotype. Besides disturbing tumor treatment responses, autophagy also participates in innate and adaptive immune signaling. Furthermore, recent studies have indicated intricate crosstalk between autophagy and the epithelial-mesenchymal transition (EMT), by which cancer cells obtain an invasive phenotype and metastatic potential. Thus, autophagy in the cancer context is far broader and complex than just a cell energy sensing mechanism. In this scenario, we will discuss the key roles of autophagy in the TME and surrounding cells, contributing to cancer development and progression/EMT. Finally, the potential intervention in autophagy processes as a strategy for cancer therapy will be addressed.

Pathogenesis of Human Immunodeficiency Virus-Mycobacterium tuberculosis Co-Infection

Given that infection with Mycobacterium tuberculosis (Mtb) is the leading cause of death amongst individuals living with HIV, understanding the complex mechanisms by which Mtb exacerbates HIV infection may lead to improved treatment options or adjuvant therapies. While it is well-understood how HIV compromises the immune system and leaves the host vulnerable to opportunistic infections such as Mtb, less is known about the interplay of disease once active Mtb is established. This review explores how glutathione (GSH) depletion, T cell exhaustion, granuloma formation, and TNF-α upregulation, as a result of Mtb infection, leads to an increase in HIV disease severity. This review also examines the difficulties of treating coinfected patients and suggests further research on the clinical use of GSH supplementation.

The relationships between PD-L1 expression, CD8+ TILs and clinico-histomorphological parameters in malignant melanomas

INTRODUCTION

Malignant melanomas (MM) are often connected with the expression of PD-L1 protein and the presence of tumor-infiltrating lymphocytes (TILs), however, their impact on prognosis remains controversial. Due to their supposed clinical significance and lack of convincing data, we decided to establish the relationships between CD8 + TIL count, PD-L1 level and certain clinical and histopathological parameters in patients with malignant melanoma, especially those associated with unfavorable prognosis.

MATERIALS AND METHODS

We performed immunohistochemistry for PD-L1 and CD8 on 56 formalin-fixed paraffin-embedded specimens from patients with cutaneous and metastatic malignant melanomas. PD-L1 expression levels were determined by immunohistochemistry (clone 28-8) and subsequently the tumor proportion scores (TPS) were evaluated. CD8 + TIL expressions were classified as either grade 0, 1+, 2+ or 3+, based on the density and distribution of the infiltrating lymphocytes.

RESULTS

The PD-L1 expression was detected in 20 out of 56 cases (35,71 %). The expression of PD-L1 on tumor cells was significantly increased with higher TILs infiltration in the tumor microenvironment (p = 0,038). Lower TIL score corresponds with poor prognostic clinicopathological parameters such as higher number of mitotic figures (p = 0,005), Clark's level (p = 0,007) and Breslow's depth (p = 0,010).

CONCLUSIONS

Our results suggest a favorable prognostic value for CD8 + TIL infiltration. Moreover, TIL density was strongly correlated and geographically associated to PD-L1 expression. This analysis provides more insight into the role of TIL count and PD-L1 level in MM and their relationship with each other and association with other prognostic indicators.

LncRNA LINC00265/miR-485-5p/IRF2-mediated autophagy suppresses apoptosis in acute myeloid leukemia cells

BACKGROUND

Extensive studies have shown that long non-coding RNAs (lncRNAs) play important roles in multiple cancers. The present study aimed to investigate the role and mechanism of lncRNA LINC00265 in the regulation of apoptosis in acute myeloid leukemia (AML) cells.

METHODS

Gain- or loss-of-function experiments were conducted in AML cells to explore the effect of LINC00265 on AML. Autophagy was assessed by examining levels of Beclin-1, p62, and ratio of LC3-II/LC3-I. Cell proliferation and apoptosis of AML cells were evaluated by CCK-8 assay and flow cytometry, respectively. RNA pull-down was performed to enrich miR-485-5p interacted with LINC00265. The interaction between miR-485-5p and IRF2 3'UTR was analyzed by luciferase reporter assay.

