Epidemiology, risk factors, prevention, and early detection of melanoma

Frequency of BRAF Mutations in Dysplastic Nevi, Lentigo Maligna, and Melanoma In Situ

Background: In melanomas, mutations in the BRAF gene are common and their occurrence represents an early oncogenic event. Our goal was to determine and compare the frequency of BRAF gene mutations in dysplastic nevi (ND) and melanomas in situ (MIS), as well as whether there is a correlation between the presence of BRAF gene mutations and various anamnestic, clinical, and histopathologic variables. Methods: A total of 175 patients-106 with ND, 41 with MIS, and 28 with lentigo maligna (LM) were included in the study. DNA was extracted from tissue samples and analyzed using the competitive allele-specific TaqMan chain reaction by polymerase in real time to detect the presence of BRAF V600E and V600K mutations. The data were compared with anamnestic, clinical, and histopathological data. Results: There is a statistically significant correlation between the presence of BRAF mutation and the diagnosis of melanoma in situ (χ2 test, χ2 = 29.17, p < 0.0001). Patients with LM had a significantly lower incidence of BRAF mutations compared to patients with ND and MIS. There was a significant correlation between the presence of a BRAF mutation and tumor localization, as well as the age of the patient, but no statistically significant correlation between the presence of a BRAF mutation and sex, tumor size, or previous melanoma diagnosis. Conclusions: BRAF mutations in ND are essentially required; however, they are an insufficient oncogenic trigger for the development of melanoma. This research contributes to a better understanding of the etiopathogenesis of melanoma and the role of ND as possible precursor lesions.

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.

The Current Status and Future Direction of Extracellular Nano-vesicles in the Alleviation of Skin Disorders

Exosomes are extracellular vesicles (EVs) that originate from endocytic membranes. The transfer of biomolecules and biological compounds such as enzymes, proteins, RNA, lipids, and cellular waste disposal through exosomes plays an essential function in cell-cell communication and regulation of pathological and physiological processes in skin disease. The skin is one of the vital organs that makes up about 8% of the total body mass. This organ consists of three layers, epidermis, dermis, and hypodermis that cover the outer surface of the body. Heterogeneity and endogeneity of exosomes is an advantage that distinguishes them from nanoparticles and liposomes and leads to their widespread usage in the remedy of dermal diseases. The biocompatible nature of these extracellular vesicles has attracted the attention of many health researchers. In this review article, we will first discuss the biogenesis of exosomes, their contents, separation methods, and the advantages and disadvantages of exosomes. Then we will highlight recent developments related to the therapeutic applications of exosomes in the treatment of common skin disorders like atopic dermatitis, alopecia, epidermolysis bullosa, keloid, melanoma, psoriasis, and systemic sclerosis.

Melanoma literacy among the general population of three western US states

Melanoma is a significant cause of cancer death, despite being detectable without specialized or invasive technologies. Understanding barriers to preventive behaviors such as skin self-examination (SSE) could help to define interventions for increasing the frequency of early detection. To determine melanoma knowledge and beliefs across three high-incidence US states, 15,000 surveys were sent to a population-representative sample. We aimed to assess (1) melanoma literacy (i.e., knowledge about melanoma risks, attitudes, and preventive behaviors) and (2) self-reported SSE and its association with melanoma literacy, self-efficacy, and belief in the benefits of SSE. Of 2326 respondents, only 21.2% provided responses indicating high knowledge of melanoma, and 62.8% reported performing an SSE at any time in their lives. Only 38.3% and 7.3% reported being "fairly" or "very" confident about doing SSE, respectively. SSE performance among respondents was most strongly associated with higher melanoma knowledge, higher self-efficacy, and personal history of melanoma. Melanoma literacy among survey respondents was modest, with greater literacy associated with a higher likelihood of reported preventive behavior. This assessment establishes a baseline and provides guidance for public health campaigns designed to increase prevention and early detection of this lethal cancer.

Machine learning identification of patient clusters for cutaneous melanoma

BACKGROUND

Cutaneous melanoma is a cancer arising in melanocyte skin cells and is the deadliest form of skin cancer worldwide. Although some risk factors are known, accurate prediction of disease progression and probability for metastasis are difficult to ascertain, given the complexity of the disease and the absence of reliable predictive markers. Since early detection and treatment are essential to enhance survival, this study utilizing machine learning (ML) aims to further delineate additional risk factors associated with cutaneous melanoma.

METHODS

A Bayesian Gaussian Mixture ML model was created with data from 2056 patients diagnosed with cutaneous melanoma and then used to group the patients into six Clusters based on a Silhouette Score analysis. A t-distributed stochastic neighbor embedding (t-SNE) model was used to visualize the six Clusters.

RESULTS

Statistical analysis revealed that Cluster 4 showed a significantly higher rate of metastatic disease, as well as higher Breslow depth at diagnosis, compared to the other five Clusters. Compared to the other five Clusters, patients represented in Cluster 4 also had lower healthcare utilization, fewer dermatology clinic visits, fewer primary care providers, and less frequent colonoscopies and mammograms, and were more likely to smoke and less likely to have a prior diagnosis of basal cell carcinoma.

CONCLUSIONS

This study uncovers gaps in healthcare utilization of services among patient groups with cutaneous melanoma as well as possible implications for management of disease progression. Data-driven analyses emphasize the importance of routine clinic visits to dermatologists and/or primary care physicians (PCPs) for early detection and management of cutaneous melanoma. The findings from this study demonstrate that unsupervised ML methodology may serve to define the best candidate patients to benefit from enhanced dermatology/primary care which, in turn, is expected to improve outcomes for cutaneous melanoma.

Identification of Dihydrolipoamide Dehydrogenase as Potential Target of Vemurafenib-Resistant Melanoma Cells

BACKGROUND

Despite recent improvements in therapy, the five-year survival rate for patients with advanced melanoma is poor, mainly due to the development of drug resistance. The aim of the present study was to investigate the mechanisms underlying this phenomenon, applying proteomics and structural approaches to models of melanoma cells.

