Development Of Cutaneous Melanoma Research Articles

Deciphering cutaneous melanoma prognosis through LDL metabolism: Single-cell transcriptomics analysis via 101 machine learning algorithms.

Cutaneous melanoma poses a formidable challenge within the field of oncology, marked by its aggressive nature and capacity for metastasis. Despite extensive research uncovering numerous genetic and molecular contributors to cutaneous melanoma development, there remains a critical knowledge gap concerning the role of lipids, notably low-density lipoprotein (LDL), in this lethal skin cancer. This article endeavours to bridge this knowledge gap by delving into the intricate interplay between LDL metabolism and cutaneous melanoma, shedding light on how lipids influence tumour progression, immune responses and potential therapeutic avenues. Genes associated with LDL metabolism were extracted from the GSEA database. We acquired and analysed single-cell sequencing data (GSE215120) and bulk-RNA sequencing data, including the TCGA data set, GSE19234, GSE22153 and GSE65904. Our analysis unveiled the heterogeneity of LDL across various cell types at the single-cell sequencing level. Additionally, we constructed an LDL-related signature (LRS) using machine learning algorithms, incorporating differentially expressed genes and highly correlated genes. The LRS serves as a valuable tool for assessing the prognosis, immunity and mutation status of patients with cutaneous melanoma. Furthermore, we conducted experiments on A375 and WM-115 cells to validate the function of PPP2R1A, a pivotal gene within the LRS. Our comprehensive approach, combining advanced bioinformatics analyses with an extensive review of current literature, presents compelling evidence regarding the significance of LDL within the cutaneous melanoma microenvironment.

Cancer Cell Biomechanical Properties Accompany Tspan8-Dependent Cutaneous Melanoma Invasion.

The intrinsic biomechanical properties of cancer cells remain poorly understood. To decipher whether cell stiffness modulation could increase melanoma cells' invasive capacity, we performed both in vitro and in vivo experiments exploring cell stiffness by atomic force microscopy (AFM). We correlated stiffness properties with cell morphology adaptation and the molecular mechanisms underlying epithelial-to-mesenchymal (EMT)-like phenotype switching. We found that melanoma cell stiffness reduction was systematically associated with the acquisition of invasive properties in cutaneous melanoma cell lines, human skin reconstructs, and Medaka fish developing spontaneous MAP-kinase-induced melanomas. We observed a systematic correlation of stiffness modulation with cell morphological changes towards mesenchymal characteristic gains. We accordingly found that inducing melanoma EMT switching by overexpressing the ZEB1 transcription factor, a major regulator of melanoma cell plasticity, was sufficient to decrease cell stiffness and transcriptionally induce tetraspanin-8-mediated dermal invasion. Moreover, ZEB1 expression correlated with Tspan8 expression in patient melanoma lesions. Our data suggest that intrinsic cell stiffness could be a highly relevant marker for human cutaneous melanoma development.

Knockdown of FOXRED2 restrains proliferation, invasion and migration of human melanoma cells

ObjectivesThis experiment investigated the role of the FAD-dependent oxidoreductase domain-containing 2 (FOXRED2) in the development of cutaneous malignant melanoma. MethodsWe explored the expression and prognostic effects of FOXRED2 in cutaneous malignant melanoma by performing bioinformatics analyses and immunohistochemical staining experiments and verified the biological influence of FOXRED2 on human melanoma cells using in vitro experiments. ResultsFOXRED2 expression was significantly higher in cutaneous malignant melanoma compared to normal skin and nevus tissues and closely associated with prognosis. The expression levels of FOXRED2 mRNA and protein were significantly upregulated in human melanoma cell lines, and knocking down FOXRED2 expression inhibits proliferation, invasion, and migration, promotes apoptosis, and alters tumor cell biology in A2058 and A375 cells. ConclusionFOXRED2 may play a crucial role in the development and progression of cutaneous malignant melanoma.

Integrated analysis reveals SMARCD1 is a potential biomarker and therapeutic target in skin cutaneous melanoma.

