Melanoma-specific MHC-II expression represents a tumour-autonomous phenotype and predicts response to anti-PD-1/PD-L1 therapy

The immune checkpoint LAG-3 is expressed by melanoma cells and correlates with clinical progression of the melanoma

Immune checkpoint blockers have substantially improved prognosis of melanoma patients, nevertheless, resistance remains a significant problem. Here, intrinsic and extrinsic factors in the tumor microenvironment are discussed, including the expression of alternative immune checkpoints such as lymphocyte activation gene 3 (LAG-3) and T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3). While most studies focus on immune cell expression of these proteins, we investigated their melanoma cell intrinsic expression by immunohistochemistry in melanoma metastases of 60 patients treated with anti-programmed cell death protein 1 (PD-1) and/or anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) therapy, and correlated it with the expression of potential ligands, RNA sequencing data and clinical outcome. LAG-3 and TIM-3 were commonly expressed in melanoma cells. In the stage IV cohort, expression of LAG-3 was associated with M1 stage (p < 0.001) and previous exposure to immune checkpoint inhibitors (p = 0.029). Moreover, in the anti-PD-1 monotherapy treatment group patients with high LAG-3 expression by tumor cells tended to have a shorter progression-free survival (p = 0.088), whereas high expression of TIM-3 was associated with a significantly longer overall survival (p = 0.007). In conclusion, we provide a systematic analysis of melanoma cell intrinsic LAG-3 and TIM-3 expression, highlighting potential implications of their expression on patient survival.

MHC class II: a predictor of outcome in melanoma treated with immune checkpoint inhibitors

This study aimed to evaluate the predictive value of MHC class II (MHC-II) expression by melanoma cells in a large cohort of metastatic cutaneous melanoma patients treated with immune checkpoint inhibitors (ICIs). We conducted a single-center, retrospective study involving stage IV cutaneous melanoma patients who received ICI as first-line therapy. MHC-II expression in melanoma cells was quantified using dual-color anti-SOX10 and anti-MHC-II immunohistochemistry on tumor samples from 95 patients. The primary endpoint was event-free survival (EFS), with secondary endpoints including 1-year EFS, 1-year overall survival (OS), disease control rate (DCR), and the correlation between MHC-II expression and clinico-biological characteristics. The cohort had a median age of 67 years (range, 33-90), with a male-to-female ratio of 50 : 45. Thirty-three percent of patients received the ipilimumab-nivolumab combination. The median follow-up was 16.8 months. Disease progression occurred in 58 patients (61%), with a median time to progression of 4.8 months. Forty-six patients (48.4%) experienced an event within the first year, and 52 patients (54.7%) died during follow-up. MHC-II positivity was observed in ≥10% of melanoma cells in 6.3% of patients. MHC-II expression was significantly associated with 1-year EFS ( P  = 0.037) and DCR ( P  = 0.032), but not with EFS or 1-year OS. Age, phototype, and brain metastases were correlated with MHC-II expression status. Our findings suggest that MHC-II expression by melanoma cells may serve as a favorable predictive biomarker for survival in metastatic cutaneous melanoma patients treated with ICIs.

Palbociclib and dsRNA sensor co-operate to enhance anti-cancer effects through ER stress and modulation of immune evasion

Cytoplasmic pattern recognition receptors (PRR) for double-stranded RNA, such as RIG-I/MDA5, are key mediators of anti-viral responses. Here we screen for synergistic drug-virotherapy combinations and find that the reovirus type III Dearing strain (Rt3D)-palbociclib combination augments oncolytic virus-induced stress responses and increases interferon production and signaling. Data from RIG-I agonist and ER stress-inducing agents further confirms the crosstalk between RNA-sensing and ER stress in inducing cancer cell death and interferon production. Combined Rt3D-palbociclib also increases innate immune activation and IFN-induced HLA expression within tumor cells, with accompanying alterations in the epigenetic landscape and endogenous retroviral (ERV) elements. Analysis of the immunopeptidome in treated cells further reveals changes to HLA-captured peptides, including altered expression of peptides from cancer or testis antigens and ERVs. Our findings thus highlight the crosstalk between stress signaling and PRR activation for mediating enhanced anti-cancer efficacy.

Association between transcriptomic metrics of exogenous antigen presentation and adaptive immunity with locoregional recurrence in localized estrogen receptor negative breast cancer: retrospective review of multi-institutional datasets

BACKGROUND

Transcriptomic features of breast cancer locoregional recurrence (LRR) remain poorly understood. We therefore sought to investigate transcriptomic features associated with LRR in newly diagnosed invasive breast tumors from our institutional dataset.

METHODS

Transcriptomic profiling was performed on 632 tumors from consecutive patients treated within our health system for newly diagnosed non-metastatic breast cancer. Univariable Cox models identified genes whose expression was associated with LRR (q-value < 0.05). Up-regulated (UR) genes were defined as hazard ratio (HR) > 1 and down-regulated (DR) genes were defined as HR < 1. Gene set enrichment analyses were performed for UR and DR gene sets and validated within two external cohorts of ER- tumors.

RESULTS

With a median follow-up of 7.6 years, we observed 38 LRRs: 28/481 (5.8%) in ER + and 10/151 (6.6%) in ER-. There were 43 UR and 7 DR genes associated with LRR in ER + tumors, while 417 UR and 1150 DR genes were associated with LRR in ER- tumors. UR genes in ER + tumors were enriched for roles in cell proliferation (q < 0.05). In contrast, LRR in ER- tumors was most strongly associated with DR genes enriched for MHC-II-mediated antigen presentation and T cell activation (q < 0.05). In external cohorts of ER- tumors, 97 significant DR genes (p < 0.05) were enriched for 18 pathways, including 5 pathways involved in MHC-II signaling, antigen presentation and T-cell activation.

CONCLUSIONS

Transcriptomic patterns associated with LRR appear distinct between ER + and ER- tumors. In ER + tumors, LRR appears predominantly associated with proliferation, whereas ER- LRR suggests a robust pattern of suppressed antigen presentation via MHC-II.

Astragalus injection antagonizes the efficacy of anti-PD-1 against melanoma through down-regulating MHC-II expression

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus injection, a solution derived from Astragalus mongholicus Bunge, has been used in cancer patients for its immune-boosting properties. The effects of Astragalus injection combined with immune checkpoint inhibitors (ICIs) in cancer remain unsuspected.

AIM OF THE STUDY

This study aims to investigate the efficacy of combining Astragalus injection with anti-PD-1 and to elucidate the potential mechanisms.

MATERIALS AND METHODS

A melanoma-bearing mouse model was established to observe the effects of Astragalus injection combined with anti-PD-1 treatment. The immune cell infiltration in tumor tissues was evaluated by flow cytometry. Subsequently, network pharmacology and RNA sequencing were conducted to anticipate latent mechanisms of Astragalus in melanoma. Finally, these predictions were validated by flow cytometry, qPCR, Western blotting, and ELISA.

RESULTS

Astragalus injection significantly antagonized the efficacy of anti-PD-1 in melanoma, resulting in a notable reduction of immune cell infiltration. The network pharmacology and RNA sequencing analysis revealed critical signaling routes, encompassing T-cell receptor activation, immune antigen presentation, and the JAK/STAT pathway. Subsequent data suggested that Astragalus injection could down-regulate the expressions of MHC-II in dendritic cells and B16-OVA cells and restrict the activation of dendritic cells. Moreover, the expressions of CIITA and phosphorylated STAT1 were prominently inhibited by Astragalus injection, whereas the overexpression of STAT1 partially reversed the Astragalus injection-induced decrease of MHC-II.

CONCLUSIONS

Astragalus antagonized the therapeutic effect of anti-PD-1 in melanoma. These effects were partially through inhibiting JAK/STAT signaling and down-regulating MHC-II expression.

Multi-omic profiling in breast cancer: utility for advancing diagnostics and clinical care

INTRODUCTION

Breast cancer remains a major global health challenge. While advances in precision oncology have contributed to improvements in patient outcomes and provided a deeper understanding of the biological mechanisms that drive the disease, historically, research and patients' allocation to treatment have heavily relied on single-omic approaches, analyzing individual molecular dimensions such as genomics, transcriptomics, or proteomics. While these have provided deep insights into breast cancer biology, they often fail to offer a complete understanding of the disease's complex molecular landscape.

AREAS COVERED

In this review, the authors explore the recent advancements in multi-omic research in the realm of breast cancer and use clinical data to show how multi-omic integration can offer a more holistic understanding of the molecular alterations and their functional consequences underlying breast cancer.

EXPERT OPINION

The overall developments in multi-omic research and AI are expected to complement precision diagnostics through potentially refining prognostic models, and treatment selection. Overcoming challenges such as cost, data complexity, and lack of standardization is crucial for unlocking the full potential of multi-omics and AI in breast cancer patient care to enable the advancement of personalized treatments and improve patient outcomes.

