Melanoma

Melanoma Skin Classification Using the Hybrid Approach Residual Network-Vision Transformer for Cancer Diagnosis

INTRODUCTION

Computer-aided diagnosis using deep neural networks allows for the analysis and processing of images or videos of different pathologies, providing valuable reference data to physicians for the diagnosis or screening of conditions such as skin cancer.

METHODS

In this work, we highlight the contribution of Convolutional Neural Networks, pre-trained models, and Vision Transformer architectures in the classification of skin melanoma. The experimental aspect will therefore involve the contribution of the classical CNN, as well as models inspired by this CNN, namely, Inception V3, ResNet 50, AlexNet, and EfficientNet in addition to the hybrid architecture.

RESULTS

The conducted experiments entailed the adjustment of multiple hyperparameters, leading to the development of an architecture that achieved optimal results. Additionally, employing a hybrid architecture not only facilitated the amalgamation of the strengths from two models (the top performing pretrained ResNet50 model with the Vision Transformer) but also led to enhanced accuracy. After training the dataset, the proposed models have contributed to progressively improving the results, eventually achieving a classification rate of 95.53% for the hybrid ResNet50-ViT model.

CONCLUSION

The aim of this research is to equip clinicians with a robust tool for melanoma diagnosis by leveraging the strengths of two models within the ResNet50-ViT hybrid framework.

Automated assessment of skin histological tissue structures by artificial intelligence in cutaneous melanoma

BACKGROUND

Prognostic histopathological features such as mitosis in melanoma are excluded from the staging systems due to inter-observer variability and time constraints. While digital pathology offers artificial intelligence-driven solutions, existing melanoma algorithms often underperform or narrowly focus on specific features, limiting their clinical utility.

OBJECTIVE

Develop and validate an automated artificial intelligence-driven segmentation framework to identify multiple histological tissue structures within cutaneous melanoma images.

METHODS

Employing 157 melanoma whole slide images, U-Net and DeepLab3+ classifiers were independently trained Oncotopix ® platform using manual annotations, to detect specific histological features, termed application. All the applications are progressively executable. The performance of each application was measured when both operating independently and with sequential detection when applied to ten independent validation set images using accuracy and F1-score as metrics. The model was further validated by applying it to 442 whole-slide melanoma images, with dermatopathologists reviewing the segmentation outputs.

RESULTS

Seven applications were developed for progressive automated detection: Whole tissue (1) and tumour microenvironment (TME) (2), Hair follicles & sebaceous gland (3) within TME, ulceration (5), and melanoma cell area (6) based on DeepLab3+. Epidermis (4) and mitosis within the tumour area (7) based on U-Net. The applications demonstrated over 92 % accuracy and F1-score surpassing 80 %, except for the ulceration application (F1-score = 75 %). The pathologist examination indicated that 92 % of the 442 images had correct segmentations.

DISCUSSION AND CONCLUSION

The developed applications demonstrated high performance, enhancing the analysis of time-consuming histological features. The model facilitates the identification of histopathological features in large datasets allowing potential refinement of melanoma staging.

A Porphyrin Nanomaterial for Photoimmunotherapy for Treatment of Melanoma

The incidence of melanoma, the third most common skin cancer, has been on the rise in recent years. In addition, it has a high mortality rate due to its high aggressiveness. Phototherapy, as a promising treatment method, can effectively kill tumor cells, but it is incapable of the treatment of tumor metastasis. Herein, a nanomaterial (TPC@OVA NPs) is developed for phototherapy in conjunction with immunotherapy against melanoma. TPC, as a derivative of porphyrin, is used as a photosensitizer with excellent biosafety and photostability. After assembly with ovalbumin (OVA), TPC@OVA NPs with vaccine properties is formed, which can not only ablate the primary tumor but also induce immunogenic cell death (ICD). In addition, DC cells can be stimulated to mature by exogenous OVA, enhancing the immune response against tumors by further activating T lymphocytes. Combined with immune checkpoint inhibitor aPD-1, the immune microenvironment is reshaped, and the increased activity of immunotherapy are validated. This work highlights the potential of combining phototherapy and immunotherapy against metastasis.

Cell Death Modalities in Therapy of Melanoma

Melanoma, one of the most lethal cancers, demands urgent and effective treatment strategies. However, a successful therapeutic approach requires a precise understanding of the mechanisms underlying melanoma initiation and progression. This review provides an overview of melanoma pathogenesis, identifies current pathogenic factors contributing to mortality, and explores targeted therapy and checkpoint inhibitor therapy. Furthermore, we examine melanoma classification and corresponding therapies, along with advancements in various cell death mechanisms for melanoma treatment. We also discuss the current treatment status along with some drawbacks encountered during research stages such as resistance and metastasis.

Discovery of cloxiquine derivatives as potent HDAC inhibitors for the treatment of melanoma via activating PPARγ

The combined treatment with histone deacetylase (HDAC) inhibitors with peroxisome proliferator-activated receptor γ (PPARγ) agonists has displayed significant anticancer efficacy. Based on these results, a series of cloxiquine derivatives were prepared as potent HDAC inhibitors for the treatment of melanoma. Among these compounds, CS4 exhibited excellent inhibitory effects on HDAC1 (IC50 = 38 nM) and HDAC6 (IC50 = 12 nM), and had good antiproliferative effects against A375 and SK-MEL-5 melanoma cells (IC50 values, 1.20 and 0.93 μM, respectively). Mechanism research indicated that CS4 inhibited SK-MEL-5 cell growth by promoting α-tubulin and histone 3 (H3) acetylation. At the metabolic level, treatment with BG11 activated PPARγ and blocked glycolysis in SK-MEL-5 cells, which mediated partial antimelanoma effects of CS4. In addition, CS4 also induced cell cycle arrest at G2, suppressed migration and facilitated apoptosis of SK-MEL-5 cells. More importantly, compound CS4 demonstrated significant in vivo anticancer effect compared with SAHA, and exhibited neglectable toxicity. Consequently, CS4 is the potent HDAC inhibitor, which may be developed as the candidate antimelanoma drug.

Aging-induced immune microenvironment remodeling fosters melanoma in male mice via γδ17-Neutrophil-CD8 axis

Aging is associated with increased tumor metastasis and poor prognosis. However, how an aging immune system contributes to the process is unclear. Here, single-cell RNA sequencing reveals that in male mice, aging shifts the lung immune microenvironment towards a premetastatic niche, characterized by an increased proportion of IL-17-expressing γδT (γδ17) and neutrophils. Mechanistically, age-dependent downregulation of the immune trafficking receptor S1pr1 drives the expansion of γδ17. Compared to young mice, expanded γδ17 recruit tumor-promoting neutrophils with lower expression levels of CD62L and higher levels of C-kit and CXCR4. These neutrophils suppress the stemness and tumor-killing functions of CD8+ T cells in aged male mice. Accordingly, antibody-mediated depletion of γδT or neutrophils reduces tumor metastatic foci in aged animals, and the administration of the senolytic agent procyanidin C1 reverses the observed immune-mediated, tumor-promoting effects of aging. Thus, we uncover a γδ17-Neutrophil-CD8 axis that promotes aging-driven tumor metastasis in male mice and provides potential insights for managing metastatic tumors.

Diagnostic and therapeutic role of non-coding RNAs regulating programmed cell death in melanoma

lncRNAs (long non-coding RNAs) are heterogeneous RNA molecules that modulate various cellular processes, such as proliferation, differentiation, migration, invasion, and apoptosis, via different mechanisms. An increasing amount of research indicates that abnormal expression of lncRNA influences the development of drug resistance as well as the genesis and advancement of cancer, including melanoma. Furthermore, they are attractive biomarkers for non-invasive cancer diagnostics due to their strongly modulated expression and improved tissue and disease specificity. This review offers a succinct overview of the present understanding concerning the potential diagnostic biomarker potential of lncRNAs in melanoma. Cell death occurs frequently during growth and throughout life and is an active, organized, and genetically determined process. It is essential for the regulation of homeostasis. Controlled cell death and non-programmed cell death are both forms of cell death. The most prevalent forms of regulatory cell death are pyroptosis, ferroptosis, autophagy, necroptosis, necrosis, and apoptosis. Ferroptosis, pyroptosis, and autophagy are less common forms of cell death compared to necrosis, apoptosis, and necroptosis. ncRNAs are regulatory RNA molecules that are not involved in encoding proteins. They primarily consist of circular RNAs (circ RNAs), lncRNAs, and microRNAs (miRNAs). Moreover, non-coding RNAs have the ability to modulate tumor cell autophagy, pyroptosis, and ferroptosis at the transcriptional or post-transcriptional stage, as well as function as oncogenes and tumor suppressor genes, which can have considerable effects on the incidence and growth of tumors. This review concentrated on the recent advancements in the research of the diagnostic and therapeutic functions of ncRNAs in the regulation of programmed cell death in melanoma.