SMARCD1 is a part of the SWI/SNF chromatin remodeling complex family, which consists of transcription factors that are implicated in various types of cancer. Examining SMARCD1 expression in human cancers can provide valuable insights into the development and progression of skin cutaneous melanoma (SKCM). Our study comprehensively examined the association between SMARCD1 expression and numerous factors, including prognosis, tumor microenvironment (TME), immune infiltration, tumor mutational burden (TMB), and microsatellite instability (MSI) in SKCM. Then we utilized immunohistochemical staining to measure the SMARCD1 expression in both SKCM tissues and normal skin tissues. Furthermore, we conducted in vitro experimentation to evaluate the effects of SMARCD1 knockdown on SKCM cells. We found that aberrant expression of SMARCD1 across 16 cancers was strongly correlated with overall survival (OS) and progression-free survival (PFS). In addition, our research revealed that SMARCD1 expression is associated with multiple factors in different types of cancer, including immune infiltration, TME, immune-related genes, MSI, TMB, and sensitivity to anti-cancer drugs.SMARCD1 is likely involved in various SKCM signaling pathways and biological processes. Additionally, our research revealed that an SMARCD1-based risk factor model accurately predicted OS in SKCM patients.Furthermore, the downregulation of SMARCD1 expression demonstrated a significant inhibition of SKCM cell proliferation and migration, as well as an increase in apoptosis and cell cycle arrest. We conclude that SMARCD1 is a promising diagnostic, prognostic, and therapeutic biomarker for SKCM, and its expression has significant clinical implications for the development of novel treatment strategies.

Similarities and Differences in the Protein Composition of Cutaneous Melanoma Cells and Their Exosomes Identified by Mass Spectrometry

Intercellular transport of proteins mediated by extracellular vesicles (EVs)-exosomes and ectosomes-is one of the factors facilitating carcinogenesis. Therefore, the research on protein cargo of melanoma-derived EVs may provide a better understanding of the mechanisms involved in melanoma progression and contribute to the development of alternative biomarkers. Proteomic data on melanoma-derived EVs are very limited. The shotgun nanoLC-MS/MS approach was applied to analyze the protein composition of primary (WM115, WM793) and metastatic (WM266-4, WM1205Lu) cutaneous melanoma cells and exosomes released by them. All cells secreted homogeneous populations of exosomes that shared a characteristic set of proteins. In total, 3514 and 1234 unique proteins were identified in melanoma cells and exosomes, respectively. Gene ontology analysis showed enrichment in several cancer-related categories, including cell proliferation, migration, negative regulation of apoptosis, and angiogenesis. The obtained results broaden our knowledge on the role of selected proteins in exosome biology, as well as their functional role in the development and progression of cutaneous melanoma. The results may also inspire future studies on the clinical potential of exosomes.

A novel risk model based on anoikis: Predicting prognosis and immune infiltration in cutaneous melanoma.

Cutaneous melanoma (CM) is a highly aggressive malignancy with a dimal prognosis and limited treatment options. Anoikis is believed to involve in the regeneration, migration, and metastasis of tumor. The exact role of anoikis-related genes (ARGs) in the development and progression of cutaneous melanoma, however, remains elusive. Four ARGs (SNAI2, TFDP1, IKBKG, and MCL1) with significant differential expression were selected through Cox regression and LASSO analyses. Data for internal and external cohorts validated the accuracy and clinical utility of the prognostic risk model based on ARGs. The Kaplan-Meier curve indicated a much better overall survival rate of low-risk patients. Notably, we also found that the action of ARGs in the CM was mediated by immune-related signaling pathways. Consensus clustering and TIME landscape analysis also indicated that the low-risk score patients have excellent immune status. Moreover, the results of immunotherapy response and drug sensitivity also confirmed the potential implications of informing individualized immune therapeutic strategies for CM. Collectively, the predictive risk model constructed based on ARGs provides an excellent and accurate prediction tool for CM patients. This present research provides a rationale for the joint application of targeted therapy and immunotherapy in CM treatment. The approach could have great therapeutic value and make a contribution to personalized medicine therapy.

