Emerging biomarkers for cancer immunotherapy in melanoma

Predictors of survival in immunotherapy-based treatments in advanced melanoma: a meta-analysis

The introduction of immunotherapy-based strategies has significantly improved the prognosis for melanoma patients. Nevertheless, some patients still have dismal outcomes, emphasizing the significance of survival predictive indicators in immunotherapy-based approaches. We systematically searched randomized controlled clinical trials investigating dual immunotherapy or chemoimmunotherapy versus placebo or mono-immunotherapy or chemotherapy alone in advanced melanoma patients. R version 4.3.0. was employed to perform all analyses. A comprehensive analysis was conducted on a total of 13,809 patients with advanced melanoma from 19 randomized clinical trials. Immunotherapy-based strategies (alone or in combination) could significantly lengthen the overall survival(OS) and recurrence-free survival (RFS) compared with corresponding controls. Mono-immunotherapy improved RFS and OS in PD-L1 positive patients, in stage AJCC IIIC, and with 4 or more positive lymph nodes, compared with chemotherapy. Combined immunotherapy statistically improved RFS and OS in those aged < 65, with an Eastern Cooperative Oncology Group (ECOG) status of 0, and LDH ≤ ULN at baseline compared with single treatment alone. Our findings indicated that certain clinicopathological and molecular features could assist in choosing appropriate melanoma patients for immune-based treatments.

Circulating IL-6 is associated with disease progression in BRAFwt metastatic melanoma patients receiving anti-PD-1 therapy

AIMS

Despite efficacy of anti-PD-1 blockade in treatment of metastatic melanoma (MM), many patients achieve rapid disease progression (DP). Therefore, the aim of this study is to better define biomarkers for DP by analysing levels of circulating cytokines TGF-β, IFN-γ, IL-6, IL-8 and IL-10 in MM patients prior to anti-PD-1 therapy.

METHODS

Cytokine levels were evaluated before therapy with pembrolizumab in peripheral blood of BRAF wild-type (wt) MM patients by ELISA method.

RESULTS

In this study, we give pretherapy levels for circulating TGF-β, IFN-γ, IL-6, IL-8 and IL-10 in BRAFwt MM patients and analyse them according to metastasis stage (M1a+M1 b, M1c, M1d groups), lactate dehydrogenase (LDH) level and occurrence of DP. Increased IL-6 level was found in M1d group (central nervous system metastasis), while LDH+patients (LDH ≥460 IU/L) have increased IL-6 and IL-8 values that correlate with LDH level. Also, IL-6 correlates with C reactive protein values. Furthermore, patients with DP have significantly higher IL-6 level compared with non-DP patients. Conversely, the other analysed cytokines are similar in investigated groups of MM patients. By receiver operating characteristics curve analysis, pretherapy IL-6 level was found to be a biomarker for the occurrence of DP with cut-off value of 3.02 pg/mL. Patients in M1d stage are prevalent in the group with IL-6 ≥3.02 pg/mL that is characterised with reduced progression-free survival and higher pretherapy IL-8 and LDH.

CONCLUSION

The evidence in this study implies that baseline IL-6 could be a biomarker of DP and poor prognosis in BRAFwt MM patients treated with pembrolizumab.

Potential of CDC25 phosphatases in cancer research and treatment: key to precision medicine

The global burden of cancer continues to rise, underscoring the urgency of developing more effective and precisely targeted therapies. This comprehensive review explores the confluence of precision medicine and CDC25 phosphatases in the context of cancer research. Precision medicine, alternatively referred to as customized medicine, aims to customize medical interventions by taking into account the genetic, genomic, and epigenetic characteristics of individual patients. The identification of particular genetic and molecular drivers driving cancer helps both diagnostic accuracy and treatment selection. Precision medicine utilizes sophisticated technology such as genome sequencing and bioinformatics to elucidate genetic differences that underlie the proliferation of cancer cells, hence facilitating the development of customized therapeutic interventions. CDC25 phosphatases, which play a crucial role in governing the progression of the cell cycle, have garnered significant attention as potential targets for cancer treatment. The dysregulation of CDC25 is a characteristic feature observed in various types of malignancies, hence classifying them as proto-oncogenes. The proteins in question, which operate as phosphatases, play a role in the activation of Cyclin-dependent kinases (CDKs), so promoting the advancement of the cell cycle. CDC25 inhibitors demonstrate potential as therapeutic drugs for cancer treatment by specifically blocking the activity of CDKs and modulating the cell cycle in malignant cells. In brief, precision medicine presents a potentially fruitful option for augmenting cancer research, diagnosis, and treatment, with an emphasis on individualized care predicated upon patients' genetic and molecular profiles. The review highlights the significance of CDC25 phosphatases in the advancement of cancer and identifies them as promising candidates for therapeutic intervention. This statement underscores the significance of doing thorough molecular profiling in order to uncover the complex molecular characteristics of cancer cells.

Polycomb repressor complex 2 suppresses interferon-responsive MHC-II expression in melanoma cells and is associated with anti-PD-1 resistance

BACKGROUND

Despite the remarkable success of immunotherapy in treating melanoma, understanding of the underlying mechanisms of resistance remains limited. Emerging evidence suggests that upregulation of tumor-specific major histocompatibility complex-II (tsMHC-II) serves as a predictive marker for the response to anti-programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) therapy in various cancer types. The genetic and epigenetic pathways modulating tsMHC-II expression remain incompletely characterized. Here, we provide evidence that polycomb repressive complex 2 (PRC2)/EZH2 signaling and resulting H3K27 hypermethylation suppresses tsMHC-II.

METHODS

RNA sequencing data from tumor biopsies from patients with cutaneous melanoma treated with or without anti-PD-1, targeted inhibition assays, and assays for transposase-accessible chromatin with sequencing were used to observe the relationship between EZH2 inhibition and interferon (IFN)-γ inducibility within the MHC-II pathway.

RESULTS

We find that increased EZH2 pathway messenger RNA (mRNA) expression correlates with reduced mRNA expression of both presentation and T-cell genes. Notably, targeted inhibition assays revealed that inhibition of EZH2 influences the expression dynamics and inducibility of the MHC-II pathway following IFN-γ stimulation. Additionally, our analysis of patients with metastatic melanoma revealed a significant inverse association between PRC2-related gene expression and response to anti-PD-1 therapy.

CONCLUSIONS

Collectively, our findings demonstrate that EZH2 inhibition leads to enhanced MHC-II expression potentially resulting from improved chromatin accessibility at CIITA, the master regulator of MHC-II. These insights shed light on the molecular mechanisms involved in tsMHC-II suppression and highlight the potential of targeting EZH2 as a therapeutic strategy to improve immunotherapy efficacy.