Carbon Dot-Linked Hydrogel for TAMs Transform: Spatiotemporal Manipulation to Reshape Tumor Microenvironment

As one of the most crucial immune cells in the tumor microenvironment (TME), regulating tumor-associated macrophages (TAMs) is vital for enhancing antitumor immunity. Here, an injectable carbon dots (CDs)-linked egg white hydrogel was developed, termed TAMs Transform Factory (TTF-L-C), to spatiotemporally manipulate TAMs. The fabricated CDs significantly promoted macrophage migration. Notably, TTF-L-C achieved macrophage spatial enrichment through CDs-induced directional recruitment with molecular Ctnnd1 upregulation. Subsequently, the recruited macrophages were locoregionally reprogrammed within TTF-L-C, as well as blocking the upregulated PD-L1. Finally, through multi-stage regulation at spatial, cellular, and molecular levels, TTF-L-C released immune-activated M1 macrophages to the tumor site as it degraded. Moreover, TTF-L-C promoted dendritic cell (DCs) maturation and further boosted T cell activation, thereby reshaping the tumor-suppressive TME. Through peritumoral injection, TTF-L-C enhanced tumor immunotherapy in both subcutaneous and recurrent 4T1 tumor models with satisfactory biosafety. Therefore, TTF-L-C is proposed to become a safe and powerful platform for various biomedical applications.

Exosomes as key mediators in immune and cancer cell interactions: insights in melanoma progression and therapy

Exosomes (30-150 nm) are small extracellular vesicles that are secreted by cells into the extracellular environment and are known to mediate cell-to-cell communication. Exosomes contain proteins, lipids, and RNA molecules in relative abundance, capable of modifying the activity of target cells. Melanoma-derived exosomes (MEXs) promote the transfer of oncogenic signals and immunosuppressive factors into immune cells, resulting in a bias of the immune response towards tumor-promoting processes. MEXs could suppress the activation and proliferation of T cells and dendritic cells and induce differentiation of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). They can induce apoptosis of antigen-specific CD8 + T cells and promote the transfer of tumor antigens, resulting in immune evasion. Specifically, MEXs can shuttle cytokines like interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) to immune cells or express programmed death-ligand 1 (PD-L1 or CD274), creating an immune-suppressive microenvironment that promotes tumorigenesis. Since exosomes preferentially accumulate in melanoma tissues, this targeted delivery could enhance the bioavailability of treatments while limiting side effects. Here, we review the molecular composition of melanoma-derived exosomes, their mechanisms of action, and their potential as therapeutic targets or biomarkers in melanoma. The summarizations of these mechanisms to appropriately influence exosome-mediated interactions could yield new tactics to elicit anti-melanoma immunity or augment the therapeutic effects of current therapies.

Real-time functional proteomics enhances therapeutic targeting in precision oncology molecular tumor boards

Collaborative review of molecular profiling data by multidisciplinary molecular tumor boards (MTB) is increasingly important for improving patient management and outcomes, though currently relies nearly exclusively on nucleic acid next-generation sequencing (NGS) and limited panels of immunohistochemistry-based protein abundance data. We examined the feasibility of incorporating real-time laser microdissection (LMD) enrichment of tumor epithelium and commercial CLIA-based reverse phase protein array (RPPA) protein drug target expression/activation profiling into our cancer center's MTB to complement standard clinical NGS-based profiling. The LMD-RPPA workflow was performed within a therapeutically permissive timeframe with a median dwell time of nine days, during which specimens were processed outside of standard clinical workflows. The RPPA-generated data supported additional and/or alternative therapeutic considerations for 54% of profiled patients following review by the MTB. These findings suggest that integrating proteomic/phosphoproteomic and NGS-based genomic data creates opportunities to further personalize clinical decision-making for precision oncology.

Restoring tumor antigenicity activates the "bystander" T cell immune cycle

Tumor-specific T cells play a crucial role in tumor immunity. However, these cells are often scarce and functionally exhausted within the tumor microenvironment (TME), leading to the limited efficacy of immunotherapy in many cancer patients. In contrast, increasing evidence suggests that the TME is rich in "bystander" T cells (TBYS), most of which are virus-specific and unrelated to the tumor. These TBYS cells retain functional memory characteristics and the potential to kill tumor cells. To utilize TBYS cells in the TME for tumor elimination, we designed an intracellular delivery system, ASCP, encoding a TBYS epitope to redirect tumor cell antigen specificity toward pre-existing TBYS cells, resulting in effective tumor inhibition in multiple preclinical models. The ASCP-antigen peptide strategy restores the antigenicity of tumor cells and induces epitope spreading of tumor antigens, thereby eliciting more diverse tumor-specific T cell responses. Remarkably, this strategy incorporates MHC-II epitopes containing unnatural amino acids (p-nitrophenylalanine, termed NiraTh), which stimulate CD4+ T cell-mediated immunity and assist CD8+ T cells in clearing tumors. Overall, the ASCP-mediated tumor antigen reprogramming strategy provides important insights for cancer immunotherapy in populations with a history of common viral infections.

Role of metabolic transformation in cancer immunotherapy resistance: molecular mechanisms and therapeutic implications

BACKGROUND

Immunotherapy in the treatment of cancer, with immune inhibitors helps in many cancer types. Many patients still encounter resistance to these treatments, though. This resistance is mediated by metabolic changes in the tumour microenvironment and cancer cells. The development of novel treatments to overcome resistance and boost immunotherapy's effectiveness depends on these metabolic changes.

OBJECTIVE

This review concentrates on the molecular mechanisms through which metabolic transformation contributes to cancer immunotherapy resistance. Additionally, research therapeutic approaches that target metabolic pathways to enhance immunotherapy for resistance.

METHODS

We used databases available on PubMed, Scopus, and Web of Science to perform a thorough review of peer-reviewed literature. focusing on the tumor microenvironment, immunotherapy resistance mechanisms, and cancer metabolism. The study of metabolic pathways covers oxidative phosphorylation, glycolysis, lipid metabolism, and amino acid metabolism.

RESULTS

An immunosuppressive tumour microenvironment is produced by metabolic changes in cancer cells, such as dysregulated lipid metabolism, enhanced glutaminolysis, and increased glycolysis (Warburg effect). Myeloid-derived suppressor cells and regulatory T cells are promoted, immune responses are suppressed, and T cell activity is impaired when lactate and other metabolites build up. changes in the metabolism of amino acids in the pathways for arginine and tryptophan, which are nutrients crucial for immune function. By enhancing their function in the tumour microenvironment, these metabolic alterations aid in resistance to immune checkpoint inhibitors.

CONCLUSION

Metabolic change plays a key role in cancer immunotherapy resistance. Gaining knowledge of metabolic processes can help develop efficient treatments that improve immunotherapy's effectiveness. In order to determine the best targets for therapeutic intervention, future studies should concentrate on patient-specific metabolic profiling.

Dual role of interferon-gamma in the response of melanoma patients to immunotherapy with immune checkpoint inhibitors

Interferon-gamma (IFN-γ) is a cytokine produced mainly by immune cells and can affect cancer cells by modulating the activity of multiple signaling pathways, including the canonical Janus-activated kinase/signal transducer and activator of transcription (JAK/STAT) cascade. In melanoma, IFN-γ can exert both anticancer effects associated with cell-cycle arrest and cell death induction and protumorigenic activity related to immune evasion leading to melanoma progression. Notably, IFN-γ plays a crucial role in the response of melanoma patients to immunotherapy with immune checkpoint inhibitors (ICIs), which are currently used in the clinic. As these agents target programmed death-1 (PD-1) and its ligand (PD-L1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) and lymphocyte-activation gene 3 (LAG-3), they are designed to restore the antimelanoma immune response. In this respect, IFN-γ produced by cells in the tumor microenvironment in response to ICIs has a beneficial influence on both immune and melanoma cells by increasing antigen presentation, recruiting additional T-cells to the tumor site, and inducing direct antiproliferative effects and apoptosis in melanoma cells. Therefore, IFN-γ itself and IFN-γ-related gene signatures during the response to ICIs can constitute biomarkers or predictors of the clinical outcome of melanoma patients treated with ICIs. However, owing to its multifaceted roles, IFN-γ can also contribute to developing mechanisms associated with the acquisition of resistance to ICIs. These mechanisms can be associated with either decreased IFN-γ levels in the tumor microenvironment or diminished responsiveness to IFN-γ due to changes in the melanoma phenotypes associated with affected activity of other signaling pathways or genetic alterations e.g., in JAK, which restricts the ability of melanoma cells to respond to IFN-γ. In this respect, the influence of IFN-γ on melanoma-specific regulators of the dynamic plasticity of the cell phenotype, including microphthalmia-associated transcription factor (MITF) and nerve growth factor receptor (NGFR)/CD271 can affect the clinical efficacy of ICIs. This review comprehensively discusses the role of IFN-γ in the response of melanoma patients to ICIs with respect to its positive influence and role in IFN-γ-related mechanisms of resistance to ICIs as well as the potential use of predictive markers on the basis of IFN-γ levels and signatures of IFN-γ-dependent genes.

Molecular determinants of response to neoadjuvant pembrolizumab plus chemotherapy in patients with high-risk, early-stage, triple-negative breast cancer: exploratory analysis of the open-label, multicohort phase 1b KEYNOTE-173 study

BACKGROUND

The multicohort, open-label, phase 1b KEYNOTE-173 study was conducted to investigate pembrolizumab plus chemotherapy as neoadjuvant therapy for triple-negative breast cancer (TNBC). This exploratory analysis evaluated features of the tumor microenvironment that might be predictive of response.