Indoor Versus Outdoor: Does Occupational Sunlight Exposure Increase Melanoma Risk? A Systematic Review

IntroductionMelanoma is the fifth most common cancer diagnosed in the United States, representing 5.6% of all new cancer cases. There are conflicting reports correlating a relationship between primarily outdoor occupations, associated with increased exposure to direct sunlight, and the incidence of cutaneous melanoma. Our objective was to outline and critically evaluate the relevant literature related to chronic occupational exposure to sunlight and risk of developing cutaneous melanoma. MethodsThe study protocol for this systematic review was submitted to the International Prospective Register of Systematic Reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. For each relevant study included, the following information was extracted: author names, publication year, study name, study design, age, exposure assessment, outcome, comparison, number of cases, case ascertainment, and descriptive and adjusted statistics. Study quality and evidence certainty was assessed using the Grading of Recommendations, Assessment, Development and Evaluations model. ResultsThe initial database search yielded 1629 articles for review and following full-text screening, a total of 14 articles were included for final analysis. Of the studies included, seven articles were retrospective case control and seven were cohort studies. The studies did not report any differences in the likelihood of cutaneous melanoma development based upon membership in the outdoor versus indoor occupation groups included in each study. ConclusionsOverall, the articles included in this systematic review did not report an increased risk of developing cutaneous melanoma among individuals with outdoor occupations. Further investigation is required to determine if other occupational or life-style–related risk factors exist, to help support the development of individualized skin screening recommendations and improve the early detection of melanoma in all populations.

HLA-DRB1: A new potential prognostic factor and therapeutic target of cutaneous melanoma and an indicator of tumor microenvironment remodeling.

Cutaneous melanoma (CM) is the most common skin cancer and one of the most aggressive cancers and its incidence has risen dramatically over the past few decades. The tumor microenvironment (TME) plays a crucial role in the occurrence and development of cutaneous melanoma. Nevertheless, the dynamics modulation of the immune and stromal components in the TME is not fully understood. In this study, 471 CM samples were obtained from TCGA database, and the ratio of tumor-infiltrating immune cells (TICs) in the TME were estimated using the ESTIMATE algorithms and CIBERSORT computational method. The differently expressed genes (DEGs) were applied to GO and KEGG function enrichment analysis, establishment of protein-protein interaction (PPI) network and univariate Cox regression analysis. Subsequently, we identified a predictive factor: HLA-DRB1 (major histocompatibility complex, class II, DR beta 1) by the intersection analysis of the hub genes of PPI network and the genes associated with the prognosis of the CM patients obtained by univariate Cox regression analysis. Correlation analysis and survival analysis showed that the expression level of HLA-DRB1 was negatively correlated with the Stage of the patients while positively correlated with the survival, prognosis and TME of melanoma. The GEPIA web server and the representative immunohistochemical images of HLA-DRB1 in the normal skin tissue and melanoma tissue from the Human Protein Atlas (HPA) database were applied to validate the expression level of HLA-DRB1. CIBERSORT analysis for the ratio of TICs indicated that 9 types of TICs were positively correlated with the expression level of HLA-DRB1 and only 4 types of TICs were negatively correlated with the expression level of HLA-DRB1. These results suggested that the expression level of HLA-DRB1 may be related to the immune activity of the TME and may affect the prognosis of CM patients by changing the status of the TME.

Atrazine modifies markers of melanocyte maturation and apoptosis in primary skin cultures

Atrazine (ATZ) is part of a group of herbicides called triazines. ATZ is widely used in agricultural areas of Mexico, commonly used for the selective control of weeds in corn and sorghum crops. The exposure to ATZ can have serious human health effects since its use was associated with the development of cutaneous melanoma in an epidemiological study. The aim of this study was to evaluate the expression of maturation and apoptotic markers in primary skin cultures exposed to ATZ. The primary skin cultures were exposed to 0.1, and 10 µM ATZ with or without ultraviolet (UV) radiation and the expression of maturation and apoptotic markers were evaluated by RT-qPCR. We observed a significant increase in all the melanocyte maturation markers in cells exposed to ATZ with or without UV, with SOX-9 and FAK (melanoblast markers) being the highest. Also, the expression of BCL-2 (anti-apoptotic marker) was the most increased gene in cells exposed to ATZ with or without UV. Low concentrations of ATZ and UV radiation induce genetic changes associated with the development of immature melanocytes and activate mechanisms associated with the inhibition of apoptosis characteristics of malignant cell transformation, which will allow proposing new therapeutic targets and generating new restrictions or care in farmers exposed to pesticides such as the ATZ.

