Resistance Mechanisms to Immune-Checkpoint Blockade in Cancer: Tumor-Intrinsic and -Extrinsic Factors

Reduced EO771-induced tumour growth and increased overall-survival of mice ablated for immune cell-specific catalytic subunit Cβ2 of protein kinase A

Ablation of the immune-specific catalytic subunit Cβ2 of protein kinase A is associated with a proinflammatory phenotype and increased sensitivity to autoimmunity in mice. Here we show that tumour growth of the adenocarcinoma cell line EO771 in the breast and in the lung after injection into the mammary fat pad and tail vein, respectively, was significantly reduced in mice ablated for Cβ2 compared to wild-type mice. In both cases, the breast and lung tumours showed increased infiltration of immune cells in the mice lacking Cβ2 compared to wild-type mice. Despite this, it appeared that solid tissue- versus intravenously injected EO771 cells evoked different immune responses. This was reflected by significantly increased levels of splenic proinflammatory immune cells and circulating cytokines in Cβ2 ablated mice carrying breast- but not the lung tumours. Moreover, Cβ2 ablated mice injected with EO771 cells showed increased overall survival compared to wild-type mice. Taken together, our results suggest for a role for immune cell-specific Cβ2 in protecting against tumour growth induced by EO771 cells in mice that is reflected in improved overall survival.

Liraglutide enhances the effect of checkpoint blockade in lung and liver cancers through the inhibition of neutrophil extracellular traps

Glucagon-like peptide-1 (GLP-1) regulates glycemic excursions by augmenting insulin production and inhibiting glucagon secretion. Liraglutide, a long-acting GLP-1 analog, can improve glycemic control for treating type 2 diabetes and prevent neutrophil extravasation in inflammation. Here, we explored the role of liraglutide in the development and therapy of murine lung and liver cancers. In this study, liraglutide substantially decreased circulating neutrophil extracellular trap (NET) markers myeloperoxidase, elastase, and dsDNA in Lewis lung cancer (LLC) and Hepa1-6 tumor-bearing mice. Furthermore, liraglutide downregulated NETs and reactive oxygen species (ROS) of neutrophils in the tumor microenvironment. Functionally, in vitro experiments showed that liraglutide reduced NET formation by inhibiting ROS. In addition, we showed that liraglutide enhanced the anti-tumoral efficiency of programmed cell death-1 (PD-1) inhibition in LLC and Hepa1-6 tumor-bearing C57BL/6 mice. However, the removal of NETs significantly weakened the antitumor efficiency of liraglutide. We further demonstrated that the long-term antitumor CD8+ T cell responses induced by the combination therapy rejected rechallenges by respective tumor cell lines. Taken together, our findings suggest that liraglutide may promote the anti-tumoral efficiency of PD-1 inhibition by reducing NETs in lung and liver cancers.

An Overview of Cancer Biology, Pathophysiological Development and It's Treatment Modalities: Current Challenges of Cancer anti-Angiogenic Therapy

A number of conditions and factors can cause the transformation of normal cells in the body into malignant tissue by changing the normal functions of a wide range of regulatory, apoptotic, and signal transduction pathways. Despite the current deficiency in fully understanding the mechanism of cancer action accurately and clearly, numerous genes and proteins that are causally involved in the initiation, progression, and metastasis of cancer have been identified. But due to the lack of space and the abundance of details on this complex topic, we have emphasized here more recent advances in our understanding of the principles implied tumor cell transformation, development, invasion, angiogenesis, and metastasis. Inhibition of angiogenesis is a significant strategy for the treatment of various solid tumors, that essentially depend on cutting or at least limiting the supply of blood to micro-regions of tumors, leading to pan-hypoxia and pan-necrosis inside solid tumor tissues. Researchers have continued to enhance the efficiency of anti-angiogenic drugs over the past two decades, to identify their potential in the drug interaction, and to discover reasonable interpretations for possible resistance to treatment. In this review, we have discussed an overview of cancer history and recent methods use in cancer therapy, focusing on anti-angiogenic inhibitors targeting angiogenesis formation. Further, this review has explained the molecular mechanism of action of these anti-angiogenic inhibitors in various tumor types and their limitations use. In addition, we described the synergistic mechanisms of immunotherapy and anti-angiogenic therapy and summarizes current clinical trials of these combinations. Many phase III trials found that combining immunotherapy and anti-angiogenic therapy improved survival. Therefore, targeting the source supply of cancer cells to grow and spread with new anti-angiogenic agents in combination with different conventional therapy is a novel method to reduce cancer progression. The aim of this paper is to overview the varying concepts of cancer focusing on mechanisms involved in tumor angiogenesis and provide an overview of the recent trends in anti-angiogenic strategies for cancer therapy.

N-linked glycosylation of PD-L1/PD-1: an emerging target for cancer diagnosis and treatment

During tumorigenesis and progression, the immune checkpoint programmed death-1 (PD-1) and its ligand programmed death ligand-1 (PD-L1) play critical roles in suppressing T cell-mediated anticancer immune responses, leading to T-cell exhaustion and subsequent tumor evasion. Therefore, anti-PD-L1/PD-1 therapy has been an attractive strategy for treating cancer over the past decade. However, the overall efficacy of this approach remains suboptimal, revealing an urgent need for novel insights. Interestingly, increasing evidence indicates that both PD-L1 on tumor cells and PD-1 on tumor-specific T cells undergo extensive N-linked glycosylation, which is essential for the stability and interaction of these proteins, and this modification promotes tumor evasion. In various preclinical models, targeting the N-linked glycosylation of PD-L1/PD-1 was shown to significantly increase the efficacy of PD-L1/PD-1 blockade therapy. Furthermore, deglycosylation of PD-L1 strengthens the signal intensity in PD-L1 immunohistochemistry (IHC) assays, improving the diagnostic and therapeutic relevance of this protein. In this review, we provide an overview of the regulatory mechanisms underlying the N-linked glycosylation of PD-L1/PD-1 as well as the crucial role of N-linked glycosylation in PD-L1/PD-1-mediated immune evasion. In addition, we highlight the promising implications of targeting the N-linked glycosylation of PD-L1/PD-1 in the clinical diagnosis and treatment of cancer. Our review identifies knowledge gaps and sheds new light on the cancer research field.

ATM inhibition enhance immunotherapy by activating STING signaling and augmenting MHC Class I

Accumulating evidence supports the concept that DNA damage response targeted therapies can improve antitumor immune response by increasing the immunogenicity of tumor cells and improving the tumor immune microenvironment. Ataxia telangiectasia mutated (ATM) is a core component of the DNA repair system. Although the ATM gene has a significant mutation rate in many human cancers, including colorectal, prostate, lung, and breast, it remains understudied compared with other DDR-involved molecules such as PARP and ATR. Here, we found that either gene knockout or drug intervention, ATM inhibition activated the cGAS/STING pathway and augmented MHC class I in CRC cells, and these effects could be amplified by radiation. Furthermore, we found that MHC class I upregulation induced by ATM inhibition is dependent on the activation of the NFκB/IRF1/NLRC5 pathway and independent of STING. Animal experiments have shown increasing infiltration and cytotoxic function of T cells and better survival in ATM-deficient tumors. This work indicated that ATM nonsense mutation predicted the clinical benefits of radiotherapy combined with immune checkpoint blockade for patients with CRC. It also provides a molecular mechanism rationale for ATM-targeted agents for patients with CRC.

Advancements in nanomedicine delivery systems: unraveling immune regulation strategies for tumor immunotherapy

This review highlights the significant role of nanodrug delivery systems (NDDS) in enhancing the efficacy of tumor immunotherapy. Focusing on the integration of NDDS with immune regulation strategies, it explores their transformative impacts on the tumor microenvironment and immune response dynamics. Key advancements include the optimization of drug delivery through NDDS, targeting mechanisms like immune checkpoint blockade and modulating the immunosuppressive tumor environment. Despite the progress, challenges such as limited clinical efficacy and complex manufacturing processes persist. The review emphasizes the need for further research to optimize these systems, potentially revolutionizing cancer treatment by improving delivery efficiency, reducing toxicity and overcoming immune resistance.

