Mechanisms of resistance to immune checkpoint inhibitors in melanoma: What we have to overcome?

Harnessing Folate Receptors: A Comprehensive Review on the Applications of Folate-Adorned Nanocarriers for the Management of Melanoma

The advancement in exclusively tailored therapeutic delivery systems has escalated a great deal of interest in targeted delivery to augment therapeutic efficacy and to lessen adverse effects. The targeted delivery approach promisingly helps to surmount the unmet clinical needs of conventional therapies, including chemoresistance, limited penetration, and side effects. In the case of melanoma, various receptors were overexpressed on the tumor site, among which folate receptor (FR) targeting is considered to be a progressive approach for managing melanoma. FRs are the macromolecules of the glycosyl phosphatidylinositol-attached protein that possess globular assembly with a greater affinity toward specific ligands. So, the functional ligands can be utilized to design targeted nanocarriers (NCs) that can effectively bind to overexpressed FRs. Hence, folate-adorned NCs (FNCs) offer various benefits such as site-specific targeting, cargo protection, and minimizing toxicity. This review focuses on the insights and implications of FRs, targeting FRs, and mechanisms, challenges, and advantages of FNCs. Further, the applications of various FNCs, such as liposomes, polymeric NCs, albumin nanoparticles, inorganic NCs, liquid crystalline nanoparticles, and nanogels, have been elaborated for melanoma therapy. Likewise, the potential of FNCs in immunotherapy, photodynamic therapy, chemotherapy, gene therapy, photothermal therapy, and tumor imaging has been exhaustively discussed. Furthermore, translational hurdles and potential solutions are discussed in detail. The present review is expected to give thoughtful ideas to researchers, industry stakeholders, and formulation scientists for the efficacious development of FNCs.

State-of-the-art in Metastatic Uveal Melanoma Treatment: A 2025 Update : How to treat Metastatic Uveal Melanoma in 2025

PURPOSE OF REVIEW

Uveal melanoma (UM) is the most common intraocular malignancy in adults, representing a rare but aggressive melanoma subtype with a distinct molecular landscape, unique metastatic behavior and limited therapeutic options in the metastatic setting. This review provides an in-depth analysis of the latest evidence on the evolving treatment landscape of metastatic UM.

RECENT FINDINGS

For liver-only metastatic disease, locoregional therapies provide significant benefit compared to systemic therapies. The recent approval of tebentafusp-tebn, a bispecific gp100 peptide-HLA-directed CD3 T-cell engager, marks a pivotal advancement for HLA-A*02:01-positive patients with unresectable/metastatic UM, demonstrating a clinically significant survival benefit. Several clinical studies are currently active, examining emerging locoregional and systemic treatments for metastatic UM, with promising early data. Despite effective local disease control through radiotherapy and enucleation, approximately 50% of patients develop metastatic disease, predominantly in the liver, with a median survival of less than one year. The approval of tebentafusp represents a landmark achievement in UM treatment, while promising experimental combinations have demonstrated clinical utility in late phase clinical trials, offering hope for further improvement in patient survival.

PathNetDRP: a novel biomarker discovery framework using pathway and protein-protein interaction networks for immune checkpoint inhibitor response prediction

BACKGROUND

Predicting immune checkpoint inhibitor (ICI) response remains a significant challenge in cancer immunotherapy. Many existing approaches rely on differential gene expression analysis or predefined immune signatures, which may fail to capture the complex regulatory mechanisms underlying immune response. Network-based models attempt to integrate biological interactions, but they often lack a quantitative framework to assess how individual genes contribute within pathways, limiting the specificity and interpretability of biomarkers. Given these limitations, we developed PathNetDRP, a framework that integrates biological pathways, protein-protein interaction networks, and machine learning to identify functionally relevant biomarkers for ICI response prediction.

RESULTS

We introduce PathNetDRP, a novel biomarker discovery approach that applies the PageRank algorithm to prioritize ICI-associated genes, maps them to relevant biological pathways, and calculates PathNetGene scores to quantify their contribution to immune response. Unlike conventional methods that focus solely on gene expression differences, PathNetDRP systematically incorporates biological context to improve biomarker selection. Validation across multiple independent cancer cohorts showed that PathNetDRP achieved strong predictive performance, with cross-validation the area under the receiver operating characteristic curves increasing from 0.780 to 0.940. Interestingly, PathNetDRP did not merely improve predictive accuracy; it also provided insights into key immune-related pathways, reinforcing its potential for identifying clinically relevant biomarkers.

CONCLUSION

The biomarkers identified by PathNetDRP demonstrated robust predictive performance across cross-validation and independent validation datasets, suggesting their potential utility in clinical applications. Furthermore, enrichment analysis highlighted key immune-related pathways, providing a deeper understanding of their role in ICI response regulation. While these findings underscore the promise of PathNetDRP, future work will explore the integration of additional predictive features, such as tumor mutational burden and microsatellite instability, to further refine its applicability.

Natural Killer Cell Activation Signature Identifies Cyclin B1/CDK1 as a Druggable Target to Overcome Natural Killer Cell Dysfunction and Tumor Invasiveness in Melanoma

Background/Objectives: Natural killer (NK) cells play a crucial role in immune surveillance against melanoma, yet they frequently exhibit dysfunction in the tumor microenvironment. This study aims to establish an NK cell activation-related prognostic signature and identify potential druggable targets to overcome NK cell dysfunction. Methods: A prognostic signature was developed using the TCGA-SKCM cohort and validated across independent datasets. NK cell activation and cytotoxicity were evaluated in melanoma-NK-92MI co-culture systems via flow cytometry. Mechanistic studies employed Western blotting, co-immunoprecipitation, ELISA, and qRT-PCR. Single-cell RNA-seq data were used to analyze cell-cell communication. Results: A four-gene NK cell activation signature was identified and validated for prognostic significance across five independent melanoma datasets. Among the identified genes, cyclin B1 (CCNB1) emerged as a novel therapeutic target for overcoming NK cell resistance. In vivo, pharmacological inhibition of the CCNB1/Cyclin-dependent kinase 1 (CDK1) complex with RO-3306 significantly suppressed melanoma growth by enhancing NK cell infiltration and IFN-γ production. In vitro, CCNB1 knockdown in melanoma cells augmented NK-92MI activation, as evidenced by increased expression of CD69, CD107a, IFN-γ, and NKG2D, thereby improving NK cell-mediated cytotoxicity. Mechanistically, in melanoma cells, the CCNB1/CDK1 complex phosphorylates STAT3, activating the IL-6/STAT3 positive feedback loop, which upregulates PD-L1 and enables resistance to NK cell-mediated cytotoxicity. Beyond its role in immune evasion, CCNB1 also promoted melanoma invasiveness by inducing epithelial-mesenchymal transition (EMT) through the TGF-β-SMAD2/3 signaling. Conclusions: This study establishes CCNB1/CDK1 as a novel immunotherapeutic target and uncovers a new role for CDK1 inhibitors in enhancing NK cell function and suppressing melanoma progression.

An Anionic Cathelicidin Exerts Antimelanoma Effects in Mice by Promoting Pyroptosis

While cationic antimicrobial peptides (AMPs) are extensively studied for antitumor effects, anionic AMPs remain underexplored. Notably, no amphibian-derived anionic cathelicidins with antitumor activity have been reported. This study identifies Boma-CATH, a novel anionic cathelicidin (net charge-3) from Bombina maxima skin, which suppresses melanoma growth in mice and triggers pyroptosis-like morphological changes in A375 cells via the NLRP3/Caspase-1/GSDMD pathway. Further investigation revealed that ROS played a crucial role in promoting pyroptosis, as NAC (ROS scavenger) and Ac-YVAD-cmk (Caspase-1 inhibitor) reversed cell death and reduced LDH/IL-1β release in vitro and in vivo. GSDMD knockdown further validated its role. Additionally, Boma-CATH inhibited A375 cell proliferation, migration, and invasion, demonstrating dual antitumor mechanisms: pyroptosis induction and metastasis suppression. Importantly, Boma-CATH caused no adverse effects in mice, highlighting its therapeutic safety. These findings position Boma-CATH as a promising melanoma treatment and expand the mechanistic understanding of anionic AMPs in oncology.

Case Report: Durable remission after abscopal effect following transcatheter hepatic arterial embolization in a patient with mucosal melanoma refractory to immunotherapy

Mucosal melanoma, a rare subtype of melanoma affecting mucosal surfaces, presents significant challenges in diagnosis and treatment, particularly due to its low programmed death-ligand 1 (PD-L1) expression and reduced response to immune checkpoint inhibitors (ICIs). This case report describes a 58-year-old woman with metastatic nasal mucosal melanoma initially resistant to neoadjuvant ipilimumab and nivolumab. After undergoing hepatic transcatheter arterial embolization, she experienced an unexpected abscopal effect, where distant metastases showed near-complete resolution despite prior lack of response to immunotherapy. The patient's disease initially progressed despite two cycles of ICI treatment, and further immunotherapy with nivolumab and relatimab did not improve her condition. Subsequently, after bland embolization of a dominant hepatic mass, the patient received re-challenged combination immunotherapy with ipilimumab and nivolumab, leading to significant regression in metastatic sites including the liver, lungs, lymph nodes, and bones. This response contrasts with prior reports and highlights a potential mechanism by which embolization therapies may alter the immune microenvironment and enhance the efficacy of immunotherapy. The abscopal effect observed following local hepatic embolization may be attributed to tumor-induced immune activation, which is further amplified by ICI treatment. This case underscores the potential for integrating local embolization with immunotherapy to overcome resistance in metastatic melanoma, particularly in mucosal subtypes. Further research is necessary to elucidate the immune mechanisms underlying these responses and to optimize treatment strategies for melanoma patients.