METHODS

Sublines from two human (A375 and SK-MEL-28) cells with acquired vemurafenib resistance were established, and their proteomic profiles when exposed to denaturation were identified through LC-MS/MS analysis. The pathways derived from bioinformatics analyses were validated by in silico and functional studies.

RESULTS

The proteomic profiles of resistant melanoma cells were compared to parental counterparts by taking into account protein folding/unfolding behaviors. Several proteins were found to be involved, with dihydrolipoamide dehydrogenase (DLD) being the only one similarly affected by denaturation in all resistant cell sublines compared to parental ones. DLD expression was observed to be increased in resistant cells by Western blot analysis. Protein modeling analyses of DLD's catalytic site coupled to in vitro assays with CPI-613, a specific DLD inhibitor, highlighted the role of DLD enzymatic functions in the molecular mechanisms of BRAFi resistance.

CONCLUSIONS

Our proteomic and structural investigations on resistant sublines indicate that DLD may represent a novel and potent target for overcoming vemurafenib resistance in melanoma cells.

Berberine Induces Autophagic Cell Death by Inactivating the Akt/mTOR Signaling Pathway

The incidence of skin cancer has been increasing over the past decades, and melanoma is considered highly malignant because of its high rate of metastasis. Plant-derived berberine, an isoquinoline quaternary alkaloid, has been reported to possess multiple pharmacological effects against various types of cancer cells. Therefore, we treated melanoma B16F10 cells with berberine to induce cell death and understand the cell death mechanisms. The berberine-treated cells showed decreased cell viability, according to berberine concentration. However, western blot analysis of apoptosis-related marker proteins showed that the expression of Bcl-2, an apoptosis inhibitory protein, and the Bcl-2/Bax ratio were increased. Therefore, by adding 3-methyladenine to the berberine-treated cells, we investigated whether the reduced cell viability was due to autophagic cell death. The results showed that 3-methyladenine restored the cell viability decreased by berberine, suggesting autophagy. To clarify autophagic cell death, we performed transmission electron microscopy analysis, which revealed the presence of autophagosomes and autolysosomes in the cells after treatment with berberine. Next, by analyzing the expression of autophagy-related proteins, we found an increase in the levels of light chain 3A-II and Atg12-Atg5 complex in the berberine-treated cells. We then assessed the involvement of the Akt/mTOR signaling pathway and found that berberine inhibited the expression of phosphorylated Akt and mTOR. Our data demonstrated that berberine induces autophagic cell death by inactivating the Akt/mTOR signaling pathway in melanoma cells and that berberine can be used as a possible target for the development of anti-melanoma drugs.

Deep autoencoder based hybrid dimensionality reduction approach for classification of SERS for melanoma cancer diagnostics

Melanoma, a kind of fatal skin cancer, originates in melanin secreting cells of the dermis. Disease identification in the early stages assures a high survival rate for the patient. Most of the existing techniques retard the cancer detection phase. Surface-Enhanced Raman Spectroscopy (SERS) can capture fine details from the specimens that machine learning models can utilize to discriminate between healthy and diseased individuals rapidly. Our research work proposes a deep autoencoder based hybrid dimensionality reduction approach with a machine learning model on SERS spectrums of human skin fibroblast for melanoma cancer diagnostics. SERS measurements of 307 samples in total, belonging to two different classes, such as normal (157 samples) and malignant melanoma (150 samples), are used in this study. The SERS spectra measurements for both the samples lie between 100cm - 1 and 4278cm - 1. The variations in the intensity of Raman bands between both classes are intrinsically subtle. Neighborhood Component Analysis (NCA) technique has been exerted to transform 2090 dimensional spectral features into 2090 dimensional vectors and then the Deep Autoencoder (DAE) model is used to handle the nonlinearity in the data and produce the latent space, while Linear Discriminant Analysis (LDA) classifier have been employed for discriminating the normal and cancer cells. The k-fold cross-validation technique with a k value of 10 is implemented to assess the metrics of the model. The stated hybrid (NCA and DAE) model with 10-dimension latent space achieves an accuracy of 98%, the sensitivity of 99% and specificity of 97%, respectively. Due to the high-intensity nature of the SERS spectrum, the existing linear dimensionality reduction based discriminating model fails if the class label (Normal or Cancer) gets distributed on the low variance side. The proposed methodology captures both linear and nonlinear underlying structures present in the spectrums, resulting in better classification compared to the standard dimensionality reduction techniques.

Identification of Keratinocyte Differentiation-Involved Genes for Metastatic Melanoma by Gene Expression Profiles

Background

Melanoma is the deadliest type of skin cancer. Until now, its pathological mechanisms, particularly the mechanism of metastasis, remain largely unknown. Our study on the identification of genes in association with metastasis for melanoma provides a novel understanding of melanoma.

Methods

From the Gene Expression Omnibus (GEO) database, the gene expression microarray datasets GSE46517, GSE7553, and GSE8401 were downloaded. We made use of R aiming at analyzing the differentially expressed genes (DEGs) between metastatic and nonmetastatic melanoma. R was also used in differentially expressed miRNA (DEM) data mining from GSE18509, GSE19387, GSE24996, GSE34460, GSE35579, GSE36236, and GSE54492 datasets referring to Li's study. Based on the DEG and DEM data, we performed functional enrichment analysis through the application of the DAVID database. Furthermore, we constructed the protein-protein interaction (PPI) network and established functional modules by making use of the STRING database. Through making use of Cytoscape, the PPI results were visualized. We predicted the targets of the DEMs through applying TargetScan, miRanda, and PITA databases and identified the overlapping genes between DEGs and predicted targets, followed by the construction of DEM-DEG pair network. The expressions of these keratinocyte differentiation-involved genes in Module 1 were identified based on the data from TCGA.