Nanoparticles Encapsulated in Red Blood Cell Membranes for Near-Infrared Second Window Imaging-Guided Photothermal-Enhanced Immunotherapy on Tumors

Photothermal therapy (PTT), which uses the high thermal conversion ability of photothermal agents to ablate tumor cells at high temperatures, has gained significant attention because it has the advantages of high selectivity and specificity, precise targeting of tumor sites, and low invasiveness and trauma. However, PTT guided by the NIR-I has limitations in tissue penetration depth, resulting in limited imaging monitoring and therapeutic effects on deep-seated tumor tissues. Moreover, nanoparticles are easily cleared by the immune system and difficult to passively target tumor sites during the process of treatment. To address these issues, we prepared nanoparticles using NIR-II dyes IR1048 and DSPE-PEG-OH and further encapsulated them in red blood cell membranes derived from mice. These biomimetic nanoparticles, called RDIR1048, showed reduced clearance by the immune system and had long circulation characteristics. They effectively accumulated at tumor sites, and strong fluorescence could still be observed at the tumor site 96 h after administration. Furthermore, through mouse thermal imaging experiments, we found that RDIR1048 exhibited good PTT ability. When used in combination with an immune checkpoint inhibitor, anti-PD-L1 antibodies, it enhanced the immunogenic cell death of tumor cells caused by PTT and improved the therapeutic effect of immunotherapy, which demonstrated good therapeutic efficacy in the treatment of tumor-bearing mice. This study provides a feasible basis for the future development of NIR-II nanoparticles with long circulation properties.

M2-type tumor-associated macrophages upregulated PD-L1 expression in cervical cancer via the PI3K/AKT pathway

BACKGROUND AND PURPOSE

PD-1/PD-L1 inhibitors have become a promising therapy. However, the response rate is lower than 30% in patients with cervical cancer (CC), which is related to immunosuppressive components in tumor microenvironment (TME). Tumor-associated macrophages (TAMs), as one of the most important immune cells, are involved in the formation of tumor suppressive microenvironment. Therefore, it will provide a theoretical basis for curative effect improvement about the regulatory mechanism of TAMs on PD-L1 expression.

METHODS

The clinical data and pathological tissues of CC patients were collected, and the expressions of PD-L1, CD68 and CD163 were detected by immunohistochemistry. Bioinformatics was used to analyze the macrophage subtypes involved in PD-L1 regulation. A co-culture model was established to observe the effects of TAMs on the morphology, migration and invasion function of CC cells, and the regulatory mechanism of TAMs on PD-L1.

RESULTS

PD-L1 expression on tumor cells could predict the poor prognosis of patients. And there was a strong correlation between PD-L1 expression with CD163+TAMs infiltration. Similarly, PD-L1 expression was associated with M1/M2-type TAMs infiltration in bioinformatics analysis. The results of cell co-culture showed that M1/M2-type TAMs could upregulate PD-L1 expression, especially M2-type TAMs may elevate the PD-L1 expression via PI3K/AKT pathway. Meanwhile, M1/M2-type TAMs can affect the morphological changes, and enhance migration and invasion abilities of CC cells.

CONCLUSIONS

PD-L1 expression in tumor cells can be used as a prognostic factor and is closely related to CD163+TAMs infiltration. In addition, M2-type TAMs can upregulate PD-L1 expression in CC cells through PI3K/AKT pathway, enhance the migration and invasion capabilities, and affect the tumor progression.

Identification of Hypoxia-ALCAMhigh Macrophage- Exhausted T Cell Axis in Tumor Microenvironment Remodeling for Immunotherapy Resistance

Although hypoxia is known to be associated with immune resistance, the adaptability to hypoxia by different cell populations in the tumor microenvironment and the underlying mechanisms remain elusive. This knowledge gap has hindered the development of therapeutic strategies to overcome tumor immune resistance induced by hypoxia. Here, bulk, single-cell, and spatial transcriptomics are integrated to characterize hypoxia associated with immune escape during carcinogenesis and reveal a hypoxia-based intercellular communication hub consisting of malignant cells, ALCAMhigh macrophages, and exhausted CD8+ T cells around the tumor boundary. A hypoxic microenvironment promotes binding of HIF-1α complex is demonstrated to the ALCAM promoter therefore increasing its expression in macrophages, and the ALCAMhigh macrophages co-localize with exhausted CD8+ T cells in the tumor spatial microenvironment and promote T cell exhaustion. Preclinically, HIF-1ɑ inhibition reduces ALCAM expression in macrophages and exhausted CD8+ T cells and potentiates T cell antitumor function to enhance immunotherapy efficacy. This study reveals the systematic landscape of hypoxia at single-cell resolution and spatial architecture and highlights the effect of hypoxia on immunotherapy resistance through the ALCAMhigh macrophage-exhausted T cell axis, providing a novel immunotherapeutic strategy to overcome hypoxia-induced resistance in cancers.

Natural killer cells in cancer immunotherapy

Natural killer (NK) cells, as innate lymphocytes, possess cytotoxic capabilities and engage target cells through a repertoire of activating and inhibitory receptors. Particularly, natural killer group 2, member D (NKG2D) receptor on NK cells recognizes stress-induced ligands-the MHC class I chain-related molecules A and B (MICA/B) presented on tumor cells and is key to trigger the cytolytic response of NK cells. However, tumors have developed sophisticated strategies to evade NK cell surveillance, which lead to failure of tumor immunotherapy. In this paper, we summarized these immune escaping strategies, including the downregulation of ligands for activating receptors, upregulation of ligands for inhibitory receptors, secretion of immunosuppressive compounds, and the development of apoptosis resistance. Then, we focus on recent advancements in NK cell immune therapies, which include engaging activating NK cell receptors, upregulating NKG2D ligand MICA/B expression, blocking inhibitory NK cell receptors, adoptive NK cell therapy, chimeric antigen receptor (CAR)-engineered NK cells (CAR-NK), and NKG2D CAR-T cells, especially several vaccines targeting MICA/B. This review will inspire the research in NK cell biology in tumor and provide significant hope for improving cancer treatment outcomes by harnessing the potent cytotoxic activity of NK cells.

Lomitapide repurposing for treatment of malignancies: A promising direction

The development of novel drugs from basic science to clinical practice requires several years, much effort, and cost. Drug repurposing can promote the utilization of clinical drugs in cancer therapy. Recent studies have shown the potential effects of lomitapide on treating malignancies, which is currently used for the treatment of familial hypercholesterolemia. We systematically review possible functions and mechanisms of lomitapide as an anti-tumor compound, regarding the aspects of apoptosis, autophagy, and metabolism of tumor cells, to support repurposing lomitapide for the clinical treatment of tumors.

Tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for hepatocellular carcinoma: recent research progress

Hepatocellular carcinoma (HCC) is one of the cancers that seriously threaten human health. Immunotherapy serves as the mainstay of treatment for HCC patients by targeting the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) axis. However, the effectiveness of anti-PD-1/PD-L1 treatment is limited when HCC becomes drug-resistant. Tumor-associated macrophages (TAMs) are an important factor in the negative regulation of PD-1 antibody targeted therapy in the tumor microenvironment (TME). Therefore, as an emerging direction in cancer immunotherapy research for the treatment of HCC, it is crucial to elucidate the correlations and mechanisms between TAMs and PD-1/PD-L1-mediated immune tolerance. This paper summarizes the effects of TAMs on the pathogenesis and progression of HCC and their impact on HCC anti-PD-1/PD-L1 immunotherapy, and further explores current potential therapeutic strategies that target TAMs in HCC, including eliminating TAMs in the TME, inhibiting TAMs recruitment to tumors and functionally repolarizing M2-TAMs (tumor-supportive) to M1-TAMs (antitumor type).

Targeted immunotherapy and nanomedicine for rhabdomyosarcoma: The way of the future

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. Histology separates two main subtypes: embryonal RMS (eRMS; 60%-70%) and alveolar RMS (aRMS; 20%-30%). The aggressive aRMS carry one of two characteristic chromosomal translocations that result in the expression of a PAX3::FOXO1 or PAX7::FOXO1 fusion transcription factor; therefore, aRMS are now classified as fusion-positive (FP) RMS. Embryonal RMS have a better prognosis and are clinically indistinguishable from fusion-negative (FN) RMS. Next to histology and molecular characteristics, RMS risk groupings are now available defining low risk tumors with excellent outcomes and advanced stage disease with poor prognosis, with an overall survival of about only 20% despite intensified multimodal treatment. Therefore, development of novel effective targeted strategies to increase survival and to decrease long-term side effects is urgently needed. Recently, immunotherapies and nanomedicine have been emerging for potent and effective tumor treatments with minimal side effects, raising hopes for effective and safe cures for RMS patients. This review aims to describe the most relevant preclinical and clinical studies in immunotherapy and targeted nanomedicine performed so far in RMS and to provide an insight in future developments.