C-reactive protein kinetics as prognostic biomarkers in advanced melanoma treated with immune checkpoint inhibitors

C-reactive protein (CRP) kinetics has emerged as a potential biomarker for predicting treatment response and survival in various tumors treated with immune checkpoint inhibitors (ICIs). However, data on CRP kinetics in melanoma are limited. This study evaluates the relationship between CRP kinetic groups and progression-free survival (PFS) and overall survival (OS) in 104 advanced melanoma patients treated with ICIs from 2015 to 2023. Patients were classified into four CRP kinetic groups: CRP flare responders, defined as patients whose CRP at least doubles within 1 month and then falls below baseline by 3 months; CRP responders, whose CRP decreases by ≥30% from baseline within 3 months without doubling; all-normal CRP, whose CRP remains below the upper limit of normal throughout the first 3 months; and CRP nonresponders, who do not meet these criteria. Amongst patients, 64.4% received anti-programmed death-1 monotherapy and 35.6% received the nivolumab-ipilimumab combination. Median PFS was 4.80 months in CRP nonresponders, 10.90 months in CRP responders, 8.83 months in CRP flare responders and 33.57 months in all-normal CRP patients (P < 0.001). Similarly, median OS was 11.9 months in CRP nonresponders, 38.1 months in CRP responders, 21.5 months in CRP flare responders and 54.5 months in all-normal CRP patients (P < 0.001). Multivariate analysis confirmed CRP kinetic groups as an independent predictor of PFS, OS and objective response. CRP kinetic classification is a simple prognostic tool for advanced melanoma patients treated with ICIs and is associated with improved survival outcomes, underscoring the clinical value of CRP monitoring.

Clinical benefit of immune checkpoint inhibitors in elderly cancer patients: Current evidence from immunosenescence pathophysiology to clinical trial results

The age-related decline in immunity appears to be associated not only with cancer development but also with differential responses to immune checkpoint inhibitors (ICIs). Despite their increasing utility across various malignancies and therapeutic settings, limited data -derived primarily from subgroup analyses of randomized controlled trials (RCTs), pooled meta-analyses, and retrospective studies- are available on the effects of aging on their efficacy and toxicity. Immunosenescence, characterized by the progressive decline of the function of the immune system, and inflammaging, a state of persistent low-grade sterile inflammation, may influence ICI outcomes. Additionally, the incidence, severity, and subtypes of immune-related adverse events (irAEs) may differ between older and younger individuals due to loss of immunotolerance. In the current review, starting from a a comprehensive discussion of the pathophysiology of immunosenescence, we proceed to critically review age-related retrospective and randomized evidence supporting FDA-approved ICIs. We highlight similarities or differences across age groups and the clinical benefit of ICIs in elderly versus younger cancer patients. The optimal integration of ICIs in geriatric oncology necessitates greater inclusion of this patient demographic in RCTs along with real-world data in order to acquire robust data which will guide evidence-based treatment decisions for this population.

Genomic profiles of patients with skin melanoma in the era of immune checkpoint inhibitors

The use of immune checkpoint inhibitors (ICIs) for treating melanoma has dramatically improved patient prognosis. The genomic profiles of patients receiving ICI therapy would provide valuable information for disease management and treatment. We investigated the genomic profiles of patients with melanoma who had received ICI therapy and explored associations with clinical features and outcomes via a large-scale nationwide database in Japan (the C-CAT database). We identified 339 patients eligible for this study. The most frequent genetic mutations were found in the BRAF (27%), TERT (24%), and NRAS (19%) genes, and the most common copy number variations (CNVs) were in the CDKN2A (36%), CDKN2B (26%), and MTAP (19%) genes. Associations with high tumor mutational burden (TMB-high) status were significant for TERT (p < 0.001), NF1 (p < 0.001), ROS1 (p = 0.015), POLE (p = 0.045), and POLD1 (p = 0.008) mutations, along with older age (≥65 years, p = 0.036). Patients with multiple metastases (two or more) were more likely to have NOTCH3 mutations (p = 0.017) and be younger than 65 years (p = 0.024). In particular, as well as younger age, patients with brain metastases were more likely to harbor BRAF mutations (p < 0.001), while those with liver metastases were more likely to harbor NOTCH3 mutations (p < 0.001) but not CDKN2B CNVs (p = 0.041). Patients with NRAS mutations were less likely to respond to ICI therapy (p = 0.014) and exhibited shorter overall survival (p = 0.006). In this population, the frequency of BRAF mutations was lower than that in fair-skinned populations, but the associations between genomic profiles, clinical features, and outcomes were similar to those previously reported in fair-skinned populations.

Transcriptomic signatures in peripheral CD4+T-lymphocytes may reflect melanoma staging and immunotherapy responsiveness prior to ICI initiation

Background and purpose

Promoting adaptive immunity with ICIs has drastically improved melanoma prognosis, but not for all patients. Some cases relapse in the first few months, while others keep durable benefit, even after immunotherapy discontinuation. To identify cellular/molecular signatures in peripheral blood that could differentiate advanced from metastatic melanoma and predict dynamics for primary/secondary immune escape, we examined 100 consecutive patients with stage III/IV melanoma scheduled to start ICIs.

Materials and methods

At melanoma diagnosis, a multiparameter flow cytometric analysis and purification scheme using standard conjugated antibodies were performed for all individuals prior to ICI initiation. In each stage(III/IV) according to their RFS/PFS, we retrospectively selected the cases with the clearest clinical outcomes and focused our analysis on the extreme responders(n=7) and non-responders(n=7) to characterize the transcriptomes of circulating CD4+T-cells by bulk RNA-seq, Differential Expression Analysis(DEA)and Gene Ontology(GO)enrichment analysis. Based on our selected patient cohort, we examined for differentially expressed genes(DEGs)and key-pathways that appear preferentially activated in stage III vs. IV melanoma, and in long vs. short immunotherapy responders.

Results

Although circulating immune-cells did not numerically differ in both sets of analysis(staging and ICI responsiveness), DEA and GO data showed that patients could be clustered separately, identifying 189vs.92 DEGs in stage IV/III and 101vs.47 DEGs in early progressors/long responders. These DEGs were functionally implicated in distinct pathways. For metastatic cases: inflammatory response(logp-value=-9.2:ADGRE5/2,CYBA,GRN,HMOX1,IRF5,ITGAM), adaptive immunity(logp-value=-7.7:CD1C,CD74,CYBB,NCF2,CTSA,S100A8/9,BCL3,FCER1G), T-cell activation(logp-value=-6.3:BCL3,CD1C,CD74,FCER1G,FGL2)and lipid metabolism/catabolism(logp-value=-2.5/-2.6:ARF3,GPX1,MVD,OCRL,PCCB,CTSA,PNPLA2,NAGLU,GBA2,ABHD4); while in early-progressors to ICIs: immune effector processing(logp-value=-13.7:BCL6,FGR,HLA-DQA1/DQB1,HLA-DRA,HLA-DRB1/DRB5,NKG7,SLC11A1,TYROBP,SPON2,HAVCR2),PD-1(logp-value=-10.2:HLA-DQA1/DQB1,HLA-DRA,HLA-DRB1/DRB5)and IFN signaling(logp-value=-8.5: HLA-DQA1/DQB1,HLA-DRA,HLA-DRB1/DRB5,NCAM1,IFITM3),positive regulation of T-cell activation(logp-value=-7.7:BCL6,HLA-DQA1/DQB1,HLA-DRA,HLA-DRB1/DRB5,SASH3,HAVCR2)and CD28 co-stimulation(logp-value=-10.3:HLA-DQA1/DQB1,HLA-DRA,HLA-DRB1/DRB5), supporting an immune-mediated behavior.

Conclusions

Specific pathways and marker genes in the peripheral CD4+T-cells may predetermine melanoma staging and immunotherapy resistance.

Epacadostat Overcomes Cetuximab Resistance in Colorectal Cancer by Targeting IDO-Mediated Tryptophan Metabolism

Primary or acquired mutations in RAS/RAF genes resulting in cetuximab resistance have limited its clinical application in colorectal cancer (CRC) patients. The mechanism of this resistance remains unclear. RNA sequencing from cetuximab-sensitive and -resistant specimens revealed an activation of the tryptophan pathway and elevation of IDO1 and IDO2 in cetuximab-resistant CRC patients. In vitro, in vivo, and clinical specimens confirmed the upregulation of IDO1and IDO2 and the Kyn/Trp after cetuximab treatment. Additionally, the IDO inhibitor, epacadostat, could effectively inhibit the migration and proliferation of cetuximab-resistant CRC cells while promoting apoptosis. Compared to epacadostat monotherapy, the combination of cetuximab and epacadostat showed a stronger synergistic anti-tumor effect. Furthermore, in vivo experiments confirmed that combination therapy effectively suppressed tumor growth. Mechanistically, KEGG pathway analysis revealed the activation of the IFN-γ pathway in cetuximab-resistant CRC tissues. Luciferase reporter assays confirmed the transcriptional activity of IDO1 following cetuximab treatment. Silencing IFN-γ then suppressed the upregulation induced by cetuximab. Moreover, we observed that the combination reduced the concentration of the tryptophan metabolite kynurenine, promoted the infiltration of CD8+ T lymphocytes, and enhanced the polarization of M1 macrophages within the tumor microenvironment, thereby exerting potent anti-tumor immune effects. Overall, our results confirm the remarkable therapeutic efficacy of combining cetuximab with epacadostat in cetuximab-resistant CRC. Our findings may provide a novel target for overcoming cetuximab resistance in CRC.

Inhibiting melanoma tumor growth: the role of oxidative stress-associated LINC02132 and COPDA1 long non-coding RNAs

Background

Cutaneous melanoma is a type of malignant tumor that is challenging to predict and is readily stimulated by various factors. Oxidative stress can induce damage and alterations in melanocytes, subsequently triggering immune responses. Given that oxidative stress is a prevalent tumor stimulus, we aimed to enhance melanoma prediction by identifying lncRNA signatures associated with oxidative stress.