Biomarkers of immune checkpoint inhibitor response and toxicity: Challenges and opportunities

Immune checkpoint inhibitors have transformed cancer therapy, but their optimal use is still constrained by lack of response and toxicity. Biomarkers of response may facilitate drug development by allowing appropriate therapy selection and focusing clinical trial enrollment. However, aside from PD-L1 staining in a subset of tumors and rarely mismatch repair deficiency, no biomarkers are routinely used in the clinic. In addition, severe toxicities may cause severe morbidity, therapy discontinuation, and even death. Here, we review the state of the field with a focus on our research in therapeutic biomarkers and toxicities from immune checkpoint inhibitors.

Potential clinical implications of CD4+CD26high T cells for nivolumab treated melanoma patients

BACKGROUND

Nivolumab is an anti-PD1 antibody that has dramatically improved metastatic melanoma patients' outcomes. Nevertheless, many patients are resistant to PD-1 inhibition, occasionally experiencing severe off-target immune toxicity. In addition, no robust and reproducible biomarkers have yet been validated to identify the correct selection of patients who will benefit from anti-PD-1 treatment avoiding unwanted side effects. However, the strength of CD26 expression on CD4+ T lymphocytes permits the characterization of three subtypes with variable degrees of responsiveness to tumors, suggesting that the presence of CD26-expressing T cells in patients might be a marker of responsiveness to PD-1-based therapies.

METHODS

The frequency distribution of peripheral blood CD26-expressing cells was investigated employing multi-parametric flow cytometry in 69 metastatic melanoma patients along with clinical characteristics and blood count parameters at baseline (W0) and compared to 20 age- and sex-matched healthy controls. Percentages of baseline CD4+CD26high T cells were correlated with the outcome after nivolumab treatment. In addition, the frequency of CD4+CD26high T cells at W0 was compared with those obtained after 12 weeks (W1) of therapy in a sub-cohort of 33 patients.

RESULTS

Circulating CD4+CD26high T cells were significantly reduced in melanoma patients compared to healthy subjects (p = 0.001). In addition, a significant association was observed between a low baseline percentage of CD4+CD26high T cells (< 7.3%) and clinical outcomes, measured as overall survival (p = 0.010) and progression-free survival (p = 0.014). Moreover, patients with clinical benefit from nivolumab therapy had significantly higher frequencies of circulating CD4+CD26high T cells than patients with non-clinical benefit (p = 0.004) at 12 months. Also, a higher pre-treatment proportion of circulating CD4+CD26high T cells was correlated with Disease Control Rate (p = 0.014) and best Overall Response Rate (p = 0.009) at 12 months. Interestingly, after 12 weeks (W1) of nivolumab treatment, percentages of CD4+CD26high T cells were significantly higher in comparison with the frequencies measured at W0 (p < 0.0001), aligning the cell counts with the ranges seen in the blood of healthy subjects.

CONCLUSIONS

Our study firstly demonstrates that peripheral blood circulating CD4+CD26high T lymphocytes represent potential biomarkers whose perturbations are associated with reduced survival and worse clinical outcomes in melanoma patients.

The Emerging Burden of Genetic Instability and Mutation in Melanoma: Role of Molecular Mechanisms

Melanoma is a severe skin cancer affecting thousands of people and a growing public health concern worldwide. The potential hallmarks of melanoma are genetic instability and mutation (GIAM), which are driving mechanisms for phenotypic variation and adaptation in melanoma. In metastatic melanoma, DNA repair-associated genes are frequently expressed at higher levels than in primary cancers, suggesting melanoma cells rely on genetic stability to spread distantly. The tumour microenvironment is affected by genomic instability and melanoma mutation (GIMM), which plays significant roles in developing GIMM and their contributions to the overall disease burden. The GIAM is the crucial vulnerability of cancer cells, determining their sensitivity to harmful treatments, including radiation and many chemotherapeutics. The high incidence of melanoma is typically associated with genetic modifications, and several clinical and genetic interventions have been critical in easing the burden.

The Predictive Value of Tumor Mutation Burden on Clinical Efficacy of Immune Checkpoint Inhibitors in Melanoma: A Systematic Review and Meta-Analysis

Background: Tumor mutational burden (TMB) is a genomic biomarker that can predict favorable responses to immune checkpoint inhibitors (ICIs). Although we have better understanding of TMB in cancer immunity and cancer immunotherapy, the relationship between TMB and the clinical efficacy of ICIs remains unknown in the treatment of melanoma patients. Here, we conduct a systematic review and meta-analysis to evaluate the predictive value of TMB on the efficacy of ICIs in patients with melanoma.

Methods: We systematically collected data from PubMed, Embase, Cochrane Library, CNKI, China Biomedical Database (CBM), and Wanfang Database. The end date was set to 26 June 2021. We included retrospective studies or clinical trials of ICIs that reported hazard ratios (HRs) for overall survival and/or progression-free survival according to TMB. Data for 1,493 patients from 15 studies were included. In addition, pooled effect size, heterogeneity analysis, sensitivity analysis, publication bias detection, and subgroup analysis were performed based on the included data.

Results: Patients with high TMB showed significantly improved OS (HR = 0.49, 95% CI: 0.33, 0.73; p = 0.001) and PFS (HR = 0.47, 95% CI: 0.33, 0.68; p < 0.001) compared with patients with low TMB. This association was very good in patients treated with monotherapy, that is, anti-CTLA-4 or anti-PD-(L)-1 inhibitors, but not for the patients treated with a combination of the two drugs. The subgroup analysis results showed that heterogeneity was substantial in the targeted next-generation sequencing (NGS) group. Publication bias was detected, and the results were visualized using the funnel chart. And sensitivity analysis and trim-and-fill method analysis showed that our results were stable and reliable.

Conclusion: High TMB is associated with improved OS and PFS in melanoma patients treated with mono-drug ICIs. TMB determined by NGS should be standardized to eliminate heterogeneity. Therefore, the role of TMB in identifying melanoma patients who may benefit from ICI should be further determined in more randomized controlled trials in the future.

Nobel Prize for immune checkpoint inhibitors, understanding the immunological switching between immunosuppression and autoimmunity

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are a revolutionary form of immunotherapy in cancer. However, the percentage of patients responding to therapy is relatively low, while adverse effects occur in a large number of patients. In addition, the therapeutic mechanisms of ICIs are not yet completely described.