Further knowledge and developments in resistance mechanisms to immune checkpoint inhibitors

The past decade has witnessed a revolution in cancer treatment, shifting from conventional drugs (chemotherapies) towards targeted molecular therapies and immune-based therapies, in particular immune-checkpoint inhibitors (ICIs). These immunotherapies release the host's immune system against the tumor and have shown unprecedented durable remission for patients with cancers that were thought incurable, such as metastatic melanoma, metastatic renal cell carcinoma (RCC), microsatellite instability (MSI) high colorectal cancer and late stages of non-small cell lung cancer (NSCLC). However, about 80% of the patients fail to respond to these immunotherapies and are therefore left with other less effective and potentially toxic treatments. Identifying and understanding the mechanisms that enable cancerous cells to adapt to and eventually overcome therapy can help circumvent resistance and improve treatment. In this review, we describe the recent discoveries on the onco-immunological processes which govern the tumor microenvironment and their impact on the resistance to PD-1/PD-L1 checkpoint blockade.

An investigative meta-analysis on the effectiveness and safety of integrating VEGF/VEGFR inhibitors with PD-1/PD-L1 inhibitors in cases with R/M HNSCC

OBJECTIVES

Exploration into the use of vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) inhibitors alongside programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors has been undertaken for treating recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). We conducted a meta-analysis to provide a more precise assessment of the efficacy and safety of this integrated approach in managing R/M HNSCC.

METHODS

A systematic exploration encompassing PubMed, Embase, the Cochrane Library, and Web of Science databases was undertaken to figure out relevant studies. It was attempted to analyze critical endpoints, such as overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) utilizing a random-effects model.

RESULTS

Eleven studies, encompassing 413 patients, were analyzed. The combined data revealed an ORR of 41 % (95 % CI: 34-49 %), a DCR of 67 % (95 % CI: 51-83 %), a median PFS of 5.87 months (95 % CI: 3.90-7.85), and a median OS of 9.63 months (95 % CI: 6.78-12.49). Furthermore, the rates for 1-year PFS and OS were 45 % (95 % CI: 27-64 %) and 65 % (95 % CI: 49-81 %), respectively. The occurrence of grade 3 or higher adverse events related to the drugs was 20 % (95 % CI: 10-30 %). Subgroup analysis within the tyrosine kinase inhibitor (TKI) group revealed an ORR of 47 % (95 % CI: 39 %-55 %) and a DCR of 67 % (95 % CI: 46 %-88 %).

CONCLUSIONS

In summary, combining VEGF/VEGFR inhibitors with PD-1/PD-L1 inhibitors shows considerable effectiveness with manageable side effects in cases with R/M HNSCC.

SYSTEMATIC REVIEW REGISTRATION

Registered with the International Prospective Register of Systematic Reviews, identifier CRD42023486345.

Integrated pan-cancer analysis reveals the immunological and prognostic potential of RBFOX2 in human tumors

Background

The role of RNA-binding fox one homolog 2 (RBFOX2) in the progression of multiple tumors is increasingly supported by evidence. However, the unclearness pertaining to the expression of RBFOX2, its prognostic potential, and its correlation with the tumor microenvironment (TME) in pan-cancer persists. This study aims to comprehensively investigate the immunological prognostic value of RBFOX2.

Methods

The Cancer Genome Atlas Gene Expression Omnibus Genotype-Tissue Expression (GTEx), TIMER2.0, Kaplan-Meier (K-M) Plotter, University of Alabama at Birmingham Cancer data analysis Portal (UALCAN), cbioportal, and Gene Expression Profiling Interactive Analysis 2 (GEPIA2) were utilized for a systematic analysis of RBFOX2. This analysis included studying its expression, prognostic value, DNA methylation, enrichment analysis, immune infiltration cells, and immune-related genes. Additionally, qRT-PCR, CCK-8, colony formation, transwell assays, and immunohistochemistry were employed to analyze the expression and biological function of RBFOX2 in liver cancer.

Results

Variations in RBFOX2 expression have been observed across diverse tumors and have been identified as indicators of unfavorable prognosis. It is closely linked to immune infiltration cells, immune checkpoints, chemokines, and chemokine receptors in the TME. Higher levels of RBFOX2 have been significantly associated with low response and poor prognosis in patients with non-small cell lung cancer (NSCLC) and melanoma who receive immunotherapy. Furthermore, the DNA methylation of RBFOX2 varies across different types of cancer and has shown better prognosis in patients with BLCA, BRCA, CESC, COAD, DLBC, HNSC, LAML, LGG, LUAD, PAAD, SKCM and THYM. Interestingly, RBFOX2 expression was found to be lower in hepatocellular carcinoma (HCC) patients' tumor tissues compared to their paired adjacent tissues. In vitro studies have shown that knockdown of RBFOX2 significantly promotes the growth and metastasis of liver cancer cells.

Conclusion

This study investigates the correlation between DNA methylation, prognostic value, and immune cell infiltration with the expression of RBFOX2 in pan-cancer and indicates its potential role to inhibit metastasis of liver cancer.

Role of m6A modifications in immune evasion and immunotherapy

RNA modification has garnered increasing attention in recent years due to its pivotal role in tumorigenesis and immune surveillance. N6-methyladenosine (m6A) modification is the most prevalent RNA modification, which can affect the expression of RNA by methylating adenylate at the sixth N position to regulate the occurrence and development of tumors. Dysregulation of m6A affects the activation of cancer-promoting pathways, destroys immune cell function, maintains immunosuppressive microenvironment, and promotes tumor cell growth. In this review, we delve into the latest insights into how abnormalities in m6A modification in both tumor and immune cells orchestrate immune evasion through the activation of signaling pathways. Furthermore, we explore how dysregulated m6A modification in tumor cells influences immune cells, thereby regulating tumor immune evasion via interactions within the tumor microenvironment (TME). Lastly, we highlight recent discoveries regarding specific inhibitors of m6A modulators and the encapsulation of m6A-targeting nanomaterials for cancer therapy, discussing their potential applications in immunotherapy.

Regulatory mechanisms of PD-1/PD-L1 in cancers

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

Molecular Markers in Melanoma Progression: A Study on the Expression of miRNA Gene Subtypes in Tumoral vs. Benign Nevi

This study investigates the differential expression of miRNA gene subtypes in tumoral versus benign nevi in individuals with melanoma, aiming to identify clinically significant correlations that could serve as reliable markers for assessing tumor stage and progression. Conducted between 2019 and 2022, this descriptive, quantitative observational research analyzed 90 formalin-fixed paraffin-embedded (FFPE) samples from the Pius Brinzeu County Emergency Clinical Hospital, Timisoara, including 45 samples of advanced-stage melanoma and 45 samples of pigmented nevi. miRNA purification and analysis were performed using the miRNeasy Kit and the Human Cancer PathwayFinder miScript miRNA PCR Array, with statistical analysis (including logistic regression) to determine associations with cancer staging, such as high Breslow index risk, number of mitoses, and vascular invasion. After the analysis and comparison of 180 miRNA gene subtypes, we selected 10 of the most upregulated and 10 most downregulated genes. The results revealed that hsa-miR-133b, hsa-miR-335-5p, hsa-miR-200a-3p, and hsa-miR-885-5p were significantly upregulated in melanoma samples, with fold changes ranging from 1.09 to 1.12. Conversely, hsa-miR-451a and hsa-miR-29b-3p showed notable downregulation in melanoma, with fold changes of 0.90 and 0.92, respectively. Additionally, logistic regression analysis identified hsa-miR-29b-3p (OR = 2.51) and hsa-miR-200a-3p (OR = 2.10) as significantly associated with an increased risk of a high Breslow index, while hsa-miR-127-3p and hsa-miR-451a were associated with a reduced risk. Conclusively, this study underscores the significant alterations in miRNA expression in melanoma compared to benign nevi and highlights the potential of specific miRNAs as biomarkers for melanoma progression. The identification of miRNAs with significant associations to melanoma characteristics suggests their utility in developing non-invasive, cost-effective diagnostic tools and in guiding therapeutic decisions, potentially improving patient outcomes in melanoma management.