Results

239 DEGs were screened out in all 3 datasets, which were inclusive of 21 positively regulated genes and 218 negatively regulated genes. Based on these 239 DEGs, we finished constructing the PPI network which was formed from 225 nodes and 846 edges. We finished establishing 3 functional modules. And we analyzed 92 overlapping genes and 26 miRNA, including 11 upregulated genes targeted by 11 negatively regulated DEMs and 81 downregulated genes targeted by 15 positively regulated DEMs. As proof of the differential expression of metastasis-associated genes, eleven keratinocyte differentiation-involved genes, including LOR, EVPL, SPRR1A, FLG, SPRR1B, SPRR2B, TGM1, DSP, CSTA, CDSN, and IVL in Module 1, were obviously downregulated in metastatic melanoma tissue in comparison with primary melanoma tissue based on the data from TCGA.

Conclusion

239 melanoma metastasis-associated genes and 26 differentially expressed miRNA were identified in our study. The keratinocyte differentiation-involved genes may take part in melanoma metastasis, providing a latent molecular mechanism for this disease.

Nanostructured systems increase the in vitro cytotoxic effect of bullfrog oil in human melanoma cells (A2058)

The aim of this work was to investigate the in vitro cytotoxic effect of previously developed nanocapsules, nanoemulsion, and microemulsion based on bullfrog oil (BFO) against human melanoma cells (A2058). The nanosystems were produced as described in previous studies and characterized according to droplet/particle distribution and zeta potential. The biocompatibility was evaluated by the determination of the hemolytic potential against human erythrocytes. The cytotoxicity assessment was based on MTT and cell death assays, determination of Reactive Oxygen Species (ROS) levels, and cell uptake. The nanosystems were successfully reproduced and showed hemolytic potential smaller than 10% at all oil concentrations (50 and 100 µg.mL^-1) (p < 0.05). The MTT assay revealed that the nanosystems decreased the mitochondrial activity up to 92 ± 2% (p < 0.05). The study showed that the free BFO induced cell apoptosis, while all the nanostructured systems caused cell death by necrosis associated with a ROS overproduction. This can be related to the increased ability of the nanostructured systems to deliver the BFO across all cellular compartments (membrane, cytoplasm, and nucleus). Finally, these results elucidate the in vitro BFO nanosystems cytotoxic effect against human melanoma cells (A2058), revealing the emulsified ones as the most cytotoxic systems. Overall, the findings suggest that the safety and antineoplastic activity of these systems can be further investigated by in vivo studies.

miR-302a-3p suppresses melanoma cell progression via targeting METTL3

The miRNA-302 family plays a critical role in carcinogenesis. As an enzyme that regulates the N6-methyladenosine modification, methyltransferase-like 3 (METTL3) plays important roles in the development and progression of various tumours. However, the upstream regulatory mechanisms of METTL3 in melanoma have not yet been fully investigated. Herein, we investigated the functions of miR-302a-3p and its target RNA METTL3 on proliferation, apoptosis, and invasion of melanoma. Quantitative real-time PCR and immunofluorescence staining were used to measure the expression of METTL3 mRNA and protein level after transfection. miR-302a-3p expression was determined by quantitative reverse transcription-PCR. The cell proliferation, cell cycle progression, apoptosis, colony formation, migration, and cell invasion ability were determined using MTT assay, propidium iodide (PI) staining, Annexin V/PI flow cytometry, plate clone assay, and Transwell migration and invasion assays, respectively. Melanoma cell metastasis was also evaluated using an in vivo model. The effect of METTL3 on the phosphorylation of PI3K and AKT was measured with western blot analysis. Our results showed that miR-302a-3p was significantly downregulated in melanoma and exerted a tumour suppressive role against melanoma progression. We identified METTL3 as a direct target of miR-302a-3p in melanoma cells using bioinformatics analysis and luciferase assay. Furthermore, the enforced overexpression of METTL3 promoted the proliferation, cell cycle progression, cell invasion, migration, expression of epithelial-to-mesenchymal transition markers, and the PI3K-AKT signalling pathway as well as suppressed the apoptosis of melanoma cells. Meanwhile, silencing the expression of METTL3 with specific shRNA demonstrated reverse outcomes of the above phenotypes in melanoma cells. By rescue experiments, we found that the restoration of METTL3 expression in miR-302a-3p-overexpressing melanoma cells successfully recovered the miR-302a-3p-mediated melanoma suppression. The in vivo results also showed that miR-302a-3p substantially inhibited melanoma cell growth and metastasis. In summary, this study demonstrated that miR-302a-3p targets METTL3 and plays tumour suppressive roles in the proliferation, apoptosis, invasion, and migration of melanoma cells.

mGPDH Deficiency leads to melanoma metastasis via induced NRF2

Oxidative stress critically influences carcinogenesis and the progression of melanoma, and aggressive malignant melanoma activity is due to its high metastatic ability. Some findings in several cancer cell lines have indicated that mGPDH, a component of the mitochondrial respiratory chain, also modulates oxidative stress. However, the role of mGPDH in melanoma remains elusive. Here, we report that the mGPDH protein level is decreased in human skin melanoma compared to normal skin and decreased in metastatic melanoma compared to primary melanoma. Our in vivo and in vitro experiments indicated that mGPDH depletion accelerated melanoma migration and invasion without affecting proliferation or apoptosis. Mechanistically, we found elevated NRF2 protein levels in human skin melanoma and mGPDH‐knockout (ko) metastatic xenografts in the lungs of nude mice. Moreover, in A375 melanoma cells, the loss of mGPDH‐induced NRF2 expression but did not affect NRF2 protein degradation. Additionally, melanoma metastasis induced by the loss of mGPDH was rescued by the further down‐regulation of NRF2 in vivo and in vitro. Consistently, mGPDH overexpression (oe) depressed NRF2 expression and attenuated the malignant properties of melanoma cells. In conclusion, our findings suggest that mGPDH suppresses melanoma metastasis by inhibiting NRF2 and downstream oxidative signals, highlighting the therapeutic potential of mGPDH for melanoma treatment.