Methods

We screened for oxidative stress-related lncRNAs that could improve melanoma patient prognosis using the TCGA and GTEx databases. Utilizing differentially expressed oxidative stress-related lncRNAs (DE-OSlncRNAs), we constructed a Lasso regression model. The accuracy of the model was validated using univariate and multivariate regression, Kaplan-Meier (K-M) curves, and ROC curves. Subsequently, we conducted immune infiltration analysis, immune checkpoint differential analysis, IC50 pharmaceutical analysis, and gene set enrichment analysis. Investigating the effects of the target gene on melanoma using fluorescence in situ hybridization (FISH), quantitative real-time PCR (qRT-PCR), Edu assay, wound healing assay, transwell assay, flow cytometry, and reactive oxygen species (ROS) detection.

Results

Thirteen lncRNAs were identified as significant prognostic factors. Four oxidative stress-related lncRNAs (COPDA1, LINC02132, LINC02812, and MIR205HG) were further validated by fluorescence in situ hybridization (FISH), with results consistent with our data analysis. LINC02132 and COPDA1 can influence the proliferation, invasion, migration, and apoptosis of melanoma.

Conclusion

Our findings suggest that upregulation of the LINC02132 or COPDA1 genes elevates intracellular reactive oxygen species (ROS) levels in melanoma cells, suppresses tumor cell proliferation, migration, and invasion, and promotes apoptosis. These results suggest a novel therapeutic strategy for melanoma treatment.

Mechanisms of Resistance to Anti-PD-1 Immunotherapy in Melanoma and Strategies to Overcome It

Resistance to anti-PD-1 therapy in melanoma remains a major obstacle in achieving effective and durable treatment outcomes, highlighting the need to understand and address the underlying mechanisms. The first key factor is innate anti-PD-1 resistance signature (IPRES), an expression of a group of genes associated with tumor plasticity and immune evasion. IPRES promotes epithelial-to-mesenchymal transition (EMT), increasing melanoma cells' invasiveness and survival. Overexpressed AXL, TWIST2, and WNT5a induce phenotypic changes. The upregulation of pro-inflammatory cytokines frequently coincides with EMT-related changes, further promoting a resistant and aggressive tumor phenotype. Inflamed tumor microenvironment may also drive the expression of resistance. The complexity of immune resistance development suggests that combination therapies are necessary to overcome it. Furthermore, targeting epigenetic regulation and exploring novel approaches such as miR-146a modulation may provide new strategies to counter resistance in melanoma.

Comprehensive Breslow thickness (BT)-based analysis to identify biological mechanisms associated with melanoma pathogenesis

Breslow thickness (BT), a parameter measuring the depth of invasion of abnormally proliferating melanocytes, is a key indicator of melanoma severity and prognosis. However, the mechanisms underlying the increase in BT remain elusive. Utilizing data from The Cancer Genome Atlas (TCGA) human skin cutaneous melanoma (SKCM), we identified a set of BT-related molecules and analyzed their expression and genomic heterogeneity across pan-cancerous and normal tissues. Through consensus clustering, we identified two distinct BT phenotypes in melanoma, which exhibited significant differences in clinical, genomic, and immune infiltration characteristics. High BT molecular expression was associated with reduced CD8+ T cell infiltration and poor immunotherapy response, potentially mediated by the Macrophage Migration Inhibitory Factor (MIF) signaling pathway. In vitro experiments confirmed that BT molecules, including TRIM29, SERPINB5, and RAB25, promoted melanoma development through distinct mechanisms. Notably, fibroblast-derived TRIM29 and B-cell-derived RAB25 interacted with SPP1+ monocytes/macrophages via different pathways. Our findings suggest that genomic variations leading to imbalanced expression of BT molecules across cancers contribute to increased BT, which is closely linked to an immunosuppressive microenvironment. The involvement of multiple cell types and complex intercellular interactions underscores the importance of evaluating dynamic cellular crosstalk in the tumor microenvironment to better understand BT increases and develop more effective immunotherapeutic strategies.

Primary resistance to nivolumab plus ipilimumab therapy affects second-line treatment outcomes in patients with metastatic renal cell carcinoma

Nivolumab plus ipilimumab (NIVO+IPI) has a long-term response rate of 30% for patients with metastatic renal cell carcinoma (mRCC). However, 20% of patients develop primary resistant disease (PRD) to NIVO+IPI and show poor survival outcomes. In this study, we aimed to evaluate the effect of PRD as a second-line treatment in patients with mRCC. The data used in this multi-institutional, retrospective cohort were collected between August 2015 and January 2023. In total, 189 patients with mRCC were treated with NIVO+IPI and then with a vascular endothelial growth factor receptor-tyrosine kinase inhibitor. Associations between PRD and progression-free survival of second-line treatment (PFS), progression-free survival 2 (PFS2), and overall survival (OS) were analyzed. The median age at NIVO+IPI initiation was 67 years in the male-dominant population (n = 140, 74.1%), and most patients had clear cell histology (n = 140, 74.1%). PRD was recorded in 42 (22.2%) of 189 patients during NIVO+IPI therapy. Patients who experienced PRD showed poor PFS (hazard ratio [HR], 1.788; 95% confidence interval [CI], 1.176-2.718; p = 0.007), PFS2 (HR, 4.127; 95% CI, 2.649-6.431; p < 0.001), and OS (HR, 3.330; 95% CI, 2.040-5.437; p < 0.001). Before starting second-line therapy, patients with PRD tended to have a poor performance status compared with non-PRD patients and a higher IMDC risk. Second-line drug therapy was not associated with treatment outcomes in patients with PRD. PRD in patients with mRCC receiving NIVO+IPI as first-line treatment was associated with poor clinical course, even with second-line therapy.

Inflammasome activation in melanoma progression: the latest update concerning pathological role and therapeutic value

The progression of melanoma is a complex process influenced by both internal and external cues which encourage the transition of tumour cells, uncontrolled growth, migration, and metastasis. Additionally, inflammation allows tumours to evade the immune system, contributing to cancer development. The inflammasome, a complex of many proteins, is crucial in enhancing immune responses to external and internal triggers. As a critical inflammatory mechanism, it contributes to the development of melanoma. These mechanisms may be triggered via various internal and external stimuli, causing the induction of specific enzymes such as caspase-1, caspase-11, or caspase-8. This, in turn, leads to the release of interleukin (IL)-1β and IL-18 and cell death by apoptosis and pyroptosis. Proper inflammasome stimulation is crucial for the host to deal with invading pathogens or tissue injury. However, inappropriate inflammasome stimulation can result in unregulated tissue reactions, thus easing many diseases, including melanoma. Hence, keeping a delicate equilibrium between the stimulation and prohibition of inflammasomes is crucial, necessitating meticulous control of the assembly and functional aspects of inflammasomes. This review examines the latest advancements in inflammasome studies, specifically focusing on the molecular processes that control inflammasome formation, signalling, and modulation in melanoma.

Engineered GM-CSF polarizes protumorigenic tumor-associated macrophages to an antitumorigenic phenotype and potently synergizes with IL-12 immunotherapy

BACKGROUND

The use of immune checkpoint inhibitors (CPIs) has become a dominant regimen in modern cancer therapy, however immune resistance induced by tumor-associated macrophages (TAMs) with immune suppressive and evasion properties limits responses. Therefore, the rational design of immune modulators that can control the immune suppressive properties of TAMs and polarize them, as well as dendritic cells (DCs), toward a more proinflammatory phenotype is a principal objective in cancer immunotherapy.

METHODS

Here, using a protein engineering approach to enhance cytokine residence in the tumor microenvironment, we examined combined stimulation of the myeloid compartment via tumor stroma-binding granulocyte-macrophage colony-stimulating factor (GM-CSF) to enhance responses in both DCs and T cells via stroma-binding interleukin-12 (IL-12). We evaluated tumor responses at the levels of outcome, cellular responses, and cytokine responses in both the tumors and the tumor-draining lymph nodes. We further investigated the potentiation of DC response to IL-12 by GM-CSF stimulation ex vivo.

RESULTS

Engineered GM-CSF restored an antitumorigenic tumor myeloid microenvironment otherwise suppressed by TAMs, while engineered IL-12 provided effector signals to T cells, thereby boosting both tumor-resident antitumor macrophage and CD8+ T cell populations. Furthermore, engineered GM-CSF potentiated DC response to IL-12, upregulating DC expression of IL-12 receptor and enhancing their expression of proinflammatory cytokines and chemokines on IL-12 exposure. This resulted in remarkable synergistic efficacy in multiple solid tumor models treated with the dual cytokine combination. The combination therapy also improved the efficacy of CPI in a CPI-resistant genetically-engineered melanoma model and exhibited synergistic antitumor efficacy in a pulmonary metastasis model.

CONCLUSION

Our strategy provides a rational design for combination immunotherapy targeting both myeloid and lymphoid compartments through complementary mechanisms.

Melanoma in people living with HIV: Immune landscape dynamics and the role of immuno- and antiviral therapies

The intersection of HIV and melanoma presents a complex and unique challenge, marked by distinct patterns in incidence, mortality, and treatment response. Higher mortality rates among people with HIV who develop melanoma underscore an urgent need to identify the factors influencing these outcomes. Investigating immune system dynamics, the effects of anti-retroviral drugs, and the evolving landscape of cancer immunotherapy in this population holds promise for new insights, though significant uncertainties remain. Over the past 25 years, melanoma research has demonstrated that a robust immune response is critical for effective treatment. In the context of chronic HIV infection, viral reservoirs enable the virus to persist despite anti-retroviral therapy and foster dysregulated myeloid and T cell compartments. The resulting chronic inflammation weakens the immune system and damages tissues, potentially creating "cold" tumor microenvironments that are less responsive to therapy. In this challenging context, animal models become invaluable for uncovering underlying biological mechanisms. While these models do not fully replicate human HIV infection, they provide essential insights into critical questions and inform the development of tailored treatments for this patient population. Clinically, increasing trial participation and creating a centralized, accessible repository for HIV and cancer samples and data are vital. Achieving these goals requires institutions to address barriers to research participation among people with HIV, focusing on patient-centered initiatives that leverage biomedical research to improve their outcomes and extend their lives.