Beyond inhibition against the PD-1/PD-L1 pathway: development of PD-L1 inhibitors targeting internalization and degradation of PD-L1

Tumor cells hijack the programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) pathway to suppress the immune response through overexpressing PD-L1 to interact with PD-1 of T cells. With in-depth ongoing research, tumor-intrinsic PD-L1 is found to play important roles in tumor progression without interaction with PD-1 expressed on T cells, which provides an additional important target and therapeutic approach for development of PD-L1 inhibitors. Existing monoclonal antibody (mAb) drugs against the PD-1/PD-L1 pathway generally behave by conformationally blocking the interactions of PD-1 with PD-L1 on the cell surface. Beyond general inhibition of the protein-protein interaction (PPI), inhibitors targeting PD-L1 currently focus on the functional inhibition of the interaction between PD-1/PD-L1 and degradation of tumor-intrinsic PD-L1. This perspective will clarify the evolution of PD-L1 inhibitors and provide insights into the current development of PD-L1 inhibitors, especially targeting internalization and degradation of PD-L1.

Akkermania muciniphila: a rising star in tumor immunology

Tumor is accompanied by complex and dynamic microenvironment development, and the interaction of all its components influences disease progression and response to treatment. Once the tumor microenvironment has been eradicated, various mechanisms can induce the tumors. Microorganisms can maintain the homeostasis of the tumor microenvironment through immune regulation, thereby inhibiting tumor development. Akkermania muciniphila (A. muciniphila), an anaerobic bacterium, can induce tumor immunity, regulate the gastrointestinal microenvironment through metabolites, outer membrane proteins, and some cytokines, and enhance the curative effect through combined immunization. Therefore, a comprehensive understanding of the complex interaction between A. muciniphila and human immunity will facilitate the development of immunotherapeutic strategies in the future and enable patients to obtain a more stable clinical response. This article reviews the most recent developments in the tumor immunity of A. muciniphila.

Systematic investigation of chemo-immunotherapy synergism to shift anti-PD-1 resistance in cancer

Chemo-immunotherapy combinations have been regarded as one of the most practical ways to improve immunotherapy response in cancer patients. In this study, we integrate the transcriptomics data from anti-PD-1-treated tumors and compound-treated cancer cell lines to systematically screen for chemo-immunotherapy synergisms in silico. Through analyzing anti-PD-1 induced expression changes in patient tumors, we develop a shift ability score to measure if a chemotherapy or a small molecule inhibitor treatment can shift anti-PD-1 resistance in tumor cells. By applying shift ability analysis to 41,321 compounds and 16,853 shRNA treated cancer cell lines transcriptomic data, we characterize the landscape of chemo-immunotherapy synergism and experimentally validated a mitochondrial RNA-dependent mechanism for drug-induced immune activation in tumor. Our study represents an effort to mechanistically characterize chemo-immunotherapy synergism and will facilitate future pre-clinical and clinical studies.

Induction of therapeutic immunity and cancer eradication through biofunctionalized liposome-like nanovesicles derived from irradiated-cancer cells

Immunotherapy has revolutionized the treatment of cancer. However, its efficacy remains to be optimized. There are at least two major challenges in effectively eradicating cancer cells by immunotherapy. Firstly, cancer cells evade immune cell killing by down-regulating cell surface immune sensors. Secondly, immune cell dysfunction impairs their ability to execute anti-cancer functions. Radiotherapy, one of the cornerstones of cancer treatment, has the potential to enhance the immunogenicity of cancer cells and trigger an anti-tumor immune response. Inspired by this, we fabricate biofunctionalized liposome-like nanovesicles (BLNs) by exposing irradiated-cancer cells to ethanol, of which ethanol serves as a surfactant, inducing cancer cells pyroptosis-like cell death and facilitating nanovesicles shedding from cancer cell membrane. These BLNs are meticulously designed to disrupt both of the aforementioned mechanisms. On one hand, BLNs up-regulate the expression of calreticulin, an "eat me" signal on the surface of cancer cells, thus promoting macrophage phagocytosis of cancer cells. Additionally, BLNs are able to reprogram M2-like macrophages into an anti-cancer M1-like phenotype. Using a mouse model of malignant pleural effusion (MPE), an advanced-stage and immunotherapy-resistant cancer model, we demonstrate that BLNs significantly increase T cell infiltration and exhibit an ablative effect against MPE. When combined with PD-1 inhibitor (α-PD-1), we achieve a remarkable 63.6% cure rate (7 out of 11) among mice with MPE, while also inducing immunological memory effects. This work therefore introduces a unique strategy for overcoming immunotherapy resistance.

A narrative review of the role of Eph receptors in head and neck squamous cell carcinoma

Tyrosine kinase receptors (TKR) coordinate a variety of pathological processes in head and neck squamous cell carcinoma (HNSCC), and eventually play a role in patient outcomes. In this review, the role of Eph receptors in HNSCC progression and the possibility of targeting these receptors are illustrated. All relevant studies were identified through a comprehensive search of four electronic databases, including PubMed, Scopus, web of science, and Embase till August 2022. EphA2 and EphB4, along with ephrin-B2, were the most extensively studied proteins in this family. However, overexpression of EphB4 and its ligand ephrin-B2 were the only proteins that consistently showed association with a poor outcome, indicating that these proteins might serve as valuable prognostic markers in HNSCC. High expression of EphA3 and EphB4 was found to play a crucial role in radioresistance of HNSCC. EphB4 loss, in particular, was observed to induce an immunosuppression phenotypic HNSCC. Currently, ongoing clinical trials are investigating the benefits of EphB4-ephrin-B2 blockade in combination with standard of care treatment in HNSCC. Further efforts are needed to explore the biological role and behavioral complexity of this family of TKR in HNSCC with great attention to avoid heterogeneity of HNSCC subsites.

Cold to Hot: Tumor Immunotherapy by Promoting Vascular Normalization Based on PDGFB Nanocomposites

Immunotherapy is a promising cancer therapeutic strategy. However, the "cold" tumor immune microenvironment (TIME), characterized by insufficient immune cell infiltration and immunosuppressive status, limits the efficacy of immunotherapy. Tumor vascular abnormalities due to defective pericyte coverage are gradually recognized as a profound determinant in "cold" TIME establishment by hindering immune cell trafficking. Recently, several vascular normalization strategies by improving pericyte coverage have been reported, whereas have unsatisfactory efficacy and high rates of resistance. Herein, a combinatorial strategy to induce tumor vasculature-targeted pericyte recruitment and zinc ion-mediated immune activation with a platelet-derived growth factor B (PDGFB)-loaded, cyclo (Arg-Gly-Asp-D-Phe-Lys)-modified zeolitic imidazolate framework 8 (PDGFB@ZIF8-RGD) nanoplatform is proposed. PDGFB@ZIF8-RGD effectively induced tumor vascular normalization, which facilitated trafficking and infiltration of immune effector cells, including natural killer (NK) cells, M1-like macrophages and CD8+ T cells, into tumor microenvironment. Simultaneously, vascular normalization promoted the accumulation of zinc ions inside tumors to trigger effector cell immune activation and effector molecule production. The synergy between these two effects endowed PDGFB@ZIF8-RGD with superior capabilities in reprogramming the "cold" TIME to a "hot" TIME, thereby initiating robust antitumor immunity and suppressing tumor growth. This combinatorial strategy for improving immune effector cell infiltration and activation is a promising paradigm for solid tumor immunotherapy.

A Comprehensive Review of Cancer Drug-Induced Cardiotoxicity in Blood Cancer Patients: Current Perspectives and Therapeutic Strategies

OPINION STATEMENT

Cardiotoxicity has emerged as a serious outcome catalyzed by various therapeutic targets in the field of cancer treatment, which includes chemotherapy, radiation, and targeted therapies. The growing significance of cancer drug-induced cardiotoxicity (CDIC) and radiation-induced cardiotoxicity (CRIC) necessitates immediate attention. This article intricately unveils how cancer treatments cause cardiotoxicity, which is exacerbated by patient-specific risks. In particular, drugs like anthracyclines, alkylating agents, and tyrosine kinase inhibitors pose a risk, along with factors such as hypertension and diabetes. Mechanistic insights into oxidative stress and topoisomerase-II-B inhibition are crucial, while cardiac biomarkers show early damage. Timely intervention and prompt treatment, especially with specific agents like dexrazoxane and beta-blockers, are pivotal in the proactive management of CDIC.