METHODS

Cell fractions from 20 paired samples collected at baseline and after one cycle of neoadjuvant pembrolizumab prior to chemotherapy initiation were analyzed by spatial localization (tumor compartment, stromal compartment, or sum of tumor and stromal compartments [total tumor]) using three six-plex immunohistochemistry panels with T-cell, myeloid cell, and natural killer cell components. Area under the receiver operating characteristic curve (AUROC) was used to assess associations between immune subsets and gene expression signatures (T-cell-inflamed gene expression profile [TcellinfGEP] and 10 non-TcellinfGEP signatures using RNA sequencing) and pathologic complete response (pCR).

RESULTS

At baseline, six immune subsets quantitated within the tumor compartment showed AUROC with 95% CIs not crossing 0.5, including CD11c+ cells (macrophage and dendritic cell [DC]: AUROC, 0.85; 95% confidence interval [CI] 0.63-1.00), CD11c+/MHCII+/CD163-/CD68- cells (DC: 0.76; 95% CI, 0.53-0.99), CD11c+/MHCII-/CD163-/CD68- cells (nonactivated/immature DC: 0.80; 95% CI 0.54-1.00), and CD11c+/CD163+ cells (M2 macrophage: 0.77; 95% CI 0.55-0.99). Other associations with pCR included baseline CD11c+/MHCII-/CD163-/CD68- (nonactivated/immature DC) within the total tumor (AUROC, 0.76; 95% CI 0.51-1.00) and the baseline CD11c/CD3 ratio within the tumor compartment (0.75; 95% CI 0.52-0.98). Changes in immune subsets following one cycle of pembrolizumab were not strongly associated with pCR. Although T-cell associations were relatively weak, specific CD8 subsets trended toward association. The AUROC for discriminating pCR based on TcellinfGEP was 0.55 (95% CI 0.25-0.85); when detrended by TcellinfGEP, AUROC varied for the non-TcellinfGEP signatures. TcellinfGEP expression trended higher in responders than in nonresponders when evaluating pCR.

CONCLUSIONS

Myeloid cell populations within the tumor compartment at baseline and TcellinfGEP show a promising trend toward an association with pCR in a small subgroup of patients with early-stage TNBC treated with neoadjuvant pembrolizumab plus chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02622074; registration date, December 2, 2015.

Revolutionary Cancer Therapy for Personalization and Improved Efficacy: Strategies to Overcome Resistance to Immune Checkpoint Inhibitor Therapy

Cancer remains a significant public health issue worldwide, standing as a primary contributor to global mortality, accounting for approximately 10 million fatalities in 2020 [...].

Prognostic Biomarkers in Evolving Melanoma Immunotherapy

Melanoma, a highly aggressive form of skin cancer, has seen significant advancements in treatment through the introduction of immunotherapy. However, the variability in patient responses underscores the need for reliable biomarkers to guide treatment decisions. This article reviews key biomarkers in melanoma immunotherapy, such as PD-L1 expression, tumor mutational burden (TMB), and gene expression profiles (GEPs). It also explores emerging biomarkers, including LAG-3 expression, immune cell phenotyping in tissue and blood, gut microbiota, and circulating tumor DNA (ctDNA). Notably, ctDNA may offer valuable insights into the efficacy of T cell-engaging bispecific molecules, such as tebentafusp. The review provides a comprehensive overview of the evolving landscape of melanoma biomarkers, their role in personalizing treatment, and future research directions, including neoadjuvant immune checkpoint inhibition.

The relationship between a high-fat diet, gut microbiome, and systemic chronic inflammation: insights from integrated multiomics analysis

BACKGROUND

The detrimental effects of a high-fat diet (HFD) extend beyond metabolic consequences and include systemic chronic inflammation (SCI), immune dysregulation, and gut health disruption.

OBJECTIVES

In this study, we used Mendelian randomization (MR) to investigate the relationship between HFD, gut microbiota, and SCI.

METHODS

Genetic variants associated with dietary fat were utilized to explore causal relationships. Genome-wide association study data for the analyses of the gut microbiota, inflammatory cytokines, immune cell characteristics, and serum metabolites were obtained from European individuals. Mediation analysis was used to reveal potential mediating factors. The GMrepo database was used to analyze the bacterial composition in different groups. Transcriptomic and single-cell sequencing analyses explored inflammation and barrier function in colonic tissue.

RESULTS

HFD consumption was linked to changes in the abundance of 3 bacterial families and 11 bacterial genera. Combined with the GMrepo database, the increased abundance of the genus Lachnospiraceae_FCS020group and the decreased abundance of genus Bacteroides and genus Barnesiella are consistent with the MR results. Transcriptomic and single-cell sequencing analyses revealed intestinal inflammation and mucosal barrier dysfunction in HFD-fed mice. MR revealed a link between HFD consumption and increased levels of interleukin (IL)-18 [odds ratio (OR): 3.64, 95%CI: 1.24, 10.69, P = 0.02], MIG (OR = 3.14, 95%CI: 1.17, 8.47, P = 0.02), IL-13 [OR = 3.21, 95% confidence interval (CI): 1.08, -9.52, P = 0.04], and IL-2RA (OR = 2.93, 95%CI: 1.01, 8.53, P = 0.049). Twenty-nine immune cell signatures, including altered monocyte and T-cell subsets, were affected by HFD consumption. Twenty-six serum metabolites that are linked to HFD consumption, particularly lipid and amino acid metabolites, were identified. The positive gut microbiota exhibit extensive associations with inflammatory cytokines. In particular, Lachnospiraceae_FCS020 group (OR: 1.93, 95% CI: 1.11, 3.37, P = 0.02) may play a mediating role in HFD-induced increases in IL-2RA concentrations.

CONCLUSIONS

Microbial dysbiosis appears to be an important mechanism for HFD-induced SCI. The Lachnospiraceae_FCS020 group may act as a key genus in HFD-mediated elevation of IL-2RA.

Decoding melanoma's cellular mosaic to unlock immunotherapy potential

Cancer evolution is driven by molecular events within cancer cells and their complex interactions with surrounding cells. Intra-tumor heterogeneity - driven by somatic genetic mutations, epigenetic dysregulation, immune cell infiltration, and microenvironmental factors - complicates the identification of reliable biomarkers and therapeutic targets. Single-cell sequencing and spatial multiomics technologies are revolutionizing our comprehension of how each component of the cellular machinery and tissue architecture collaborates to propel cancer progression. Much like how the restoration and interpretation of Pompeii mosaics have enriched our understanding of ancient Roman life, unraveling the intricate mosaic of cancer will transform the way this disease is diagnosed and treated. This review describes how the advent of single-cell multiomics has provided crucial insights into cutaneous melanoma biology and the mechanisms underlying resistance to immunotherapy.

Threading the Needle: Navigating Novel Immunotherapeutics in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a poor prognosis. Currently, chemotherapy is the only option for most patients with advanced-stage PDAC. Further, conventional immunotherapies and targeted therapies improve survival outcomes only in rare PDAC patient subgroups. To date, combinatory immunotherapeutic strategies to overcome the immune-hostile PDAC tumor microenvironment (TME) have resulted in limited efficacy in clinical studies. However, efforts are ongoing to develop new treatment strategies for patients with PDAC with the evolving knowledge of the TME, molecular characterization, and immune resistance mechanisms. Further, the growing arsenal of various immunotherapeutic agents, including novel classes of immune checkpoint inhibitors and oncolytic, chimeric antigen receptor T cell, and vaccine therapies, reinforces these efforts. This review will focus on the place of immunotherapy and future possible strategies in PDAC.

Clinical Approaches for the Management of Skin Cancer: A Review of Current Progress in Diagnosis, Treatment, and Prognosis for Patients with Melanoma

Melanoma represents a significant public health challenge due to its increasing incidence and potential for metastasis. This review will explore the current clinical approaches to the management of melanoma, focusing on advancements in diagnosis, treatment, and prognosis. Methods for early detection and accurate staging have been enhanced by new diagnostic strategies. Treatment modalities have expanded beyond traditional surgical excision to include targeted therapy and immunotherapy. Prognostic assessment has benefited from the development of novel biomarkers and genetic profiling. This review will highlight the progress made in the multidisciplinary management of melanoma, underscoring the importance of continuous research to improve patient outcomes.

Antigen-presenting fibroblasts: emerging players in immune modulation and therapeutic targets

Antigen-presenting fibroblasts are a newly recognized subset that challenges the traditional view of these cells as mere structural components. Under pathological or environmental stimuli, fibroblasts acquire antigen-presenting capabilities through the expression of MHC-II molecules and co-stimulatory factors, enabling them to interact with T cells and modulate immune responses. These specialized fibroblasts have been identified across various tissues and diseases, where they play context-dependent roles, either amplifying immune dysregulation or contributing to immune homeostasis. This review synthesizes recent advances in understanding the origins, activation, and functions of antigen-presenting fibroblasts. It highlights their role in promoting pathogenic immune responses and offering therapeutic opportunities through targeted modulation. Advancing our understanding of antigen-presenting fibroblasts holds great promise for developing innovative approaches to immune modulation and therapy across a range of diseases.