Identification of Metastasis-Associated MicroRNAs in Metastatic Melanoma by miRNA Expression Profile and Experimental Validation

It is reported that microRNAs (miRNA) have paramount functions in many cellular biological processes, development, metabolism, differentiation, survival, proliferation, and apoptosis included, some of which are involved in metastasis of tumors, such as melanoma. Here, three metastasis-associated miRNAs, miR-18a-5p (upregulated), miR-155-5p (downregulated), and miR-93-5p (upregulated), were identified from a total of 63 different expression miRNAs (DEMs) in metastatic melanoma compared with primary melanoma. We predicted 262 target genes of miR-18a-5p, 904 miR-155-5p target genes, and 1220 miR-93-5p target genes. They participated in pathways concerning melanoma, such as TNF signaling pathway, pathways in cancer, FoxO signaling pathway, cell cycle, Hippo signaling pathway, and TGF-beta signaling pathway. We identified the top 10 hub nodes whose degrees were higher for each survival-associated miRNA as hub genes through constructing the PPI network. Using the selected miRNA and the hub genes, we constructed the miRNA-hub gene network, and PTEN and CCND1 were found to be regulated by all three miRNAs. Of note, miR-155-5p was obviously downregulated in metastatic melanoma tissues, and miR-18a-5p and miR-93-5p were obviously regulated positively in metastatic melanoma tissues. In validating experiments, miR-155-5p's overexpression inhibited miR-18a-5p's and miR-93-5p's expression, which could all significantly reduce SK-MEL-28 cells' invasive ability. Finally, miR-93-5p and its potential target gene UBC were selected for further validation. We found that miR-93-5p's inhibition could reduce SK-MEL-28 cell's invasive ability through upregulated the expression of UBC, and the anti-invasive effect was reserved by downregulation of UBC. The results show that the selected three metastasis-associated miRNAs participate in the process of melanoma metastasis via regulating their target genes, providing a potential molecular mechanism for this disease.

Chemotherapy in focus: A meta-analysis confronts immunotherapy in the treatment of advanced melanoma

This study aimed to analyze the efficacy of the monoclonal antibodies ipilimumab, nivolumab, and pembrolizumab when compared with conventional chemotherapy in the treatment of advanced melanoma. Three authors made the search independently and five articles matched the eligibility criteria. A fourth expert confirmed their quality (κ = 1). The meta-analysis for overall survival and 12-month overall survival was impaired due to remarkably high heterogeneity (I2 = 91 % and 86 %, respectively). However, chemotherapy showed benefits on 24-months overall survival (RR = 1.60; IC95 %: 1.29, 1.98; p < 0.0001). The interruption by toxicity outcome showed no significant differences between therapies. Some studies used monoclonal antibodies in monotherapy or in combination and some groups of participants showed heterogeneity, which made the analysis difficult. Given the exorbitant costs of monoclonal antibodies in low and middle-income countries, the evidence of its benefits is limited when considering the replacement of conventional therapy with immunotherapy in public health systems.

Emodin Suppresses the Migration and Invasion of Melanoma Cells

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), as an active ingredient in rhubarb roots and rhizomes, has been reported to possess various pharmacological properties including anti-tumor effects. Recent studies have confirmed that emodin inhibited cell proliferation and induced apoptosis of cancer cells. However, the inhibitory effect of emodin on the migration and invasion of melanoma cells and its underlying mechanism are still unclear. In the study, we observed the impercipient effects of emodin in B16F10 and A375 melanoma cells with strong metastatic abilities, focusing on the functions and mechanisms of migration and invasion of B16F10 and A375 melanoma cells. Cell counting kit-8 (CCK-8), colony formation test and Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining tests confirmed that emodin possessed anti-proliferative and pro-apoptotic activities in B16F10 and A375 cells. The inhibitory effects on the migration and invasion of B16F10 and A375 cells were proved by wound healing assay and Transwell methods. Moreover, immunofluorescence assay approved the decrease in protein expression of matrix metalloproteinas (MMP)-2/-9 by emodin, and Western blot analyses revealed that emodin could increase the Bax/Bcl-2 ratio and inhibit the MMP-2/-9 protein expression and Wnt/β-catenin pathway in a dose-depended manner. BML-284, as an agonist of Wnt/β-catenin signaling pathway, reversed the effects of emodin on cell growth, migration and invasion in B16F10 cells. These findings may suggest that emodin treatment can be a promising therapeutic strategy for melanoma with highly metastatic abilities.

Exploring the relationship between Overall Survival (OS), Progression Free Survival (PFS) and Objective Response Rate (ORR) in patients with advanced melanoma

PURPOSE

From 2011 to 2016, 13 randomized clinical trials with active controls were submitted to U.S. Food and Drug Administration (FDA) for the treatment of advanced melanoma. While regular approval is generally granted due to a substantial improvement in overall survival (OS), or a large, clinically meaningful improvement in progression-free survival (PFS), accelerated approval can be granted based on incremental change in a surrogate end point reasonably likely to predict clinical benefit, such as objective response (ORR) of large magnitude and long duration. However, the relationship between objective response rate and progression free survival or objective response rate and overall survival in advanced melanoma has not been established.

PATIENTS AND METHODS

We conducted analyses to assess the correlation of objective response rate with progression free survival as well as overall survival by examining all advanced melanoma trials submitted to the FDA between 2011 and 2016. In order to examine these relationships, associations between trial-level hazard ratio (HR) of progression free survival, hazard ration of survival and odds ratio of objective response rate were analyzed using a weighted linear regression model. Patient-level responder analyses comparing progression free survival and overall survival between patients with and without an objective response were performed using pooled data from all studies.

RESULTS

In the trial-level analysis, the linear relationships between progression free survival and objective response rate, and overall survival and objective response rate were weak (R²_adj = 0.019 and 0.093, respectively). The linear relationship between overall survival and progression free survival (R²_adj = 0.075) was also weak. In the patient-level responder analyses, patients who achieved a response had better progression free survival and overall survival compared with non-responders in both the control drug treatment and the experimental drug treatment.

CONCLUSION

Based on this analysis, use of objective response rate as a surrogate endpoint for overall survival or progression free survival in this population appears not appropriate. However, due to the nature of heterogeneity, interpretation needs to be cautious.