AREAS COVERED

The initial view (articles published in PubMed, Scopus, Web of Science, etc.) was that ICIs increase tumor-specific immunity. Recent data (collected from the same databases) suggest that the ICIs pharmacotherapy actually extends beyond the topic of immune reactivity, including additional immune pathways, such as disrupting immunosuppression and increasing tumor-specific autoimmunity. Unfortunately, there is no clear delimitation between these specific autoimmune reactions that are therapeutically beneficial, and nonspecific autoimmune reactions/toxicity that can be extremely severe side effects.

EXPERT OPINION

Immune checkpoint mechanisms perform a non-selective immune regulation, maintaining a dynamic balance between immunosuppression and autoimmunity. By blocking these mechanisms, ICIs actually perform an immunological reset, decreasing immunosuppression and increasing tumor-specific immunity and predisposition to autoimmunity. The predisposition to autoimmunity induces both side effects and beneficial autoimmunity. Consequently, further studies are necessary to maximize the beneficial tumor-specific autoimmunity, while reducing the counterproductive effect of associated autoimmune toxicity.

Identification of an m6A Regulators-Mediated Prognosis Signature For Survival Prediction and Its Relevance to Immune Infiltration in Melanoma

Despite robust evidence for the role of m6A in cancer development and progression, its association with immune infiltration and survival outcomes in melanoma remains obscure. Here, we aimed to develop an m6A-related risk signature to improve prognostic and immunotherapy responder prediction performance in the context of melanoma. We comprehensively analyzed the m6A cluster and immune infiltration phenotypes of public datasets. The TCGA (n = 457) and eleven independent melanoma cohorts (n = 758) were used as the training and validation datasets, respectively. We identified two m6A clusters (m6A-clusterA and m6A-clusterB) based on the expression pattern of m6A regulators via unsupervised consensus clustering. IGF2BP1 (7.49%), KIAA1429 (7.06%), and YTHDC1 (4.28%) were the three most frequently mutated genes. There was a correlation between driver genes mutation statuses and the expression of m6A regulators. A significant difference in tumor-associated immune infiltration between two m6A clusters was detected. Compared with m6A-clusterA, the m6A-clusterB was characterized by a lower immune score and immune cell infiltration but higher mRNA expression-based stemness index (mRNAsi). An m6A-related risk signature consisting of 12 genes was determined via Cox regression analysis and divided the patients into low- and high-risk groups (IL6ST, MBNL1, NXT2, EIF2A, CSGALNACT1, C11orf58, CD14, SPI1, NCCRP1, BOK, CD74, PAEP). A nomogram was developed for the prediction of the survival rate. Compared with the high-risk group, the low-risk group was characterized by high expression of immune checkpoints and immunophenoscore (IPS), activation of immune-related pathways, and more enriched in immune cell infiltrations. The low-risk group had a favorable prognosis and contained the potential beneficiaries of the immune checkpoint blockade therapy and verified by the IMvigor210 cohort (n = 298). The m6A-related signature we have determined in melanoma highlights the relationships between m6A regulators and immune cell infiltration. The established risk signature was identified as a promising clinical biomarker of melanoma.

Development and Validation of Tumor Immunogenicity Based Gene Signature for Skin Cancer Risk Stratification

Melanoma is one of the most aggressive types of skin cancer, with significant heterogeneity in overall survival. Currently, tumor-node-metastasis (TNM) staging is insufficient to provide accurate survival prediction and appropriate treatment decision making for several types of tumors, such as those in melanoma patients. Therefore, the identification of more reliable prognosis biomarkers is urgently essential. Recent studies have shown that low immune cells infiltration is significantly associated with unfavorable clinical outcome in melanoma patients. Here we constructed a prognostic-related gene signature for melanoma risk stratification by quantifying the levels of several cancer hallmarks and identify the Wnt/β-catenin activation pathway as a primary risk factor for low tumor immunity. A series of bioinformatics and statistical methods were combined and applied to construct a Wnt-immune-related prognosis gene signature. With this gene signature, we computed risk scores for individual patients that can predict overall survival. To evaluate the robustness of the result, we validated the signature in multiple independent GEO datasets. Finally, an overall survival-related nomogram was established based on the gene signature and clinicopathological features. The Wnt-immune-related prognostic risk score could better predict overall survival compared with standard clinicopathological features. Our results provide a comprehensive map of the oncogene-immune-related gene signature that can serve as valuable biomarkers for better clinical decision making.

Prospective prediction of plasma pharmacokinetics of a novel immune-modulating agent in cancer patients after intra-tumoral administration: translation from non-clinical species to humans

Intra-tumoral (I-TUMOUR) delivery is being widely explored for novel anti-cancer agents. This route is anticipated to result in high tumour concentrations leading to better efficacy and safety. Prediction of human systemic pharmacokinetics (PK) from non-clinical species facilitates understanding of pharmacokinetic-pharmacodynamic relationships, efficient dose selection, and risk assessment of novel drugs. However, there is limited knowledge on the predictability of human pharmacokinetics following I-TUMOUR delivery.In this publication, we present a case study wherein human systemic PK of a novel agent administered intra-tumourally was prospectively predicted and compared with observed human PK.Simple allometry was used to project the human clearance (10.5 mL/min/kg) and steady-state volume of distribution (1.4 L/kg) after intravenous (IV) dosing. Using these IV PK parameters and assuming rapid absorption and complete I-TUMOUR bioavailability, human plasma PK profile was simulated. The projected 30 min concentrations and AUC_(0-6h) were within 1.9 to 2.5-fold and 1 to 1.4-fold of the observed PK indicating a reasonable concordance between predicted and observed PK.To our knowledge, this is the first article that prospectively projected human pharmacokinetics after I-TUMOUR dosing. The results from this study indicate that similar approaches can be used to project the human PK of other I-TUMOUR agents.

B7 score and T cell infiltration stratify immune status in prostate cancer

BACKGROUND

Although immune checkpoint inhibitors (ICIs), especially programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) axis blockers, exhibit prominent antitumor effects against numerous malignancies, their benefit for patients with prostate cancer (PCa) has been somewhat marginal. This study aimed to assess the feasibility of B7-H3 or HHLA2 as alternative immunotherapeutic targets in PCa.

METHODS

Immunohistochemistry was performed to evaluate the expression pattern of PD-L1, B7-H3 and HHLA2 and the infiltration of CD8⁺ and Foxp3⁺ lymphocytes in 239 PCa tissues from two independent cohorts. The correlations between B7-H3 and HHLA2 and clinicopathological features, including the presence of CD8⁺ and Foxp3⁺ tumor-infiltrating lymphocytes (TILs), were explored.