Immune Specific and Tumor-Dependent mRNA Vaccines for Cancer Immunotherapy: Reprogramming Clinical Translation into Tumor Editing Therapy

Extensive research into mRNA vaccines for cancer therapy in preclinical and clinical trials has prepared the ground for the quick development of immune-specific mRNA vaccines during the COVID-19 pandemic. Therapeutic cancer vaccines based on mRNA are well tolerated, and are an attractive choice for future cancer immunotherapy. Ideal personalized tumor-dependent mRNA vaccines could stimulate both humoral and cellular immunity by overcoming cancer-induced immune suppression and tumor relapse. The stability, structure, and distribution strategies of mRNA-based vaccines have been improved by technological innovations, and patients with diverse tumor types are now being enrolled in numerous clinical trials investigating mRNA vaccine therapy. Despite the fact that therapeutic mRNA-based cancer vaccines have not yet received clinical approval, early clinical trials with mRNA vaccines as monotherapy and in conjunction with checkpoint inhibitors have shown promising results. In this review, we analyze the most recent clinical developments in mRNA-based cancer vaccines and discuss the optimal platforms for the creation of mRNA vaccines. We also discuss the development of the cancer vaccines' clinical research, paying particular attention to their clinical use and therapeutic efficacy, which could facilitate the design of mRNA-based vaccines in the near future.

Enzyme/pH Dual-Responsive Engineered Nanoparticles for Improved Tumor Immuno-Chemotherapy

Combining immune checkpoint blockade (ICB) therapy with chemotherapy can enhance the efficacy of ICB and expand its indications. However, the limited tumor specificity of chemotherapy drugs results in severe adverse reactions. Additionally, the low tissue penetration and immune-related adverse events associated with monoclonal antibodies restrict their widespread application. To address challenges faced by traditional combination therapies, we design a dual-responsive engineered nanoparticle based on ferritin (denoted as CMFn@OXA), achieving tumor-targeted delivery and controlled release of the anti-PD-L1 peptide CLP002 and oxaliplatin (OXA). Our results demonstrate that CMFn@OXA not only exhibits tumor-specific accumulation but also responds to matrix metalloproteinase-2/9 (MMP-2/9), facilitating the controlled release of CLP002 to block PD-1/PD-L1 interaction. Simultaneously, it ensures the precise delivery of the OXA to tumor cells and its subsequent release within the acidic environment of lysosomes, thereby fostering a synergistic therapeutic effect. Compared to traditional combination therapies, CMFn@OXA demonstrates superior performance in inhibiting tumor growth, extending the survival of tumor-bearing mice, and exhibiting excellent biocompatibility. Collectively, our results highlight CMFn@OXA as a novel and promising strategy in the field of cancer immunotherapy.

Fatty acid synthase (FASN) signalome: A molecular guide for precision oncology

The initial excitement generated more than two decades ago by the discovery of drugs targeting fatty acid synthase (FASN)-catalyzed de novo lipogenesis for cancer therapy was short-lived. However, the advent of the first clinical-grade FASN inhibitor (TVB-2640; denifanstat), which is currently being studied in various phase II trials, and the exciting advances in understanding the FASN signalome are fueling a renewed interest in FASN-targeted strategies for the treatment and prevention of cancer. Here, we provide a detailed overview of how FASN can drive phenotypic plasticity and cell fate decisions, mitochondrial regulation of cell death, immune escape and organ-specific metastatic potential. We then present a variety of FASN-targeted therapeutic approaches that address the major challenges facing FASN therapy. These include limitations of current FASN inhibitors and the lack of precision tools to maximize the therapeutic potential of FASN inhibitors in the clinic. Rethinking the role of FASN as a signal transducer in cancer pathogenesis may provide molecularly driven strategies to optimize FASN as a long-awaited target for cancer therapeutics.

Body composition change indices combined with Prognostic Nutritional Index predicts the clinical outcomes of patients with gastric cancer treated with immune checkpoint inhibitor

OBJECTIVE

This study aimed to investigate the prognostic significance of the Prognostic Nutritional Index (PNI) in conjunction with body composition change indices, namely subcutaneous fat area (SFA) and skeletal muscle index (SMI), with regard to clinical outcomes in patients with gastric cancer (GC) undergoing immune checkpoint inhibitors (ICIs) treatment.

METHODS

This retrospective investigation encompassed patients with comprehensive clinical and pathological data, inclusive of portal phase enhanced CT images. Continuous variables underwent analysis utilizing the Student t-test or Mann-Whitney U-test, while categorical variables were assessed employing the Pearson chi-squared test or Fisher test. Survival outcomes were evaluated using Kaplan-Meier survival curves and the Log-rank test. Independent prognostic indicators were determined through Cox regression analysis, and a nomogram predicting survival probability for progression-free survival (PFS) and overall survival (OS) was constructed.

RESULTS

Within the PNI-SFA groups, patients in Group 1 exhibited inferior PFS and OS compared to the other two groups. Similarly, among the PNI-SMI groups, Group 1 patients demonstrated poorer PFS and OS. PNI-SMI and Eosi were identified as independent prognostic factors through Cox regression analysis. Furthermore, positive associations with patient prognosis were observed for BMI, SAF, SMI, and PNI.

CONCLUSION

The comprehensive consideration of PNI-SFA and PNI-SMI proved to be a superior prognostic predictor for GC patients undergoing ICI treatment.

Biological insights from plasma proteomics of non-small cell lung cancer patients treated with immunotherapy

Introduction

Immune checkpoint inhibitors have made a paradigm shift in the treatment of non-small cell lung cancer (NSCLC). However, clinical response varies widely and robust predictive biomarkers for patient stratification are lacking. Here, we characterize early on-treatment proteomic changes in blood plasma to gain a better understanding of treatment response and resistance.

Methods

Pre-treatment (T0) and on-treatment (T1) plasma samples were collected from 225 NSCLC patients receiving PD-1/PD-L1 inhibitor-based regimens. Plasma was profiled using aptamer-based technology to quantify approximately 7000 plasma proteins per sample. Proteins displaying significant fold changes (T1:T0) were analyzed further to identify associations with clinical outcomes using clinical benefit and overall survival as endpoints. Bioinformatic analyses of upregulated proteins were performed to determine potential cell origins and enriched biological processes.

Results

The levels of 142 proteins were significantly increased in the plasma of NSCLC patients following ICI-based treatments. Soluble PD-1 exhibited the highest increase, with a positive correlation to tumor PD-L1 status, and, in the ICI monotherapy dataset, an association with improved overall survival. Bioinformatic analysis of the ICI monotherapy dataset revealed a set of 30 upregulated proteins that formed a single, highly interconnected network, including CD8A connected to ten other proteins, suggestive of T cell activation during ICI treatment. Notably, the T cell-related network was detected regardless of clinical benefit. Lastly, circulating proteins of alveolar origin were identified as potential biomarkers of limited clinical benefit, possibly due to a link with cellular stress and lung damage.

Conclusions

Our study provides insights into the biological processes activated during ICI-based therapy, highlighting the potential of plasma proteomics to identify mechanisms of therapy resistance and biomarkers for outcome.

LAPTM4B-mediated hepatocellular carcinoma stem cell proliferation and MDSC migration: implications for HCC progression and sensitivity to PD-L1 monoclonal antibody therapy

In hepatocellular carcinoma (HCC), immunotherapy is vital for advanced-stage patients. However, diverse individual responses and tumor heterogeneity have resulted in heterogenous treatment outcomes. Our mechanistic investigations identified LAPTM4B as a crucial gene regulated by ETV1 (a transcription factor), especially in liver cancer stem cells (LCSCs). The influence of LAPTM4B on LCSCs is mediated via the Wnt1/c-Myc/β-catenin pathway. CXCL8 secretion by LAPTM4B drove myeloid-derived suppressor cell (MDSC) migration, inducing unfavorable patient prognosis. LAPTM4B affected PD-L1 receptor expression in tumor microenvironment and enhanced tumor suppression induced by PD-L1 monoclonal antibodies in HCC patients. LAPTM4B up-regulation is correlated with adverse outcomes in HCC patients, sensitizing them to PD-L1 monoclonal antibody therapy.