The In Vitro and In Vivo Anticancer Properties of Chalcone Flavokawain B through Induction of ROS-Mediated Apoptotic and Autophagic Cell Death in Human Melanoma Cells

Melanoma is the most prevalent type of skin cancer with high mortality rates. This study demonstrates the in vitro and in vivo anticancer properties of chalcone flavokawain B (FKB) induced ROS-mediated apoptosis and autophagy in human melanoma (human epithelial melanoma cell line A375 and/or human skin lymph node derived melanoma cell line A2058) cells. Cell viability was calculated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the expression patterns of various apoptosis, autophagy-associated proteins were determined by Western blot methods. Annexin V was detected by flow cytometry, whereas acidic vesicular organelles (AVOs) and intracellular ROS levels were measured by fluorescence microscopy. The in vivo anticancer properties of FKB were evaluated by xenografting the A375 cells into nude mice. The results convey that FKB inhibited cell viability, B-Raf proto-oncogene, serine/threonine kinase (BRAF)/extracellular signal-regulated kinase (ERK) expression in human melanoma cells. Caspase-3 activation, poly (ADP-ribose) polymerase (PARP) cleavage pathway, and Bcl2 associated X (Bax)/B-cell lymphoma 2 (Bcl-2) dysregulation were involved in the execution of apoptosis. Moreover, FKB-induced autophagy was observed through increased microtubule-associated protein 1A/1B-light chain 3B (LC3-II) accumulation and AVOs formation, which was also associated with an increase in sequestosome 1 (SQSTM1/p62), decreased protein kinase B (AKT)/mammalian target of rapamycin (mTOR) expressions, and dysregulated Beclin-1/Bcl-2 levels. Autophagy inhibitors [3-methyladenine (3-MA)/chloroquine (CQ)] and LC3 silencing suppressed FKB-induced apoptosis by decreasing caspase-3 in melanoma cells. The antioxidant N-acetylcysteine (NAC) diminished FKB-induced apoptotic and autophagic cell death. However, the inhibition of apoptosis decreased FKB-induced autophagy (LC3-I/II). The in vivo study confirmed that FKB inhibited melanoma growth in A375-xenografted nude mice. This study concluded that FKB is critically associated with the execution and generation of ROS-modulated apoptotic and autophagic cell death of melanoma cells. FKB also repressed tumor growth in xenografted nude mice. Therefore, flavokawain B might be a potential anti-tumor agent in human melanoma treatment.

Quercetin Inhibits Proliferation and Induces Apoptosis of B16 Melanoma Cells In Vitro

Malignant melanoma is an aggressive cancer with a poor prognosis despite numerous advances in therapeutic strategies. Quercetin is a plant-derived flavonoid suggested to have potent anticancer properties. Quercetin has no demonstrable toxicity in humans, further supporting the possibility of using quercetin therapeutically. We chose to investigate quercetin efficacy against B16 murine melanoma cells and identify the mechanisms of anticancer activity. Treatment of B16 melanoma cells with 50 μg/mL quercetin resulted in a 75% reduction in viability from 6 through 48 h post-treatment. The reduction in cancer cell viability was comparable to or greater than what was observed with etoposide, an established chemotherapeutic. Specifically, we found Quercetin reduced the proliferation of B16 melanoma cells at 48 h as much or more than etoposide. Although quercetin reduced the proportion of cells in the S and G2/M stages of the cell cycle, this could largely be explained by an increase in the subG1 population in quercetin-treated cells (suggesting apoptosis). Quercetin-induced apoptosis was confirmed by flow cytometry analysis of Annexin V+ cells. Collectively, our findings demonstrate quercetin reduces proliferation and induces apoptosis of B16 melanoma cells in vitro.

Association between Citrus Consumption and Melanoma Risk in the NIH-AARP Diet and Health Study

It has been hypothesized that consumption of citrus, a group of foods particularly rich in a class of photoactive compounds known as furocoumarins, may increase the risk of malignant melanoma. However, this hypothesis has not been rigorously studied in a general sample of US men and women. This study examined the relationship between citrus intake and melanoma risk in subjects of the NIH-AARP Diet and Health Study. Among 388,467 adults, 3,894 melanoma cases were identified during a median follow-up of 15.5 years. After adjustment for relevant potential confounders, total citrus consumption was not significantly associated with melanoma risk in this cohort. Among those with higher estimated exposure to ultraviolet radiation, and among those aged 60+ years at baseline, there were significant trends toward increased melanoma risk associated with whole citrus fruit consumption (P trends = 0.01 and 0.02, respectively), but the hazard ratios of the top consumers (2+ cups per week) vs. nonconsumers were nonsignificant. Further research is needed to explore associations of citrus with melanoma risk among older adults and those with high sun exposure.

Recent advances and future directions in anti-tumor activity of cryptotanshinone: A mechanistic review

In respect to the enhanced incidence rate of cancer worldwide, studies have focused on cancer therapy using novel strategies. Chemotherapy is a common strategy in cancer therapy, but its adverse effects and chemoresistance have limited its efficacy. So, attempts have been directed towards minimally invasive cancer therapy using plant derived-natural compounds. Cryptotanshinone (CT) is a component of salvia miltiorrihiza Bunge, well-known as Danshen and has a variety of therapeutic and biological activities such as antioxidant, anti-inflammatory, anti-diabetic and neuroprotective. Recently, studies have focused on anti-tumor activity of CT against different cancers. Notably, this herbal compound is efficient in cancer therapy by targeting various molecular signaling pathways. In the present review, we mechanistically describe the anti-tumor activity of CT with an emphasis on molecular signaling pathways. Then, we evaluate the potential of CT in cancer immunotherapy and enhancing the efficacy of chemotherapy by sensitizing cancer cells into anti-tumor activity of chemotherapeutic agents, and elevating accumulation of anti-tumor drugs in cancer cells. Finally, we mention strategies to enhance the anti-tumor activity of CT, for instance, using nanoparticles to provide targeted drug delivery.

Mutations in the BRAF, NRAS, and C-KIT Genes of Patients Diagnosed with Melanoma in Colombia Population

INTRODUCTION

Mutations in the BRAF, NRAS, and C-KIT genes have been associated with the histopathological characteristics of melanoma. Likewise, the incidence of each of these subtypes changes according to the geographical origin of the population analyzed.