MAP1LC3C repression reduces CIITA- and HLA class II expression in non-small cell lung cancer

In the last decade, advancements in understanding the genetic landscape of lung squamous cell carcinoma (LUSC) have significantly impacted therapy development. Immune checkpoint inhibitors (ICI) have shown great promise, improving overall and progression-free survival in approximately 25% of the patients. However, challenges remain, such as the lack of predictive biomarkers, difficulties in patient stratification, and identifying mechanisms that cancers use to become immune-resistant ("immune-cold"). Analysis of TCGA datasets reveals reduced MAP1LC3C expression in cancer. Further analysis indicates that low MAP1LC3C is associated with reduced CIITA and HLA expression and with decreased immune cell infiltration. In tumor cells, silencing MAP1LC3C inhibits CIITA expression and suppresses HLA class II production. These findings suggest that cancer cells are selected for low MAP1LC3C expression to evade efficient immune responses.

Imaging antigen processing and presentation in cancer

Introduction

Antigen processing and presentation are vital processes of the adaptive immunity. These processes involve a series of intracellular and extracellular events, including the enzymology within cells during antigen processing, the loading and presentation of antigenic peptides on major histocompatibility complexes, the recruitment of T cells, their interaction with antigen-presenting cells, and the expression of adhesion, co-stimulatory and co-inhibitory molecules at the T cell immunological synapse. These events collectively fine-tune and sustain antigen recognition and T cell function. Dysregulation of this machinery can profoundly impact the efficacy of cancer immunotherapy. Imaging technologies have emerged as powerful tools for elucidating the mechanisms underlying antigen processing and presentation. By providing complementary perspectives into the cellular and molecular interactions at play, imaging has significantly enhanced our understanding of these complex immunological events in cancer. Such insights can improve the monitoring of immunotherapy responses, facilitate the identification of effective treatments, and aid in predicting patient outcomes.

Methods

This review explores the role of imaging in studying antigen processing and presentation in the context of cancer.

Conclusion

It highlights key considerations for developing imaging tools and biomarkers to detect components of these pathways. Additionally, it examines the strengths and limitations of various imaging approaches and discusses their potential for clinical translation.

Loss of tumor cell MHC Class II drives insensitivity of BRAF-mutant anaplastic thyroid cancers to MAPK inhibitors

Cancer cells present neoantigens dominantly through MHC class I (MHCI) to drive tumor rejection through cytotoxic CD8+ T-cells. There is growing recognition that a subset of tumors express MHC class II (MHCII), causing recognition of antigens by TCRs of CD4+ T-cells that contribute to the anti-tumor response. We find that mouse Braf V600E -driven anaplastic thyroid cancers (ATC) respond markedly to the RAF + MEK inhibitors dabrafenib and trametinib (dab/tram) and that this is associated with upregulation of MhcII in cancer cells and increased CD4+ T-cell infiltration. A subset of recurrent tumors lose MhcII expression due to silencing of Ciita , the master transcriptional regulator of MhcII, despite preserved interferon gamma signal transduction, which can be rescued by EZH2 inhibition. Orthotopically-implanted Ciita -/- and H2-Ab1 -/- ATC cells into immune competent mice become unresponsive to the MAPK inhibitors. Moreover, depletion of CD4+, but not CD8+ T-cells, also abrogates response to dab/tram. These findings implicate MHCII-driven CD4+ T cell activation as a key determinant of the response of Braf-mutant ATCs to MAPK inhibition.

Uridine-cytidine kinase 2 is correlated with immune, DNA damage repair and promotion of cancer stemness in pan-cancer

Background

UCK2 (Uridine-Cytidine Kinase 2) is a promising prognostic marker for malignant tumors, but its association with immune infiltration and cancer stemness in pan-cancer remains to be fully understood. we find that gene UCK2 is closed related to RNA stemness scores (RNAss) and DNA stemness scores (DNAss), which is measured the tumor stemness. We also discover an association between UCK2 expression and immune cells by CIBERSORT algorithm, ESTIMATE algorithm and ssGSEA algorithm, especially, related to T cell, monocytes, mast cells, and macrophages. This study aims to shed light on the role and possible mechanism of UCK2 in pan-cancer.

Methods

We used the R programming language for pan-cancer bulk sequencing data analysis, which were obtained from the University of California, Santa Cruz (UCSC) datasets. UCSC database is a very useful for explore data from TCGA and other cancer genomics datasets, The data we explored at the UCK2 transcriptome level came from TCGA data in the UCSC database. We explored differential UCK2 expression between tumor and normal samples. Immunohistochemistry (IHC) was utilized to validate the expression of UCK2 in different types cancers using tumor tissue chips. The correlations of UCK2 with prognosis, genetic instability, DNA repair, cancer stem cell characteristics, and immune cell infiltration were investigated. Furthermore, single-cell datasets, acquired from the Gene Expression Omnibus (GEO) database, were used to validate the relationship between UCK2 and immune cells. GEO is a famous public genomics database supporting freely disseminates microarray data. Finally, we analyzed the correlation between UCK2 and drug sensitivity.

Results

UCK2 expression was observed to be high in most cancers and was remarkably related to the prognosis of pan-cancers. We found that the increased UCK2 expression was associated with higher genetic instability. Additionally, positive relationships were observed between UCK2 expression and mismatch repair genes, homologous recombination repair genes, and cancer stemness across different cancer types. There were significant correlations between UCK2 and T cells, monocytes, mast cells, and macrophages. Moreover, as expected, the immune checkpoint human leucocyte antigen (HLA) was found to be negatively related to UCK2. Similarly, UCK2 was also observed to have a negative association with major histocompatibility complex (MHC) genes. We noted that UCK2 had significant correlations with the sensitivity to various anti-cancer drug.

Conclusion

We have observed that UCK2 plays pivotal roles in prognosis and tumor immunity, and it is associated with DNA repair and cancer stemness. The UCK2 gene exhibits a strong correlation with the immune checkpoints HLA. This study highlights its potential impact on drug sensitivity.

OASL promotes immune evasion in pancreatic ductal adenocarcinoma by enhancing autolysosome-mediated degradation of MHC-I

Rationale: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a global prevalence and poor prognosis, largely due to immune escape mechanisms. However, the potential reasons for the decreased infiltration of cytotoxic T lymphocytes (CTLs) in PDAC remain inadequately understood. In this study, we aimed to elucidate the molecular mechanisms contributing to the low-CTLs infiltration in patients with PDAC. Methods: Bioinformatic analyses were used to identify key factors associated with low-CTLs infiltration in PDAC and the role of oligoadenylate synthetase-like (OASL) was mainly focused in our study. Immunohistochemistry (IHC) was used to assess the relationship between the expression of OASL and the prognosis of patients. Western blotting, Flow cytometry, Co-immunoprecipitation and Immunofluorescence were applied to elucidate the molecular mechanism by which OASL mediates immune escape in PDAC. The orthotopic PDAC models were constructed to evaluate the effects of OASL-knockdown on CD8+ T cells infiltration and tumor growth in vivo. Results: OASL was found to be significantly upregulated in PDAC and negatively correlated with the major histocompatibility complex class I (MHC-I) expression, which is associated with worse patient prognosis. Notably, OASL-knockdown leads to a significant increase in CD8+ T cell infiltration and slows tumor growth in vivo. Mechanistic studies revealed that OASL -knockdown restored the total and surface MHC-I level through impairing neighbor of BRCA1 gene 1 (NBR1)-mediated autophagy-lysosomal degradation of MHC-I. Conclusions: Targeting OASL enhances the immune response in PDAC, providing a novel therapeutic strategy to improve outcomes in PDAC patients.

ANXA10 sensitizes microsatellite instability-high colorectal cancer to anti-PD-1 immunotherapy via assembly of HLA-DR dimers by regulating CD74

BACKGROUND

Microsatellite instability-high (MSI-H) metastatic colorectal cancer (CRC) patients are the dominant population in immune checkpoint blockade treatments, while more than half of them could not benefit from single-agent immunotherapy. We tried to identify the biomarker of MSI-H CRC and explore its role and mechanism in anti-PD-1 treatments. Tumor-specific MHC-II was linked to a better response to anti-PD-1 in MSI-H CRC and CD74 promoted assembly and transport of HLA-DR dimers.

METHODS

The characteristic gene was screened by data analysis of single-cell and bulk transcriptome sequencing from public datasets. MSI-H CRC cells co-cultured with peripheral blood mononuclear cells and syngeneic model in C57BL/6 mice were performed to detect the sensitivity to anti-PD-1 treatments respectively.

RESULTS

ANXA10 was identified as a characteristic gene of MSI-H CRC and its expression was obviously greater in MSI-H than MSS CRC. ANXA10 significantly sensitized MSI-H CRC to anti-PD-1 treatments in vitro and in vivo. Specifically, ANXA10 promoted HLA-DR dimers in and on the surface of MSI-H CRC by increasing CD74 expression. Besides, this work demonstrated that ANXA10 contributed to better clinical benefits with anti-PD-1 therapy in MSI-H CRC patients.