RESULTS

HHLA2 expression was much higher than PD-L1 expression but lower than B7-H3 expression in PCa tissues. High expression of both B7-H3 and HHLA2 was significantly associated with higher Gleason score and tumor stage, lymph node metastasis and dismal overall survival (OS) and cancer-specific survival (CSS). Moreover, a high B7 score, defined as high B7-H3 expression and/or high HHLA2 expression, was an independent prognostic predictor for PCa. Of note, a high B7 score was negatively correlated with CD8⁺ TILs. Importantly, a new immune classification, based on the B7 score and CD8⁺ TILs, successfully stratified OS and CSS in PCa.

CONCLUSIONS

Both B7-H3 and HHLA2 have a critical impact on the immunosuppressive microenvironment, and the B7 score could be used as an independent prognostic factor for PCa. The B7 score combined with CD8⁺ TILs could be used as a new immune classification to stratify the risk of death, especially cancer-related death, for patients with PCa. These findings may provide insights that could improve response to immune-related comprehensive therapy for PCa in the future.

Enhanced B7-H4 expression in gliomas with low PD-L1 expression identifies super-cold tumors

Background

Characterizing expression profiles of different immune checkpoint molecules are promising for personalized checkpoint inhibitory immunotherapy. Gliomas have been shown as potential targets for immune checkpoint inhibitors recently. Our study was performed to determine coexpression levels of two major B7 immune regulatory molecules programmed death ligand 1 (PD-L1) and B7-H4, both of which have been demonstrated to inhibit antitumor host immunity in gliomas.

Methods

We assessed tumor tissues from stage II–IV primary gliomas (n=505) by immunohistochemistry (IHC) for protein levels of both PD-L1 and B7-H4. Gene coexpression analysis assessing clusters based on extent of PD-L1/B7-H4 classifier genes expression were investigated in two transcriptome datasets (The Cancer Genome Atlas and Chinese Glioma Genome Atlas). In addition, levels of immune cell infiltrates were estimated with IHC and RNA-seq data for assessing the tumor immune microenvironment of PD-L1/B7-H4 subgroups.

Results

High expression of PD-L1 and B7-H4 in gliomas was 23% and 20%, respectively, whereas coexpression of two proteins at high levels was limited to 2% of the cases. Comparable results were seen in RNA-seq datasets where PD-L1 mRNA expression levels negatively correlated with that of B7-H4. Gene coexpression modules clustered within each grade of gliomas demonstrated lack of double-high modules (cluster with high expression of both PD-L1 and B7-H4 classifier genes). B7-H4 mRNA expression levels showed negative correlation with extent of immune cell infiltration and High-B7-H4 module gliomas (high B7-H4 but low PD-L1 classifier genes expression) had less tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs). IHC assessment also showed few TILs and TAMs in High-B7-H4 subgroup gliomas.

Conclusions

The majority of gliomas express PD-L1 or B7-H4, however, coexpression of both at high levels is minimal. The high-B7-H4 patients could be considered as ‘super-cold’ gliomas with significantly deficient in TILs, suggesting that B7-H4 might inhibit T-cell trafficking into the central nervous system. This study demonstrated that PD-L1 and B7-H4 may serve as mutually compensatory immune checkpoint molecules in gliomas for immune targeted or active-specific immunotherapy. The distinct B7-H4 pathways modulating T-cell function and immune evasion in glioma patients deserved to be further explored in the future during immunotherapy.

Clinical and Molecular Correlates of NLRC5 Expression in Patients With Melanoma

NLRC5 is an important regulator in antigen presentation and inflammation, and its dysregulation promotes tumor progression. In melanoma, the impact of NLRC5 expression on molecular phenotype, clinical characteristics, and tumor features is largely unknown. In the present study, public datasets from the Cancer Cell Line Encyclopedia (CCLE), Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and cBioPortal were used to address these issues. We identify that NLRC5 is expressed in both immune cells and melanoma cells in melanoma samples and its expression is regulated by SPI1 and DNA methylation. NLRC5 expression is closely associated with Breslow thickness, Clark level, recurrence, pathologic T stage, and ulceration status in melanoma. Truncating/splice mutations rather than missense mutations in NLRC5 could compromise the expression of downstream genes. Low expression of NLRC5 is associated with poor prognosis, low activity of immune-related signatures, low infiltrating level of immune cells, and low cytotoxic score in melanoma. Additionally, NLRC5 expression correlates with immunotherapy efficacy in melanoma. In summary, these findings suggest that NLRC5 acts as a tumor suppressor in melanoma via modulating the tumor immune microenvironment. Targeting the NLRC5 related pathway might improve efficacy of immunotherapy for melanoma patients.

Impact of a preceding radiotherapy on the outcome of immune checkpoint inhibition in metastatic melanoma: a multicenter retrospective cohort study of the DeCOG

Background

Immune checkpoint inhibition (ICI) is an essential treatment option in melanoma. Its outcome may be improved by a preceding radiation of metastases. This study aimed to investigate the impact of a preceding radiotherapy on the clinical outcome of ICI treatment.

Methods

This multicenter retrospective cohort study included patients who received anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or anti-programmed cell death protein 1 (PD-1) ICI with or without preceding radiotherapy for unresectable metastatic melanoma. ICI therapy outcome was measured as best overall response (BOR), progression-free (PFS) and overall survival (OS). Response and survival analyses were adjusted for confounders identified by directed acyclic graphs. Adjusted survival curves were calculated using inverse probability treatment weighting.

Results

835 patients who received ICI (anti-CTLA-4, n=596; anti-PD-1, n=239) at 16 centers were analyzed, whereof 235 received a preceding radiotherapy of metastatic lesions in stage IV disease. The most frequent organ sites irradiated prior to ICI therapy were brain (51.1%), lymph nodes (17.9%) and bone (17.9%). After multivariable adjustment for confounders, no relevant differences in ICI therapy outcome were observed between cohorts with and without preceding radiotherapy. BOR was 8.7% vs 13.0% for anti-CTLA-4 (adjusted relative risk (RR)=1.47; 95% CI=0.81 to 2.65; p=0.20), and 16.5% vs 25.3% for anti-PD-1 (RR=0.93; 95% CI=0.49 to 1.77; p=0.82). Survival probabilities were similar for cohorts with and without preceding radiotherapy, for anti-CTLA-4 (PFS, adjusted HR=1.02, 95% CI=0.86 to 1.25, p=0.74; OS, HR=1.08, 95% CI=0.81 to 1.44, p=0.61) and for anti-PD-1 (PFS, HR=0.84, 95% CI=0.57 to 1.26, p=0.41; OS, HR=0.73, 95% CI=0.43 to 1.25, p=0.26). Patients who received radiation last before ICI (n=137) revealed no better survival than those who had one or more treatment lines between radiation and start of ICI (n=86). In 223 patients with brain metastases, we found no relevant survival differences on ICI with and without preceding radiotherapy.