The role of Tim-3 blockade in the tumor immune microenvironment beyond T cells

Numerous preclinical studies have demonstrated the inhibitory function of T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) on T cells as an inhibitory receptor, leading to the clinical development of anti-Tim-3 blocking antibodies. However, recent studies have shown that Tim-3 is expressed not only on T cells but also on multiple cell types in the tumor microenvironment (TME), including dendritic cells (DCs), natural killer (NK) cells, macrophages, and tumor cells. Therefore, Tim-3 blockade in the immune microenvironment not only affect the function of T cells but also influence the functions of other cells. For example, Tim-3 blockade can enhance the ability of DCs to regulate innate and adaptive immunity. The role of Tim-3 blockade in NK cells function is controversial, as it can enhance the antitumor function of NK cells under certain conditions while having the opposite effect in other situations. Additionally, Tim-3 blockade can promote the reversal of macrophage polarization from the M2 phenotype to the M1 phenotype. Furthermore, Tim-3 blockade can inhibit tumor development by suppressing the proliferation and metastasis of tumor cells. In summary, increasing evidence has shown that Tim-3 in other cell types also plays a critical role in the efficacy of anti-Tim-3 therapy. Understanding the function of anti-Tim-3 therapy in non-T cells can help elucidate the diverse responses observed in clinical patients, leading to better development of relevant therapeutic strategies. This review aims to discuss the role of Tim-3 in the TME and emphasize the impact of Tim-3 blockade in the tumor immune microenvironment beyond T cells.

Targeting anticancer immunity in melanoma tumour microenvironment: unleashing the potential of adjuvants, drugs, and phytochemicals

Melanoma poses a challenge in oncology because of its aggressive nature and limited treatment modalities. The tumour microenvironment (TME) in melanoma contains unique properties such as an immunosuppressive and high-density environment, unusual vasculature, and a high number of stromal and immunosuppressive cells. In recent years, numerous experiments have focused on boosting the immune system to effectively remove malignant cells. Adjuvants, consisting of phytochemicals, toll-like receptor (TLR) agonists, and cytokines, have shown encouraging results in triggering antitumor immunity and augmenting the therapeutic effectiveness of anticancer therapy. These adjuvants can stimulate the maturation of dendritic cells (DCs) and infiltration of cytotoxic CD8+ T lymphocytes (CTLs). Furthermore, nanocarriers can help to deliver immunomodulators and antigens directly to the tumour stroma, thereby improving their efficacy against malignant cells. The remodelling of melanoma TME utilising phytochemicals, agonists, and other adjuvants can be combined with current modalities for improving therapy outcomes. This review article explores the potential of adjuvants, drugs, and their nanoformulations in enhancing the anticancer potency of macrophages, CTLs, and natural killer (NK) cells. Additionally, the capacity of these agents to repress the function of immunosuppressive components of melanoma TME, such as immunosuppressive subsets of macrophages, stromal and myeloid cells will be discussed.

Immunotherapy after progression to double immunotherapy: pembrolizumab and lenvatinib versus conventional chemotherapy for patients with metastatic melanoma after failure of PD-1/CTLA-4 inhibition

Background

Programmed cell death 1 receptor (PD-1) inhibition as monotherapy followed by Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) inhibition in case of progression or as upfront double co-inhibition has drastically improved the survival outcomes of metastatic melanoma. Still, many patients develop primary or acquired resistance to both agents, relapse soon, and survive less. For these patients, the therapeutic options are very limited, and for many years, conventional chemotherapy (CC) was the standard of care. Recently, the phase II LEAP-004 trial supported that pembrolizumab/lenvatinib could potentially overcome anti-PD-1/anti-CTLA-4 immunotherapy refractoriness.

Materials and methods

In the absence of any prospective comparative study and to evaluate in a real-world context the clinical benefit of re-administering a PD-1 inhibitor (pembrolizumab 200 mg i.v. every 3 weeks, Q3W) with a multi-kinase inhibitor (lenvatinib, but at a reduced dose 10 mg p.o. daily due to its known toxicity) in this frail population of unmet need, we conducted here a retrospective comparison of LEAP-004-proposed combination with CC (carboplatin 4 AUC and dacarbazine 850 mg/m2 i.v. Q3W) in melanoma patients who relapsed to both checkpoint inhibitors, either in combinatorial or in sequential setting, between July 2022 and January 2024. Baseline demographics, disease characteristics, and treatment outcomes (objective response rate (ORR), progression-free survival (PFS), and overall survival (OS)) were recorded. Survival analyses were performed using the Kaplan-Meier method. All patients were also considered for safety analysis.

Results

A total of 84 patients were included in the effectiveness and safety analysis (pembrolizumab/lenvatinib, n=39 and CC, n=45). The median age was 67 (45-87) years and 64 (34-87) years, and men were 33.3% and 46.7%, respectively. The distribution of their metastatic sites was comparable, including 12.8% and 20% with brain involvement. Most patients had a good PS<2 (69.9% and 56.5%), increased lactate dehydrogenase (LDH) (71.8% and 84.4%), BRAF-wild status (82.1% and 84.8%), and received ≥2 previous systemic therapies (61.5% and 53.3%). The median follow-up was 18 months. The ORR was 23.1% and 11.1% (p<0.0001), the median PFS was 4.8 months and 3.8 months [HR (95%CI), 0.57 (0.36-0.92); p=0.017], and the median OS was 14.2 months and 7.8 months [HR (95%CI), 0.39 (0.22-0.69), p=0.0009] in pembrolizumab/lenvatinib and CC arms, respectively. Grade 3-5 treatment-related adverse events were documented in 48.7% (pembrolizumab/lenvatinib) and 75.6% (CC) of patients (p=0.034), which led to treatment discontinuation in 10.3% and 17.8% of cases, respectively.

Conclusions

This is the first comparative study in patients with metastatic melanoma refractory to PD-1/CTLA-4 inhibition and showed significantly longer outcomes in cases treated with pembrolizumab/lenvatinib versus CC.

Immune Checkpoint Inhibitor Therapy for Metastatic Melanoma: What Should We Focus on to Improve the Clinical Outcomes?

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment by enhancing anti-tumour immune responses, demonstrating significant efficacy in various malignancies, including melanoma. However, over 50% of patients experience limited or no response to ICI therapy. Resistance to ICIs is influenced by a complex interplay of tumour intrinsic and extrinsic factors. This review summarizes current ICIs for melanoma and the factors involved in resistance to the treatment. We also discuss emerging evidence that the microbiota can impact ICI treatment outcomes by modulating tumour biology and anti-tumour immune function. Furthermore, microbiota profiles may offer a non-invasive method for predicting ICI response. Therefore, future research into microbiota manipulation could provide cost-effective strategies to enhance ICI efficacy and improve outcomes for melanoma patients.

Cyclic tachyplesin I kills proliferative, non-proliferative and drug-resistant melanoma cells without inducing resistance

Acquired drug resistance is the major cause for disease recurrence in cancer patients, and this is particularly true for patients with metastatic melanoma that carry a BRAF V600E mutation. To address this problem, we investigated cyclic membrane-active peptides as an alternative therapeutic modality to kill drug-tolerant and resistant melanoma cells to avoid acquired drug resistance. We selected two stable cyclic peptides (cTI and cGm), previously shown to have anti-melanoma properties, and compared them with dabrafenib, a drug used to treat cancer patients with the BRAF V600E mutation. The peptides act via a fast membrane-permeabilizing mechanism and kill metastatic melanoma cells that are sensitive, tolerant, or resistant to dabrafenib. Melanoma cells do not become resistant to long-term treatment with cTI, nor do they evolve their lipid membrane composition, as measured by lipidomic and proteomic studies. In vivo studies in mice demonstrated that the combination treatment of cTI and dabrafenib resulted in fewer metastases and improved overall survival. Such cyclic membrane-active peptides are thus well suited as templates to design new anticancer therapeutic strategies.

Prognostic and immune infiltration implications of SIGLEC9 in SKCM

The occurrence and progression of skin cutaneous melanoma (SKCM) is strongly associated with immune cells infiltrating the tumor microenvironment (TME). This study examined the expression, prognosis, and immune relevance of SIGLEC9 in SKCM using multiple online databases. Analysis of the GEPIA2 and Ualcan databases revealed that SIGLEC9 is highly expressed in SKCM, and patients with high SIGLEC9 expression had improved overall survival (OS). Furthermore, the mutation rate of SIGLEC9 in SKCM patients was found to be 5.41%, the highest observed. The expression of SIGLEC9 was positively correlated with macrophages, neutrophils and B cells, CD8 + T cells, CD4 + T cells, and dendritic cells, according to TIMER. Based on TCGA-SKCM data, we verified that high SIGLEC9 expression is closely associated with a good prognosis for SKCM patients, including overall survival, progression-free interval, and disease-specific survival. This positive prognosis could be due to the infiltration of immune cells into the TME. Additionally, our analysis of single-cell transcriptome data revealed that SIGLEC9 not only played a role in the normal skin immune microenvironment, but is also highly expressed in immune cell subpopulations of SKCM patients, regulating the immune response to tumors. Our findings suggest that the close association between SIGLEC9 and SKCM prognosis is primarily mediated by its effect on the tumor immune microenvironment.