861P Association of genetic variants in JAK/STAT signaling pathway with cutaneous melanoma susceptibility

Janus kinase signal transducer and activator of transcription (JAK/STAT) signaling pathway is involved in cell proliferation, angiogenesis, apoptosis inhibition, metastasis, and immune suppression. Due to these multiple functions, this pathway regulates cutaneous melanoma (CM) development and progression. The JAK1, JAK2 and STAT3 proteins are encoded by polymorphic genes. This study aimed to verify whether single-nucleotide variants (SNVs) in JAK1 (c.1648+1272G>A, c.991-27C>T), JAK2 (c.-1132G>T, c.-139G>A) and STAT3 (c.*1671T>C, c.-1937C>G) altered risk, clinicopathological aspects, survival of CM patients, as well as protein activity. CM patients (N = 248) and controls (N = 274) were included in this study. Genotyping was performed by real-time polymerase chain reaction (PCR) and JAK1, JAK2 and STAT3 expression was assessed by quantitative PCR (qPCR). STAT3 c.-1937C>G SNV was investigated by luciferase, qPCR, western blot, apoptosis, and cell cycle assays in SKMEL-28 cells with CC or GG genotype. In addition, fourteen melanoma cell lines with different genotypes were used to analyze STAT3 expression with non-intervention. Individuals with STAT3 c.*1671TT and c.-1937CC genotypes, and TC haplotype of both SNVs were under 2.0-fold increased risk of CM. Specific JAK1, JAK2 and STAT3 combined genotypes were associated with up to 4.0-fold increased risk of CM. Higher luciferase activity (4,013.34 vs. 2,463.32 arbitrary unit (AU); p = 0.009), STAT3 expression by qPCR (649.20 vs. 0.04 AU; p = 0.003) and western blot (1.69 vs. 1.16 AU; p = 0.01), and percentage of cells in S phase of cell cycle (57.54 vs. 30.73 %; p = 0.04) were more frequent in SKMEL-28 with STAT3 c.-1937CC than with GG genotype. CM cell lines with CC genotype presented higher STAT3 protein levels than those with GG genotype (1.93 versus 1.27 AU, p = 0.0027). Our data present for the first-time preliminary evidence that JAK1, JAK2 and STAT3 SNVs alter risk and clinical aspects of CM patients. If validated in a further epidemiological study, our data can be used to select individuals at high-risk of CM, who should receive special attention in tumor prevention and early detection.

BRCA1-associated protein 1 c.368delG mutation leads to the development of multiple BAPomas and cutaneous melanomas: a novel pathogenic variant in BRCA1-associated protein tumor predisposition syndrome.

BRCA1-associated protein 1 c.368delG mutation leads to the development of multiple BAPomas and cutaneous melanomas: a novel pathogenic variant in BRCA1-associated protein tumor predisposition syndrome.

Association of JAK/STAT genetic variants with cutaneous melanoma.

BackgroundThe Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway regulates cutaneous melanoma (CM) development and progression. The JAK1, JAK2, and STAT3 proteins are encoded by polymorphic genes. This study aimed to verify whether single-nucleotide variants (SNVs) in JAK1 (c.1648+1272G>A, c.991-27C>T), JAK2 (c.-1132G>T, c.-139G>A), and STAT3 (c.*1671T>C, c.-1937C>G) altered the risk, clinicopathological aspects, and survival of CM patients as well as protein activity.MethodsCM patients (N = 248) and controls (N = 274) were enrolled in this study. Genotyping was performed by real-time polymerase chain reaction (PCR), and JAK1, JAK2, and STAT3 expression was assessed by quantitative PCR (qPCR). STAT3 c.-1937C>G SNV was investigated by luciferase, qPCR, western blot, apoptosis, and cell cycle assays in SKMEL-28 cells with CC or GG genotype.ResultsIndividuals with STAT3 c.*1671TT and c.-1937CC genotypes and TC haplotype of both SNVs were under about 2.0-fold increased risk of CM. Specific JAK1, JAK2, and STAT3 combined genotypes were associated with up to 4.0-fold increased risk of CM. Higher luciferase activity [4,013.34 vs. 2,463.32 arbitrary units (AU); p = 0.004], STAT3 expression by qPCR (649.20 vs. 0.03 AU; p = 0.003) and western blot (1.69 vs. 1.16 AU; p = 0.01), and percentage of cells in the S phase of the cell cycle (57.54 vs. 30.73%; p = 0.04) were more frequent in SKMEL-28 with STAT3 c.-1937CC than with GG genotype. CM cell line with CC genotype presented higher STAT3 protein levels than the one with GG genotype (1.93 versus 1.27 AU, p = 0.0027).ConclusionOur data present preliminary evidence that inherited abnormalities in the JAK/STAT pathway can be used to identify individuals at a high risk of CM, who deserve additional attention for tumor prevention and early detection.