Synergistic Anti-Cancer Effects of Curcumin and Thymoquinone Against Melanoma

Combining anti-cancer agents in cancer therapies is becoming increasingly common because of their improved efficacy, reduced toxicity, and decreased risk of resistance development. Melanoma, a highly aggressive form of skin cancer characterized by limited treatment options due to chemoresistance, poses a considerable challenge for effective management. Here, we test the hypothesis that dietary supplements such as thymoquinone (TQ) and curcumin (CU) cooperatively modulate cancer-associated cellular mechanisms to inhibit melanoma progression. Through a series of in vitro experiments utilizing the A375 melanoma cell line, including assessments of cell viability, apoptosis, multicellular tumor spheroid models, reactive oxygen species (ROS) quantification, metabolomics analysis, and RNA sequencing, we established that the combined application of TQ and CU exhibited superior anti-tumor effects compared to their individual use. Our results indicate that the combination treatment significantly inhibited cell viability and induced apoptosis more effectively than either agent alone, with optimal synergy observed at concentrations of 25 µM CU and 10 µM TQ against A375 cells. Additionally, the combination treatment markedly elevated ROS levels, selectively activating the mitochondrial apoptotic pathway via caspase-9. Differential gene expression analysis further revealed a unique synergistic effect of the combination treatment, with enhanced regulation of genes related to oxidative stress and apoptosis. Notably, pathways such as mitochondrial apoptotic signaling and redox homeostasis were more effectively influenced by the combination, with genes such as GPX3, CYP4F11, and HSPB8 cooperatively regulated. Overall, the findings suggest that, in combination, TQ and CU acts synergistically against melanoma; however, further experimental and clinical studies are required to confirm its therapeutic potential.

Metformin regulates the proliferation and motility of melanoma cells by modulating the LINC00094/miR-1270 axis

BACKGROUND

Melanoma is an aggressive tumor with a high mortality rate. Metformin, a commonly prescribed diabetes medication, has shown promise in cancer prevention and treatment. Long noncoding RNAs (lncRNAs) are non-protein-coding RNA molecules that play a key role in tumor development by interacting with cellular chromatins. Despite the benefits of metformin, the anticancer mechanism underlying its effect on the regulation of lncRNAs in melanoma remains unclear.

METHODS

We investigated the lncRNA profiles of human melanoma cells with and without metformin treatment using a next-generation sequencing approach (NGS). Utilizing public databases, we analyzed the expression levels and clinical impacts of LINC00094 and miR-1270 in melanoma. The expression levels of LINC00094 and miR-1270 were verified in human cell lines and clinical samples by real-time PCR and in situ hybridization. The biological roles of LINC00094 and miR-1270 in cell growth, proliferation, cell cycle, apoptosis, and motility were studied using in vitro assays.

RESULTS

We identify a novel long noncoding RNA, namely LINC00094, whose expression considerably decreased in melanoma cells after metformin treatment. In situ hybridization analysis revealed substantially higher expression of LINC00094 in cutaneous melanoma tissue compared with adjacent normal epidermis and normal control tissues (P < 0.001). In nondiabetic patients with melanoma, the overall survival of high LINC00094 expression group was shorter than the low LINC00094 expression group with borderline statistical significance (log-rank test, P = 0.057). Coexpression analysis of LINC00094 indicated its involvement in the mitochondrial respiratory pathway, with its knockdown suppressing genes associated with mitochondrial oxidative phosphorylation, glycolysis, antioxidant production, and metabolite levels. Functional analysis revealed that silencing-LINC00094 inhibited the proliferation, colony formation, invasion, and migration of melanoma cells. Cell cycle analysis following LINC00094 knockdown revealed G1 phase arrest with reduced cell cycle protein expression. Combined TargetScan and reporter assays revealed a direct link between miR-1270 and LINC00094. Ectopic miR-1270 expression inhibited melanoma cell growth and motility while inducing apoptosis. Finally, through in silico analysis, we identified two miR-1270 target genes, CD276 and centromere protein M (CENPM), which may be involved in the biological functions of LINC00094.

CONCLUSIONS

Overall, LINC00094 expression may regulate melanoma cell growth and motility by modulating the expression of miR-1270, and targeting genes of CD276 and CENPM indicating its therapeutic potential in melanoma treatment.

The Pseudoinflammatory Pattern Revisited

In 1973, Dr. Martin C. Mihm, Jr. presented the finding that congenital melanocytic nevi, when viewed at low magnification, resemble superficial and deep perivascular dermatitis, forming the so-called "pseudoinflammatory" pattern. One year earlier, Dr. Richard A. Sagebiel had put forward the concept of "pseudovascular spaces" in melanocytic nevi. A retrospective look at these early studies confirms that alert observation at the microscope can lead to a deeper understanding of the fundamental biology underlying melanocytic tumors.

ZnO nanoparticles induce melanoma-like lesions via recruiting dermal dendritic cells in barrier-damaged skin in mice

ZnO nanoparticles (NPs) are used in skin treatments and cosmetics, the toxicity of long-term and continuous exposure to ZnO NPs is unknown. Mice with epidermal barrier dysfunction revealed melanoma-like lesions after continuous exposure to ZnO NPs. However, the effects of metallic NPs on the skin microenvironment and immune system remain poorly understood. Mice with epidermal barrier failure were given continuous exposure to ZnO NPs for 7 weeks. The malignant transformation of melanocytes was induced with ZnO NPs 2.5 μg/ml for 72 h exposure. The supernatant of the culture medium from dendritic cells after being exposed to 10 μg/ml ZnO NPs for 24 h was applied to melanocytes to explore the effect of recruitment of DCs. The expressure of ZnO NPs resulted in a tendency of malignant transformation of melanocytes, the recruitment of DCs induces this process by produce inflammatory factors such as TNF-α. These DC-produced inflammatory factors, which were induced by ZnO NP exposure, increased the production of matrix metalloproteinases in melanocytes and expedited the malignant transformation process. Our findings revealed that the disrupted cutaneous microenvironment by ZnO NPs penetrated directly promoted the malignant transformation of melanocytes, which process also indirectly enhanced by the TNF-αsecreted from the recruited DCs.

Th17 cell function in cancers: immunosuppressive agents or anti-tumor allies?

T helper (Th) 17 cells, a distinct subset of Th lymphocytes, are known for their prominent interleukin (IL)-17 production and other pro-inflammatory cytokines. These cells exhibit remarkable plasticity, allowing them to exhibit different phenotypes in the cancer microenvironment. This adaptability enables Th17 cells to promote tumor progression by immunosuppressive activities and angiogenesis, but also mediate anti-tumor immune responses through employing immune cells in tumor setting or even by directly converting toward Th1 phenotype and producing interferon-gamma (IFN-γ). This dual role of Th17 cells in cancer makes it a double-edged sword in encountering cancer. In this review, we aim to elucidate the complexities of Th17 cell function in cancer by summarizing recent studies and, ultimately, to design novel therapeutic strategies, especially targeting Th17 cells in the tumor milieu, which could pave the way for more effective cancer treatments.

Metastatic melanoma of the gallbladder: A case report and systematic review

We report a case of metastatic melanoma of the gallbladder diagnosed by contrast-enhanced ultrasound and systematically review the characteristics of transabdominal ultrasound, clinical manifestations, and treatment methods of gallbladder metastatic melanoma in order to provide reference ideas for the diagnosis and treatment of metastatic melanoma of gallbladder.

Aged fibroblast-derived extracellular vesicles promote angiogenesis in melanoma

Advancing age is a negative prognostic factor for cutaneous melanoma. However, the role of extracellular vesicles (EVs) within the melanoma tumor microenvironment (TME) has remained unexplored in the context of aging. While the size and morphology of the EVs isolated from young vs. aged fibroblasts remained unaltered, the contents of the protein cargo were changed. Aging reduced the expression of the tetraspanin CD9 in both the dermal fibroblasts and released EVs. CD9 is a crucial regulator of EV cargo sorting. Modulating the CD9 expression in fibroblasts was sufficient to alter its levels in EVs. Mass spectrometry analysis of EVs released by CD9 knockdown (KD) vs. control cells revealed a significant increase in angiopoietin-like protein 2 (ANGPTL2), an angiogenesis promoter. Analysis of primary endothelial cells confirmed increased sprouting under CD9 KD conditions. Together, our data indicate that aged EVs play an important role in promoting a tumor-permissive microenvironment.