OBJECTIVE

To determine the mutation frequency in exons 11 and 15 of the BRAF gene, exons 1 and 2 of the NRAS gene, and exons 11, 13, and 17 of the C-KIT gene and to relate it with histological subtypes in patients from a region with high levels of ultraviolet radiation. Methodology. The clinicopathological characteristics of 54 cutaneous melanoma samples were analyzed. Mutation analysis was performed via qPCR on paraffin-embedded tumor tissue samples using probes specific for the V600E mutation. Amplification of exons 11 and 15 of the BRAF gene, exons 1 and 2 of the NRAS gene, and exons 11, 13, and 17 of the C-KIT gene was performed for subsequent sequencing using the Sanger method.

RESULT

The most frequent histological subtype in the analyzed sample was lentigo maligna/lentigo maligna melanoma (52%) followed by acral lentiginous melanoma (20%). The BRAF-V600 variant was the most frequent (63.6%). The most frequent (54%) mutation in NRAS was p.Lys5∗. In the C-KIT gene, only the Val560Ala mutation was found.

CONCLUSION

Differences in histological subtypes and mutations in the BRAF, NRAS, and C-KIT genes were found in the analyzed population. This indicates that environmental and genetic factors significantly influence the introduction of the disease in this geographic region.

BRAF Inhibitors: Molecular Targeting and Immunomodulatory Actions

The BRAF inhibitors vemurafenib, dabrafenib and encorafenib are used in the treatment of patients with BRAF-mutant melanoma. They selectively target BRAF kinase and thus interfere with the mitogen-activated protein kinase (MAPK) signalling pathway that regulates the proliferation and survival of melanoma cells. In addition to their molecularly targeted activity, BRAF inhibitors have immunomodulatory effects. The MAPK pathway is involved in T-cell receptor signalling, and interference in the pathway by BRAF inhibitors has beneficial effects on the tumour microenvironment and anti-tumour immune response in BRAF-mutant melanoma, including increased immune-stimulatory cytokine levels, decreased immunosuppressive cytokine levels, enhanced melanoma differentiation antigen expression and presentation of tumour antigens by HLA 1, and increased intra-tumoral T-cell infiltration and activity. These effects promote recognition of the tumour by the immune system and enhance anti-tumour T-cell responses. Combining BRAF inhibitors with MEK inhibitors provides more complete blockade of the MAPK pathway. The immunomodulatory effects of BRAF inhibition alone or in combination with MEK inhibition provide a rationale for combining these targeted therapies with immune checkpoint inhibitors. Available data support the synergy between these treatment approaches, indicating such combinations provide an additional beneficial effect on the tumour microenvironment and immune response in BRAF-mutant melanoma.

Marital Status and Survival in Patients Diagnosed with Melanoma

Introduction

Previous research suggests the presence of a spouse may considerably affect melanoma detection rates through more frequent examinations, better access to healthcare, and improved social support. Yet, the role of marital status on melanoma survival is currently unknown. The aim of this study is to assess whether marital status is associated with survival following melanoma diagnosis.

Methods

We performed secondary analysis of data from all participants of the Florida Cancer Data System (FCDS) and included adult melanoma patients diagnosed between 2001 and 2009 with follow-up information available until 2015. Marital status was categorized as single, married, divorced, or widowed. The primary outcome was survival interval after melanoma diagnosis, which was assessed according to the time from the date of diagnosis to the time of death or last contact. Cox proportional hazard models were used to assess the independent association between marital status and survival.

Results

We assessed data from 36,578 melanoma patients. Married patients were significantly more likely to survive than single patients (Hazard ratio (HR) = 0.65; 99% Confidence Interval (CI): 0.57–0.74; P < 0.001) after adjusting for age, sex, race, ethnicity, geographic location, insurance status, tobacco use, primary site, stage, and histology. There was no evidence of effect modification by gender (P=0.189).

Conclusions

Married patients, including both men and women, had a 35% reduction in the risk of death after melanoma diagnosis compared with single patients, and mechanisms independent of earlier detection, such as social support, may play a role in survival in patients with melanoma.

Functional Roles of Matrix Metalloproteinases and Their Inhibitors in Melanoma

The extracellular matrix (ECM) plays an important role in the regulation of the tissue microenvironment and in the maintenance of cellular homeostasis. Several proteins with a proteolytic activity toward several ECM components are involved in the regulation and remodeling of the ECM. Among these, Matrix Metalloproteinases (MMPs) are a class of peptidase able to remodel the ECM by favoring the tumor invasive processes. Of these peptidases, MMP-9 is the most involved in the development of cancer, including that of melanoma. Dysregulations of the MAPKs and PI3K/Akt signaling pathways can lead to an aberrant overexpression of MMP-9. Even ncRNAs are implicated in the aberrant production of MMP-9 protein, as well as other proteins responsible for the activation or inhibition of MMP-9, such as Osteopontin and Tissue Inhibitors of Metalloproteinases. Currently, there are different therapeutic approaches for melanoma, including targeted therapies and immunotherapies. However, no biomarkers are available for the prediction of the therapeutic response. In this context, several studies have tried to understand the diagnostic, prognostic and therapeutic potential of MMP-9 in melanoma patients by performing clinical trials with synthetic MMPs inhibitors. Therefore, MMP-9 may be considered a promising molecule for the management of melanoma patients due to its role as a biomarker and therapeutic target.

A new medical imaging technique for diagnosing dermatologic diseases: A clue to treatment choices

Recently, it has been shown that DNA could emit some waves which carry main information about its evolution. Using this idea, we design a new method to image the behavior of skin cells, especially melanocytes, and diagnose their damage. In this method, we make use of a circuit which is formed from DNAs within the damaged melanocytes, a graphene sheet, DNAs within the healthy cells, and a scope. To amplify exchanged waves between hexagonal and pentagonal manifolds of DNAs, we induce some defects in the graphene sheets and replace some hexagonal molecules by pentagonal ones to build a structure similar to the structure of DNAs. We show that unprotected exposure to UVA and UVB damages the DNA in melanocyte cells, producing genetic defects, or mutations, that can lead to exchanged waves between cells and the emergence of a current in our circuit. By analyzing the evolution of this current, we can estimate the rate of destruction in melanocytes, and predict the emergence of cancer.