An Updated Algorithm Integrated With Patient Data for the Differentiation of Atypical Nevi From Early Melanomas: the idScore 2021.

IntroductionIt is well known that multiple patient-related risk factors contribute to the development of cutaneous melanoma, including demographic, phenotypic and anamnestic factors.ObjectivesWe aimed to investigate which MM risk factors were relevant to be incorporated in a risk scoring-classifier based clinico-dermoscopic algorithm.MethodsThis retrospective study was performed on a monocentric dataset of 374 atypical melanocytic skin lesions sharing equivocal dermoscopic features, excised in the suspicion of malignancy. Dermoscopic standardized images of 258 atypical nevi (aN) and 116 early melanomas (eMM) were collected along with objective lesional data (i.e., maximum diameter, specific body site and body area) and 7 dermoscopic data. All cases were combined with a series of 10 MM risk factors, including demographic (2), phenotypic (5) and anamnestic (3) ones.ResultsThe proposed iDScore 2021 algorithm is composed by 9 variables (age, skin phototype I/II, personal/familiar history of MM, maximum diameter, location on the lower extremities (thighs/legs/ankles/back of the feet) and 4 dermoscopic features (irregular dots and globules, irregular streaks, blue gray peppering, blue white veil). The algorithm assigned to each lesion a score from 0 to 18, reached an area under the ROC curve of 92% and, with a score threshold ≥ 6, a sensitivity (SE) of 98.2% and a specificity (SP) of 50.4%, surpassing the experts in SE (+13%) and SP (+9%).ConclusionsAn integrated checklist combining multiple anamnestic data with selected relevant dermoscopic features can be useful in the differential diagnosis and management of eMM and aN exhibiting with equivocal features.

638 Inverse genetic risk between cutaneous melanoma, basal cell carcinoma, squamous cell carcinoma and vitiligo

Several epidemiological studies have reported an inverse association between vitiligo and skin cancers such as cutaneous melanoma, basal cell carcinoma and squamous cell carcinoma. There are conflicting reports whether this association is a consequence of increased immunosurveillance observed in vitiligo patients or rather a shared genetic contribution. The latter hypothesis however, is not currently sustained by available evidence. Herein, we compared 23 vitiligo-associated variants (P<5x10-8) from a recently published genome-wide association study and identified three variants—contained within the TYR, MC1R-DEF8, and RALY-EIF252-ASIP-ACHY-ITCH loci—that have been associated with increased risk for melanoma, basal cell carcinoma, and squamous cell carcinoma and a concurrent decreased risk for vitiligo. We then subjected GWAS summary statistics for vitiligo and each skin cancer to an unbiased two-sample mendelian randomization analysis. We observed a protective role for vitiligo in the development of cutaneous melanoma (effect size=-6.78x10-4; p=5.41x10-2), basal cell carcinoma (effect size=-1.29x10-3; p=1.77x10-3), and squamous cell carcinoma (effect size=-2.19-4; p=1.81x10-3). When the vitiligo-associated signature was subjected to the same analysis, a significantly increased protective relationship was observed for each skin cancer (melanoma effect size=-0.511; p=2.41x10-5; basal cell carcinoma effect size=-0.454; p=4.36x10-7; squamous cell carcinoma effect size=-0.489; p=5.59x10-10). Our results support a causal inverse genetic relationship between these skin cancers and vitiligo, and reveal potential therapeutic targets for the prevention and effective treatment of vitiligo-associated skin cancer.