RESULTS

LINC00265 expression was significantly up-regulated, whereas miR-485-5p was down-regulated in serum of AML patients and AML cell lines. LINC00265 promoted, whereas miR-485-5p suppressed autophagy in AML cells. Mechanistically, LINC00265 functioned as a ceRNA for miR-485-5p to facilitate IRF2 expression. More importantly, LINC00265 overexpression or miR-485-5p inhibitor reversed the 3-methyladenine (3-MA, an autophagy inhibitor)-mediated proliferation-inhibitory and pro-apoptotic effects, whereas LINC00265 silencing or miR-485-5p mimic overturned the proliferation-promoting and anti-apoptotic effects of autophagy activator rapamycin.

CONCLUSION

LINC00265 attenuates AML cell apoptosis by inducing autophagy via miR-485/IRF2 axis.

Profiles of PD-1, PD-L1, PD-L2 in Gastric Cancer and Their Relation with Mutation, Immune Infiltration, and Survival

Background

Although multiple types of cancers demonstrated favorable outcome after immunotherapy of PD-1/PD-L1 blockade, the specific regulatory mechanism of PD genes in gastric cancer (GC) remains largely unknown.

Materials and Methods

Expression of RNA, copy number variants, and clinical parameters of GC individuals from TCGA were analyzed. Coexpressed genes for PD-1, PD-L1, and PD-L2 were selected by correlation analysis and confirmed by STRING. Gene Ontology and KEGG pathway analyses were performed by clusterProfiler. The influence of PD-1/PD-L1/PD-L2 on immune cell infiltration was investigated by MCP-counter.

Results

PD-L2 demonstrated significant relation with clinical stage of GC (P = 0.043). Survival analysis showed that PD-1 expression was correlated with better prognosis of GC patients (HR = 0.70, P = 0.031), but PD-L2 expression was related with worse survival (HR = 1.42, P = 0.032). Mutation of PIK3CA could alter the level of PD-1, PD-L1, and PD-L2 (P < 0.001), and TP53 mutation demonstrated significant correlation with PD-L1 (P = 0.015) and PD-L2 (P = 0.014) expression. Enrichment analysis of PD-1/PD-L1/PD-L2 coexpressed genes indicated a biological process of mononuclear cell proliferation, leukocyte cell-cell adhesion, and lymphocyte activation as well as KEGG pathways including cell differentiation of Th1 and Th2, cell differentiation of Th17, and hematopoietic cell landscape. As for immune infiltration analysis, PD-1 was mainly related with cytotoxic lymphocytes and endothelial cells; PD-L1 were associated with monocytic lineage; PD-L2 showed significant correlation with myeloid dendritic cells.

Conclusion

PD-1 expression showed association with better prognosis of GC, and PD-L2 expression was related with worse survival. Mutations of PIK3CA and TP53 significantly correlated with PD-1/PD-L1/PD-L2 axis. PD-1/PD-L1/PD-L2 coexpressed genes demonstrated enrichment in mononuclear cell proliferation, leukocyte cell-cell adhesion, and lymphocyte activation as well as KEGG pathways including cell differentiation of Th1, Th2, and Th17.

Clinical characteristics and PD-L1 expression in primary lung squamous cell carcinoma: A case series

Background

Squamous cell lung carcinoma(SCLC), accounts for 20% of lung cancer(LC). The binding of programmed cell death 1(PD-1) to its ligand PD-L1 is a key checkpoint regulator of immune response, and overexpression of the latter leads to immune surveillance escape. This might represent an important oncogenic mechanism, as well as a predictor for immunotherapy treatment success in SCLC.

Methods

A retrospective series of 24 patients with SCLC was included(2009–2013). These patients presented with a single pulmonary lesion and no history of previous cancer. Expression of PD-L1 was evaluated on tumoral biopsies with immunohistochemistry. PD-L1 tumor proportion score(TPS) was considered high when ≥50%. Clinical characteristics regarding diagnosis were reviewed and recorded. Data were analysed in STATA v.14®.

Results

Twenty four patients were included in this series. Mean age was 67 + 14 years, and 62.5% were men. Smoking status was positive in 54%. Cancer stage IV was present in 54%. PD-L1 was positive in 13(54%). (+)PD-L1 was more frequent in smokers than in non-smokers(11 vs 2)(p = 0.001), as well as in COPD patients(p = 0.006). General overall survival was 21.8% at 5 years. Overall survival at one year in PD-L1(+) was 30.7% and 72.7% for PD-L1(-) patients. Survival median for PD-L1(+) patients was 10.5mo, as well as for the whole series.