[Translated article] Epidemiology of Primary Cutaneous Melanoma in the Migjorn Health Sector of Mallorca, Spain From 2003 Through 2021

The study of the increasing incidence of melanoma over the past few decades is essential regarding prevention and optimization of health resources. We collected cases of melanoma from Hospital son Llàtzer from the Migjorn health sector of Mallorca, Spain from 2003 through 2021, and calculated the incidence of melanoma adjusted to the standard European population. In addition, other demographic and clinicopathological data were descriptively analyzed too. A total of 690 new cases of melanoma were detected with a progressive increase in the age-standardized incidence from 7.47 cases per 100,000 inhabitants/year in 2003 up to 23.84 in 2021 mainly due to early stages of the disease. The incidence of melanoma has increased significantly in Mallorca probably due to the increasing population coming from northern Europe (low phototypes), sun exposure habits (tourism, fishing, agriculture), and improved early diagnosis.

Epidemiology of Primary Cutaneous Melanoma in the Migjorn Health Sector of Mallorca, Spain From 2003 Through 2021

The study of the increasing incidence of melanoma over the past few decades is essential regarding prevention and optimization of health resources. We collected cases of melanoma from Hospital son Llàtzer from the Migjorn health sector of Mallorca, Spain from 2003 through 2021, and calculated the incidence of melanoma adjusted to the standard European population. In addition, other demographic and clinicopathological data were descriptively analyzed too. A total of 690 new cases of melanoma were detected with a progressive increase in the age-standardized incidence from 7.47 cases per 100,000 inhabitants/year in 2003 up to 23.84 in 2021 mainly due to early stages of the disease. The incidence of melanoma has increased significantly in Mallorca probably due to the increasing population coming from northern Europe (low phototypes), sun exposure habits (tourism, fishing, agriculture), and improved early diagnosis.

Comparative Whole-Genome Sequencing Analysis of In-situ and Invasive Acral Lentiginous Melanoma: Markedly Increased Copy Number Gains of GAB2 , PAK1 , UCP2 , and CCND1 are Associated with Melanoma Invasion

Acral lentiginous melanoma (ALM) is the most common subtype of acral melanoma. Even though recent genetic studies are reported in acral melanomas, the genetic differences between in-situ and invasive ALM remain unclear. We aimed to analyze specific genetic changes in ALM and compare genetic differences between in-situ and invasive lesions to identify genetic changes associated with the pathogenesis and progression of ALM. We performed whole genome sequencing of 71 tissue samples from 29 patients with ALM. Comparative analyses were performed, pairing in-situ ALMs with normal tissues and, furthermore, invasive ALMs with normal and in-situ tissues. Among 21 patients with in-situ ALMs, 3 patients (14.3%) had SMIM14 , SLC9B1 , FRG1 , FAM205A , ESRRA , and ESPN mutations, and copy number (CN) gains were identified in only 2 patients (9.5%). Comparing 13 invasive ALMs with in-situ tissues, CN gains were identified in GAB2 in 8 patients (61.5%), PAK1 in 6 patients (46.2%), and UCP2 and CCND1 in 5 patients (38.5%). Structural variants were frequent in in-situ and invasive ALM lesions. Both in-situ and invasive ALMs had very low frequencies of common driver mutations. Structural variants were common in both in-situ and invasive ALMs. Invasive ALMs had markedly increased CN gains, such as GAB2 , PAK1 , UCP2 , and CCND1 , compared with in-situ lesions. These results suggest that they are associated with melanoma invasion.

High charge of cerebroid nests in nodular melanomas predicts tumor aggressiveness and high mutational tumoral burden: a pilot study

PURPOSE

Even today, melanoma is a highly aggressive neoplasm with a high mortality rate. The nodular type is very aggressive and has cerebroid nests of melanocytes (CNMs) at the growth edge, morphologically similar to the poorly differentiated neoplastic epithelial cell clusters described in colorectal, breast, and endometrioid endometrial cancers.

PATIENTS AND METHODS

We selected 25 nodular melanomas (NMs) with known molecular profiles, of which the entire paraffin-embedded lesion was available. We counted CNMs under a microscopic at a magnification of 20x (i.e., a microscopic field with a major axis of 1 mm). Based on the number of CNMs in the area, melanomas were classified into three groups: G1 (CNMs ranging from 0 to 4), G2 (CNMs ranging from 5 to 9), and G3 (CNMs ≥ 10). The presence of CNMs and their counts were compared with molecular and histopathological data.

RESULTS

Seventeen (NMs) were grouped as G1 (68%), 5 as G2 (20%), and 3 as G3 (12%) based on CNMs count. The presence of CNMs correlated with epithelioid cell morphology (p < 0.05), Clark IV and V levels (p < 0.05), vascular invasion (p < 0.05), and biological mutants (p < 0.05). Melanomas with ≥ 10 CNMs more frequently show ulceration (p < 0.02) and the BRAF V600E mutation (p < 0.02).

CONCLUSION

CNMs count has a predictive role regardless of tumor size; their association with the BRAF V600E mutation suggests their predictive significance in response to biologics. However, further investigations are needed to strengthen this hypothesis.

Transcriptome-Wide Association Study Reveals New Molecular Interactions Associated with Melanoma Pathogenesis

A transcriptome-wide association study (TWAS) was conducted on genome-wide association study (GWAS) summary statistics of malignant melanoma of skin (UK Biobank dataset) and The Cancer Genome Atlas-Skin Cutaneous Melanoma (TCGA-SKCM) gene expression weights to identify melanoma susceptibility genes. The GWAS included 2465 cases and 449,799 controls, while the gene expression testing was conducted on 103 cases. Afterward, a gene enrichment analysis was applied to identify significant TWAS associations. The melanoma's gene-microRNA (miRNA) regulatory network was constructed from the TWAS genes and their corresponding miRNAs. At last, a disease enrichment analysis was conducted on the corresponding miRNAs. The TWAS detected 27 genes associated with melanoma with p-values less than 0.05 (the top three genes are LOC389458 (RBAK), C16orf73 (MEIOB), and EIF3CL). After the joint/conditional test, one gene (AMIGO1) was dropped, resulting in 26 significant genes. The Gene Ontology (GO) biological process associated the extended gene set (76 genes) with protein K11-linked ubiquitination and regulation of cell cycle phase transition. K11-linked ubiquitin chains regulate cell division. Interestingly, the extended gene set was related to different skin cancer subtypes. Moreover, the enriched pathways were nsp1 from SARS-CoV-2 that inhibit translation initiation in the host cell, cell cycle, translation factors, and DNA repair pathways full network. The gene-miRNA regulatory network identified 10 hotspot genes with the top three: TP53, BRCA1, and MDM2; and four hotspot miRNAs: mir-16, mir-15a, mir-125b, and mir-146a. Melanoma was among the top ten diseases associated with the corresponding (106) miRNAs. Our results shed light on melanoma pathogenesis and biologically significant molecular interactions.

A Proteomics Approach Identifies RREB1 as a Crucial Molecular Target of Imidazo-Pyrazole Treatment in SKMEL-28 Melanoma Cells

Cutaneous melanoma is the most dangerous and deadly form of human skin malignancy. Despite its rarity, it accounts for a staggering 80% of deaths attributed to cutaneous cancers overall. Moreover, its final stages often exhibit resistance to drug treatments, resulting in unfavorable outcomes. Hence, ensuring access to novel and improved chemotherapeutic agents is imperative for patients grappling with this severe ailment. Pyrazole and its fused systems derived thereof are heteroaromatic moieties widely employed in medicinal chemistry to develop effective drugs for various therapeutic areas, including inflammation, pain, oxidation, pathogens, depression, and fever. In a previous study, we described the biochemical properties of a newly synthesized group of imidazo-pyrazole compounds. In this paper, to improve our knowledge of the pharmacological properties of these molecules, we conduct a differential proteomic analysis on a human melanoma cell line treated with one of these imidazo-pyrazole derivatives. Our results detail the changes to the SKMEL-28 cell line proteome induced by 24, 48, and 72 h of 3e imidazo-pyrazole treatment. Notably, we highlight the down-regulation of the Ras-responsive element binding protein 1 (RREB1), a member of the zinc finger transcription factors family involved in the tumorigenesis of melanoma. RREB1 is a downstream element of the MAPK pathway, and its activation is mediated by ERK1/2 through phosphorylation.

Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling

Melanoma, originating through malignant transformation of melanin-producing melanocytes, is a formidable malignancy, characterized by local invasiveness, recurrence, early metastasis, resistance to therapy, and a high mortality rate. This review discusses etiologic and risk factors for melanoma, diagnostic and prognostic tools, including recent advances in molecular biology, omics, and bioinformatics, and provides an overview of its therapy. Since the incidence of melanoma is rising and mortality remains unacceptably high, we discuss its inherent properties, including melanogenesis, that make this disease resilient to treatment and propose to use AI to solve the above complex and multidimensional problems. We provide an overview on vitamin D and its anticancerogenic properties, and report recent advances in this field that can provide solutions for the prevention and/or therapy of melanoma. Experimental papers and clinicopathological studies on the role of vitamin D status and signaling pathways initiated by its active metabolites in melanoma prognosis and therapy are reviewed. We conclude that vitamin D signaling, defined by specific nuclear receptors and selective activation by specific vitamin D hydroxyderivatives, can provide a benefit for new or existing therapeutic approaches. We propose to target vitamin D signaling with the use of computational biology and AI tools to provide a solution to the melanoma problem.

Cost-effectiveness of encorafenib with binimetinib in unresectable or metastatic BRAF-mutant melanoma

OBJECTIVE

The objective of this study was to determine the cost-effectiveness of encorafenib with binimetinib (EncoBini) as compared to other targeted double combination therapies, namely dabrafenib with trametinib (DabraTrame) and vemurafenib with cobimetinib (VemuCobi), for the treatment of BRAF V600-mutant unresectable or metastatic melanoma (MM) from the French payer perspective.

METHODS

A partitioned survival model was developed considering a lifetime horizon. The model structure simulated the clinical pathway of patients with BRAF V600-mutant MM. Clinical effectiveness and safety inputs were sourced from the COLUMBUS trial, a network meta-analysis and published literature. Costs, resource use, and the quality of life inputs were obtained from the literature and appropriate French sources.

RESULTS

Over a lifetime horizon, EncoBini was associated, on average, with reduced costs and increased quality adjusted life years (QALYs), dominating both targeted double combination therapies. For a willingness-to-pay threshold of €90,000 per QALY, the probability of EncoBini being cost-effective against either comparator remained above 80%. The most influential model parameters were the hazard ratios for the overall survival of EncoBini vs DabraTrame and VemuCobi, the pre- and post-progression utility values, as well as treatment dosages and the relative dose intensity of all interventions.

CONCLUSION

EncoBini is associated with reduced costs and increased QALYs, dominating other targeted double combination therapies (DabraTrame, VemuCobi) for patients with BRAF V600-mutant MM in France. EncoBini is a highly cost-effective intervention in MM.

Regression of metastatic malignant melanoma with dupilumab: A case report

Excoriated pruritus can be an intolerable symptom in patients with cancer where Type 2 inflammation and its associated cytokines IL-4 and IL-13 play major roles in the pruritus. Dupilumab, an antibody blocking IL-4 and IL-13, is approved for treating moderate to severe atopic dermatitis (AD) where itching is a significant symptom. We present a case report of intractable malignancy-associated AD and pruritus with eosinophilia in a patient with stage IV malignant melanoma who was treated with dupilumab. Biweekly treatment with dupilumab led to an immediate improvement in itching and resolution of the AD, which subsided after a few doses and without significant adverse effects. Routine radiologic monitoring of the malignant melanoma showed concomitant resolution of secondary nodules in the lung, liver, and pleura. It was concluded that dupilumab may be a safe and effective treatment for intractable malignancy-associated AD with pruritus and may have potential for moderating metastatic malignant melanoma.

Review of the comparative pathological and immunohistochemical features of human and canine cutaneous melanocytic neoplasms

Melanocytic neoplasms originate from melanocytes and melanoma, the malignant form, is a common canine neoplasm and the most aggressive human skin cancer. Despite many similarities between these neoplasms in both species, only a limited number of studies have approached these entities in a comparative manner. Therefore, this review compares benign and malignant melanocytic neoplasms in dogs and humans, exclusively those arising in the haired skin, with regard to their clinicopathological, immunohistochemical and molecular aspects. Shared features include spontaneous occurrence, macroscopic features and microscopic findings when comparing human skin melanoma in the advanced/invasive stage and canine cutaneous melanoma, immunohistochemical markers and several histopathological prognostic factors. Differences include the apparent absence of active mutations in the BRAF gene in canine cutaneous melanoma and less aggressive clinical behaviour in dogs than in humans. Further studies are required to elucidate the aetiology and genetic development pathways of canine cutaneous melanocytic neoplasms. Evaluation of the applicability of histopathological prognostic parameters commonly used in humans for dogs are also needed. The similarities between the species and the recent findings regarding genetic mutations in canine cutaneous melanomas suggest the potential utility of dogs as a natural model for human melanomas that are not related to ultraviolet radiation.

Discovery of novel peptide-dehydroepiandrosterone hybrids inducing endoplasmic reticulum stress with effective in vitro and in vivo anti-melanoma activities

Steroid hybrids have emerged as a type of advantageous compound as they could offer improved pharmacological and pharmaceutical properties. Here, we report a series of novel peptide-dehydroepiandrosterone hybrids, which would effectively induce endoplasmic reticulum stress (ERS) and lead to apoptosis with outstanding in vitro and in vivo anti-melanoma effects. The lead compound IId among various steroids conjugated with peptides and pyridines showed effective in vivo activity in B16 xenograft mice: in medium- and high-dose treatment groups (60 and 80 mg/kg), compound IId would significantly inhibit the growth of tumours by 98%-99% compared to the control group, with the highest survival rate as well. Further mechanism studies showed that compound IId would damage the endoplasmic reticulum and upregulate the ERS markers C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78), which could further regulate caspase and Bcl-2 family proteins and lead to cell apoptosis. The compound IId was also proven to be effective in inhibiting B16 cell migration and invasion.

The podoplanin-CLEC-2 interaction promotes platelet-mediated melanoma pulmonary metastasis

BACKGROUND

Podoplanin (PDPN) expressed on tumour cells interacts with platelet C-type lectin-like receptor 2 (CLEC-2). This study aimed to investigate the role of the PDPN-platelet CLEC-2 interaction in melanoma pulmonary metastasis.

METHODS

Murine melanoma B16-F0 cells, which have two populations that express podoplanin, were sorted by FACS with anti-podoplanin staining to obtain purified PDPN + and PDPN- B16-F0 cells. C57BL/6J mice transplanted with CLEC-2-deficient bone marrow cells were used for in vivo experiments.

RESULTS

The in vivo data showed that the number of metastatic lung nodules in WT mice injected with PDPN + cells was significantly higher than that in WT mice injected with PDPN- cells and in WT or CLEC-2 KO mice injected with PDPN- cells. In addition, our results revealed that the platelet Syk-dependent signalling pathway contributed to platelet aggregation and melanoma metastasis.

CONCLUSIONS

Our study indicates that the PDPN-CLEC-2 interaction promotes experimental pulmonary metastasis in a mouse melanoma model. Tumour cell-induced platelet aggregation mediated by the interaction between PDPN and CLEC-2 is a key factor in melanoma pulmonary metastasis.

Proteomic Analysis Highlights the Impact of the Sphingolipid Metabolizing Enzyme β-Galactosylceramidase on Mitochondrial Plasticity in Human Melanoma

Mitochondrial plasticity, marked by a dynamism between glycolysis and oxidative phosphorylation due to adaptation to genetic and microenvironmental alterations, represents a characteristic feature of melanoma progression. Sphingolipids play a significant role in various aspects of cancer cell biology, including metabolic reprogramming. Previous observations have shown that the lysosomal sphingolipid-metabolizing enzyme β-galactosylceramidase (GALC) exerts pro-oncogenic functions in melanoma. Here, mining the cBioPortal for a Cancer Genomics data base identified the top 200 nuclear-encoded genes whose expression is negatively correlated with GALC expression in human melanoma. Their categorization indicated a significant enrichment in Gene Ontology terms and KEGG pathways related to mitochondrial proteins and function. In parallel, proteomic analysis by LC-MS/MS of two GALC overexpressing human melanoma cell lines identified 98 downregulated proteins when compared to control mock cells. Such downregulation was confirmed at a transcriptional level by a Gene Set Enrichment Analysis of the genome-wide expression profiling data obtained from the same cells. Among the GALC downregulated proteins, we identified a cluster of 42 proteins significantly associated with GO and KEGG categorizations related to mitochondrion and energetic metabolism. Overall, our data indicate that changes in GALC expression may exert a significant impact on mitochondrial plasticity in human melanoma cells.