CONCLUSIONS

Our results provided a novel molecular marker ANXA10 to identify benefit population of MSI-H CRC for improving efficacy of anti-PD-1 and contributed to selection of treatment strategies.

Hypoxia is linked to acquired resistance to immune checkpoint inhibitors in lung cancer

Despite the established use of immune checkpoint inhibitors (ICIs) to treat non-small cell lung cancer (NSCLC), only a subset of patients benefit from treatment and ∼50% of patients whose tumors respond eventually develop acquired resistance (AR). To identify novel drivers of AR, we generated murine Msh2 knock-out (KO) lung tumors that initially responded but eventually developed AR to anti-PD-1, alone or in combination with anti-CTLA-4. Resistant tumors harbored decreased infiltrating T cells and reduced cancer cell-intrinsic MHC-I and MHC-II levels, yet remained responsive to IFNγ. Resistant tumors contained extensive regions of hypoxia, and a hypoxia signature derived from single-cell transcriptional profiling of resistant cancer cells was associated with decreased progression-free survival in a cohort of NSCLC patients treated with anti-PD-1/PD-L1 therapy. Targeting hypoxic tumor regions using a hypoxia-activated pro-drug delayed AR to ICIs in murine Msh2 KO tumors. Thus, this work provides a rationale for targeting tumor metabolic features, such as hypoxia, in combination with immune checkpoint inhibition.

Advances in LAG3 cancer immunotherapeutics

Cancer treatment has entered the age of immunotherapy. Immune checkpoint inhibitor (ICI) therapy has shown robust therapeutic potential in clinical practice, with significant improvements in progression-free survival (PFS) and overall survival (OS). Recently, checkpoint blockade of the lymphocyte activation gene 3 (LAG3) inhibitory receptor (IR) in combination with programmed death protein 1 (PD1) inhibition has been FDA approved in patients with advanced melanoma. This has encouraged the clinical evaluation of new LAG3-directed biologics in combination with other checkpoint inhibitors. Several of these studies are evaluating bispecific antibodies that target exhausted T (TEX) cells expressing multiple IRs. This review discusses the current understanding of LAG3 in regulating antitumor immunity and the ongoing clinical testing of LAG3 inhibition in cancer.

RECQL4 affects MHC class II-mediated signalling and favours an immune-evasive signature that limits response to immune checkpoint inhibitor therapy in patients with malignant melanoma

BACKGROUND

Cancer immunotherapy has transformed metastatic cancer treatment, yet challenges persist regarding therapeutic efficacy. RECQL4, a RecQ-like helicase, plays a central role in DNA replication and repair as part of the DNA damage response, a pathway implicated in enhancing efficacy of immune checkpoint inhibitor (ICI) therapies. However, its role in patient response to ICI remains unclear.

METHODS

We analysed whole exome and bulk RNA sequencing data from a pan-cancer cohort of 25 775 patients and cutaneous melanoma cohorts (untreated: n = 471, anti-progressive disease [PD]-1 treated: n = 212). RECQL4 copy number variations and expression levels were assessed for patient outcomes. We performed gene set enrichment analysis to identify RECQL4-dependent signalling pathways and explored the association between RECQL4 levels and immunoscores. We evaluated the interplay of ICI response and RECQL4 expression in melanoma cohorts of 95 responders and 85 non-responders prior to and after ICI-targeted therapy and tested the prognostic power of RECQL4. Finally, we generated genetically engineered RECQL4 variants and conducted comprehensive multi-omic profiling, employing techniques such as liquid chromatography with tandem mass spectrometry, to elucidate mechanistic insights.

RESULTS

We identified RECQL4 as a critical negative regulator of poor prognosis and response to ICI therapy, but also demonstrated its suitability as an independent biomarker in melanoma. High tumour purity and limited signatures of tumour immunogenicity associated with response to anti-PD-1 correlated with high RECQL4 activity. We found alterations in the secretion profile of immune regulatory factors and immune-related pathways robustly suppressed in tumours with high RECQL4 levels, underscoring its crucial role in fostering immune evasion. Mechanistically, we identified RECQL4-mediated regulation of major histocompatibility complex class II molecule expression and uncovered class II major histocompatibility complex transactivator as a mediator bridging this regulation.

CONCLUSIONS

Our findings unraveled the pivotal role of RECQL4 in immune modulation and its potential as both a predictive biomarker and therapeutic target for optimising immunotherapeutic strategies across various cancer types.

HIGHLIGHTS

High RECQL4 expression limits survival and can act as an independent prognostic factor in melanoma patients. RECQL4 has the potential to act as a negative feedback mediator of immune checkpoint-targeted therapy by limiting signatures associated with therapeutic efficacy. RECQL4 favours an immune-evasive phenotype by downregulating major histocompatibility complex class II molecules.

Germline Human Leukocyte Antigen Status is Associated With Immunotherapy-Induced Pneumonitis and Treatment Response in Patients With Non-Small Cell Lung Cancer With High Programmed Death-Ligand 1 Expression

Introduction

The germline human leukocyte antigen (HLA) status has been found to be associated with immunotherapy outcomes in patients with NSCLC, but its correlation to immunotherapy-induced pneumonitis and prognostic impact in the Asian population remains largely unknown.

Methods

We evaluated the HLA genotype of the germline and available tumor samples in 42 patients with programmed death-ligand 1 expression of 50% or higher undergoing pembrolizumab immunotherapy. The HLA allele expression was correlated with tumor response, disease survival, and the occurrence of pneumonitis.

Results

It was observed that the germline HLA-C homozygosity and HLA-DRB1∗13 expression were related to a worse progression-free survival and treatment response. Importantly, all patients (7/7 patients) who developed pneumonitis in our cohort expressed the HLA-DPB1∗02 allele, and the incidence of pneumonitis was 31.8% (7/22 patients) in patients expressing this allele compared with 0% (0/20 patients) in those without this allele (p = 0.009). Investigation of the tumor samples from 15 patients revealed some degree of HLA loss in the HLA class I loci in 40% (6/15) of patients, and no significant difference in tumor mutation burden was found among patients with different treatment responses.

Conclusion

Taken together, this study evaluated the impact of HLA status in both germline and tumor samples in patients with NSCLC with high programmed death-ligand 1 expression, and the high incidence of immunotherapy-induced pneumonitis in patients expressing the HLA-DPB1∗02 allele may suggest a routine HLA typing and closer monitoring in this patient subset.

Mutation in CDC42 Gene Set as a Response Biomarker for Immune Checkpoint Inhibitor Therapy

BACKGROUND

Immune checkpoint inhibitors (ICIs) have achieved great success; however, a subset of patients exhibits no response. Consequently, there is a critical need for reliable predictive biomarkers. Our focus is on CDC42, which stimulates multiple signaling pathways promoting tumor growth. We hypothesize that an impaired function of CDC42 may serve as an indicator of a patient's response to ICI therapy.

METHODS

We consider CDC42 and its downstream binding and effector proteins as a gene set, as mutations in these components could lead to defective CDC42 function. To elucidate the biomarker function of mutations within the CDC42 gene set, we curated a comprehensive discovery dataset that included seven ICI treatment cohorts. And we curated two ICI treatment cohorts for validation. We explored the mechanism based on The Cancer Genome Atlas database. We also examined whether combining a CDC42 inhibitor with ICI could enhance ICI's efficacy.

RESULTS

Mutations in the CDC42 gene set were associated with improved overall survival and progression-free survival. Furthermore, our analysis of immune response landscapes among different statuses of the CDC42 gene set supports its role as a biomarker. Animal experiments also revealed that the combination of the CDC42 inhibitor (ML141) with anti-PD-1 blockade can additively reduce tumor growth.

CONCLUSIONS

Our study suggests that the CDC42 gene set mutations could potentially serve as a novel biomarker for the clinical response to ICI treatment. This finding also provides insights into the potential of combining ICI and CDC42 inhibitor use for more efficient patient treatment.

A landscape of checkpoint blockade resistance in cancer: underlying mechanisms and current strategies to overcome resistance

The discovery of immune checkpoints and the development of immune checkpoint inhibitors (ICI) have achieved a durable response in advanced-stage cancer patients. However, there is still a high proportion of patients who do not benefit from ICI therapy due to a lack of response when first treated (primary resistance) or detection of disease progression months after objective response is observed (acquired resistance). Here, we review the current FDA-approved ICI for the treatment of certain solid malignancies, evaluate the contrasting responses to checkpoint blockade in different cancer types, explore the known mechanisms associated with checkpoint blockade resistance (CBR), and assess current strategies in the field that seek to overcome these mechanisms. In order to improve current therapies and develop new ones, the immunotherapy field still has an unmet need in identifying other molecules that act as immune checkpoints, and uncovering other mechanisms that promote CBR.