Conclusions

This study detected no evidence for a relevant favorable impact of a preceding radiotherapy on anti-CTLA-4 or anti-PD-1 ICI treatment outcome in metastatic melanoma.

Immunotherapy in Acral and Mucosal Melanoma: Current Status and Future Directions

Acral and mucosal melanomas are extremely rare in Caucasians; however, they are the predominant melanoma subtypes in Asians and other non-Caucasian populations. Acral and mucosal melanomas share many clinicopathological features, including aggressive phenotypes, similar genetic landscapes, and grim prognoses. In spite of advances in melanoma management, patients with acral and mucosal melanomas show limited benefit from current therapies. The rarity of these subtypes of melanoma is a significant factor contributing to the poor understanding of these pathological subtypes and the lack of effective interventions. Furthermore, the mechanisms contributing to disparities between different types of melanoma remain largely unclear. Herein, we comprehensively review current knowledge on the clinicopathological characteristics and mutational landscapes of acral and mucosal melanomas, as well as providing an overview of current therapies for patients with these aggressive melanoma subtypes, focusing on available immunotherapeutic interventions. We also discuss pathological differences between different melanoma subtypes and summarize current knowledge on melanoma disparities between Asians and Caucasians. Finally, we discuss emerging immunotherapeutic strategies for the treatment of acral and mucosal melanomas, focusing on combination therapies with immune checkpoint inhibitors. Unraveling the unique features of acral and mucosal melanomas is key for their early diagnosis and for the development of effective therapies.

The Ratio of GrzB+ - FoxP3+ over CD3+ T Cells as a Potential Predictor of Response to Nivolumab in Patients with Metastatic Melanoma

Simple Summary

Despite the recent success of immunotherapy in the treatment of malignant melanoma, many patients still do not benefit from these treatments, due to their failure to activate an antitumor immune response them. There is therefore a need to select patients who can truly benefit from these treatments. We have focused our study on immune cells present in the tumor microenvironment, and we have developed a formula (ratio) that correlates with the response to anti-PD1 therapy and progression-free and overall survival, based on the numerical difference between GRZB⁺ and FOXP3⁺ cells over the total CD3⁺ lymphocytes. This developed ratio could be useful to better select patients that may or may not benefit from anti-PD-1 treatment.

Abstract

The understanding of the molecular pathways involved in the dynamic modulation of the tumor microenvironment (TME) has led to the development of innovative treatments for advanced melanoma, including immune checkpoint blockade therapies. These approaches have revolutionized the treatment of melanoma, but are not effective in all patients, resulting in responder and non-responder populations. Physical interactions among immune cells, tumor cells and all the other components of the TME (i.e., cancer-associated fibroblasts, keratinocytes, adipocytes, extracellular matrix, etc.) are essential for effective antitumor immunotherapy, suggesting the need to define an immune score model which can help to predict an efficient immunotherapeutic response. In this study, we performed a multiplex immunostaining of CD3, FOXP3 and GRZB on both primary and unmatched in-transit metastatic melanoma lesions and defined a novel ratio between different lymphocyte subpopulations, demonstrating its potential prognostic role for cancer immunotherapy. The application of the suggested ratio can be useful for the stratification of melanoma patients that may or may not benefit from anti-PD-1 treatment.

Gene expression and immune infiltration in melanoma patients with different mutation burden

BACKGROUND

Immunotherapy is a vital component in cancer treatment. However, due to the complex genetic bases of cancer, a clear prediction index for efficacy has not been established. Tumor mutation burden (TMB) is one of the essential factors that affect immunotherapeutic efficacies, but it has not been determined whether the mutation is associated with the survival of Skin Cutaneous Melanoma (SKCM) patients. This study aimed at evaluating the correlation between TMB and immune infiltration.

METHODS

Somatic mutation profiles (n = 467), transcriptome data (n = 471), and their clinical information (n = 447) of all SKCM samples were downloaded from The Cancer Genome Atlas (TCGA) database. For each sample, TMB was calculated as the number of variants per megabase. Based on K-M survival analysis, they were allocated into the high-TMB and low-TMB groups (the optimal cutoff was determined by the 'surv_cutpoint' algorithm of survival R package). Then, Gene ontology (GO) and Gene Set Enrichment Analyses (GSEA) were performed, with immune-associated biological pathways found to be significantly enriched in the low-TMB group. Therefore, immune genes that were differentially expressed between the two groups were evaluated in Cox regression to determine their prognostic values, and a four-gene TMB immune prognostic model (TMB-IP) was constructed.

RESULTS

Elevated TMB levels were associated with better survival outcomes in SKCM patients. Based on the cutoff value in OS analysis, they were divided into high-TMB and low-TMB groups. GSEA revealed that the low-TMB group was associated with immunity while intersection analysis revealed that there were 38 differentially expressed immune-related genes between the two groups. Four TMB-associated immune genes were used to construct a TMB-IP model. The AUC of the ROC curve of this model reached a maximum of 0.75 (95%CI, 0.66-0.85) for OS outcomes. Validation in each clinical subgroup confirmed the efficacy of the model to distinguish between high and low TMB-IP score patients.

CONCLUSIONS

In SKCM patients, low TMB was associated with worse survival outcomes and enriched immune-associated pathways. The four TMB-associated immune genes model can effectively distinguish between high and low-risk patients.

Elevated baseline serum PD-1 or PD-L1 predicts poor outcome of PD-1 inhibition therapy in metastatic melanoma

BACKGROUND

Programmed cell death protein 1 (PD-1) checkpoint inhibition has recently advanced to one of the most effective treatment strategies in melanoma. Nevertheless, a considerable proportion of patients show upfront therapy resistance and baseline predictive biomarkers of treatment outcome are scarce. In this study we quantified PD-1 and programmed death-ligand 1 (PD-L1) in baseline sera from melanoma patients in relation to therapy response and survival.

PATIENTS AND METHODS

Sera taken at therapy baseline from a total of 222 metastatic melanoma patients (two retrospectively selected monocentric discovery cohorts, n = 130; one prospectively collected multicentric validation cohort, n = 92) and from 38 healthy controls were analyzed for PD-1 and PD-L1 concentration by sandwich enzyme-linked immunosorbent assay.