PhotoPyro-Induced cGAS-STING Pathway Activation Enhanced Anti-Melanoma Immunotherapy via a Manganese-Coordinated Nanomedicine

Malignant melanoma is an aggressive skin cancer with a high metastatic and mortality rate. Owing to genetic alterations, melanoma cells are resistant to apoptosis induction, which reduces the efficacy of most adjuvant systemic anticancer treatments in clinical. Here, a noninvasive strategy for anti-melanoma immunotherapy based on a manganese-coordinated nanomedicine is provided. Supplemented with photoirradiation, photon-mediated reactive oxygen species generation by photosensitizer chlorin e6 initiates photon-controlled pyroptosis activation (PhotoPyro) and promotes antitumor immunity. Simultaneously, photoirradiation-triggered double-stranded DNA generation in the cytosol would activate the Mn2+ -sensitized cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which further augment the PhotoPyro-induced immune response. The syngeneic effect of these immunostimulatory pathways significantly benefits dendritic cell maturation by damage-associated molecular patterns and proinflammatory cytokines secretion, thereby activating T cells and remarkably eliciting a systemic antitumor immune response to inhibiting both primary and distant tumor growth. Collaboratively, the photoirradiation-triggered PhotoPyro and cGAS-STING pathway activation by nanomedicine administration could enhance the antitumor capacity of immunotherapy and serve as a promising strategy for melanoma treatment.

Immune checkpoint inhibitors in metastatic melanoma therapy (Review)

An increase in the incidence of melanoma has been observed in recent decades, which poses a significant challenge due to its poor prognosis in the advanced and metastatic stages. Previously, chemotherapy and high doses of interleukin-2 were available treatments for melanoma; however, they offered limited survival benefits and were associated with severe toxicities. The treatment of metastatic melanoma has been transformed by new developments in immunotherapy. Immune checkpoint inhibitors (ICIs), monoclonal antibodies that target cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1) and its ligand, PDL-1, have emerged as promising therapeutic options. Commonly used ICIs, such as ipilimumab, nivolumab and pembrolizumab, have been found to be associated with an improved median overall survival, recurrence-free survival and response rates compared to traditional chemotherapies. Combination therapies involving different types of ICIs, such as anti-PD1 with anti-CTLA-4, have further enhanced the overall survival and response rates by targeting various phases of T-cell activation. Additionally, the development of novel biomarkers has facilitated the assessment of responses to ICI therapy, with tissue and serum-based prognostic and predictive biomarkers now available. The increased response observed with ICIs also provides potential for immune-related adverse effects on various organ systems. Further research is required to evaluate the efficacy and safety of various combinations of ICIs, while ongoing clinical trials explore the potential of newer ICIs. Concerns regarding the development of resistance to ICIs also warrant attention. The present review summarizes and discusses the advent of ICIs with a marked significant breakthrough in the treatment of metastatic melanoma, providing improved outcomes compared to traditional therapies.

Cancer-associated Fibroblast-specific Expression of the Matricellular Protein CCN1 Coordinates Neovascularization and Stroma Deposition in Melanoma Metastasis

Melanoma is the leading cause of skin cancer-related death. As prognosis of patients with melanoma remains problematic, identification of new therapeutic targets remains essential. Matricellular proteins are nonstructural extracellular matrix proteins. They are secreted into the tumor microenvironment to coordinate behavior among different cell types, yet their contribution to melanoma is underinvestigated. Examples of matricellular proteins include those comprising the CCN family. The CCN family member, CCN1, is highly proangiogenic. Herein, we show that, in human patients with melanoma, although found in several tumor cell types, CCN1 is highly expressed by a subset of cancer-associated fibroblasts (CAF) in patients with melanoma and this expression correlates positively with expression of proangiogenic genes and progressive disease/resistance to anti-PD1 checkpoint inhibitors. Consistent with these observations, in a syngeneic C57BL6 mouse model of melanoma, loss of CCN1 expression from Col1A2-Cre-, herein identified as "universal," fibroblasts, impaired metastasis of subcutaneously injected B16F10 tumor cells to lung, concomitant with disrupted neovascularization and collagen organization. Disruption of the extracellular matrix in the loss of CCN1 was validated using a novel artificial intelligence-based image analysis platform that revealed significantly decreased phenotypic fibrosis and composite morphometric collagen scores. As drug resistance is linked to matrix deposition and neoangiogenesis, these data suggest that CCN1, due to its multifaceted role, may represent a novel therapeutic target for drug-resistant melanoma. Our data further emphasize the essential role that cancer-associated, (universal) Col1A2-Cre-fibroblasts and extracellular matrix remodeling play in coordinating behavior among different cell types within the tumor microenvironment.

SIGNIFICANCE

In human patients, the expression of proangiogenic matricellular protein CCN1 in CAFs correlates positively with expression of stroma and angiogenic markers and progressive disease/resistance to checkpoint inhibitor therapy. In an animal model, loss of CCN1 from CAFs impaired metastasis of melanoma cells, neovascularization, and collagen deposition, emphasizing that CAFs coordinate cellular behavior in a tumor microenvironment and that CCN1 may be a novel target.

Isothiocyanates Potentiate Tazemetostat-Induced Apoptosis by Modulating the Expression of Apoptotic Genes, Members of Polycomb Repressive Complex 2, and Levels of Tri-Methylating Lysine 27 at Histone 3 in Human Malignant Melanoma Cells

In this study, we utilized an in vitro model consisting of human malignant melanoma as well as non-tumorigenic immortalized keratinocyte cells with the aim of characterizing the therapeutic effectiveness of the clinical epigenetic drug Tazemetostat alone or in combination with various isothiocyanates. In doing so, we assessed markers of cell viability, apoptotic induction, and expression levels of key proteins capable of mediating the therapeutic response. Our data indicated, for the first time, that Tazemetostat caused a significant decrease in viability levels of malignant melanoma cells in a dose- and time-dependent manner via the induction of apoptosis, while non-malignant keratinocytes were more resistant. Moreover, combinatorial treatment protocols caused a further decrease in cell viability, together with higher apoptotic rates. In addition, a significant reduction in the Polycomb Repressive Complex 2 (PRC2) members [e.g., Enhancer of Zeste Homologue 2 (EZH2), Embryonic Ectoderm Development (EED), and suppressor of zeste 12 (SUZ12)] and tri-methylating lysine 27 at Histone 3 (H3K27me3) protein expression levels was observed, at least partially, under specific combinatorial exposure conditions. Reactivation of major apoptotic gene targets was determined at much higher levels in combinatorial treatment protocols than Tazemetostat alone, known to be involved in the induction of intrinsic and extrinsic apoptosis. Overall, we developed an optimized experimental therapeutic platform aiming to ensure the therapeutic effectiveness of Tazemetostat in malignant melanoma while at the same time minimizing toxicity against neighboring non-tumorigenic keratinocyte cells.

Size-exclusion chromatography combined with DIA-MS enables deep proteome profiling of extracellular vesicles from melanoma plasma and serum

Extracellular vesicles (EVs) are important players in melanoma progression, but their use as clinical biomarkers has been limited by the difficulty of profiling blood-derived EV proteins with high depth of coverage, the requirement for large input amounts, and complex protocols. Here, we provide a streamlined and reproducible experimental workflow to identify plasma- and serum- derived EV proteins of healthy donors and melanoma patients using minimal amounts of sample input. SEC-DIA-MS couples size-exclusion chromatography to EV concentration and deep-proteomic profiling using data-independent acquisition. From as little as 200 µL of plasma per patient in a cohort of three healthy donors and six melanoma patients, we identified and quantified 2896 EV-associated proteins, achieving a 3.5-fold increase in depth compared to previously published melanoma studies. To compare the EV-proteome to unenriched blood, we employed an automated workflow to deplete the 14 most abundant proteins from plasma and serum and thereby approximately doubled protein group identifications versus native blood. The EV proteome diverged from corresponding unenriched plasma and serum, and unlike the latter, separated healthy donor and melanoma patient samples. Furthermore, known melanoma markers, such as MCAM, TNC, and TGFBI, were upregulated in melanoma EVs but not in depleted melanoma plasma, highlighting the specific information contained in EVs. Overall, EVs were significantly enriched in intact membrane proteins and proteins related to SNARE protein interactions and T-cell biology. Taken together, we demonstrated the increased sensitivity of an EV-based proteomic workflow that can be easily applied to larger melanoma cohorts and other indications.