Unveiling the Dynamic Interplay between Cancer Stem Cells and the Tumor Microenvironment in Melanoma: Implications for Novel Therapeutic Strategies

Cutaneous melanoma still represents a significant health burden worldwide, being responsible for the majority of skin cancer deaths. Key advances in therapeutic strategies have significantly improved patient outcomes; however, most patients experience drug resistance and tumor relapse. Cancer stem cells (CSCs) are a small subpopulation of cells in different tumors, including melanoma, endowed with distinctive capacities of self-renewal and differentiation into bulk tumor cells. Melanoma CSCs are characterized by the expression of specific biomarkers and intracellular pathways; moreover, they play a pivotal role in tumor onset, progression and drug resistance. In recent years, great efforts have been made to dissect the molecular mechanisms underlying the protumor activities of melanoma CSCs to provide the basis for novel CSC-targeted therapies. Herein, we highlight the intricate crosstalk between melanoma CSCs and bystander cells in the tumor microenvironment (TME), including immune cells, endothelial cells and cancer-associated fibroblasts (CAFs), and its role in melanoma progression. Specifically, we discuss the peculiar capacities of melanoma CSCs to escape the host immune surveillance, to recruit immunosuppressive cells and to educate immune cells toward an immunosuppressive and protumor phenotype. We also address currently investigated CSC-targeted strategies that could pave the way for new promising therapeutic approaches for melanoma care.

Circulating interleukin-8 and osteopontin are promising biomarkers of clinical outcomes in advanced melanoma patients treated with targeted therapy

BACKGROUND

Circulating cytokines can represent non-invasive biomarkers to improve prediction of clinical outcomes of cancer patients. Here, plasma levels of IL-8, CCL4, osteopontin, LIF and BDNF were determined at baseline (T0), after 2 months of therapy (T2) and, when feasible, at progression (TP), in 70 melanoma patients treated with BRAF and MEK inhibitors. The association of baseline cytokine levels with clinical response, progression-free survival (PFS) and overall survival (OS) was evaluated.

METHODS

Cytokine concentrations were measured using the xMAP technology. Their ability to discriminate between responding (Rs) and non-responding (NRs) patients was assessed by Receiver Operating Characteristics analysis. PFS and OS were estimated with the Kaplan-Meier method. The Cox proportional hazard model was used in the univariate and multivariate analyses to estimate crude and adjusted hazard ratios with 95% confidence intervals.

RESULTS

CCL4 and LIF were undetectable in the majority of samples. The median osteopontin concentration at T0 and T2 was significantly higher in NRs than in Rs. The median T0 and T2 values of IL-8 were also higher in NRs than in Rs, although the statistical significance was not reached. No differences were detected for BDNF. In 39 Rs with matched T0, T2, and TP samples, osteopontin and IL-8 significantly decreased from T0 to T2 and rose again at TP, while BDNF levels remained unchanged. In NRs, none of the cytokines showed a significant decrease at T2. Only osteopontin demonstrated a good ability to discriminate between Rs and NRs. A high IL-8 T0 level was associated with significantly shorter PFS and OS and higher risk of progression and mortality, and remained an independent negative prognostic factor for OS in multivariate analysis. An elevated osteopontin T0 concentration was also significantly associated with worse OS and increased risk of death. Patients with high IL-8 and high osteopontin showed the lowest PFS and OS, and in multivariate analysis this cytokine combination remained independently associated with a three- to six-fold increased risk of mortality.

CONCLUSION

Circulating IL-8 and osteopontin appear useful biomarkers to refine prognosis evaluation of patients undergoing targeted therapy, and deserve attention as potential targets to improve its clinical efficacy.

Negative association of steroids with immunotherapy efficacy in a multi-tumor cohort: time and dose-dependent

Previous studies have suggested a negative impact of steroids on the efficacy of immune checkpoint inhibitors (ICI), but how this effect is modulated by the dosage and time of administration is yet to be clarified. We have performed a retrospective analysis of 475 patients with advanced solid tumors treated with ICI as monotherapy from 2015 to 2022. Data regarding immune-related adverse events (irAEs) and clinical outcomes were collected. For each patient, the daily steroid dose (in mg/kg of prednisone) was registered until disease progression or death. The impact of cumulative doses on response rates and survival outcomes was analyzed within different periods. The objective response rate (ORR) was significantly lower among patients exposed to steroids within 30 days before the first cycle of ICI (C1) (20.3% vs. 36.7%, p < 0.01) and within the first 90 days of treatment (25.7% vs. 37.7%, p = 0.01). This negative association was confirmed by multivariable analysis. Higher mean steroid doses were observed among non-responders, and cumulative doses were inversely correlated with the disease control rate (DCR) around ICI initiation. Remarkably, poorer outcomes were observed even in patients belonging to the lowest dose quartile compared to the steroid-naïve population. The exposure to steroids after 6 months of ICI was not associated with worse survival outcomes. Our results suggest that the potential impact of steroids on ICI efficacy may be time-dependent, prevailing around ICI initiation, and dose-dependent, with modulation of neutrophil-to-lymphocyte ratio as a possible underlying mechanism.

The Nectin family ligands, PVRL2 and PVR, in cancer immunology and immunotherapy

In recent years, immunotherapy has emerged as a crucial component of cancer treatment. However, its efficacy remains limited across various cancer types, highlighting unmet needs. Poliovirus receptor-related 2 (PVRL2) and Poliovirus receptor (PVR) are members of the Nectin and Nectin-like Molecules family, known for their role as cell-cell adhesion molecules. With the development of immunotherapy, their involvement in tumor immune mechanisms as immune checkpoint factors has garnered significant attention. PVRL2 and PVR are predominantly expressed on tumor cells and antigen-presenting cells, binding to PVRIG and TIGIT, respectively, which are primarily found on T and NK cells, thereby suppressing antitumor immunity. Notably, gynecological cancers such as ovarian and endometrial cancers exhibit high expression levels of PVRL2 and PVR, with similar trends observed in various other solid and hematologic tumors. Targeting these immune checkpoint pathways offers a promising therapeutic avenue, potentially in combination with existing treatments. However, the immunomodulatory mechanism involving these bindings, known as the DNAM-1 axis, is complex, underscoring the importance of understanding it for developing novel therapies. This article comprehensively reviews the immunomodulatory mechanisms centered on PVRL2 and PVR, elucidating their implications for various cancer types.

m6A- and m5C- modified lncRNAs orchestrate the prognosis in cutaneous melanoma and m6A- modified LINC00893 regulates cutaneous melanoma cell metastasis

BACKGROUND

As the most important modifications on the RNA level, N6-methyladenosine (m6A-) and 5-methylcytosine (m5C-) modification could have a direct influence on the RNAs. Long non-coding RNAs (lncRNAs) could also be modified by methylcytosine modification. Compared with mRNAs, the function of lncRNAs could be more potent to some extent in biological processes like tumorigenesis. Until now, rare reports have been done associated with cutaneous melanoma. Herein, we wonder if the m6A- and m5C- modified lncRNAs could influence the immune landscape and prognosis in melanoma, and we also want to find some lncRNAs which could directly affect the malignant behaviors of melanoma.

METHODS

Systematically, we explored the expression pattern of m6A- and m5C- modified lncRNAs in melanoma from datasets including UCSC Xena and NCBI GEO, and the prognostic lncRNAs were selected. Then, according to the expression pattern of lncRNAs, melanoma samples from these datasets were divided into several subtypes. Prognostic model, nomogram survival model, drug sensitivity, GO, and KEGG pathway analysis were performed. Furthermore, among several selected lncRNAs, we identified one lncRNA named LINC00893 and investigated its expression pattern and its biological function in melanoma cell lines.

RESULTS

We identified 27 m6A- and m5C- related lncRNAs which were significantly associated with survival, and we made a subtype analysis of melanoma samples based on these 27 lncRNAs. Among the two subtypes, we found differences of immune cells infiltration between these two subtypes. Then, LASSO algorithm was used to screen the optimized lncRNAs combination including ZNF252P-AS1, MIAT, FAM13A-AS1, LINC-PINT, LINC00893, AGAP2-AS1, OIP5-AS1, and SEMA6A-AS1. We also found that there was a significant correlation between the different risk groups predicted based on RS model and the actual prognosis. The nomogram survival model based on independent survival prognostic factors was also constructed. Besides, sensitivity to chemotherapeutic agents, GO and KEGG analysis were performed. In different risk groups, a total of 14 drug molecules with different distributions were obtained, which included AZD6482, AZD7762, AZD8055, camptothecin, dasatinib, erlotinib, gefitinib, gemcitabine, GSK269962A, nilotinib, rapamycin, and sorafenib. A total of 55 significantly related biological processes and 17 KEGG signaling pathways were screened. At last, we noticed that LINC00893 had a relatively lower expression in melanoma tissue and cell lines compared with adjacent tissues and epidermal melanocyte, and down-regulation of LINC00893 could promote the malignant behavior of melanoma cells in A875 and MV3. In these two melanoma cell lines, down-regulation of m6A-related molecules like YTHDF3 and METTL3 could promote the expression of LINC00893.

CONCLUSION

We made an analysis of m6A- and m5C- related lncRNAs in melanoma samples and a prediction of these lncRNAs' role in prognosis, tumor microenvironment, immune infiltration, and clinicopathological features. We also found that LINC00893, which is potentially regulated by m6A modification, could serve as a tumor-suppressor in melanoma and play an inhibitory role in melanoma metastasis.