Tumor-Infiltrating Immune Cells and HLA Expression as Potential Biomarkers Predicting Response to PD-1 Inhibitor Therapy in Stage IV Melanoma Patients

PD-1 inhibitors are known to be effective in melanoma; however, a considerable proportion of patients fail to respond to therapy, necessitating the identification of predictive markers. We examined the predictive value of tumor cell HLA class I and II expression and immune cell infiltration in melanoma patients treated with PD-1 inhibitors. Pretreatment surgical samples from 40 stage IV melanoma patients were studied immunohistochemically for melanoma cell expression of HLA class I molecules (using four antibody clones with different specificities), HLA-II, and immune cell infiltration (using a panel of 10 markers). Among the responders, the ratio of patients showing melanoma cell HLA-II expression was higher compared to non-responders (p = 0.0158), and similar results were obtained in the case of two anti-HLA-I antibodies. A combined score of HLA-I/II expression also predicted treatment response (p = 0.0019). Intratumoral infiltration was stronger in the responders for most immune cell types. Progression-free survival showed an association with HLA-II expression, the combined HLA score, and the density of immune cells expressing CD134 and PD-1, while overall survival was significantly associated only with HLA class II expression. Our findings corroborate previous results indicating the importance of immune cell infiltration and tumor cell HLA-II expression in the efficacy of PD-1 inhibitor treatment in a "real world" patient cohort and suggest the potential predictive role of HLA class I expression.

DIPAN: Detecting personalized intronic polyadenylation derived neoantigens from RNA sequencing data

Intronic polyadenylation (IPA) refers to a particular type of alternative polyadenylation where a gene makes use of a polyadenylation site located within its introns. Aberrant IPA events have been observed in various types of cancer. IPA can produce noncoding transcripts or truncated protein-coding transcripts with altered coding sequences in the resulting protein product. Therefore, IPA events hold the potential to act as a reservoir of tumor neoantigens. Here, we developed a computational method termed DIPAN, which incorporates IPA detection, protein fragmentation, and MHC binding prediction to predict IPA-derived neoantigens. Utilizing RNA-seq from breast cancer cell lines and ovarian cancer clinical samples, we demonstrated the significant contribution of IPA events to the neoantigen repertoire. Through mass spectrometry immunopeptidome analysis, we further illustrated the processing and presentation of IPA-derived neoantigens on the surface of cancer cells. While most IPA-derived neoantigens are sample-specific, shared neoantigens were identified in both cancer cell lines and clinical samples. Furthermore, we demonstrated an association between IPA-derived neoantigen burden and overall survival in cancer patients.

Inflammatory response signature score model for predicting immunotherapy response and pan-cancer prognosis

Background

Inflammatory responses influence the outcome of immunotherapy and tumorigenesis by modulating host immunity. However, systematic inflammatory response assessment models for predicting cancer immunotherapy (CIT) responses and survival across human cancers remain unexplored. Here, we investigated an inflammatory response score model to predict CIT responses and patient survival in a pan-cancer analysis.

Methods

We retrieved 12 CIT response gene expression datasets from the Gene Expression Omnibus database (GSE78220, GSE19423, GSE100797, GSE126044, GSE35640, GSE67501, GSE115821 and GSE168204), Tumor Immune Dysfunction and Exclusion database (PRJEB23709, PRJEB25780 and phs000452.v2.p1), European Genome-phenome Archive database (EGAD00001005738), and IMvigor210 cohort. The tumor samples from six cancers types: metastatic urothelial cancer, metastatic melanoma, gastric cancer, primary bladder cancer, renal cell carcinoma, and non-small cell lung cancer.We further established a binary classification model to predict CIT responses using the least absolute shrinkage and selection operator (LASSO) computational algorithm.

Findings

The model had high predictive accuracy in both the training and validation cohorts. During sub-group analysis, area under the curve (AUC) values of 0.82, 0.80, 0.71, 0.7, 0.67, and 0.64 were obtained for the non-small cell lung cancer, gastric cancer, metastatic urothelial cancer, primary bladder cancer, metastatic melanoma, and renal cell carcinoma cohorts, respectively. CIT response rates were higher in the high-scoring training cohort subjects (51%) than the low-scoring subjects (27%). The five-year survival rates in the high- and low score groups of the training cohorts were 62% and 21%, respectively, while those of the validation cohorts were 54% and 22%, respectively (P < 0·001 in all cases). Inflammatory response signature score derived from on-treatment tumor specimens are highly predictive of response to CIT in patients with metastatic melanoma. A significant correlation was observed between the inflammatory response scores and tumor purity. Regardless of the tumor purity, patients in the low score group had a significantly poorer prognosis than those in the high score group. Immune cell infiltration analysis indicated that in the high score cohort, tumor-infiltrating lymphocytes were significantly enriched, particularly effector and natural killer cells. Inflammatory response scores were positively correlated with immune checkpoint genes, suggesting that immune checkpoint inhibitors may have benefited patients with high scores. Analysis of signature scores across different cancer types from The Cancer Genome Atlas revealed that the prognostic performance of inflammatory response scores for survival in patients who have not undergone immunotherapy can be affected by tumor purity. Interleukin 21 (IL21) had the highest weight in the inflammatory response model, suggesting its vital role in the prediction mode. Since the number of metastatic melanoma patients (n = 429) was relatively large among CIT cohorts, we further performed a co-culture experiment using a melanoma cell line and CD8 + T cell populations generated from peripheral blood monocytes. The results showed that IL21 therapy combined with anti-PD1 (programmed cell death 1) antibodies (trepril monoclonal antibodies) significantly enhanced the cytotoxic activity of CD8 + T cells against the melanoma cell line.

Conclusion

In this study, we developed an inflammatory response gene signature model that predicts patient survival and immunotherapy response in multiple malignancies. We further found that the predictive performance in the non-small cell lung cancer and gastric cancer group had the highest value among the six different malignancy subgroups. When compared with existing signatures, the inflammatory response gene signature scores for on-treatment samples were more robust predictors of the response to CIT in metastatic melanoma.

TET2 promotes tumor antigen presentation and T cell IFN-γ, which is enhanced by vitamin C

Immune evasion by tumors is promoted by low T cell infiltration, ineffective T cell activity directed against the tumor, and reduced tumor antigen presentation. The TET2 DNA dioxygenase gene is frequently mutated in hematopoietic malignancies and loss of TET enzymatic activity is found in a variety of solid tumors. We showed previously that vitamin C (VC), a cofactor of TET2, enhances tumor-associated T cell recruitment and checkpoint inhibitor therapy responses in a TET2-dependent manner. Using single-cell RNA sequencing (scRNA-seq) analysis performed on B16-OVA melanoma tumors, we have shown here that an additional function for TET2 in tumors is to promote expression of certain antigen presentation machinery genes, which is potently enhanced by VC. Consistently, VC promoted antigen presentation in cell-based and tumor assays in a TET2-dependent manner. Quantifying intercellular signaling from the scRNA-seq dataset showed that T cell-derived IFN-γ-induced signaling within the tumor and tumor microenvironment requires tumor-associated TET2 expression, which is enhanced by VC treatment. Analysis of patient tumor samples indicated that TET activity directly correlates with antigen presentation gene expression and with patient outcomes. Our results demonstrate the importance of tumor-associated TET2 activity as a critical mediator of tumor immunity, which is augmented by high-dose VC therapy.

MDM2 inhibitors in cancer immunotherapy: Current status and perspective

Murine double minute 2 (MDM2) plays an essential role in the cell cycle, apoptosis, DNA repair, and oncogene activation through p53-dependent and p53-independent signaling pathways. Several preclinical studies have shown that MDM2 is involved in tumor immune evasion. Therefore, MDM2-based regulation of tumor cell-intrinsic immunoregulation and the immune microenvironment has attracted increasing research attention. In recent years, immune checkpoint inhibitors targeting PD-1/PD-L1 have been widely used in the clinic. However, the effectiveness of a single agent is only approximately 20%-40%, which may be related to primary and secondary drug resistance caused by the dysregulation of oncoproteins. Here, we reviewed the role of MDM2 in regulating the immune microenvironment, tumor immune evasion, and hyperprogression during immunotherapy. In addition, we summarized preclinical and clinical findings on the use of MDM2 inhibitors in combination with immunotherapy in tumors with MDM2 overexpression or amplification. The results reveal that the inhibition of MDM2 could be a promising strategy for enhancing immunotherapy.

Perioperative chemoimmunotherapy induces strong immune responses and long-term survival in patients with HLA class I-deficient non-small cell lung cancer

BACKGROUND

Loss of human leukocyte antigen (HLA) class I expression and loss of heterozygosity (LOH) are common events implicated in the primary resistance of non-small cell lung cancer (NSCLC) to immunotherapy. However, there is no data on perioperative chemoimmunotherapy (ChIO) efficacy or response mechanisms in the context of HLA class I defects.

METHODS

Baseline HLA class I tumor status (HLA-deficient (HLA-DEF) or HLA-proficient (HLA-PRO)) was determined by DNA LOH combined with immunohistochemistry for protein levels in tissue of 24 patients with NSCLC treated with perioperative nivolumab plus chemotherapy from NADIM trial (NCT03081689). We integrated HLA tumor status with molecular data (programmed death-ligand 1 (PD-L1), TMB, TCR repertoire, TILs populations, bulk RNA-seq, and spatial transcriptomics (ST)) and clinical outcomes (pathological response and survival data) to study the activity of perioperative ChIO considering HLA class I defects.