Disruption of MerTK increases the efficacy of checkpoint inhibitor by enhancing ferroptosis and immune response in hepatocellular carcinoma

Immune checkpoint inhibitors, particularly PD-1/PD-L1 blockades, have been approved for unresectable hepatocellular carcinoma (HCC). However, high resistance rates still limit their efficacy, highlighting the urgent need to understand the underlying mechanisms and develop strategies for overcoming the resistance. In this study, we demonstrate that HCC with high MER proto-oncogene tyrosine kinase (MerTK) expression exhibits anti-PD-1/PD-L1 resistance in two syngeneic mouse models and in patients who received anti-PD-1/PD-L1 therapy. Mechanistically, MerTK renders HCC resistant to anti-PD-1/PD-L1 by limiting ferroptosis with the upregulation of SLC7A11 via the ERK/SP1 pathway and facilitating the development of an immunosuppressive tumor microenvironment (TME) with the recruitment of myeloid-derived suppressor cells (MDSCs). Sitravatinib, an inhibitor of MerTK, sensitizes resistant HCC to anti-PD-L1 therapy by promoting tumor ferroptosis and decreasing MDSC infiltration into the TME. In conclusion, we find that MerTK could serve as a predictive biomarker for patient stratification and as a promising target to overcome anti-PD-1/PD-L1 resistance in HCC.

A dual-functional oncolytic adenovirus ZD55-aPD-L1 scFv armed with PD-L1 inhibitor potentiates its antitumor activity

BACKGROUND

Clinical data indicate that a substantial portion of cancer patients, though eligible for immune checkpoint inhibitor (ICI) therapy, cannot fully benefit from ICI monotherapy due to the poor immunogenicity of tumors and lack of tumor-infiltrating lymphocytes within the 'cold' tumor microenvironment (TME). In addition to poor antibody penetrance into the TME, systemic delivery of ICIs is associated with immune-related adverse events (irAEs) among recipients, some of which are life-threatening. Oncolytic virotherapy is a potentially viable approach to improving the efficacy of ICI therapy because of their ability to selectively replicate and lyse tumor cells, release tumor-associated antigens (TAAs), induce inflammatory response and promote lymphocyte infiltration in tumors.

METHODS

A recombinant oncolytic adenoviruses (OAd), denoted ZD55-aPD-L1 scFv, which carried the expression cassette for anti-PD-L1 scFv was constructed by molecular cloning. Western blot and ELISA assay were performed to detect aPD-L1 scFv expression. Flow cytometry were used to analyse PD-L1 expression and count tumor cells. Co-culture assay of human peripheral blood mononuclear cells (PBMCs) with tumor cells in vitro and triple-negative breast cancer (TNBC) MDA-MB-231 tumor-bearing model in vivo were evaluated the antitumor effects of recombinant oncolytic adenoviruses ZD55-aPD-L1 scFv.

RESULTS

We found that cells infected with recombinant oncolytic adenovirus ZD55-aPD-L1 scFv can effectively express aPD-L1 scFv, which function similarly to its full-length anti-PD-L1 antibody. PBMCs have inherently very limited killing effect on tumor cells even with administration of anti-PD-L1 antibody as observed from our in vitro co-cultures. Treatment consisting of ZD55 alone or ZD55 combined with anti-PD-L1 antibody yielded mediocre antitumor efficacy in subsequent in vitro and in vivo investigations, but were all substantially surpassed by the synergistic antitumor effects observed with ZD55-aPD-L1 scFv treatment. We show that the concomitant direct oncolysis by the recombinant OAd and localized autocrine/paracrine interception of PD-1:PD-L1 checkpoint interaction mediated by ZD55-aPD-L1 scFv-infected cells is exceedingly superior to co-administration of ZD55 and anti-PD-L1 antibody in the human TNBC mice model.

CONCLUSIONS

Our results provided evidence for the development of novel strategies, in this case an anti-PD-L1 scFv-armed OAd, to bolster immune responses to 'cold' tumors and to improve therapeutic responsiveness to ICIs.

The need for paradigm shift: prognostic significance and implications of standard therapy-related systemic immunosuppression in glioblastoma for immunotherapy and oncolytic virotherapy

Despite significant advances in our knowledge regarding the genetics and molecular biology of gliomas over the past two decades and hundreds of clinical trials, no effective therapeutic approach has been identified for adult patients with newly diagnosed glioblastoma, and overall survival remains dismal. Great hopes are now placed on combination immunotherapy. In clinical trials, immunotherapeutics are generally tested after standard therapy (radiation, temozolomide, and steroid dexamethasone) or concurrently with temozolomide and/or steroids. Only a minor subset of patients with progressive/recurrent glioblastoma have benefited from immunotherapies. In this review, we comprehensively discuss standard therapy-related systemic immunosuppression and lymphopenia, their prognostic significance, and the implications for immunotherapy/oncolytic virotherapy. The effectiveness of immunotherapy and oncolytic virotherapy (viro-immunotherapy) critically depends on the activity of the host immune cells. The absolute counts, ratios, and functional states of different circulating and tumor-infiltrating immune cell subsets determine the net immune fitness of patients with cancer and may have various effects on tumor progression, therapeutic response, and survival outcomes. Although different immunosuppressive mechanisms operate in patients with glioblastoma/gliomas at presentation, the immunological competence of patients may be significantly compromised by standard therapy, exacerbating tumor-related systemic immunosuppression. Standard therapy affects diverse immune cell subsets, including dendritic, CD4+, CD8+, natural killer (NK), NKT, macrophage, neutrophil, and myeloid-derived suppressor cell (MDSC). Systemic immunosuppression and lymphopenia limit the immune system's ability to target glioblastoma. Changes in the standard therapy are required to increase the success of immunotherapies. Steroid use, high neutrophil-to-lymphocyte ratio (NLR), and low post-treatment total lymphocyte count (TLC) are significant prognostic factors for shorter survival in patients with glioblastoma in retrospective studies; however, these clinically relevant variables are rarely reported and correlated with response and survival in immunotherapy studies (e.g., immune checkpoint inhibitors, vaccines, and oncolytic viruses). Our analysis should help in the development of a more rational clinical trial design and decision-making regarding the treatment to potentially improve the efficacy of immunotherapy or oncolytic virotherapy.

A promising target for breast cancer: B7-H3

Breast cancer (BC) is the second-leading factor of mortality for women globally and is brought on by a variety of genetic and environmental causes. The conventional treatments for this disease have limitations, making it difficult to improve the lifespan of breast cancer patients. As a result, extensive research has been conducted over the past decade to find innovative solutions to these challenges. Targeting of the antitumor immune response through the immunomodulatory checkpoint protein B7 family has revolutionized cancer treatment and led to intermittent patient responses. B7-H3 has recently received attention because of its significant demodulation and its immunomodulatory effects in many cancers. Uncontrolled B7-H3 expression and a bad outlook are strongly associated, according to a substantial body of cancer research. Numerous studies have shown that BC has significant B7-H3 expression, and B7-H3 induces an immune evasion phenotype, consequently enhancing the survival, proliferation, metastasis, and drug resistance of BC cells. Thus, an innovative target for immunotherapy against BC may be the B7-H3 checkpoint.In this review, we discuss the structure and regulation of B7-H3 and its double costimulatory/coinhibitory function within the framework of cancer and normal physiology. Then we expound the malignant behavior of B7-H3 in BC and its role in the tumor microenvironment (TME) and finally focus on targeted drugs against B7-H3 that have opened new therapeutic opportunities in BC.

Circular RNAs, Noncoding RNAs, and N6-methyladenosine Involved in the Development of MAFLD

Noncoding RNAs (ncRNAs), including circular RNAs (circRNAs) and N6-methyladenosine (m6A), have been shown to play a critical role in the development of various diseases including obesity and metabolic disorder-associated fatty liver disease (MAFLD). Obesity is a chronic disease caused by excessive fat accumulation in the body, which has recently become more prevalent and is the foremost risk factor for MAFLD. Causes of obesity may involve the interaction of genetic, behavioral, and social factors. m6A RNA methylation might add a novel inspiration for understanding the development of obesity and MAFLD with post-transcriptional regulation of gene expression. In particular, circRNAs, microRNAs (miRNAs), and m6A might be implicated in the progression of MAFLD. Interestingly, m6A modification can modulate the translation, degradation, and other functions of ncRNAs. miRNAs/circRNAs can also modulate m6A modifications by affecting writers, erasers, and readers. In turn, ncRNAs could modulate the expression of m6A regulators in different ways. However, there is limited evidence on how these ncRNAs and m6A interact to affect the promotion of liver diseases. It seems that m6A can occur in DNA, RNA, and proteins that may be associated with several biological properties. This study provides a mechanistic understanding of the association of m6A modification and ncRNAs with liver diseases, especially for MAFLD. Comprehension of the association between m6A modification and ncRNAs may contribute to the development of treatment tactics for MAFLD.