DNA damage in peripheral blood mononuclear cells in patients with melanoma

Introduction. The incidence and mortality of malignant melanoma have increased steadily over the last decades; therefore, the development of novel diagnostic markers for malignant melanoma is of great importance. The purpose of the study was to assess whether the development of melanoma before any treatment is accompanied by the body changes and, in particular, DNA damage in the mononuclear cells of the peripheral blood of patients. Material and Methods. In 93 patients (26 men and 67 women) admitted to the N.N. Petrov National Medical Research Center of Oncology for surgical treatment of stage T1c-2a-b-3a-b4a-bN0-1 cutaneous malignant melanoma, and in 118 healthy people as a comparison group, the level of damage to DNA in peripheral blood mononuclear cells was studied using the “comet” method. All patients were divided into two groups: group 1 included 45 patients (13 men and 32 women) who were examined before a decision on treatment was made and group 2 consisted of 48 patients (13 men and 35 women) who previously underwent excision biopsy for melanoma. Results. The level of DNA damage in peripheral blood mononuclear cells, assessed by the comet assay, was found to be signifcantly higher in patients with melanoma than in the comparison group. Moreover, the increase in the level of DNA damage was similar both in patients with a primary tumor before starting any treatment and in those who previously underwent excision biopsy for melanoma. The relationship between the level of DNA damage in peripheral blood mononuclear cells and the morphological characteristics of the tumor cells was revealed. The Spearman correlation analysis showed that all parameters that determined DNA damage positively correlated with the thickness of melanoma according to the Breslow’s depth, and the percentage of DNA in the comet and the comet tail moment correlated with the stage of the disease. Conclusion. The development of cutaneous melanoma is accompanied by an increase in the level of DNA damage in peripheral blood mononuclear cells. The level of DNA damage in peripheral blood mononuclear cells refects the changes that occur in the patient’s body under the infuence of the tumor process, which may allow using this indicator as an additional criterion for the diagnosis and aggressiveness of melanoma.

Bee pollen in zebrafish diet affects intestinal microbiota composition and skin cutaneous melanoma development

Bee pollen is recommended as dietary supplement due to immunostimulating functions including antioxidant, anti-inflammatory and anti-carcinogenic properties. Nevertheless, the effectiveness of such properties is still not well understood. As diet can be associated with animal performance, microbiota modulation and potentially factor for cancer, this study aimed to analyze if bee pollen could influence growth, gut microbial and skin cutaneous melanoma development in zebrafish. Control diets based on commercial flakes and Artemia were compared with the same diet supplemented with bee pollen. Fish weight gain, increased length, intestinal bacteria metagenomics analysis, serum amyloid A gene expression and cutaneous melanoma transplantation assays were performed. Bee pollen affected microbiota composition and melanoma development. Differential abundance revealed higher abundance in the control group for Aeromonadaceae family, Aeromonas and Pseudomonas genus, A. sobria, A. schubertii, A. jandaei and P. alcaligenes species compared with pollen diet group. Pollen group presented higher abundance for Chromobacterium genus and for Gemmobacter aquaticus, Flavobacterium succinicans and Bifidobacterium breve compared with control group. Unexpectedly, fish fed with bee pollen showed higher tumor growth rate and larger tumor size than control group. This is the first study to report intestinal microbial changes and no protective cancer properties after bee pollen administration.

Loss of 'Epidermal Melanin Unit' Integrity in Human Skin During Melanoma-Genesis.

Cutaneous melanoma can be a most challenging neoplasm of high lethality, in part due to its extreme heterogeneity and characteristic aggressive and invasive nature. Indeed, its moniker ‘the great masquerader’ reflects that not all melanomas are created equal in terms of their originating cellular contexts, but also that melanoma cells in the malignant tumor can adopt a wide range of different cell states and variable organotropism. In this review, we focus on the early phases of melanomagenesis by discussing how the originating pigment cell of the melanocyte lineage can be influenced to embark on a wide range of tumor fates with distinctive microanatomical pathways. In particular, we assess how cells of the melanocyte lineage can differ by maturation status (stem cell; melanoblast; transiently amplifying cell; differentiated; post-mitotic; terminally-differentiated) as well as by micro-environmental niche (in the stratum basale of the epidermis; within skin appendages like hair follicle, eccrine gland, etc). We discuss how the above variable contexts may influence the susceptibility of the epidermal-melanin unit (EMU) to become unstable, which may presage cutaneous melanoma development. We also assess how unique features of follicular-melanin unit(s) (FMUs) can, by contrast, protect melanocytes from melanomagenesis. Lastly, we postulate how variable melanocyte fates in vitiligo, albinism, psoriasis, and alopecia areata may provide new insights into immune-/non immune-mediated outcomes for melanocytes in cutaneous melanin units.