RESULTS

Melanoma patients showed higher serum concentrations of PD-1 (P = 0.0054) and PD-L1 (P < 0.0001) than healthy controls. Elevated serum PD-1 and PD-L1 levels at treatment baseline were associated with an impaired best overall response (BOR) to anti-PD-1 (P = 0.014, P = 0.041), but not to BRAF inhibition therapy. Baseline PD-1 and PD-L1 serum levels correlated with progression-free (PFS; P = 0.0081, P = 0.053) and overall survival (OS; P = 0.055, P = 0.0062) in patients who received anti-PD-1 therapy, but not in patients treated with BRAF inhibitors. By combining both markers, we obtained a strong discrimination between favorable and poor outcome of anti-PD-1 therapy, with elevated baseline serum levels of PD-1 and/or PD-L1 associated with an impaired BOR (P = 0.037), PFS (P = 0.048), and OS (P = 0.0098). This PD-1/PD-L1 combination serum biomarker was confirmed in an independent multicenter validation set of serum samples prospectively collected at baseline of PD-1 inhibition (BOR, P = 0.019; PFS, P = 0.038; OS, P = 0.022). Multivariable Cox regression demonstrated serum PD-1/PD-L1 as an independent predictor of PFS (P = 0.010) and OS (P = 0.003) in patients treated with PD-1 inhibitors.

CONCLUSION

Our findings indicate PD-1 and PD-L1 as useful serum biomarkers to predict the outcome of PD-1 inhibition therapy in melanoma patients and to select patients for PD-1-based versus BRAF-based therapy strategies.

Baseline IFN-γ and IL-10 expression in PBMCs could predict response to PD-1 checkpoint inhibitors in advanced melanoma patients

Anti-PD-1 antibodies revolutionized the treatment of advanced melanoma patients. However, one out of three do not respond to this therapy, with an overall poor prognosis. Identification of predictive biomarkers in patients receiving immune-based therapies is necessary for minimizing risk of toxicity and optimizing patient benefit and is still an important unmet clinical need. Recently, many studies have evaluated peripheral blood markers as potential biomarkers, but none so far have been validated. We collected at baseline peripheral blood samples from 18 consecutive advanced melanoma patients treated with anti-PD-1 therapy. Main pro- and anti-inflammatory cytokines were studied in PBMCs from baseline blood samples both evaluating mRNA expression by qRT-PCR and identifying PBMCs subpopulations by FACS analysis. We found that IFN-γ mRNA expression levels were significantly higher in responder patients compared to non-responder ones. Moreover, to better validate its role, we evaluated the IFN-γ/IL-10 ratio. This value was higher in responder patients. FACS analysis confirmed that CD4 + IFN-γ + PBMCs percentage was higher in responders. Our data suggest an interesting correlation between IFN-γ/IL-10 ratio and response to anti-PD-1 therapy in advanced melanoma patients, suggesting a new biomarker that could be easily incorporated in clinical practice.

Integrated genomic analysis identifies a genetic mutation model predicting response to immune checkpoint inhibitors in melanoma

Several biomarkers such as tumor mutation burden (TMB), neoantigen load (NAL), programmed cell‐death receptor 1 ligand (PD‐L1) expression, and lactate dehydrogenase (LDH) have been developed for predicting response to immune checkpoint inhibitors (ICIs) in melanoma. However, some limitations including the undefined cut‐off value, poor uniformity of test platform, and weak reliability of prediction have restricted the broad application in clinical practice. In order to identify a clinically actionable biomarker and explore an effective strategy for prediction, we developed a genetic mutation model named as immunotherapy score (ITS) for predicting response to ICIs therapy in melanoma, based on whole‐exome sequencing data from previous studies. We observed that patients with high ITS had better durable clinical benefit and survival outcomes than patients with low ITS in three independent cohorts, as well as in the meta‐cohort. Notably, the prediction capability of ITS was more robust than that of TMB. Remarkably, ITS was not only an independent predictor of ICIs therapy, but also combined with TMB or LDH to better predict response to ICIs than any single biomarker. Moreover, patients with high ITS harbored the immunotherapy‐sensitive characteristics including high TMB and NAL, ultraviolet light damage, impaired DNA damage repair pathway, arrested cell cycle signaling, and frequent mutations in NF1 and SERPINB3/4. Overall, these findings deserve prospective investigation in the future and may help guide clinical decisions on ICIs therapy for patients with melanoma.

A retrospective analysis of eosinophilia as a predictive marker of response and toxicity to cancer immunotherapy

Aim:

To investigate eosinophilia as a potential on-treatment biomarker for patients receiving cancer immunotherapy.

Materials & methods:

We evaluated the association between eosinophilia and treatment response and toxicity in a retrospective cohort of patients receiving cancer immunotherapy.

Results:

The study involved 146 patients. Eosinophilia developed in 22%. Patients who developed eosinophilia were more likely to achieve disease control (p = 0.009), with every 0.1 × 10⁹/l rise in eosinophil count, while receiving treatment was associated with a 28% relative increased chance achieving disease control. Although there was a trend toward improved survival, there was no significant association between eosinophilia and improved overall survival (p = 0.136). Patients with eosinophilia were more likely to develop toxicity (p = 0.042).

Conclusion:

Eosinophilia is a potentially useful biomarker warranting further prospective clinical investigation.

Immunotherapy has revolutionized the way we treat many cancers. However, we do not have good predictors for which patients are going to respond to treatment or experience side effects. ‘Eosinophilia’ is when a particular type of white blood cell is present at high levels in the blood. This can occur in patients on immunotherapy. This paper reports a possible link between eosinophilia and the likelihood of responding well to immunotherapy but also the possibility of developing side effects.

Outcomes after progression of disease with anti-PD-1/PD-L1 therapy for patients with advanced melanoma

BACKGROUND

Greater than one-half of patients with melanoma who are treated with antibodies blocking programmed cell death protein 1 receptor (anti-PD-1) experience disease progression. The objective of the current study was to identify prognostic factors and outcomes in patients with metastatic melanoma that progressed while they were receiving anti-PD-1 therapy.

METHODS

The authors evaluated 383 consecutively treated patients who received anti-PD-1 for advanced melanoma between 2009 and 2019. Patient and disease characteristics at baseline and at the time of progression, subsequent therapies, objective response rate (ORR), overall survival, and progression-free survival were assessed.