Epigenetic regulation of tumor immunity

Although cancer has long been considered a genetic disease, increasing evidence shows that epigenetic aberrations play a crucial role in affecting tumor biology and therapeutic response. The dysregulated epigenome in cancer cells reprograms the immune landscape within the tumor microenvironment, thereby hindering antitumor immunity, promoting tumor progression, and inducing immunotherapy resistance. Targeting epigenetically mediated tumor-immune crosstalk is an emerging strategy to inhibit tumor progression and circumvent the limitations of current immunotherapies, including immune checkpoint inhibitors. In this Review, we discuss the mechanisms by which epigenetic aberrations regulate tumor-immune interactions and how epigenetically targeted therapies inhibit tumor progression and synergize with immunotherapy.

STC1 competitively binding βPIX enhances melanoma progression via YAP nuclear translocation and M2 macrophage recruitment through the YAP/CCL2/VEGFA/AKT feedback loop

This study investigates the role of Stanniocalcin-1 (STC1) in melanoma progression, with a focus on its impact on metastasis, angiogenesis, and immune evasion. Systematic bioinformatics analysis revealed the potential influence of STC1 dysregulation on prognosis, immune cell infiltration, response to immune therapy, and cellular functions. In vitro assays were conducted to assess the proliferation, invasion, migration, and angiogenesis capabilities of A375 cells. In vivo experiments utilizing C57BL/6 J mice established a lung metastasis model using B16-F10 cells to evaluate macrophage infiltration and M2 polarization. A Transwell co-culture system was employed to explore the crosstalk between melanoma and macrophages. Molecular interactions among STC1, YAP, βPIX, and CCL2 are investigated using mass spectrometry, Co-Immunoprecipitation, Dual-Luciferase Reporter Assay, and Chromatin Immunoprecipitation experiments. STC1 was found to enhance lung metastasis by promoting the recruitment and polarization of M2 macrophages, thereby fostering an immunosuppressive microenvironment. Mechanistically, STC1 competes with YAP for binding to βPIX within the KER domain in melanoma cells, leading to YAP activation and subsequent CCL2 upregulation. CCL2-induced M2 macrophages secrete VEGFA, which enhances tumor vascularization and increases STC1 expression via the AKT signaling pathway in melanoma cells, establishing a pro-metastatic feedback loop. Notably, STC1-induced YAP activation increases PD-L1 expression, promoting immune evasion. Silencing STC1 enhances the efficacy of PD-1 immune checkpoint therapy in mice. This research elucidates STC1's role in melanoma metastasis and its complex interactions with tumor-associated macrophages, proposing STC1 as a potential therapeutic target for countering melanoma metastasis and augmenting the efficacy of PD-1 immunotherapy.

Therapeutic Implications of Targeting YY1 in Glioblastoma

The transcription factor Yin Yang 1 (YY1) plays a pivotal role in the pathogenesis of glioblastoma multiforme (GBM), an aggressive form of brain tumor. This review systematically explores the diverse roles of YY1 overexpression and activities in GBM, including its impact on the tumor microenvironment (TME) and immune evasion mechanisms. Due to the poor response of GBM to current therapies, various findings of YY1-associated pathways in the literature provide valuable insights into novel potential targeted therapeutic strategies. Moreover, YY1 acts as a significant regulator of immune checkpoint molecules and, thus, is a candidate therapeutic target in combination with immune checkpoint inhibitors. Different therapeutic implications targeting YY1 in GBM and its inherent associated challenges encompass the use of nanoparticles, YY1 inhibitors, targeted gene therapy, and exosome-based delivery systems. Despite the inherent complexities of such methods, the successful targeting of YY1 emerges as a promising avenue for reshaping GBM treatment strategies, presenting opportunities for innovative therapeutic approaches and enhanced patient outcomes.

Role of Exosomes in Cancer and Aptamer-Modified Exosomes as a Promising Platform for Cancer Targeted Therapy

Exosomes are increasingly recognized as important mediators of intercellular communication in cancer biology. Exosomes can be derived from cancer cells as well as cellular components in tumor microenvironment. After secretion, the exosomes carrying a wide range of bioactive cargos can be ingested by local or distant recipient cells. The released cargos act through a variety of mechanisms to elicit multiple biological effects and impact most if not all hallmarks of cancer. Moreover, owing to their excellent biocompatibility and capability of being easily engineered or modified, exosomes are currently exploited as a promising platform for cancer targeted therapy. In this review, we first summarize the current knowledge of roles of exosomes in risk and etiology, initiation and progression of cancer, as well as their underlying molecular mechanisms. The aptamer-modified exosome as a promising platform for cancer targeted therapy is then briefly introduced. We also discuss the future directions for emerging roles of exosome in tumor biology and perspective of aptamer-modified exosomes in cancer therapy.

Self-supplying Cu2+ and H2O2 synergistically enhancing disulfiram-mediated melanoma chemotherapy

Disulfiram (DSF) can target and kill cancer cells by disrupting cellular degradation of extruded proteins and has therefore received particular attention for its tumor chemotherapeutic potential. However, the uncontrollable Cu2+/DSF ratio reduces the efficacy of DSF-mediated chemotherapy. Herein, self-supplying Cu2+ and oxidative stress synergistically enhanced DSF-mediated chemotherapy is proposed for melanoma-based on PVP-coated CuO2 nanodots (CPNDs). Once ingested, DSF is broken down to diethyldithiocarbamate (DTC), which is delivered into a tumor via the circulation. Under the acidic tumor microenvironment, CPNDs produce sufficient Cu2+ and H2O2. DTC readily chelates Cu2+ ions to generate CuET, which shows antitumor efficacy. CuET-mediated chemotherapy can be enhanced by H2O2. Sufficient Cu2+ generation can guarantee the maximum efficacy of DSF-mediated chemotherapy. Furthermore, released Cu2+ can be reduced to Cu+ by glutathione (GSH) and O2- in tumor cells, and Cu+ can react with H2O2 to generate toxic hydroxyl radicals (·OH) via a Fenton-like reaction, promoting the efficacy of CuET. Therefore, this study hypothesizes that employing CPNDs instead of Cu2+ ions could enhance DSF-mediated melanoma chemotherapy, providing a simple but efficient strategy for achieving chemotherapeutic efficacy.

Inhibiting autophagy enhanced mitotic catastrophe-mediated anticancer immune responses by regulating the cGAS-STING pathway

Given the limitations of the response rate and efficacy of immune checkpoint inhibitors (ICIs) in clinical applications, exploring new therapeutic strategies for cancer immunotherapy is necessary. We found that 5-(3,4,5-trimethoxybenzoyl)-4-methyl-2-(p-tolyl)imidazole (BZML), a microtubule-targeting agent, exhibited potent anticancer activity by inducing mitotic catastrophe in A549/Taxol and L929 cells. Nuclear membrane disruption and nuclease reduction provided favorable conditions for cGAS-STING pathway activation in cells with mitotic catastrophe. Similar results were obtained in paclitaxel-, docetaxel- and doxorubicin-induced mitotic catastrophe in various cancer cells. Notably, the surface localization of CALR and MHC-I and the release of HMGB1 were also significantly increased in cells with mitotic catastrophe, but not in apoptotic cells, suggesting that mitotic catastrophe is an immunogenic cell death. Furthermore, activated CD8+T cells enhanced the anticancer effects originating from mitotic catastrophe induced by BZML. Inhibiting the cGAS-STING pathway failed to affect BZML-induced mitotic catastrophe but could inhibit mitotic catastrophe-mediated anticancer immune effects. Interestingly, the expression of p-TBK1 first increased and then declined; however, autophagy inhibition reversed the decrease in p-TBK1 expression and enhanced mitotic catastrophe-mediated anticancer immune effects. Collectively, the inhibition of autophagy can potentiate mitotic catastrophe-mediated anticancer immune effects by regulating the cGAS-STING pathway, which explains why the anticancer immune effects induced by chemotherapeutics have not fully exerted their therapeutic efficacy in some patients and opens a new area of research in cancer immunotherapy.

A cuproptosis-related gene expression signature predicting clinical prognosis and immune responses in intrahepatic cholangiocarcinoma detected by single-cell RNA sequence analysis

BACKGROUND

Cholangiocarcinoma represents a malignant neoplasm originating from the hepatobiliary tree, with a subset of tumors developing inside the liver. Intrahepatic cholangiocarcinomas (ICC) commonly exhibit an asymptomatic presentation, rendering both diagnosis and treatment challenging. Cuproptosis, an emerging regulated cell death pathway induced by copper ions, has garnered attention recently. As cancer cells show altered copper metabolism and comparatively higher copper needs, cuproptosis may play a role in the development of ICC. However, studies investigating this possibility are currently lacking.

METHODS

Single-cell and bulk RNA sequence data were analyzed, and correlations were established between the expression of cuproptosis-related molecules and ICC patient survival. Genes with predicting survival were used to create a CUPT score using Cox and LASSO regression and tumor mutation burden (TMB) analysis. The CIBERSORT software was employed to characterize immune cell infiltration within the tumors. Furthermore, immune infiltration prediction, biological function enrichment, and drug sensitivity analyses were conducted to explore the potential implications of the cuproptosis-related signature. The effects of silencing solute carrier family 39 member 4 gene (SLC39A4) expression using siRNA were investigated using assays measuring cell proliferation, colony formation, and cell migration. Key genes of cuproptosis were detected by western blotting.

RESULTS

The developed CUPT score divided patients into high and low CUPT score groups. Those with a low score had significantly better prognosis and longer survival. In contrast, high CUPT scores were associated with worse clinical outcomes and significantly higher TMB. Comparisons of the two groups also indicated differences in the immune infiltrate present in the tumors. Finally, we were able to identify 95 drugs potentially affecting the cuproptosis pathway. Some of these might be effective in the treatment of ICC. The in vitro experiments revealed that suppressing the expression of SLC39A4 in ICC cell lines resulted in reduced cell proliferation, colony formation, and cell migration. It also led to an increase in cell death and the upregulation of key genes associated with cuproptosis, namely ferredoxin 1 (FDX1) and dihydrolipoyl transacetylase (DLAT). These findings strongly suggest that this cuproptosis-associated molecule may play a pivotal role in the development and metastasis of ICC.