The clinicopathological impact of tumor-associated macrophages in patients with cutaneous malignant melanoma

BACKGROUND

Tumor-associated macrophages (TAMs) are an immune component of the cutaneous malignant melanoma (CMM) microenvironment and affect tumor growth. TAMs can polarize into different phenotypes, that is, proinflammatory M1 and anti-inflammatory M2 macrophages. However, the role of the macrophage phenotype in CMM remains unclear.

METHODS

We examined 88 patients with CMM. Tissue microarrays were constructed, and the density of M1 and M2 macrophages was analyzed by immunohistochemistry. Immune cells coexpressing CD68 and phosphorylated signal transducer and activator of transcription 1 (pSTAT1) were considered M1 macrophages, whereas those coexpressing CD68 and c-macrophage activating factor (c-Maf) were defined as M2 macrophages. These TAMs were counted, and the relationships between the density of M1 and M2 macrophages and clinicopathological factors including prognosis were investigated.

RESULTS

The CD68/c-Maf score ranged from 0 to 34 (median: 5.5). The patients were divided based on the median score into the CD68/c-Maf high (≥5.5) and low (<5.5) expression groups. Univariate and multivariate analyses revealed that CD68/c-Maf expression was an independent predictive factor for progression-free survival and an independent prognostic factor for overall survival. CD68/pSTAT1 expression was found in only two patients.

CONCLUSION

We suggest that CD68/pSTAT1 coexpression is rarely observed in patients with CMM, and high CD68/c-Maf expression is a predictor of worse prognosis in these patients.

Dermoscopic Changes in Melanocytic Lesions in 368 Patients With Atypical Nevus Syndrome and Their Association With Melanoma Incidence: A Cohort Study

BACKGROUND AND OBJECTIVE

Atypical nevus syndrome has been described as one of the main risk factors for melanoma. The aim of this study was to analyze dermoscopic changes observed in melanocytic lesions over a follow-up period of 5 years in patients with atypical nevus syndrome.

MATERIAL AND METHODS

We conducted a retrospective follow-up study of a cohort of patients seen at a specialized skin cancer and digital body mapping clinic in Medellin, Colombia, between January 2017 and December 2022. We analyzed the dermoscopic changes observed during this period and explored their association with newly diagnosed melanoma.

RESULTS

A total of 368 patients (187 women) with a median (interquartile range) age of 43 (37-51) years were included. The dermoscopic features observed at 5 years were an atypical network (222 patients, 60.3%), asymmetric globules (163, 44.2%), white-gray regression areas (105, 28.5%), lesion regression (72, 19.5%), a negative pigment network (59, 16%), asymmetric eccentric pigmentation (28, 7.6%), asymmetric projections (21, 5.7%), and asymmetric vascular patterns (8, 2.1%). Melanoma was diagnosed in 12.2% of patients during follow-up. Features significantly associated with a shorter time to melanoma onset were grayish-white areas (P <.001), asymmetric globules (P=.011), asymmetric eccentric pigmentation (P=.047), and a negative pigment network (P=.001).

CONCLUSIONS

The main dermoscopic features of melanocytic lesions in patients with atypical nevus syndrome associated with progression to melanoma were grayish-white areas, asymmetric globules, asymmetric spots, and a negative pigment network.

[Translated article] Dermoscopic Changes in Melanocytic Lesions in 368 Patients With Atypical Nevus Syndrome and Their Association With Melanoma Incidence: A Cohort Study

BACKGROUND AND OBJECTIVE

Atypical nevus syndrome has been described as one of the main risk factors for melanoma. The aim of this study was to analyze dermoscopic changes observed in melanocytic lesions over a follow-up period of 5 years in patients with atypical nevus syndrome.

MATERIAL AND METHODS

We conducted a retrospective follow-up study of a cohort of patients seen at a specialized skin cancer and digital body mapping clinic in Medellin, Colombia, between January 2017 and December 2022. We analyzed the dermoscopic changes observed during this period and explored their association with newly diagnosed melanoma.

RESULTS

A total of 368 patients (187 women) with a median (interquartile range) age of 43 (37-51) years were included. The dermoscopic features observed at 5 years were an atypical network (222 patients, 60.3%), asymmetric globules (163, 44.2%), white-gray regression areas (105, 28.5%), lesion regression (72, 19.5%), a negative pigment network (59, 16%), asymmetric eccentric pigmentation (28, 7.6%), asymmetric projections (21, 5.7%), and asymmetric vascular patterns (8, 2.1%). Melanoma was diagnosed in 12.2% of patients during follow-up. Features significantly associated with a shorter time to melanoma onset were grayish-white areas (P<.001), asymmetric globules (P=.011), asymmetric eccentric pigmentation (P=.047), and a negative pigment network (P=.001).

CONCLUSIONS

The main dermoscopic features of melanocytic lesions in patients with atypical nevus syndrome associated with progression to melanoma were grayish-white areas, asymmetric globules, asymmetric spots, and a negative pigment network.

MGRN1 depletion promotes intercellular adhesion in melanoma by upregulation of E-cadherin and inhibition of CDC42

Mahogunin Ring Finger 1 is an E3-ubiquitin ligase encoded by the color gene MGRN1. Our previous in vitro and in vivo studies demonstrated that Mgrn1 deletion in mouse melanoma cells induced cell differentiation and adhesion, and decreased cell motility and invasion on collagen I, and lung colonization in an in vivo model. Here, we investigated the role of MGRN1 on human melanoma cell morphology, adhesion and expression of genes/proteins involved in an EMT-like transition. We demonstrated that wild-type BRAF human melanoma cells adopted a clustering-like morphology on collagen I, with permanent MGRN1 abrogation resulting in bigger cell clusters. Enhanced intercellular adhesion was mostly mediated by induction of E-cadherin and higher co-localization with β-catenin. Transcriptional upregulation of E-cadherin likely occurred through downregulation of the ZEB1 repressor. Finally, pulldown assays showed reduced activation of CDC42 in the absence of MGRN1, which was reverted after E-cadherin silencing. Overall, these findings highlight a new MGRN1-dependent pathway regulating melanoma cell shape, motility, and invasion potential.

The fatty acid-related gene signature stratifies poor prognosis patients and characterizes TIME in cutaneous melanoma

BACKGROUND

The aim of this study is to build a prognostic model for cutaneous melanoma (CM) using fatty acid-related genes and evaluate its capacity for predicting prognosis, identifying the tumor immune microenvironment (TIME) composition, and assessing drug sensitivity.

METHODS

Through the analysis of transcriptional data from TCGA-SKCM and GTEx datasets, we screened for differentially expressed fatty acids-related genes (DEFAGs). Additionally, we employed clinical data from TCGA-SKCM and GSE65904 to identify genes associated with prognosis. Subsequently, utilizing all the identified prognosis-related fatty acid genes, we performed unsupervised clustering analysis using the ConsensusClusterPlus R package. We further validated the significant differences between subtypes through survival analysis and pathway analysis. To predict prognosis, we developed a LASSO-Cox prognostic signature. This signature's predictive ability was rigorously examined through multivariant Cox regression, survival analysis, and ROC curve analysis. Following this, we constructed a nomogram based on the aforementioned signature and evaluated its accuracy and clinical utility using calibration curves, cumulative hazard rates, and decision curve analysis. Using this signature, we stratified all cases into high- and low-risk groups and compared the differences in immune characteristics and drug treatment responsiveness between these two subgroups. Additionally, in this study, we provided preliminary confirmation of the pivotal role of CD1D in the TIME of CM. We analyzed its expression across various immune cell types and its correlation with intercellular communication using single-cell data from the GSE139249 dataset.

RESULTS

In this study, a total of 84 DEFAGs were identified, among which 18 were associated with prognosis. Utilizing these 18 prognosis-related genes, all cases were categorized into three subtypes. Significant differences were observed between subtypes in terms of survival outcomes, the expression of the 18 DEFAGs, immune cell proportions, and enriched pathways. A LASSO-Cox regression analysis was performed on these 18 genes, leading to the development of a signature comprising 6 DEFAGs. Risk scores were calculated for all cases, dividing them into high-risk and low-risk groups. High-risk patients exhibited significantly poorer prognosis than low-risk patients, both in the training group (p < 0.001) and the test group (p = 0.002). Multivariate Cox regression analysis indicated that this signature could independently predict outcomes [HR = 2.03 (1.69-2.45), p < 0.001]. The area under the ROC curve for the training and test groups was 0.715 and 0.661, respectively. Combining risk scores with clinical factors including metastatic status and patient age, a nomogram was constructed, which demonstrated significant predictive power for 3  and 5 years patient outcomes. Furthermore, the high and low-risk subgroups displayed differences in the composition of various immune cells, including M1 macrophages, M0 macrophages, and CD8+ T cells. The low-risk subgroup exhibited higher StromalScore, ImmuneScore, and ESTIMATEScore (p < 0.001) and demonstrated better responsiveness to immune therapy for patients with PD1-positive and CTLA4-negative or positive expressions (p < 0.001). The signature gene CD1D was found to be mainly expressed in monocytes/macrophages and dendritic cells within the TIME. Through intercellular communication analysis, it was observed that cases with high CD1D expression exhibited significantly enhanced signal transductions from other immune cells to monocytes/macrophages, particularly the (HLA-A/B/C/E/F)-CD8A signaling from natural killer (NK) cells to monocytes/macrophages (p < 0.01).