RESULTS

Of 383 patients, 247 experienced disease progression. The median survival after progression was 6.8 months. There was no difference in survival noted after disease progression based on primary tumor subtype, receipt of prior therapy, or therapy type. However, significantly improved survival after disease progression correlated with clinical features at the time of progression, including normal lactate dehydrogenase, more favorable metastatic stage (American Joint Committee on Cancer eighth edition stage IV M1a vs M1b, M1c, or M1d), mutation status (NRAS or treatment-naive BRAF V600 vs BRAF/NRAS wild-type or treatment-experienced BRAF-mutant), decreasing tumor bulk, and progression at solely existing lesions. After progression, approximately 54.3% of patients received additional systemic therapy. A total of 41 patients received BRAF/MEK inhibition (ORR of 58.6%, including 70.4% for BRAF/MEK-naive patients), 30 patients received ipilimumab (ORR of 0%), and 11 patients received ipilimumab plus nivolumab (ORR of 27.3%).

CONCLUSIONS

The current study identified prognostic factors in advanced melanoma for patients who experienced disease progression while receiving anti-PD-1, including lactate dehydrogenase, stage of disease, site of disease progression, tumor size, and mutation status.

A novel predictive model incorporating immune-related gene signatures for overall survival in melanoma patients

Melanoma is the most invasive type of skin cancer, in which the immune system plays a vital role. In this study, we aimed to establish a prognostic prediction nomogram for melanoma patients that incorporates immune-related genes (IRGs). Ninety-seven differentially expressed IRGs between melanoma and normal skin were screened using gene expression omnibus database (GEO). Among these IRGs, a two-gene signature consisting of CCL8 and DEFB1 was found to be closely associated with patient prognosis using the cancer genome atlas (TCGA) database. Survival analysis verified that the IRGs score based on the signature gene expressions efficiently distinguished between high- and low-risk patients, and was identified to be an independent prognostic factor. A nomogram integrating the IRGs score, age and TNM stage was established to predict individual prognosis for melanoma. The prognostic performance was validated by the TCGA/GEO-based concordance indices and calibration plots. The area under the curve demonstrated that the nomogram was superior than the conventional staging system, which was confirmed by the decision curve analysis. Overall, we developed and validated a nomogram for prognosis prediction in melanoma based on IRGs signatures and clinical parameters, which could be valuable for decision making in the clinic.

Melanoma and Vitiligo: In Good Company

Cutaneous melanoma represents the most aggressive form of skin cancer, whereas vitiligo is an autoimmune disorder that leads to progressive destruction of skin melanocytes. However, vitiligo has been associated with cutaneous melanoma since the 1970s. Most of the antigens recognized by the immune system are expressed by both melanoma cells and normal melanocytes, explaining why the autoimmune response against melanocytes that led to vitiligo could be also present in melanoma patients. Leukoderma has been also observed as a side effect of melanoma immunotherapy and has always been associated with a favorable prognosis. In this review, we discuss several characteristics of the immune system responses shared by melanoma and vitiligo patients, as well as the significance of occurrence of leukoderma during immunotherapy, with special attention to check-point inhibitors.

The molecular clock in the skin, its functionality, and how it is disrupted in cutaneous melanoma: a new pharmacological target?

The skin is the interface between the organism and the external environment, acting as its first barrier. Thus, this organ is constantly challenged by physical stimuli such as UV and infrared radiation, visible light, and temperature as well as chemicals and pathogens. To counteract the deleterious effects of the above-mentioned stimuli, the skin has complex defense mechanisms such as: immune and neuroendocrine systems; shedding of epidermal squamous layers and apoptosis of damaged cells; DNA repair; and pigmentary system. Here we have reviewed the current knowledge regarding which stimuli affect the molecular clock of the skin, the consequences to skin-related biological processes and, based on such knowledge, we suggest some therapeutic targets. We also explored the recent advances regarding the molecular clock disruption in melanoma, its impact on the carcinogenic process, and its therapeutic value in melanoma treatment.

The mechanisms of acute interstitial nephritis in the era of immune checkpoint inhibitors in melanoma

Treatment with immune checkpoint inhibitors (ICIs) has improved the prognosis of patients with a number of types of cancer, but the frequent development of immune-related adverse effects (irAEs) can worsen the outcome. The most common irAEs involve the gastrointestinal, cutaneous, and endocrine systems, but nephrotoxicity, resulting from damage to the tubule-interstitial compartment, may occur in some patients. The early phases of acute interstitial nephritis (AIN) are characterized by systemic symptoms that indicate a poor clinical state as well as a mild deterioration of renal function. Tubular injury is due to a direct effect mediated by cytotoxic CD8⁺ T cells, which sustain the local production of pro-inflammatory cytokines that progressively impair renal function. The treatment of AIN is mainly based on high-dose steroids, which in most instances leads to the recovery of renal function. However, the premature discontinuation of ICI therapy may prevent the impact of treatment on the clinical progression of the malignancy. Adequately addressing irAEs requires a standardized therapy that is based on the results of large clinical trials.

Circulating biomarkers predictive of tumor response to cancer immunotherapy

Introduction: The advent of checkpoint blockade immunotherapy has revolutionized cancer treatment, but clinical response to immunotherapies is highly heterogeneous among individual patients and between cancer types. This represents a challenge to oncologists when choosing specific immunotherapies for personalized medicine. Thus, biomarkers that can predict tumor responsiveness to immunotherapies before and during treatment are invaluable. Areas covered: We review the latest advances in 'liquid biopsy' biomarkers for noninvasive prediction and in-treatment monitoring of tumor response to immunotherapy, focusing primarily on melanoma and non-small cell lung cancer. We concentrate on high-quality studies published within the last five years on checkpoint blockade immunotherapies, and highlight significant breakthroughs, identify key areas for improvement, and provide recommendations for how these diagnostic tools can be translated into clinical practice. Expert opinion: The first biomarkers proposed to predict tumor response to immunotherapy were based on PD1/PDL1 expression, but their predictive value is limited to specific cancers or patient populations. Recent advances in single-cell molecular profiling of circulating tumor cells and host cells using next-generation sequencing has dramatically expanded the pool of potentially useful predictive biomarkers. As immunotherapy moves toward personalized medicine, a composite panel of both genomic and proteomic biomarkers will have enormous utility in therapeutic decision-making.