CONCLUSIONS

Changes in the expression of a cuproptosis-related gene signature can predict the clinical prognosis of ICC with considerable accuracy. This supports the notion that cuproptosis influences the diversity and complexity of the immune microenvironment, mutational landscape, and biological behavior of ICC. Understanding this pathway better may hold promise for the development of innovative strategies in the management of this disease.

Alpha-fetoprotein predicts the treatment efficacy of immune checkpoint inhibitors for gastric cancer patients

BACKGROUND

Immune checkpoint inhibitors (ICIs) are commonly used in conjunction with chemotherapy to improve treatment outcomes for patients with gastric cancer. Since AFP could influence immunity by both inhibiting natural killer (NK) cells and regulating negatively the function of dendritic cells, we evaluated the influence of baseline serum alpha-fetoprotein (AFP) levels on the curative effect of ICIs in advanced gastric cancer (AGC) patients.

METHODS

A retrospective analysis was conducted on 158 AGC patients who underwent ICI treatment. The patients were divided into high and low groups based on the AFP threshold of 20 ng/ml. The efficacy of ICI treatment was assessed using objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS).

RESULTS

The higher levels of baseline AFP were found to be associated with a decrease in the effectiveness of ICIs, as evidenced by a DCR of 50.0% in the group with high AFP levels compared to 87.7% in the group with low AFP levels (P < 0.001). Further analysis using Kaplan-Meier survival techniques indicated that a high AFP level was linked to shorter progression-free survival (PFS) (P < 0.001) and overall survival (OS) (P = 0.001) in AGC individuals receiving ICIs. After propensity score matching, a log rank test revealed that the high AFP group had a decrease in median PFS (P = 0.011) and median OS (P = 0.036) compared to the low AFP group. The high AFP levels also showed its association with shorter PFS and OS in the subgroup analysis of ICI plus chemotherapy patients.

CONCLUSIONS

Baseline AFP levels may predict immune checkpoint inhibitor treatment efficacy in AGC patients.

Biological mechanisms of resistance to immune checkpoint inhibitors and overcoming this resistance: Challenges in medical oncology

Immune checkpoint inhibitors have opened up new possibilities in clinical oncology. Monoclonal antibodies have shown their high clinical efficiency. They block CTLA-4, PD-1, and PD-L1 receptors and activate the immune response. Many patients have stable and even complete responses. However, some patients have primary or acquired resistance. Therefore, the treatment results in this category of patients are not predictable. Mechanisms of resistance to immune checkpoint inhibitors have not been definitively studied. Many theories try to explain the mechanisms of this phenomenon. Our study aimed to structure and combine the data into groups depending on the etiological factor that reduces the immune response. In addition, based on understanding the mechanisms of resistance and the results of recent clinical studies, we aimed to identify the main ways to overcome it. Therefore, mechanisms that lead to resistance may be associated with tumor properties, tumor microenvironment, or patient characteristics. Tumor properties that reduce the immune response include a) low tumor mutation burden and loss of tumor neoantigens, b) changes in the processing or presentation of neoantigens, and c) changes in signaling pathways of tumor development and epigenetic modifications in genes. The tumor microenvironment is represented by stromal and immune cells, extracellular matrix, cytokines, and blood vessels. Each structure can enhance or reduce the immune response and contribute to the acquired resistance to immune checkpoint inhibitors. The effectiveness of the treatment depends not only on the cells in the tumor microenvironment but also on the metabolic background. In addition, the basic characteristics of the patient ( gender, gut microbiota, HLA-I genotype) can modify the immune response. Based on knowledge about the mechanisms of resistance to immune checkpoint inhibitors, several therapeutic strategies aimed at activating antitumor activity have been evaluated. All of them are based on combining immune checkpoint inhibitors with other drugs. One of the most common options is a combination of PD-1/PD-L1 and CTLA-4 inhibitors. Alternative immune checkpoints are TIM-3, LAG-3, TIGIT and VISTA. Combining immunotherapy with chemotherapy, targeted therapy, neoangiogenesis inhibitors, epigenetic modifiers, PARP or TGF-β inhibitors enhances antitumor response by preventing depletion of effector T cells, enhancing T cell infiltration in the tumor, changes on the tumor microenvironment, and decreasing the accumulation of immunosuppressive cells. This review explores the biological mechanisms of resistance and potential ways of solving this problem.

Tumor characteristics of dissociated response to immune checkpoint inhibition in advanced melanoma

INTRODUCTION

Immune checkpoint inhibition (ICI) has improved patients' outcomes in advanced melanoma, often resulting in durable response. However, not all patients have durable responses and the patients with dissociated response are a valuable subgroup to identify mechanisms of ICI resistance.

METHODS

Stage IV melanoma patients treated with ICI and dissociated response were retrospectively screened for available samples containing sufficient tumor at least at two time-points. Included were one patient with metachronous regressive and progressive lesions at the same site, two patients with regressive and novel lesion at different sites, and three patients with regressive and progressive lesions at different sites. In addition, four patients with acquired resistant tumor samples without a matched second sample were included.

RESULTS

In the majority of patients, the progressive tumor lesion contained higher CD8+ T cell counts/mm2 and interferon-gamma (IFNγ) signature level, but similar tumor PD-L1 expression. The tumor mutational burden levels were in 2 out 3 lesions higher compared to the corresponding regressive tumors lesion. In the acquired tumor lesions, high CD8+/mm2 and relatively high IFNγ signature levels were observed. In one patient in both the B2M and PTEN gene a stop gaining mutation and in another patient a pathogenic POLE mutation were found.

CONCLUSION

Intrapatient comparison of progressive versus regressive lesions indicates no defect in tumor T cell infiltration, and in general no tumor immune exclusion were observed.

New Emerging Targets in Cancer Immunotherapy: The Role of B7-H3

Immune checkpoints (ICs) are molecules implicated in the fine-tuning of immune response via co-inhibitory or co-stimulatory signals, and serve to secure minimized host damage. Targeting ICs with various therapeutic modalities, including checkpoint inhibitors/monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and CAR-T cells has produced remarkable results, especially in immunogenic tumors, setting a paradigm shift in cancer therapeutics through the incorporation of these IC-targeted treatments. However, the large proportion of subjects who experience primary or secondary resistance to available IC-targeted options necessitates further advancements that render immunotherapy beneficial for a larger patient pool with longer duration of response. B7-H3 (B7 Homolog 3 Protein, CD276) is a member of the B7 family of IC proteins that exerts pleiotropic immunomodulatory effects both in physiologic and pathologic contexts. Mounting evidence has demonstrated an aberrant expression of B7-H3 in various solid malignancies, including tumors less sensitive to current immunotherapeutic options, and has associated its expression with advanced disease, worse patient survival and impaired response to IC-based regimens. Anti-B7-H3 agents, including novel mAbs, bispecific antibodies, ADCs, CAR-T cells, and radioimmunotherapy agents, have exhibited encouraging antitumor activity in preclinical models and have recently entered clinical testing for several cancer types. In the present review, we concisely present the functional implications of B7-H3 and discuss the latest evidence regarding its prognostic significance and therapeutic potential in solid malignancies, with emphasis on anti-B7-H3 modalities that are currently evaluated in clinical trial settings. Better understanding of B7-H3 intricate interactions in the tumor microenvironment will expand the oncological utility of anti-B7-H3 agents and further shape their role in cancer therapeutics.

The role of immune checkpoints in antitumor response: a potential antitumor immunotherapy

Immunotherapy aims to stimulate the immune system to inhibit tumor growth or prevent metastases. Tumor cells primarily employ altered expression of human leukocyte antigen (HLA) as a mechanism to avoid immune recognition and antitumor immune response. The antitumor immune response is primarily mediated by CD8+ cytotoxic T cells (CTLs) and natural killer (NK) cells, which plays a key role in the overall anti-tumor immune response. It is crucial to comprehend the molecular events occurring during the activation and subsequent regulation of these cell populations. The interaction between antigenic peptides presented on HLA-I molecules and the T-cell receptor (TCR) constitutes the initial signal required for T cell activation. Once activated, in physiologic circumstances, immune checkpoint expression by T cells suppress T cell effector functions when the antigen is removed, to ensures the maintenance of self-tolerance, immune homeostasis, and prevention of autoimmunity. However, in cancer, the overexpression of these molecules represents a common method through which tumor cells evade immune surveillance. Numerous therapeutic antibodies have been developed to inhibit immune checkpoints, demonstrating antitumor activity with fewer side effects compared to traditional chemotherapy. Nevertheless, it's worth noting that many immune checkpoint expressions occur after T cell activation and consequently, altered HLA expression on tumor cells could diminish the clinical efficacy of these antibodies. This review provides an in-depth exploration of immune checkpoint molecules, their corresponding blocking antibodies, and their clinical applications.

The combination of circulating IgM and geriatric nutritional risk index predicts the prognostic of hepatocellular carcinoma patients who underwent immune checkpoint inhibitors

OBJECTIVE

Immune checkpoint inhibitors (ICIs) have shown promise in hepatocellular carcinoma (HCC) treatment. With the increasing use of ICIs in cancer treatment, identifying biomarkers that can predict the prognosis of patients receiving ICIs is of great importance. We aimed to investigate the potential of circulating immunoglobulins and the combination of Geriatric Nutritional Risk Index (GNRI) with IgM to predict prognosis in patients with HCC who received ICIs.

METHODS

Clinical and pathological data were collected from 101 patients with HCC who were administered ICIs and underwent circulating immunoglobulin testing between January 2018 and December 2021. Survival analysis, Cox regression analysis, and nomogram construction were performed to evaluate the prognostic value of the indicators.