Conclusion

Patients with primary SCLC who have a high PD-L1 TPS, had a worse overall survival than their counterparts. PD-L1 expression in SCLC in a Colombian sample lies between the one found in the literature.

Autophagy in cancer: Recent advances and future directions

Autophagy is being explored as a potential therapeutic target for enhancing the cytotoxic effects of chemotherapeutic regimens in various malignancies. Autophagy plays a very important role in cancer pathogenesis. Here, we discuss the updates on the modulation of autophagy via dynamic interactions with different organelles and the exploitation of selective autophagy for exploring therapeutic strategies. We further discuss the role of autophagy inhibitors in cancer preclinical and clinical trials, novel autophagy inhibitors, and challenges likely to be faced by clinicians while inducting autophagy modulators in clinical practice.

Autophagy-related genes prognosis signature as potential predictive markers for immunotherapy in hepatocellular carcinoma

Autophagy-related genes (ATGs) depress tumorigenesis. However, in tumor tissue, it promotes tumor progression. Here, we demonstrated that 63 ATGs were differentially expressed in normal tissues and tumor tissues of hepatocellular carcinoma (HCC), and seven prognostic-related genes were chosen to establish prognostic risk signatures. It is not just an independent prognostic factor for HCC, but also closely related to the degree of malignancy of HCC. Further, the hallmarks of PI3K–AKT–mTOR signaling was significantly enriched in the high-risk group. Moreover, AKT–pS473 and mTOR–pS2448 expression was down-regulated and correlated with patient prognosis in high-risk group. Finally, we demonstrate that the prognosis signature of ATGs is closely related to immune cell infiltration and PD-L1 expression. In conclusion, ATGs are a crucial factor in the malignant progression of HCC and will be a new prognostic marker for diagnosis and treatment. ATGs prognostic signatures are potentially useful for predicting PD-L1 therapeutic effects.

Autophagy in the Immunosuppressive Perivascular Microenvironment of Glioblastoma

Glioblastoma (GB) has been shown to up-regulate autophagy with anti- or pro-oncogenic effects. Recently, our group has shown how GB cells aberrantly up-regulate chaperone-mediated autophagy (CMA) in pericytes of peritumoral areas to modulate their immune function through cell-cell interaction and in the tumor’s own benefit. Thus, to understand GB progression, the effect that GB cells could have on autophagy of immune cells that surround the tumor needs to be deeply explored. In this review, we summarize all the latest evidence of several molecular and cellular immunosuppressive mechanisms in the perivascular tumor microenvironment. This immunosuppression has been reported to facilitate GB progression and may be differently modulated by several types of autophagy as a critical point to be considered for therapeutic interventions.

Interrupting cyclic dinucleotide-cGAS-STING axis with small molecules

The cyclic dinucleotide-cGAS-STING axis plays important roles in host immunity. Activation of this signaling pathway, via cytosolic sensing of bacterial-derived c-di-GMP/c-di-AMP or host-derived cGAMP, leads to the production of inflammatory interferons and cytokines that help resolve infection. Small molecule activators of the cGAS-STING axis have the potential to augment immune response against various pathogens or cancer. The aberrant activation of this pathway, due to gain-of-function mutations in any of the proteins that are part of the signaling axis, could lead to various autoimmune diseases. Inhibiting various nodes of the cGAS-STING axis could provide relief to patients with autoimmune diseases. Many excellent reviews on the cGAS-STING axis have been published recently, and these have mainly focused on the molecular details of the cGAS-STING pathway. This review however focuses on small molecules that can be used to modulate various aspects of the cGAS-STING pathway, as well as other parallel inflammatory pathways.