Clinical potential of microbiota in thyroid cancer therapy

Thyroid cancer is one of the most common tumors of the endocrine system because of its rapid and steady increase in incidence and prevalence. In recent years, a growing number of studies have identified a key role for the gut, thyroid tissue and oral microbiota in the regulation of metabolism and the immune system. A growing body of evidence has conclusively demonstrated that the microbiota influences tumor formation, prevention, diagnosis, and treatment. We provide extensive information in which oral, gut, and thyroid microbiota have an effect on thyroid cancer development in this review. In addition, we thoroughly discuss the various microbiota species, their potential functions, and the underlying mechanisms for thyroid cancer. The microbiome offers a unique opportunity to improve the effectiveness of immunotherapy and radioiodine therapy thyroid cancer by maintaining the right type of microbiota, and holds great promise for improving clinical outcomes and quality of life for thyroid cancer patients.

Analysis of Immune Resistance Mechanisms in TNBC: Dual Effects Inside and Outside the Tumor

Triple-negative breast cancer (TNBC) is a unique subtype of breast cancer characterized by the lack of expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. TNBC exhibits a high degree of aggressiveness, metastatic potential, and a poor prognosis. Despite the limited success of conventional treatments, immune checkpoint inhibitors (ICIs) have emerged as promising therapeutics for TNBC. Therefore, understanding the mechanisms underlying innate and acquired resistance to ICIs in TNBC is essential. Numerous studies suggest that intrinsic and extrinsic factors significantly contribute to the development of ICI resistance in TNBC. Intrinsic resistance may result from alterations in tumor-intrinsic signaling pathways, such as dysregulation of interferon (IFN) signaling or other signaling pathways. In contrast, extratumoral mechanisms may develop due to alterations in the tumor microenvironment, changes in T cell-related factors or adaptations within the immune system itself. In this paper, we endeavor to elucidate the underlying mechanisms of immune resistance by systematically examining immune mechanisms, the present state of immunotherapy, and the processes of immune resistance. Nonetheless, enhancing our understanding of the mechanisms underlying intratumoral and extratumoral resistance to ICIs in TNBC is crucial for optimizing patient outcomes in this challenging disease. Persistent efforts to identify novel targets for combination therapies, biomarkers that can predict the response to immunotherapy, and resistance mechanisms will be instrumental in achieving this objective.

Anti-CTLA-4 nanobody as a promising approach in cancer immunotherapy

Cancer is one of the most common diseases and causes of death worldwide. Since common treatment approaches do not yield acceptable results in many patients, developing innovative strategies for effective treatment is necessary. Immunotherapy is one of the promising approaches that has been highly regarded for preventing tumor recurrence and new metastases. Meanwhile, inhibiting immune checkpoints is one of the most attractive methods of cancer immunotherapy. Cytotoxic T lymphocyte-associated protein-4 (CTLA-4) is an essential immune molecule that plays a vital role in cell cycle modulation, regulation of T cell proliferation, and cytokine production. This molecule is classically expressed by stimulated T cells. Inhibition of overexpression of immune checkpoints such as CTLA-4 receptors has been confirmed as an effective strategy. In cancer immunotherapy, immune checkpoint-blocking drugs can be enhanced with nanobodies that target immune checkpoint molecules. Nanobodies are derived from the variable domain of heavy antibody chains. These small protein fragments have evolved entirely without a light chain and can be used as a powerful tool in imaging and treating diseases with their unique structure. They have a low molecular weight, which makes them smaller than conventional antibodies while still being able to bind to specific antigens. In addition to low molecular weight, specific binding to targets, resistance to temperature, pH, and enzymes, high ability to penetrate tumor tissues, and low toxicity make nanobodies an ideal approach to overcome the disadvantages of monoclonal antibody-based immunotherapy. In this article, while reviewing the cellular and molecular functions of CTLA-4, the structure and mechanisms of nanobodies' activity, and their delivery methods, we will explain the advantages and challenges of using nanobodies, emphasizing immunotherapy treatments based on anti-CTLA-4 nanobodies.

Targeting CENP-E augments immunotherapy in non-small cell lung cancer via stabilizing PD-L1

Centromere-associated protein E (CENP-E) plays a critical role in mitosis and chromosome misalignment, which may represent a potential therapeutic target in tumors. CENP-E is frequently overexpressed in lung cancer and act as a driver gene. However, it remains unclear whether CENP-E regulates the immune microenvironment in non-small cell lung cancer (NSCLC). Our study revealed that CENP-E is highly expressed and predicts a worse survival in NSCLC patients; inhibition of CENP-E leads to an upregulation of PD-L1 expression, consequently impacting the immune microenvironment of NSCLC by modulating the balance between CD8+ T cells and regulatory T cells (Tregs). Mechanistically, we demonstrated that downregulation of CENP-E could stabilize PD-L1 mRNA through the targeting of its 3'UTR by TTP. The genetic knockdown or pharmacological inhibition of CENP-E, in combination with PD-L1 antibody, could enhance the antitumor effect in NSCLC. Thus, our findings have revealed a role of CENP-E in immunotherapy and suggest that combination of CENP-E inhibitor with PD-L1 antibody could be an effective treatment option for NSCLC.

The BCL-2 inhibitor APG-2575 resets tumor-associated macrophages toward the M1 phenotype, promoting a favorable response to anti-PD-1 therapy via NLRP3 activation

The main challenges in the use of immune checkpoint inhibitors (ICIs) are ascribed to the immunosuppressive tumor microenvironment and the lack of sufficient infiltration of activated CD8+ T cells. Transforming the tumor microenvironment (TME) from "cold" to "hot" and thus more likely to potentiate the effects of ICIs is a promising strategy for cancer treatment. We found that the selective BCL-2 inhibitor APG-2575 can enhance the antitumor efficacy of anti-PD-1 therapy in syngeneic and humanized CD34+ mouse models. Using single-cell RNA sequencing, we found that APG-2575 polarized M2-like immunosuppressive macrophages toward the M1-like immunostimulatory phenotype with increased CCL5 and CXCL10 secretion, restoring T-cell function and promoting a favorable immunotherapy response. Mechanistically, we demonstrated that APG-2575 directly binds to NF-κB p65 to activate NLRP3 signaling, thereby mediating macrophage repolarization and the activation of proinflammatory caspases and subsequently increasing CCL5 and CXCL10 chemokine production. As a result, APG-2575-induced macrophage repolarization could remodel the tumor immune microenvironment, thus improving tumor immunosuppression and further enhancing antitumor T-cell immunity. Multiplex immunohistochemistry confirmed that patients with better immunotherapeutic efficacy had higher CD86, p-NF-κB p65 and NLRP3 levels, accompanied by lower CD206 expression on macrophages. Collectively, these data provide evidence that further study on APG-2575 in combination with immunotherapy for tumor treatment is required.

[Mechanisms of cancer drug resistance]

Despite decades of research into the molecular mechanisms of cancer and the development of new treatments, drug resistance persists as a major problem. This is in part due to the heterogeneity of cancer, including the diversity of tumor cell lineage and cell plasticity, the spectrum of somatic mutations, the complexity of microenvironments, and immunosuppressive characteristic, then necessitating the use of many different therapeutic approaches. We summarize here the biological causes of resistance, thus offering new perspectives for tackle drug resistance.