Effect of 10 UV Filters on the Brine Shrimp Artemia salina and the Marine Microalga Tetraselmis sp

The presence of pharmaceutical and personal care product (PPCP) residues in the aquatic environment is an emerging issue due to their uncontrolled release through gray water, and accumulation in the environment that may affect living organisms, ecosystems and public health. The aim of this study is to assess the toxicity of benzophenone-3 (BP-3), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), butyl methoxydibenzoylmethane (BM), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT), 2-ethylhexyl salicylate (ES), diethylaminohydroxybenzoyl hexyl benzoate (DHHB), diethylhexyl butamido triazone (DBT), ethylhexyl triazone (ET), homosalate (HS) and octocrylene (OC) on marine organisms from two major trophic levels, including autotrophs (Tetraselmis sp.) and heterotrophs (Artemia salina). In general, results showed that both HS and OC were the most toxic UV filters for our tested species, followed by a significant effect of BM on Artemia salina due to BM—but only at high concentrations (1 mg/L). ES, BP3 and DHHB affected the metabolic activity of the microalgae at 100 µg/L. BEMT, DBT, ET, MBBT had no effect on the tested organisms, even at high concentrations (2 mg/L). OC toxicity represents a risk for those species, since concentrations used in this study are 15–90 times greater than those reported in occurrence studies for aquatic environments. For the first time in the literature, we report HS toxicity on a microalgae species at concentrations complementing those found in aquatic environments. These preliminary results could represent a risk in the future if concentrations of OC and HS continue to increase.

Anti-angiogenic role of microRNA-23b in melanoma by disturbing NF-κB signaling pathway via targeted inhibition of NAMPT

Aim: Melanoma is the major cause of death in patients inflicting skin cancer. We identify miR-23b plays an anti-angiogenic role in melanoma. Materials & methods: We collected tumor tissues from melanoma patients. Experiments in vivo and in vitro were designed to evaluate the role of miR-23b in melanoma. Results & conclusion: miR-23b was found to be downregulated in melanoma tissues, and associated with poor patient survival. Elevating miR-23b inhibited cell viability and colony formation, reduced pro-angiogenetic ability, and accelerated apoptosis in SK-MEL-28 cells. miR-23b targeted NAMPT. Disturbing NF-κB signaling pathway with ammonium pyrrolidinedithiocarbamate (an inhibitor of NF-kB signaling pathway) impeded acquired pro-angiogenetic ability of nicotinamide phosphoribosyl transferase-overexpressed SK-MEL-28 cells. MiR-23b is a prognostic factor in melanoma. This study provides an enhanced understanding of microRNA-based targets for melanoma treatment.

Silencing of microRNA-517a induces oxidative stress injury in melanoma cells via inactivation of the JNK signaling pathway by upregulating CDKN1C

Background

Melanoma is notoriously resistant to current treatments, and less than 25% of metastatic melanoma cases respond to existing therapies. Growing evidence has shown that microRNAs (miRNAs) play a vital role in the prognosis of melanoma. MiR-517a has been implicated in many types of cancer; however, its expressional features and potential biological functions in melanoma remain unclear. The present study aimed to investigate the possible effects of miR-517a on oxidative stress (OS) in melanoma cells.

Methods

miR-517a expression in melanoma was determined using RT-qPCR. After treatment with different concentrations of H₂O₂, cell viability was determined in order to identify the most appropriate H₂O₂ concentration. Through loss and gain of function experiments, the interactions between miR-517a, the cyclin dependent kinase inhibitor 1C (CDKN1C) and the c-Jun NH2-terminal kinase (JNK) signaling pathway, as well as their roles in OS of melanoma cells were identified. Moreover, the expression of Cleaved Caspase-3, extent of ERK1/2 phosphorylation, Bax/Bcl-2 ratio, levels of T-AOC, ROS and MDA, and SOD activity were also tested. Finally, melanoma cell viability and apoptosis were detected.

Results

MiR-517a was upregulated, while CDKN1C was downregulated in melanoma tissues and cells. MiR-517a targets CDKN1C and consequently reduced its expression. Inhibition of miR-517a was shown to increase Cleaved Caspase-3 expression, Bax/Bcl-2 ratio, levels of ROS and MDA, as well as cell apoptosis but decrease extent of ERK1/2 phosphorylation, T-AOC levels, SOD activity, along with cell proliferation and mitochondrial membrane potential.

Conclusions

Overall, silencing miR-517a results in upregulated CDKN1C expression, and inhibited JNK signaling pathway activation, consequently promoting OS in melanoma cells.

Kalantuboside B induced apoptosis and cytoprotective autophagy in human melanoma A2058 cells: An in vitro and in vivo study

Kalantuboside B (KB), a natural bufadienolide derivative extracted from the succulent plant Kalanchoe tubiflora, is well-known for its cardiotonic, immunomodulatory, and anti-inflammatory properties. In this study, we tested in vitro and in vivo anti-cancer efficacy with low concentrations of KB (5-30 ng/mL; 8.7-52.2 nM) on A2058 melanoma cells; and for the molecular mechanisms that underlie them. KB significantly inhibited the cell viability and colony formation via arresting the cell cycle at G2/M phase. There was an association with a decrease in Cyclin A/B1, Cdc25C, and Cdc2 expressions. Further, this treatment indicated the induction of apoptosis, DNA fragmentation, cytochrome c release, and caspase-3, -8, -9, and -12 activation, and PARP cleavage, which shows that mitochondrial, death-receptor, and ER-stress signaling pathways are involved. KB-induced autophagy was apparent from enhanced LC3-II accumulation, GFP-LC3 puncta, and AVO formation. Surprisingly, KB-mediated cell death was potentiated by 3-MA and CQ to suggest the role of autophagy as a cytoprotective mechanism. Moreover, KB-treated A2058 cells enhanced intracellular ROS generation and antioxidant NAC prevented apoptosis and reversed cytoprotective autophagy. Interestingly, KB-induced apoptosis (PARP cleavage) and cytoprotective autophagy (LC3-II accumulation) were mediated by the up-regulation of the ERK signaling pathway. It was also shown that KB promoted cytoprotective autophagy by a calcium dependent-p53 downregulation pathway. In vivo data showed that KB suppressed tumor growth significantly in A2058-xenografted nude mice. A Western blot indicated cell-cycle inhibition (cyclin A reduction), apoptosis induction (PARP cleavage and Bcl-2 inhibition), and cytoprotective autophagy (LC3-II upregulation and p53 downregulation) in KB-treated A2058-xenografted mice. Our findings suggested that KB-induced ROS pathway plays a role in mediating the apoptosis and cytoprotective autophagy in human melanoma cells. Thus, KB is considered to be a putative anti-tumor agent.