CONCLUSIONS

The prognostic signature constructed in this study, based on six fatty acid-related genes, exhibits strong capabilities in predicting patient outcomes, identifying the TIME, and assessing drug sensitivity. This signature can aid in patient risk stratification and provide guidance for clinical treatment strategies. Additionally, our research highlights the crucial role of CD1D in the CM's TIME, laying a theoretical foundation for future related studies.

Non-invasive transdermal delivery of biomacromolecules with fluorocarbon-modified chitosan for melanoma immunotherapy and viral vaccines

Transdermal drug delivery has been regarded as an alternative to oral delivery and subcutaneous injection. However, needleless transdermal delivery of biomacromolecules remains a challenge. Herein, a transdermal delivery platform based on biocompatible fluorocarbon modified chitosan (FCS) is developed to achieve highly efficient non-invasive delivery of biomacromolecules including antibodies and antigens. The formed nanocomplexes exhibits effective transdermal penetration ability via both intercellular and transappendageal routes. Non-invasive transdermal delivery of immune checkpoint blockade antibodies induces stronger immune responses for melanoma in female mice and reduces systemic toxicity compared to intravenous injection. Moreover, transdermal delivery of a SARS-CoV-2 vaccine in female mice results in comparable humoral immunity as well as improved cellular immunity and immune memory compared to that achieved with subcutaneous vaccine injection. Additionally, FCS-based protein delivery systems demonstrate transdermal ability for rabbit and porcine skins. Thus, FCS-based transdermal delivery systems may provide a compelling opportunity to overcome the skin barrier for efficient transdermal delivery of bio-therapeutics.

Tryptophanyl-Transfer RNA Synthetase Is Involved in a Negative Feedback Loop Mitigating Interferon-γ-Induced Gene Expression

Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes responsible for linking a transfer RNA (tRNA) with its cognate amino acid present in all the kingdoms of life. Besides their aminoacyl-tRNA synthetase activity, it was described that many of these enzymes can carry out non-canonical functions. They were shown to be involved in important biological processes such as metabolism, immunity, development, angiogenesis and tumorigenesis. In the present work, we provide evidence that tryptophanyl-tRNA synthetase might be involved in a negative feedback loop mitigating the expression of certain interferon-γ-induced genes. Mining the available TCGA and Gtex data, we found that WARS was highly expressed in cutaneous melanoma (SKCM) compared to other cancers and is of good prognosis for this particular cancer type. WARS expression correlates with genes involved in antigen processing and presentation but also transcription factors involved in IFN-γ signaling such as STAT1. In addition, WARS was found in complex with STAT1 in A375 cells treated with IFN-γ. Finally, we showed that knocking down WARS expression during IFN-γ stimulation further increases the expression of GBP2, APOL1, ISG15, HLA-A and IDO1.

Revisiting the Role of B-RAF Kinase as a Therapeutic Target in Melanoma

Malignant melanoma is the rarest but most aggressive and deadly skin cancer. Melanoma is the result of a malignant transformation of melanocytes, which leads to their uncontrolled proliferation. Mutations in the mitogen-activated protein kinase (MAPK) pathway, which are crucial for the control of cellular processes, such as apoptosis, division, growth, differentiation, and migration, are one of its most common causes. BRAF kinase, as one of the known targets of this pathway, has been known for many years as a prominent molecular target in melanoma therapy, and the following mini-review outlines the state-of-the-art knowledge regarding its structure, mutations and mechanisms.

Dynamized ultra-low dilution of Ruta graveolens disrupts plasma membrane organization and decreases migration of melanoma cancer cell

Cutaneous melanoma is a cancer with a very poor prognosis mainly because of metastatic dissemination and therefore a deregulation of cell migration. Current therapies can benefit from complementary medicines as supportive care in oncology. In our study, we show that a dynamized ultra-low dilution of Ruta Graveolens leads to an in vitro inhibition of migration on fibronectin of B16F10 melanoma cells, as well as a decrease in metastatic dissemination in vivo. These effects appear to be due to a disruption of plasma membrane organization, with a change in cell and membrane stiffness, associated with a disorganization of the actin cytoskeleton and a modification of the lipid composition of the plasma membrane. Together, these results demonstrate, in in vitro and in vivo models of cutaneous melanoma, an anti-cancer and anti-metastatic activity of ultra-low dynamized dilution of Ruta graveolens and reinforce its interest as complementary medicine in oncology.

QGD-Net: A Lightweight Model Utilizing Pixels of Affinity in Feature Layer for Dermoscopic Lesion Segmentation

RESPONSE

Pixels with location affinity, which can be also called "pixels of affinity," have similar semantic information. Group convolution and dilated convolution can utilize them to improve the capability of the model. However, for group convolution, it does not utilize pixels of affinity between layers. For dilated convolution, after multiple convolutions with the same dilated rate, the pixels utilized within each layer do not possess location affinity with each other. To solve the problem of group convolution, our proposed quaternion group convolution uses the quaternion convolution, which promotes the communication between to promote utilizing pixels of affinity between channels. In quaternion group convolution, the feature layers are divided into 4 layers per group, ensuring the quaternion convolution can be performed. To solve the problem of dilated convolution, we propose the quaternion sawtooth wave-like dilated convolutions module (QS module). QS module utilizes quaternion convolution with sawtooth wave-like dilated rates to effectively leverage the pixels that share the location affinity both between and within layers. This allows for an expanded receptive field, ultimately enhancing the performance of the model. In particular, we perform our quaternion group convolution in QS module to design the quaternion group dilated neutral network (QGD-Net). Extensive experiments on Dermoscopic Lesion Segmentation based on ISIC 2016 and ISIC 2017 indicate that our method has significantly reduced the model parameters and highly promoted the precision of the model in Dermoscopic Lesion Segmentation. And our method also shows generalizability in retinal vessel segmentation.

Ex vivo mapping of enhancer networks that define the transcriptional program driving melanoma metastasis

Mortality from vmelanoma is associated with metastatic disease, but the mechanisms leading to spreading of the cancer cells remain obscure. Spatial profiling revealed that melanoma is characterized by a high degree of heterogeneity, which is established by the ability of melanoma cells to switch between different phenotypical stages. This plasticity, likely a heritage from embryonic pathways, accounts for a relevant part of the metastatic potential of these lesions, and requires the rapid and efficient reorganization of the transcriptional landscape of melanoma cells. A large part of the non-coding genome cooperates to control gene expression, specifically through the activity of enhancers (ENHs). In this study, we aimed to identify ex vivo the network of active ENHs and to outline their cooperative interactions in supporting transcriptional adaptation during melanoma metastatic progression. We conducted a genome-wide analysis to map active ENHs distribution in a retrospective cohort of 39 melanoma patients, comparing the profiles obtained in primary (N = 19) and metastatic (N = 20) melanoma lesions. Unsupervised clustering showed that the profile for acetylated histone H3 at lysine 27 (H3K27ac) efficiently segregates lesions into three different clusters corresponding to progressive stages of the disease. We reconstructed the map of super-ENHs (SEs) and cooperative ENHs that associate with metastatic progression in melanoma, which showed that cooperation among regulatory elements is a mandatory requirement for transcriptional plasticity. We also showed that these elements carry out specialized and non-redundant functions, and indicated the existence of a hierarchical organization, with SEs on top as masterminds of the entire transcriptional program and classical ENHs as executors. By providing an innovative vision of how the chromatin landscape of melanoma works during metastatic spreading, our data also point out the need to integrate functional profiling in the analysis of cancer lesions to increase definition and improve interpretation of tumor heterogeneity.