The dual roles of autophagy in gliomagenesis and clinical therapy strategies based on autophagic regulation mechanisms

Autophagy, a self-digestion intracellular catabolic process, plays a crucial role in cellular homeostasis under conditions of starvation, oxidative stress and genotoxic stress. The capability of maintaining homeostasis contributes to preventing malignant behavior in normal cells. Many studies have provided compelling evidence that autophagy is involved in brain tumor recurrence and chemotherapy and radiotherapy resistance. Gliomas, as the primary central nervous system (CNS) tumors, are characterized by rapid, aggressive growth and recurrence and have a poor prognosis and bleak outlook even with modern multimodality strategies involving maximal surgical resection, radiotherapy and alkylating agent-based chemotherapy. Autophagy-associated signaling pathways, such as the extracellular signal-regulated kinase1/2 (ERK1/2) pathway, class I phosphatidylinositol 3-phosphate kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway and nuclear factor kappa-B (NF-κB) pathway, act as tumor suppressors or protect tumor cells against chemotherapy/radiotherapy-induced cytotoxicity in gliomagenesis. Through these pathways, both lethal autophagy and protective autophagy play crucial roles in tumor initiation, chemoresistance and glioma stem cell differentiation. Moreover, lethal autophagy and protective autophagy have been identified as novel therapeutic targets in glioma according to the mechanisms described above. Here, we discuss the multiple impacts of the autophagic response on distinct phases of gliomagenesis and the advanced progress of therapies based on this concept.

On the Horizon: Targeting Next-Generation Immune Checkpoints for Cancer Treatment

BACKGROUND

Immune checkpoints are critical regulatory pathways of the immune system which finely tune the response to biological threats. Among them, the CD-28/CTLA-4 and PD-1/PD-L1 axes play a key role in tumour immune escape and are well-established targets of cancer immunotherapy.

SUMMARY

The clinical experience accumulated to date provides unequivocal evidence that anti-CTLA-4, PD-1, or PD-L1 monoclonal antibodies, used as monotherapy or in combination regimes, are effective in a variety of advanced/metastatic types of cancer, with improved clinical outcomes compared to conventional chemotherapy. However, the therapeutic success is currently restricted to a limited subset of patients and reliable predictive biomarkers are still lacking. Key Message: The identification and characterization of additional co-inhibitory pathways as novel pharmacological targets to improve the clinical response in refractory patients has led to the development of different immune checkpoint inhibitors, the activities of which are currently under investigation. In this review, we discuss recent literature data concerning the mechanisms of action of next-generation monoclonal antibodies targeting LAG-3, TIM-3, and TIGIT co-inhibitory molecules that are being explored in clinical trials, as single agents or in combination with other immune-stimulating agents.

PD-L1 Expression and Its Regulation in Lung Adenocarcinoma with ALK Translocation

BACKGROUND

The mechanism of regulation of PD-L1 expression by ALK translocation remains unclear. We detected PD-L1 protein expression and its regulation in lung adenocarcinoma patients with EML4-ALK fusion gene.

METHODS

PD-L1 and ALK expression at protein level in human lung adenocarcinoma cell lines and tumor tissue specimens was evaluated by immunohistochemistry analysis and Western blotting. The expression at DNA level and RNA level was indicated by quantitative real-time PCR analysis. The signal pathway was indicated at protein level by western blotting.

RESULTS

The PD-L1 protein expression was higher in human lung adenocarcinoma cell lines with EML4-ALK fusion gene than that without this fusion gene. Induced expression of EML4-ALK in A549 cells significantly increased PD-L1 protein expression, whereas PD-L1 protein expression was downregulated after crizotinib and pembrolizumab successively. Significant positive correlations between PD-L1 and p-ERK, p-STAT3 or p-AKT expression were observed in ALK-translocated tumors. PD-L1 overexpression was significantly associated with shorter progressive survival and overall survival after crizotinib in ALK-translocated patients.

CONCLUSIONS

We demonstrate that ALK translocation can upregulate PD-L1 expression by activating ERK, STAT3 and AKT pathways. ALK inhibitor combined with a PD-L1-targeted therapy may be a potential strategy in ALK-translocated lung adenocarcinoma patients.

Modulation of autophagy in human diseases strategies to foster strengths and circumvent weaknesses

Autophagy is central to the maintenance of intracellular homeostasis across species. Accordingly, autophagy disorders are linked to a variety of diseases from the embryonic stage until death, and the role of autophagy as a therapeutic target has been widely recognized. However, autophagy-associated therapy for human diseases is still in its infancy and is supported by limited evidence. In this review, we summarize the landscape of autophagy-associated diseases and current autophagy modulators. Furthermore, we investigate the existing autophagy-associated clinical trials, analyze the obstacles that limit their progress, offer tactics that may allow barriers to be overcome along the way and then discuss the therapeutic potential of autophagy modulators in clinical applications.