RESULTS

HLA-DEF tumors comprised 41.7% of analyzed tumors and showed a desert-like microenvironment at baseline, with lower PD-L1 levels and reduced immune infiltrate. However, perioperative ChIO induced similar complete pathological response (CPR) rates in both HLA-DEF and PRO tumors (50% and 60% respectively, p=0.670), as well as 3-year survival rates: Progression-free survival (PFS) and overall survival (OS) of 70% (95% CI 32.9% to 89.2%) for HLA-DEF, and PFS 71.4% (95% CI 40.6% to 88.2%) and OS 92.9% (95% CI 59.1% to 99.0%) for HLA-PRO (log-rank PFS p=0.909, OS p=0.137). Proof-of-concept ST analysis of a CPR HLA-DEF tumor after ChIO showed a strong immune response with tertiary lymphoid structures (TLS), CD4+T cells with HLA class II colocalization, and activated CD8+T cells.

CONCLUSIONS

Our findings highlight the activity of perioperative ChIO, and the potential role of TLS and T-cell immune response, in NSCLC HLA-DEF tumors.

Integrative multi-omics analysis reveals the role of tumor-associated endothelial cells and their signature in prognosis of intrahepatic cholangiocarcinoma

This study aims to investigate the interplay between tumor-associated endothelial cells (TECs) and immune cells within the tumor microenvironment (TME) and its impact on tumor prognosis. We conducted single-cell RNA sequencing (scRNA-seq) of tumor, normal, and lymph node tissues obtained from intrahepatic cholangiocarcinoma (ICC) patients to reveal the role of TECs in tumor angiogenesis and their significant heterogeneity. Meanwhile, we identified genes highly expressed in TECs and constructed TEC signatures (TEC.Sig). Next, we calculated TEC scores of samples based on TEC.Sig. Patients with higher TEC scores exhibited a higher frequency of KRAS mutations, which was associated with increased infiltration of neutrophils and immature dendritic cells (iDCs), and decreased numbers of natural killer (NK), CD4 + T, and CD8 + T effector memory (Tem) cells, indicating an inflammation-dominated immunosuppressive phenotype. In contrast, BAP1 mutations and CXCL12 overexpression showed a contrasting trend. Spatial transcriptomics analysis and histological experiments further confirmed that TECs interacted with various tumor-killing immune cells through the CXCL12/CXCR4 axis. Multiple tumor immunotherapy datasets confirmed that the TEC.Sig could predict patient responses to immunotherapy. The TEC score is a promising and reliable biomarker for predicting genetic mutations and prognosis in ICC patients. Enhancing the regulation of the CXCL12/CXCR4 signaling pathway may represent a potential novel therapeutic target for ICC treatment.

NPM1 inhibits tumoral antigen presentation to promote immune evasion and tumor progression

BACKGROUND

Tumor cells develop multiple mechanisms to facilitate their immune evasion. Identifying tumor-intrinsic factors that support immune evasion may provide new strategies for cancer immunotherapy. We aimed to explore the function and the mechanism of the tumor-intrinsic factor NPM1, a multifunctional nucleolar phosphoprotein, in cancer immune evasion and progression.

METHODS

The roles of NPM1 in tumor progression and tumor microenvironment (TME) reprogramming were examined by subcutaneous inoculation of Npm1-deficient tumor cells into syngeneic mice, and then explored by CyTOF, flow cytometry, immunohistochemistry staining, and RNA-seq. The in-vitro T-cell killing of OVA-presenting tumor cells by OT-1 transgenic T cells was observed. The interaction of NPM1 and IRF1 was verified by Co-IP. The regulation of NPM1 in IRF1 DNA binding to Nlrc5, Ciita promoter was determined by dual-luciferase reporter assay and ChIP-qPCR.

RESULTS

High levels of NPM1 expression predict low survival rates in various human tumors. Loss of NPM1 inhibited tumor progression and enhanced the survival of tumor-bearing mice. Npm1-deficient tumors showed increased CD8+ T cell infiltration and activation alongside the reduced presence of immunosuppressive cells. Npm1 deficiency increased MHC-I and MHC-II molecules and specific T-cell killing. Mechanistically, NPM1 associates with the transcription factor IRF1 and then sequesters IRF1 from binding to the Nlrc5 and Ciita promoters to suppress IRF1-mediated expression of MHC-I and MHC-II molecules in tumor cells.

CONCLUSIONS

Tumor-intrinsic NPM1 promotes tumor immune evasion via suppressing IRF1-mediated antigen presentation to impair tumor immunogenicity and reprogram the immunosuppressive TME. Our study identifies NPM1 as a potential target for improving cancer immunotherapy.

CD4+ T cells in antitumor immunity

Advances in cancer immunotherapy have transformed cancer care and realized unprecedented responses in many patients. The growing arsenal of novel therapeutics - including immune checkpoint inhibition (ICI), adoptive T cell therapies (ACTs), and cancer vaccines - reflects the success of cancer immunotherapy. The therapeutic benefits of these treatment modalities are generally attributed to the enhanced quantity and quality of antitumor CD8+ T cell responses. Nevertheless, CD4+ T cells are now recognized to play key roles in both the priming and effector phases of the antitumor immune response. In addition to providing T cell help through co-stimulation and cytokine production, CD4+ T cells can also possess cytotoxicity either directly on MHC class II-expressing tumor cells or to other cells within the tumor microenvironment (TME). The presence of specific populations of CD4+ T cells, and their intrinsic plasticity, within the TME can represent an important determinant of clinical response to immune checkpoint inhibitors, vaccines, and chimeric antigen receptor (CAR) T cell therapies. Understanding how the antitumor functions of specific CD4+ T cell types are induced while limiting their protumorigenic attributes will enable more successful immunotherapies.

Associations of Immune Checkpoint Predictive Biomarkers (MHC-I and MHC-II) with Clinical and Molecular Features in a Diverse Breast Cancer Cohort

PURPOSE

Immunotherapy (IO) in triple-negative breast cancer (TNBC) has improved survival outcomes, with promising improvements in pCR rates among early high-risk hormone receptor (HR)+/HER2- breast cancers. However, biomarkers are needed to select patients likely to benefit from IO. MHC-I and tumor-specific MHC-II (tsMHC-II) expression are candidate biomarkers for PD-(L)1 checkpoint inhibition but existing data from clinical trials included limited racial/ethnic diversity.

EXPERIMENTAL DESIGN

We performed multiplexed immunofluorescence assays in the Carolina Breast Cancer Study (CBCS; n = 1,628, 48% Black, 52% non-Black). Intrinsic subtype and P53 mutant-like status were identified using RNA-based multigene assays. We ranked participants based on tumoral MHC-I intensity (top 33% categorized as "MHC-Ihigh") and MHC-II+ (≥5% of tumor cells as tsMHC-II+). MHC-I/II were evaluated in association with clinicopathological features by race.

RESULTS

Black participants had higher frequency of TNBC (25% vs. 12.5%, P ≤ 0.001) and basal-like (30% vs. 14%, P ≤ 0.001) tumors overall, and higher frequency of basal-like (11% vs. 5.5%, P = 0.002) and TP53 mutant tumors (26% vs. 17%, P = 0.002) among HR+/HER2-. The frequency of tsMHC-II+ was higher in HR+/HER2- Black participants (7.9% vs. 4.9%, P = 0.04). Black participants also had higher frequency of MHC-Ihigh (38.7% vs. 28.2%, P < 0.001), which was significant among HR+/HER2- (28.2% vs. 22.1%, P = 0.02).

CONCLUSIONS

In this diverse study population, MHC-I and MHC-II tumor cell expression were more highly expressed in HR+/HER2- tumors from Black women, underscoring the importance of diverse and equitable enrollment in future IO trials.

Predictive Biomarkers and Resistance Mechanisms of Checkpoint Inhibitors in Malignant Solid Tumors

Predictive biomarkers for immune checkpoint inhibitors (ICIs) in solid tumors such as melanoma, hepatocellular carcinoma (HCC), colorectal cancer (CRC), non-small cell lung cancer (NSCLC), endometrial carcinoma, renal cell carcinoma (RCC), or urothelial carcinoma (UC) include programmed cell death ligand 1 (PD-L1) expression, tumor mutational burden (TMB), defective deoxyribonucleic acid (DNA) mismatch repair (dMMR), microsatellite instability (MSI), and the tumor microenvironment (TME). Over the past decade, several types of ICIs, including cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, anti-programmed cell death 1 (PD-1) antibodies, anti-programmed cell death ligand 1 (PD-L1) antibodies, and anti-lymphocyte activation gene-3 (LAG-3) antibodies have been studied and approved by the Food and Drug Administration (FDA), with ongoing research on others. Recent studies highlight the critical role of the gut microbiome in influencing a positive therapeutic response to ICIs, emphasizing the importance of modeling factors that can maintain a healthy microbiome. However, resistance mechanisms can emerge, such as increased expression of alternative immune checkpoints, T-cell immunoglobulin (Ig), mucin domain-containing protein 3 (TIM-3), LAG-3, impaired antigen presentation, and alterations in the TME. This review aims to synthesize the data regarding the interactions between microbiota and immunotherapy (IT). Understanding these mechanisms is essential for optimizing ICI therapy and developing effective combination strategies.