Genetic Aberrations in the CDK4 Pathway Are Associated with Innate Resistance to PD-1 Blockade in Chinese Patients with Non-Cutaneous Melanoma

PURPOSE

PD-1 checkpoint blockade immunotherapy induces long and durable response in patients with advanced melanoma. However, only a subset of patients with melanoma benefit from this approach. The mechanism triggering the innate resistance of anti-PD-1 therapy remains unclear.Experimental Design: Whole-exome sequencing (WES) and RNA sequencing (RNA-Seq) analyses were performed in a training cohort (n = 31) using baseline tumor biopsies of patients with advanced melanoma treated with the anti-PD-1 antibody. Copy-number variations (CNVs) for the genes CDK4, CCND1, and CDKN2A were assayed using a TaqMan copy-number assay in a validation cohort (n = 85). The effect of CDK4/6 inhibitors combined with anti-PD-1 antibody monotherapy was evaluated in PD-1-humanized mouse (C57BL/6-hPD-1) and humanized immune system (HIS) patient-derived xenograft (PDX) models.

RESULTS

WES revealed several significant gene copy-number gains in the patients of no clinical benefit cohort, such as 12q14.1 loci, which harbor CDK4. The association between CDK4 gain and innate resistance to anti-PD-1 therapy was validated in 85 patients with melanoma (P < 0.05). RNA-Seq analysis of CDK4-normal cell lines and CDK4-normal tumors showed altered transcriptional output in TNFα signaling via NF-κB, inflammatory response, and IFNγ response gene set. In addition, CDK4/6 inhibitor (palbociclib) treatment increased PD-L1 protein levels and enhanced efficacy (P < 0.05) in the C57BL/6-hPD-1 melanoma cell and the HIS PDX model.

CONCLUSIONS

In summary, we discovered that genetic aberrations in the CDK4 pathway are associated with innate resistance to anti-PD-1 therapy in patients with advanced melanoma. Moreover, our study provides a strong rationale for combining CDK4/6 inhibitors with anti-PD-1 antibody for the treatment of advanced melanomas.

The metabolic milieu in melanoma: Role of immune suppression by CD73/adenosine

The mechanisms leading to immune escape of melanoma have been largely investigated in relation to its tumour immunogenicity and features of inflamed microenvironment that promote the immune suppression during the disease progression. These findings have recently led to advantages in terms of immunotherapy-based approaches as rationale for overcoming the immune escape. However, besides immune checkpoints, other mechanisms including the adenosine produced by ectonucleotidases CD39 and CD73 contribute to the melanoma progression due to the immunosuppression induced by the tumour milieu. On the other hand, CD73 has recently emerged as both promising therapeutic target and unfavourable prognostic biomarker. Here, we review the major mechanisms of immune escape activated by the CD39/CD73/adenosine pathway in melanoma and focus potential therapeutic strategies based on the control of CD39/CD73 downstream adenosine receptor signalling. These evidences provide the basis for translational strategies of immune combination, while CD73 would serve as potential prognostic biomarker in metastatic melanoma.

Single-cell technologies for profiling T cells to enable monitoring of immunotherapies

Immunotherapy relies on the reinvigoration of immune system to combat diseases and has transformed the landscape of cancer treatments. Clinical trials using immune checkpoint inhibitors (ICI), and adoptive transfer of genetically modified T cells have demonstrated durable remissions in subsets of cancer patients. A comprehensive understanding of the polyfunctionality of T lymphocytes in ICI or adoptive cell transfer (ACT), at single-cell resolution, will quantify T-cell properties that are essential for therapeutic benefit. We briefly highlight several emerging integrated single-cell technologies focusing on the profiling of multiple properties/functionalities of T cells. We envision that these tools have the potential to provide valuable experimental and clinical insights on T-cell biology, and eventually pave the road for the discovery of surrogate T-cell biomarkers for immunotherapy.

Bacterial ghosts as adjuvant to oxaliplatin chemotherapy in colorectal carcinomatosis

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and a major cause of cancer mortality worldwide. At late stage of the disease CRC often shows (multiple) metastatic lesions in the peritoneal cavity which cannot be efficiently targeted by systemic chemotherapy. This is one major factor contributing to poor prognosis. Oxaliplatin is one of the most commonly used systemic treatment options for advanced CRC. However, drug resistance - often due to insufficient drug delivery - is still hampering successful treatment. The anticancer activity of oxaliplatin includes besides DNA damage also a strong immunogenic component. Consequently, the aim of this study was to investigate the effect of bacterial ghosts (BGs) as adjuvant immunostimulant on oxaliplatin efficacy. BGs are empty envelopes of gram-negative bacteria with a distinct immune-stimulatory potential. Indeed, we were able to show that the combination of BGs with oxaliplatin treatment had strong synergistic anticancer activity against the CT26 allograft, resulting in prolonged survival and even a complete remission in this murine model of CRC carcinomatosis. This synergistic effect was based on an enhanced induction of immunogenic cell death and activation of an efficient T-cell response leading to long-term anti-tumor memory effects. Taken together, co-application of BGs strengthens the immunogenic component of the oxaliplatin anticancer response and thus represents a promising natural immune-adjuvant to chemotherapy in advanced CRC.

Benzylamine and Thenylamine Derived Drugs Induce Apoptosis and Reduce Proliferation, Migration and Metastasis Formation in Melanoma Cells

Melanomas are heterogeneous and aggressive tumors, and one of the worse in prognosis. Melanoma subtypes follow distinct pathways until terminal oncogenic transformation. Here, we have evaluated a series of molecules that exhibit potent cytotoxic effects over the murine and human melanoma cell lines B16F10 and MalMe-3M, respectively, both ex vivo and in animals carrying these melanoma cells. Ex vivo mechanistic studies on molecular targets involved in melanoma growth, migration and viability were evaluated in cultured cells treated with these drugs which exhibited potent proapoptotic and cytotoxic effects and reduced cell migration. These drugs altered the Wnt/β-catenin pathway, which is important for the oncogenic phenotype of melanoma cells. In in vivo experiments, male C57BL/6 or nude mice were injected with melanoma cells that rapidly expanded in these animals and, in some cases were able to form metastasis in lungs. Treatment with anti-tumor drugs derived from benzylamine and 2-thiophenemethylamine (F10503LO1 and related compounds) significantly attenuated tumor growth, impaired cell migration, and reduced the metastatic activity. Several protocols of administration were applied, all of them leading to significant reduction in the tumor size and enhanced animal survival. Tumor cells carrying a luciferase transgene allowed a time-dependent study on the progression of the tumor. Molecular analysis of the pathways modified by F10503LO1 and related compounds defined the main relevant targets for tumor regression: the activation of pro-apoptotic and anti-proliferative routes. These data might provide the proof-of-principle and rationale for its further clinical evaluation.