Aptamer-Assisted Blockade of the Immune Suppressor Sialic Acid-Binding Immunoglobulin-Like Lectin-15 for Cancer Immunotherapy

The percentage of low response and adaptive resistance to current antibody-based immune checkpoint blockade (ICB) therapy requires the development of novel immunotherapy strategies. Here, we developed an aptamer-assisted immune checkpoint blockade (Ap-ICB) against sialic acid-binding immunoglobulin-like lectin-15 (Siglec-15), a novel immune suppressor broadly upregulated on cancer cells and tumor infiltrating myeloid cells, which is mutually exclusive of programmed cell death ligand 1 (PD-L1). Using protein aptamer selection, we identified WXY3 aptamer with high affinity against Siglec-15 protein/Siglec-15 positive cells. We demonstrated that WXY3 aptamer rescued antigen-specific T cell responses in vitro and in vivo. Importantly, the WXY3 Ap-ICB against Siglec-15 amplified anti-tumor immunity in the tumor microenvironment and inhibited tumor growth/metastasis in syngeneic mouse model, which may result from enhanced macrophage and T cell functionality. In addition, by using aptamer-based spherical nucleic acids, we developed a synergetic ICB strategy of multivalent binding and steric hindrance, which further improves the in vivo anti-tumor effect. Taken together, our results support Ap-ICB targeted Siglec-15 as a potential strategy for normalization cancer immunotherapy.

Overcoming Resistance Mechanisms to Immune Checkpoint Inhibitors: Leveraging the Anti-Tumor Immune Response

As far back as 3000 years ago, the immune system was observed to play a role in mediating tumor regression. Since then, many strategies have been developed to leverage the anti-tumor immune response. However, while many patients respond to ICIs up front some do not, and many of those that do eventually experience tumor progression. Currently, there are several predictive biomarkers of the immune checkpoint inhibitor response; however, no one test appears to be universally predictive and their application varies by disease site. There are many ways in which cancer cells develop primary or acquired resistance to immune checkpoint inhibitors. Efforts to reverse resistance include ways to combat T cell exhaustion, reprogram the tumor microenvironment, increase the availability of tumor neo-antigens, target alternative immune checkpoints, restore a normal/healthy patient gut microbiome, oncolytic viruses and tumor vaccines. The most studied and most promising methods include combining ICIs with therapies targeting alternative immune checkpoints and restoring a normal/healthy patient gut microbiome. This review will discuss T cell-mediated immunity, how this is leveraged by modern immunotherapy to treat cancer and mechanisms of immune checkpoint inhibitor resistance, while highlighting strategies to overcome primary and secondary resistance mechanisms.

Microbial metabolites are involved in tumorigenesis and development by regulating immune responses

The human microbiota is symbiotic with the host and can create a variety of metabolites. Under normal conditions, microbial metabolites can regulate host immune function and eliminate abnormal cells in a timely manner. However, when metabolite production is abnormal, the host immune system might be unable to identify and get rid of tumor cells at the early stage of carcinogenesis, which results in tumor development. The mechanisms by which intestinal microbial metabolites, including short-chain fatty acids (SCFAs), microbial tryptophan catabolites (MTCs), polyamines (PAs), hydrogen sulfide, and secondary bile acids, are involved in tumorigenesis and development by regulating immune responses are summarized in this review. SCFAs and MTCs can prevent cancer by altering the expression of enzymes and epigenetic modifications in both immune cells and intestinal epithelial cells. MTCs can also stimulate immune cell receptors to inhibit the growth and metastasis of the host cancer. SCFAs, MTCs, bacterial hydrogen sulfide and secondary bile acids can control mucosal immunity to influence the occurrence and growth of tumors. Additionally, SCFAs, MTCs, PAs and bacterial hydrogen sulfide can also affect the anti-tumor immune response in tumor therapy by regulating the function of immune cells. Microbial metabolites have a good application prospect in the clinical diagnosis and treatment of tumors, and our review provides a good basis for related research.

Targeted Immunotherapies for Cancers

Advancements in immunotherapy have revolutionized cancer treatment in a broad variety of hematological and solid malignancies and rejuvenated the field of cancer immunology [...].

Synergistically Enhancing Immunotherapy Efficacy in Glioblastoma with Gold-Core Silica-Shell Nanoparticles and Radiation

Purpose

Glioblastoma is a highly aggressive brain tumor with universally poor outcomes. Recent progress in immune checkpoint inhibitors has led to increased interest in their application in glioblastoma. Nonetheless, the unique immune milieu in the brain has posed remarkable challenges to the efficacy of immunotherapy. We aimed to leverage the radiation-induced immunogenic cell death to overcome the immunosuppressive network in glioblastoma.

Methods

We developed a novel approach using the gold-core silica-shell nanoparticles (Au@SiO2 NPs) in combination with low-dose radiation to enhance the therapeutic efficacy of the immune checkpoint inhibitor (atezolizumab) in brain tumors. The biocompatibility, immune cell recruitment, and antitumor ability of the combinatorial strategy were determined using in vitro assays and in vivo models.

Results

Our approach successfully induced the migration of macrophages towards brain tumors and promoted cancer cell apoptosis. Subcutaneous tumor models demonstrated favorable safety profiles and significantly enhanced anticancer effects. In orthotopic brain tumor models, the multimodal therapy yielded substantial prognostic benefits over any individual modalities, achieving an impressive 40% survival rate.

Conclusion

In summary, the combination of Au@SiO2 NPs and low-dose radiation holds the potential to improve the clinical efficacy of immune checkpoint inhibitors. The synergetic strategy modulates tumor microenvironments and enhances systemic antitumor immunity, paving a novel way for glioblastoma treatment.

Causal analysis of the gut microbiota in differentiated thyroid carcinoma: a two-sample Mendelian randomization study

Objective: Numerous studies have highlighted an association between the gut microbiota (GM) and thyroid tumors. Employing Mendelian randomization methodology, we seek to elucidate the causal link between the gut microbiota and thyroid neoplasms. Methods: We procured data from the Mibiogen database encompassing 211 distinct gut microbiota taxa, alongside extensive genome-wide association studies (GWAS) summary data for differentiated thyroid carcinoma (DTC). Our principal analytical approach involved the application of the Inverse-Variance Weighted method (IVW) within the framework of Mendelian randomization. Simultaneously, we conducted sensitivity analyses to assess result heterogeneity, horizontal pleiotropy, and outcome stability. Results: IVW analysis revealed a dual role of the GM in thyroid carcinoma. The phylum Actinobacteria (OR, 0.249 [95% CI, 0.121-0.515]; p < 0.001) was associated with a decreased risk of DTC. Conversely, the genus Ruminiclostridium9 (OR, 11.276 [95% CI, 4.406-28.860]; p < 0.001), class Mollicutes (OR, 5.902 [95% CI, 1.768-19.699]; p = 0.004), genus RuminococcaceaeUCG004 (OR, 3.831 [95% CI, 1.516-9.683]; p = 0.005), genus Paraprevotella (OR, 3.536 [95% CI, 1.330-9.401]; p = 0.011), and phylum Tenericutes (OR, 5.902 [95% CI, 1.768-19.699]; p = 0.004) were associated with an increased risk of DTC. Conclusion: Our findings underscore that the presence of genus Ruminiclostridium9, class Mollicutes, genus RuminococcaceaeUCG004, genus Paraprevotella, and phylum Tenericutes is associated with an elevated risk of DTC, whereas the presence of the phylum Actinobacteria is linked to a decreased risk. These discoveries enhance our comprehension of the relationship between the GM and DTC.

Understanding immune checkpoints and PD-1/PD-L1-mediated immune resistance towards tumour immunotherapy

Immunotherapy has emerged as a transformative approach in the treatment of various cancers, offering new hope for patients previously faced with limited treatment options. A cornerstone of cancer immunotherapy lies in targeting immune checkpoints, particularly the programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) pathway. Immune checkpoints serve as crucial regulators of the immune response, preventing excessive immune activity and maintaining self-tolerance. PD-1, expressed on the surface of T cells, and its ligand PD-L1, expressed on various cell types, including cancer cells and immune cells, play a central role in this regulatory process. Although the success rate associated with these immunotherapies is very promising, most patients still show intrinsic or acquired resistance. Since the mechanisms related to PD-1/PD-L1 resistance are not well understood, an in-depth analysis is necessary to improve the success rate of anti-PD-1/PD-L1 therapy. Hence, here we provide an overview of PD-1, its ligand PD-L1, and the resistance mechanism towards PD-1/PD-L1. Furthermore, we have discussed the plausible solution to increase efficacy and clinical response. For the following research, joint endeavours of clinicians and basic scientists are essential to address the limitation of resistance towards immunotherapy.