Tumor antigen presentation and the associated signal transduction during carcinogenesis

Numerous developments have been achieved in the study and treatment of cancer throughout the decades that it has been common. After decades of research, about 100 different kinds of cancer have been found, each with unique subgroups within certain organs. This has significantly expanded our understanding of the illness. A mix of genetic, environmental, and behavioral variables contribute to the complicated and diverse process of cancer formation. Mutations, or changes in the DNA sequence, are crucial to the development of cancer. These mutations have the ability to downregulate the expression and function of Major Histocompatibility Complex class I (MHC I) and MHCII receptors, as well as activate oncogenes and inactivate tumor suppressor genes. Cancer cells use this tactic to avoid being recognized by cytotoxic CD8+T lymphocytes, which causes issues with antigen presentation and processing. This review goes into great length into the PI3K pathway, changes to MHC I, and positive impacts of tsMHC-II on disease-free survival and overall survival and the involvement of dendritic cells (DCs) in different tumor microenvironments. The vital functions that the PI3K pathway and its link to the mTOR pathway are highlighted and difficulties in developing effective cancer targeted therapies and feedback systems has also been mentioned, where resistance mechanisms include RAS-mediated oncogenic changes and active PI3K signalling.

Ovarian cancer ascites proteomic profile reflects metabolic changes during disease progression

Ovarian cancer (OC) patients develop ascites, an accumulation of ascitic fluid in the peritoneal cavity anda sign of tumour dissemination within the peritoneal cavity. This body fluid is under-researched, mainly regarding the ascites formed during tumour progression that have no diagnostic value and, therefore, are discarded. We performed a discovery proteomics study to identify new biomarkers in the ascites supernatant of OC patients. In this preliminary study, we analyzed a small amount of OC ascites to highlight the importance of not discarding such biological material during treatment, which could be valuable for OC management. Our findings reveal that OC malignant ascitic fluid (MAF) displays a proliferative environment that promotes the growth of OC cells that shift the metabolic pathway using alternative sources of nutrients, such as the cholesterol pathway. Also, OC ascites drained from patients during treatment showed an immunosuppressive environment, with up-regulation of proteins from the signaling pathways of IL-4 and IL-13 and down-regulation from the MHC-II. This preliminary study pinpointed a new protein (Transmembrane Protein 132A) in the OC context that deserves to be better explored in a more extensive cohort of patients' samples. The proteomic profile of MAF from OC patients provides a unique insight into the metabolic kinetics of cancer cells during disease progression, and this information can be used to develop more effective treatment strategies.

Potential protumor function of CD74 in clear cell renal cell carcinoma

CD74 is a transmembrane protein that functions as a specialized chaperone of HLA class II and CD74 in tumor cells was suggested to be involved in cell proliferation in several kinds of malignant tumors. CD74 is also known to be expressed in macrophages, therefore, we investigated the CD74 expression in clear cell renal cell carcinoma (ccRCC). Immunohistochemistry of CD74 indicated that CD74 was expressed not only in cancer cells but also macrophages. CD74 was detected in surface membrane and cytoplasm of cancer cells in 92 of 94 cases (98%) and of 87 of 94 cases (93%). CD74 was expressed both in cancer cells and TAMs in 86 of 94 cases (91%). In vitro studies using cancer cell lines and monocyte-derived macrophages stimulated by anti-CD74 antibodies showed that CD74 signal accelerated cancer cell proliferation and macrophage activation. However, macrophage activation via CD74 signal did not influence macrophage-mediated cancer cell growth. RNA-sequence of macrophages stimulated by anti-CD74 antibodies indicated that CD74 signal was associated to inflammatory responses in macrophages. In conclusion, we examined the expression and functional significance of CD74 in ccRCC using tissue specimens and cell culture studies. The function of CD74 was suggested to be different in cancer cells and in macrophages, and further studies are necessary to clarify the functional significance of CD74 in ccRCC.

Ubiquitin modification in the regulation of tumor immunotherapy resistance mechanisms and potential therapeutic targets

Although immune checkpoint-based cancer immunotherapy has shown significant efficacy in various cancers, resistance still limits its therapeutic effects. Ubiquitination modification is a mechanism that adds different types of ubiquitin chains to proteins, mediating protein degradation or altering their function, thereby affecting cellular signal transduction. Increasing evidence suggests that ubiquitination modification plays a crucial role in regulating the mechanisms of resistance to cancer immunotherapy. Drugs targeting ubiquitination modification pathways have been shown to inhibit tumor progression or enhance the efficacy of cancer immunotherapy. This review elaborates on the mechanisms by which tumor cells, immune cells, and the tumor microenvironment mediate resistance to cancer immunotherapy and the details of how ubiquitination modification regulates these mechanisms, providing a foundation for enhancing the efficacy of cancer immunotherapy by intervening in ubiquitination modification.

Supramolecular assembly of polycation/mRNA nanoparticles and in vivo monocyte programming

Size-dependent phagocytosis is a well-characterized phenomenon in monocytes and macrophages. However, this size effect for preferential gene delivery to these important cell targets has not been fully exploited because commonly adopted stabilization methods for electrostatically complexed nucleic acid nanoparticles, such as PEGylation and charge repulsion, typically arrest the vehicle size below 200 nm. Here, we bridge the technical gap in scalable synthesis of larger submicron gene delivery vehicles by electrostatic self-assembly of charged nanoparticles, facilitated by a polymer structurally designed to modulate internanoparticle Coulombic and van der Waals forces. Specifically, our strategy permits controlled assembly of small poly(β-amino ester)/messenger ribonucleic acid (mRNA) nanoparticles into particles with a size that is kinetically tunable between 200 and 1,000 nm with high colloidal stability in physiological media. We found that assembled particles with an average size of 400 nm safely and most efficiently transfect monocytes following intravenous administration and mediate their differentiation into macrophages in the periphery. When a CpG adjuvant is co-loaded into the particles with an antigen mRNA, the monocytes differentiate into inflammatory dendritic cells and prime adaptive anticancer immunity in the tumor-draining lymph node. This platform technology offers a unique ligand-independent, particle-size-mediated strategy for preferential mRNA delivery and enables therapeutic paradigms via monocyte programming.

Molecular Susceptibility and Treatment Challenges in Melanoma

Melanoma is the most aggressive subtype of cancer, with a higher propensity to spread compared to most solid tumors. The application of OMICS approaches has revolutionized the field of melanoma research by providing comprehensive insights into the molecular alterations and biological processes underlying melanoma development and progression. This review aims to offer an overview of melanoma biology, covering its transition from primary to malignant melanoma, as well as the key genes and pathways involved in the initiation and progression of this disease. Utilizing online databases, we extensively explored the general expression profile of genes, identified the most frequently altered genes and gene mutations, and examined genetic alterations responsible for drug resistance. Additionally, we studied the mechanisms responsible for immune checkpoint inhibitor resistance in melanoma.

Identification of a novel immunogenic death-associated model for predicting the immune microenvironment in lung adenocarcinoma from single-cell and Bulk transcriptomes

Background: Studies on immunogenic death (ICD) in lung adenocarcinoma are limited, and this study aimed to determine the function of ICD in LUAD and to construct a novel ICD-based prognostic model to improve immune efficacy in lung adenocarcinoma patients. Methods: The data for lung adenocarcinoma were obtained from the Cancer Genome Atlas (TCGA) database and the National Center for Biotechnology Information (GEO). The single-cell data were obtained from Bischoff P et al. To identify subpopulations, we performed descending clustering using TSNE. We collected sets of genes related to immunogenic death from the literature and identified ICD-related genes through gene set analysis of variance (GSVA) and weighted gene correlation network analysis (WGCNA). Lung adenocarcinoma patients were classified into two types using consistency clustering. The difference between the two types was analyzed to obtain differential genes. An immunogenic death model (ICDRS) was established using LASSO-Cox analysis and compared with lung adenocarcinoma models of other individuals. External validation was performed in the GSE31210 and GSE50081 cohorts. The efficacy of immunotherapy was assessed using the TIDE algorithm and the IMvigor210, GSE78220, and TCIA cohorts. Furthermore, differences in mutational profiles and immune microenvironment between different risk groups were investigated. Subsequently, ROC diagnostic curves and KM survival curves were used to screen ICDRS key regulatory genes. Finally, RT-qPCR was used to verify the differential expression of these genes. Results: Eight ICD genes were found to be highly predictive of LUAD prognosis and significantly correlated with it. Multivariate analysis showed that patients in the low-risk group had a higher overall survival rate than those in the high-risk group, indicating that the model was an independent predictor of LUAD. Additionally, ICDRS demonstrated better predictive ability compared to 11 previously published models. Furthermore, significant differences in biological function and immune cell infiltration were observed in the tumor microenvironment between the high-risk and low-risk groups. It is noteworthy that immunotherapy was also significant in both groups. These findings suggest that the model has good predictive efficacy. Conclusions: The ICD model demonstrated good predictive performance, revealing the tumor microenvironment and providing a new method for evaluating the efficacy of pre-immunization. This offers a new strategy for future treatment of lung adenocarcinoma.