Melanoma-specific survival is worse in the elderly: a multicentric cohort study

We aimed to characterise cutaneous melanoma in the elderly and determine its association with poorer prognosis. We studied a prospective cohort of the melanoma population in Catalonia between 2012 and 2016. We compared young patient group (<75 years old) with elderly patient group (≥75 years old). We included 3009 patients (52.5% women) from 14 centres, with a mean age at diagnosis of 61.1 years. In the ≥75-year-old group there was a predominance of men (53.9% vs. 45.5%, P  < 0.001), melanoma was more frequently located in the head and neck area (37.7% vs. 15.5%, P  < 0.001) and lentigo maligna melanoma subtype was significantly more frequent (31.4% vs. 11.6%, P  < 0.001), as were nodular melanoma and acral lentiginous melanoma ( P  < 0.001). In older people, Breslow index, the presence of ulceration and mitotic rate were higher than in younger people. Kaplan-Meier survival curves showed longer melanoma-specific survival (MSS) and melanoma-free survival (MFS) in <75-year-old group compared to the elderly group. Cox regression models demonstrated reduced MSS in patients ≥75 years regardless of gender, location, IB, ulceration and lymph node status at diagnosis (HR 1.54, P  = 0.013) whereas MFS was not independently associated with elderly when head and neck location was considered. Age appears to be an independent risk factor for MSS but not for MFS. Worse melanoma prognosis in elderly could be explained by factors unrelated to the tumour, such as age-related frailty and comorbidities that limit the access to systemic treatments and, eventually, age-related immune dysfunction.

CD3ζ as a novel predictive biomarker of PD-1 inhibitor resistance in melanoma

Malignant melanoma is the most lethal form of skin cancer, and its incidence rates are increasing in Europe, America, and Oceania countries. Despite immune checkpoint inhibitors, such as PD-1 inhibitors, have been shown to have significant therapeutic effects on malignant melanoma, many patients are unresponsive to these treatments, even emerged resistance. There is an urgent need to discover novel biomarkers that might distinguish resistant patients from responders. In this study, we used a series of bioinformatics analyses and experimental validation. The GSE65041 was used for differential expression analysis. Kaplan-Meier was used to assess the prognostic value. ESTIMATE, ssGSEA, EPIC, TIMER, quanTiseq and MCPcounter for estimation of immune infiltration in the tumor microenvironment. We eventually identified that CD3ζ was significantly down-regulated in IHC PD-L1(-) melanoma patients. Low level of CD3ζ expression possessed a poor prognosis. CD3ζ low expression population is significantly associated with lower immune infiltration. In vivo experiment, CD3ζ expression was significantly down-regulated in mice melanoma after intradermally injected with B16-F10R cells. Compared to their wildtype counterparts, melanoma resistant mice treated with nivolumab showed significant reductions in tumor volume and weight when adding CD3ζ. In vitro experiment, the addition of CD3ζ increased nivolumab effection on inhibiting B16-F10R cell viability. Our findings indicated that CD3ζ could be a novel predictive biomarker of PD-1 inhibitor resistance in melanoma.

Detection of micro-plasma-induced exosomes secretion in a fibroblast-melanoma co-culture model

BACKGROUND

Melanoma is a highly aggressive tumor and a significant cause of skin cancer-related death. Timely diagnosis and treatment require identification of specific biomarkers in exosomes secreted by melanoma cells. In this study, label-free surface-enhanced Raman spectroscopy (SERS) method with size-matched selectivity was used to detect membrane proteins in exosomes released from a stimulated environment of fibroblasts (L929) co-cultured with melanoma cells (B16-F10). To promote normal secretion of exosomes, micro-plasma treatment was used to gently induce the co-cultured cells and slightly increase the stress level around the cells for subsequent detection using the SERS method.

RESULTS AND DISCUSSION

Firstly, changes in reactive oxygen species/reactive nitrogen species (ROS/RNS) concentrations in the cellular microenvironment and the viability and proliferation of healthy cells are assessed. Results showed that micro-plasma treatment increased extracellular ROS/RNS levels while modestly reducing cell proliferation without significantly affecting cell survival. Secondly, the particle size of secreted exosomes isolated from the culture medium of L929, B16-F10, and co-cultured cells with different micro-plasma treatment time did not increase significantly under single-cell conditions at short treatment time but might be changed under co-culture condition or longer treatment time. Third, for SERS signals related to membrane protein biomarkers, exosome markers CD9, CD63, and CD81 can be assigned to significant Raman shifts in the range of 943-1030 and 1304-1561 cm-1, while the characteristics SERS peaks of L929 and B16-F10 cells are most likely located at 1394/1404, 1271 and 1592 cm-1 respectively.

SIGNIFICANCE AND NOVELTY

Therefore, this micro-plasma-induced co-culture model provides a promising preclinical approach to understand the diagnostic potential of exosomes secreted by cutaneous melanoma/fibroblasts. Furthermore, the label-free SERS method with size-matched selectivity provides a novel approach to screen biomarkers in exosomes secreted by melanoma cells, aiming to reduce the use of labeling reagents and the processing time traditionally required.

Therapeutic applications of local injection of hsa-miR-634 into canine spontaneous malignant melanoma tumors

Malignant melanoma (MM) is one of the most common tumors in both dogs and humans. As canine MM (CMM) and human MM (HMM) have similar clinical characteristics, CMM appears to be a good clinical model for HMM. We previously demonstrated that the introduction of a synthetic double-strand-microRNA-634 (miR-634) mimic triggered apoptotic cell death by directly targeting the genes associated with cytoprotective processes in various human cancer cell lines, including those of HMM. This study aimed to investigate the antitumor effects of the local administration of miR-634 on spontaneous CMMs to provide a basis for future applications of miR-634 formulations in HMM treatment. We found that miR-634 administration induced apoptosis in CMM cell lines in vitro via downregulation of Asct2, Nrf2, and survivin expression, similar to the mechanisms in HMM cell lines. Furthermore, intratumoral miR-634 administration induced antitumor effects in four of seven spontaneous CMM cases, with no adverse effects. Local administration of miR-634 to lung metastasis under ultrasound guidance induced tumor shrinkage. These results confirm the antitumor effect of the local administration of miR-634 in spontaneous CMM, a model for spontaneous HMM, thereby providing a novel treatment strategy for HMM.

GREB1 isoform 4 is specifically transcribed by MITF and required for melanoma proliferation

Growth regulation by estrogen in breast cancer 1 (GREB1) is involved in hormone-dependent and -independent tumor development (e.g., hepatoblastoma). In this study, we found that a GREB1 splicing variant, isoform 4 (Is4), which encodes C-terminal half of full-length GREB1, is specifically expressed via microphthalmia-associated transcription factor (MITF) in melanocytic melanoma, and that two MITF-binding E-box CANNTG motifs at the 5'-upstream region of GREB1 exon 19 are necessary for GREB1 Is4 transcription. MITF and GREB1 Is4 were strongly co-expressed in approximately 20% of the melanoma specimens evaluated (17/89 cases) and their expression was associated with tumor thickness. GREB1 Is4 silencing reduced melanoma cell proliferation in association with altered expression of cell proliferation-related genes in vitro. In addition, GREB1 Is4 targeting by antisense oligonucleotide (ASO) decreased melanoma xenograft tumor formation and GREB1 Is4 expression in a BRAFV600E; PTENflox melanoma mouse model promoted melanoma formation, demonstrating the crucial role of GREB1 Is4 for melanoma proliferation in vivo. GREB1 Is4 bound to CAD, the rate-limiting enzyme of pyrimidine metabolism, and metabolic flux analysis revealed that GREBI Is4 is necessary for pyrimidine synthesis. These results suggest that MITF-dependent GREB1 Is4 expression leads to melanoma proliferation and GREB1 Is4 represents a new molecular target in melanoma.

Exploring the Complex and Multifaceted Interplay between Melanoma Cells and the Tumor Microenvironment

Malignant melanoma is a very aggressive skin cancer, characterized by a heterogeneous nature and high metastatic potential. The incidence of melanoma is continuously increasing worldwide, and it is one of the most common cancers in young adults. In the past twenty years, our understanding of melanoma biology has increased profoundly, and disease management for patients with disseminated disease has improved due to the emergence of immunotherapy and targeted therapy. However, a significant fraction of patients relapse or do not respond adequately to treatment. This can partly be explained by the complex signaling between the tumor and its microenvironment, giving rise to melanoma phenotypes with different patterns of disease progression. This review focuses on the key aspects and complex relationship between pathogenesis, genetic abnormalities, tumor microenvironment, cellular plasticity, and metabolic reprogramming in melanoma. By acquiring a deeper understanding of the multifaceted features of melanomagenesis, we can reach a point of more individualized and patient-centered disease management and reduced costs of ineffective treatments.