RESULTS

In the preliminary survival analysis, we observed a significant correlation between patient prognosis and IgM levels. Patients with low IgM had shorter survival times. Upon combining the GNRI with IgM, patients with low GNRI and IgM levels had shorter progression-free survival (PFS) and overall survival (OS) (P < 0.001). Additionally, GNRI-IgM had the highest area under the curve (AUC) and was identified as an independent prognostic marker in this study. The C-indices of the nomograms for PFS and OS were 0.797 (0.734-0.860) and 0.827 (0.778-0.876), respectively.

CONCLUSIONS

IgM was significantly associated with the prognosis of patients with HCC receiving ICIs. The combination of the GNRI with IgM provided superior prognostic value and served as an independent prognostic marker. The GNRI-IgM can be used to effectively identify patients with HCC who are responsive to ICIs.

BCKDHA contributes to melanoma progression by promoting the expressions of lipogenic enzymes FASN and ACLY

The dysregulation of branched-chain amino acid (BCAA) metabolism and related enzymes has been greatly implicated in the progression of multiple types of cancer, whereas remains far from understood in melanoma. Here, we explored the role of the BCAA metabolism enzyme BCKDHA in melanoma pathogenesis and elucidated the underlying mechanisms. In vitro cell biology experiments and in vivo pre-clinical mice model experiments were performed to investigate the role of BCKDHA in melanoma progression. RNA sequencing, immunohistochemical/immunofluorescence staining and bioinformatics analysis were used to examine the underlying mechanism. BCKDHA expression was prominently increased in both melanoma tissues and cell lines. The up-regulation of BCKDHA promoted long-term tumour cell proliferation, invasion and migration in vitro and tumour growth in vivo. Through RNA-sequencing technology, it was found that BCKDHA regulated the expressions of lipogenic fatty acid synthase (FASN) and ATP-citrate lyase (ACLY), which was thereafter proved to mediate the oncogenic role of BCKDHA in melanoma. Our results demonstrate that BCKDHA promotes melanoma progression by regulating FASN and ACLY expressions. Targeting BCKDHA could be exploited as a promising strategy to restrain tumour progression in melanoma.

Pro-Apoptotic Activity of MCL-1 Inhibitor in Trametinib-Resistant Melanoma Cells Depends on Their Phenotypes and Is Modulated by Reversible Alterations Induced by Trametinib Withdrawal

BACKGROUND

Although BRAFV600/MEK inhibitors improved the treatment of melanoma patients, resistance is acquired almost inevitably.

METHODS

Trametinib withdrawal/rechallenge and MCL-1 inhibition in trametinib-resistance models displaying distinct p-ERK1/2 levels were investigated.

RESULTS

Trametinib withdrawal/rechallenge caused reversible changes in ERK1/2 activity impacting the balance between pro-survival and pro-apoptotic proteins. Reversible alterations were found in MCL-1 levels and MCL-1 inhibitors, BIM and NOXA. Taking advantage of melanoma cell dependency on MCL-1 for survival, we used S63845. While it was designed to inhibit MCL-1 activity, we showed that it also significantly reduced NOXA levels. S63845-induced apoptosis was detected as the enhancement of Annexin V-positivity, caspase-3/7 activation and histone H2AX phosphorylation. Percentages of Annexin V-positive cells were increased most efficiently in trametinib-resistant melanoma cells displaying the p-ERK1/2low/MCL-1low/BIMhigh/NOXAlow phenotype with EC50 values at concentrations as low as 0.1 μM. Higher ERK1/2 activity associated with increased MCL-1 level and reduced BIM level limited pro-apoptotic activity of S63845 further influenced by a NOXA level.

CONCLUSIONS

Our study supports the notion that the efficiency of an agent designed to target a single protein can largely depend on the phenotype of cancer cells. Thus, it is important to define appropriate phenotype determinants to stratify the patients for the novel therapy.

TCF12 Activates TGFB2 Expression to Promote the Malignant Progression of Melanoma

As one of the most common malignant tumors, melanoma is a serious threat to human health. More than half of melanoma patients have a BRAF mutation, and 90% of them have a BRAF(V600E) mutation. There is a targeted therapy for patients using a BRAF(V600E) inhibitor. However, no response to treatment is generally inevitable due to the heterogeneity of melanoma. Coupled with its high metastatic character, melanoma ultimately leads to poor overall survival. This study aimed to explore the possible mechanisms of melanoma metastasis and identify a more effective method for the treatment of melanoma. In this paper, we report that TCF12 expression is higher in melanoma, especially in metastatic tumors, through analyzing data from TCGA. Then, cell proliferation, colony formation, and transwell assays show that the upregulated expression of TCF12 can promote proliferation and metastasis of melanoma cells in vitro. The same result is confirmed in the subcutaneous tumor formation assay. Moreover, TGFB2 is identified as a direct downstream target of TCF12 by RNA-seq, qPCR, immunoblotting, ChIP, and a dual luciferase reporting assay. Interestingly, depletion of TCF12 can sensitize melanoma to BRAF inhibition both in vitro and in vivo. Overall, our results demonstrate that TCF12 promotes melanoma progression and can be a potential tumor therapeutic target.

CD4 T cells and toxicity from immune checkpoint blockade

Immune-related toxicities, otherwise known as immune-related adverse events (irAEs), occur in a substantial fraction of cancer patients treated with immune checkpoint inhibitors (ICIs). Ranging from asymptomatic to life-threatening, ICI-induced irAEs can result in hospital admission, high-dose corticosteroid treatment, ICI discontinuation, and in some cases, death. A deeper understanding of the factors underpinning severe irAE development will be essential for improved irAE prediction and prevention, toward maximizing the benefits and safety profiles of ICIs. In recent work, we applied mass cytometry, single-cell RNA sequencing, single-cell V(D)J sequencing, bulk RNA sequencing, and bulk T-cell receptor (TCR) sequencing to identify pretreatment determinants of severe irAE development in patients with advanced melanoma. Across 71 patients separated into three cohorts, we found that two baseline features in circulation-elevated activated CD4 effector memory T-cell abundance and TCR diversity-are associated with severe irAE development, independent of the affected organ system within 3 months of ICI treatment initiation. Here, we provide an extended perspective on this work, synthesize and discuss related literature, and summarize practical considerations for clinical translation. Collectively, these findings lay a foundation for data-driven and mechanistic insights into irAE development, with the potential to reduce ICI morbidity and mortality in the future.

Advances in targeted therapy and immunotherapy for melanoma (Review)

Melanoma is the most aggressive and deadly type of skin cancer and is known for its poor prognosis as soon as metastasis occurs. Since 2011, new and effective therapies for metastatic melanoma have emerged, with US Food and Drug Administration approval of multiple targeted agents, such as V-Raf murine sarcoma viral oncogene homolog B1/mitogen-activated protein kinase kinase inhibitors and multiple immunotherapy agents, such as cytotoxic T lymphocyte-associated protein 4 and anti-programmed cell death protein 1/ligand 1 blockade. Based on insight into the respective advantages of the above two strategies, the present article provided a review of clinical trials of the application of targeted therapy and immunotherapy, as well as novel approaches of their combinations for the treatment of metastatic melanoma in recent years, with a focus on upcoming initiatives to improve the efficacy of these treatment approaches for metastatic melanoma.

Pembrolizumab-Induced Fatal Myasthenia, Myocarditis, and Myositis in a Patient with Metastatic Melanoma: Autopsy, Histological, and Immunohistochemical Findings-A Case Report and Literature Review

Immune checkpoint inhibitors (ICIs) represent a major advance in cancer treatment. The lowered immune tolerance induced by ICIs brought to light a series of immune-related adverse events (irAEs). Pembrolizumab belongs to the ICI class and is a humanized IgG4 anti-PD-1 antibody that blocks the interaction between PD-1 and PD-L1. The ICI-related irAEs involving various organ systems and myocarditis are uncommon (incidence of 0.04% to 1.14%), but they are associated with a high reported mortality. Unlike idiopathic inflammatory myositis, ICI-related myositis has been reported to frequently co-occur with myocarditis. The triad of myasthenia, myositis, and myocarditis must not be underestimated as they can rapidly deteriorate, leading to death. Herein we report a case of a patient with metastatic melanoma who fatally developed myasthenia gravis, myocarditis, and myositis, after a single cycle of pembrolizumab. Considering evidence from the literature review, autopsy, histological, and immunohistochemical investigations on heart and skeletal muscle are presented and discussed, also from a medical-legal perspective.

The Assessment of Anti-Melanoma Potential of Tigecycline-Cellular and Molecular Studies of Cell Proliferation, Apoptosis and Autophagy on Amelanotic and Melanotic Melanoma Cells

High mortality, aggressiveness, and the relatively low effectiveness of therapy make melanoma the most dangerous of skin cancers. Previously published studies presented the promising therapeutic potential of minocycline, doxycycline, and chlortetracycline on melanoma cells. This study aimed to assess the cytotoxicity of tigecycline, a third-generation tetracycline, on melanotic (COLO 829) and amelanotic (A375) melanoma cell lines. The obtained results showed that tigecycline, proportionally to the concentration and incubation time, efficiently inhibited proliferation of both types of melanoma cells. The effect was accompanied by the dysregulation of the cell cycle, the depolarization of the mitochondrial membrane, and a decrease in the reduced thiols and the levels of MITF and p44/42 MAPK. However, the ability to induce apoptosis was only found in COLO 829 melanoma cells. A375 cells appeared to be more resistant to the treatment with tigecycline. The drug did not induce apoptosis but caused an increase in LC3A/B protein levels-an autophagy marker. The observed differences in drug action on the tested cell lines also involved an increase in p21 and p16 protein levels in melanotic melanoma, which was related to cell cycle arrest in the G1/G0 phase. The greater sensitivity of melanotic melanoma cells to the action of tigecycline suggests the possibility of considering the use of the drug in targeted therapy.