Development of a method for isolation of melanin from archival FFPE tissues of human melanoma for structural studies by pyrolysis-gas chromatography-tandem mass spectrometry

Abstract Introduction There is some evidence that pheomelanin produced in skin melanocytes may be involved in the development of cutaneous melanoma, particularly in individuals with a light skin/red hair phenotype. However, nothing is known about possible correlation between the type and/or clinical stage of melanoma and the content of pheomelanin in the tumor tissue. We believe that archival formalin-fixed and paraffin-embedded (FFPE) melanoma tissues could be a good source of melanin pigment for future large-scale research on that issue. Aim The aim of this work was to develop a method for isolation and purification of melanin from FFPE samples of human melanoma. To test the suitability of the isolation protocol for planned structural studies, the obtained melanin was analyzed for pheomelanin content by the method based on pyrolysis (Py) coupled with gas chromatography and tandem mass spectrometry (GC/MS/MS). Material and methods For melanin isolation, microtome sections of FFPE tissue of primary lesion and lymph node metastases were subjected to a multistep procedure of paraffin removal, tissue rehydration, homogenization, and digestion with the set of proteolytic enzymes. The pigment samples were then pyrolyzed at 500 °C, and the GC-separated thermal degradation products were identified using a triple quadrupole mass spectrometer operating in the multiple reaction monitoring mode. Results GC/MS/MS analysis of the pyrolysis products revealed the presence of pheomelanin markers, which allowed quantitation of a pheomelanin component of each of the isolated pigments. Melanin from the FFPE primary melanoma was found to contain 6.6%, and the pigment from FFPE metastatic lymph node 7.5% of pheomelanin. Conclusions The developed protocol allows for the isolation of melanin from FFPE melanoma specimens. The pigment can be successfully studied for pheomelanin content by Py-GC/MS/MS method. The results of our study indicate that archival FFPE tumor tissues can be used as a good source of melanin for future structural studies aimed at shedding more light on the role of pheomelanin in the pathomechanism of cutaneous melanoma.

DTL promotes melanoma progression through rewiring cell glucose metabolism.

BackgroundTo investigate the role of DTL in the development of skin cutaneous melanoma (SKCM) and possible mechanisms.MethodsWe examined the expression of DTL in SKCM in The Cancer Genome Atlas (TCGA) and Oncomine database and analyzed the relationship between DTL expression and melanoma prognosis. Furthermore, we silenced the DTL gene by RNA interference in A375 cells and investigated the effect of DTL silencing on the biological function of melanoma cells.ResultsThe expression of DTL in SKCM was upregulated in the tumor tissues compared with the paired normal tissues. Survival analysis showed that higher DTL expression in SKCM patients was associated with poor clinical outcome compared with the lower DTL expression group. Silencing of DTL in A375 cells significantly inhibited the melanoma cell growth and proliferation ability, and also significantly decreased the total glucose consumption and lactate production. Gene set enrichment analysis (GSEA) showed that MYC targets gene set pathway was highly enriched in the DTL high expression group. The expression levels of some MYC targets-related oncogenes, including c-MYC, HK1, HK2, PGK1, ENO1, LDHA, IDH1, ACLY, and HMGCR, were reduced in the A375 cells with knockdown DTL and upregulated in SKCM tissues with high DTL expression, and there was a positive correlation between them.ConclusionsAn important role is played by DTL in promoting melanoma cell growth and glucose metabolism, possibly through activation of the MYC target pathway.

Melanoma in patients with mycosis fungoides

The development of both malignant neoplasms mycosis fungoides and cutaneous malignant melanoma is a rare condition; nevertheless, the literature describes both cases of the development of mycosis fungoides in patients with a primary diagnosis of melanoma and the detection of cutaneous malignant melanoma in patients with T-cell lymphomas of the skin. The question of the effect of previous therapy for mycosis fungoides on the risk of cutaneous malignant melanoma remains controversial. Currently, the world community is considering a possible pathogenetic relationship between these two oncopathologies. The clinical observations of the development of cutaneous malignant melanoma in 2 patients with mycosis fungoides presented in the article emphasize the importance of a thorough clinical and dermatoscopic examination of all pigmented formations for the timely detection of malignant melanocytic neoplasms, the presence of which radically affects the further choice of treatment tactics for patients.