Novel MicroRNA Biomarkers, miR-142-5p, miR-550a, miR-1826, and miR-1201, Were Identified for Primary Melanoma

This study was aimed to identify novel miRNA biomarkers and explore the cooperative function of multi-RNAs in the progress of primary melanoma. The miRNA expression profile GSE62370 generated from 9 congenital nevi and 92 primary melanoma samples was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs between primary melanoma and congenital nevi were compared and the target genes of them were selected. Pathway enrichment analysis and protein/protein interaction (PPI) network of miRNA target genes were performed. In addition, the differential expression of miRNAs to identify the tumor stage-dependent differences in miRNA expression was analyzed. Differentially expressed miRNAs, including 6 upregulated and 23 downregulated, were found in primary melanoma. Besides, the miRNA-associated gene regulatory network revealed 274 nodes, including miR-142-5p and miR-125b, and 307 miRNA-target pairs. miRNA-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, such as melanoma, was found. Target genes in the PPI module were mainly enriched in cancer-related pathways. Finally, the melanoma stage-related overexpressed miR-142-5p and the downregulated miR-550, miR-1826, miR-1201, miR-205, and miR-125b were identified. Some validated miRNAs, including miR-125a/b, let-7a/b, and miR-205, were found and illustrated the reliability of our study. Four novel miRNAs, including miR-142-5p, miR-550a, miR-1826, and miR-1201, were considered to have potential prognostic values for primary melanoma.

Magnetic resonance features of sinonasal melanotic mucosal melanoma

A 67-year-old man presented to ear, nose and throat department complaining of nasal congestion and recurrent epistaxis for 5 months. Nasal endoscopy revealed a pigmented polyp obstructing the right nasal cavity. MRI with contrast agent showed a right nasal cavity polypoid mass with hyper signal intensity (SI) both in non-enhanced T1-w and diffusion imaging, marked hypo SI in T2-w sequences and avidly contrast enhancement characterised by rapid wash-in without significant wash-out on dynamic perfusion imaging. Histological specimen showed epithelioid and spindle cells with focal intense pigmentations and immunohistochemical features compatible with primary melanotic sinonasal mucosal melanoma (SNM). As melanotic SNM shows MRI pathognomonic high non-enhanced T1-w SI, this case underlines the crucial role of MRI not only in assessing the local tumour extension/recurrence but also in increasing the diagnostic confidence of detecting melanotic SNM. Thus, MRI should be always performed in case of clinical-endoscopic suspicion of SNM.

Juniperus communis Suppresses Melanoma Tumorigenesis by Inhibiting Tumor Growth and Inducing Apoptosis

Melanoma, which has a high metastatic capacity and death rate, is a common skin cancer in Western countries. The purpose of this study was to address whether Juniperus communis (JCo) extract is effective in the suppression of melanoma and to elucidate the anticancer mechanisms involved in vitro and in vivo. The antitumor capacities of JCo extract on tumor suppression and toxicity were evaluated and the results demonstrated that the tumor burden was reduced via mediation of cell cycle, reduction of autocrine signaling, and induction of apoptosis. Moreover, JCo extract significantly prolonged the survival rate of the test subjects with only low pathological and physiological toxicity. Additionally, JCo extract also reduced cancer stem cell-related angiogenic and metastatic proteins in the process of tumor elimination. Based on these results, this study suggests that JCo extract suppresses tumor growth and induces apoptosis, and JCo extract may be useful for the prevention of melanoma tumorigenesis.

Evaluación de la exposición solar y las medidas de fotoprotección en deportistas del Valle de Aburrá en el 2018

Antecedentes: el cáncer de piel es el más común en humanos y su incidencia continúa en aumento. La radiación ultravioleta (RUV) es el principal factor ambiental asociado con este cáncer. Los deportistas presentan un mayor riesgo para desarrollar cáncer de piel; sin embargo en nuestro país, hasta el momento, no se ha estudiado esta población.Objetivo general: describir las conductas de riesgo del cáncer de piel en deportistas del Valle de Aburrá, a través de una encuesta realizada en los centros más importantes de la región.Materiales y métodos: estudio de corte transversal descriptivo; se evaluaron variables sociodemográficas, clínicas y relacionadas con hábitos de fotoprotección. Según el tipo de variable, se usó media y desviación estándar o conteos absolutos y relativos.Resultados: se incluyeron 122 deportistas, la edad promedio del grupo estudiado fue de 20 años, el 56 % de los incluidos fueron hombres. El 74 % de los deportes se realizaban al aire libre, el fútbol fue el deporte más frecuente. El 75 % de los participantes entrenaba cuatro o más veces por semana y el 55 % lo hacía en horas con muy alta RUV. El 27 % de los deportistas reportó de 1 a 3 insolaciones en la infancia. La fotoprotección química se utilizaba con más frecuencia que la física.Conclusiones: este es el primer estudio realizado en Colombia que evidencia la necesidad de mejorar la educación en prevención primaria y secundaria sobre el cáncer de piel en esta población.

Methylwogonin exerts anticancer effects in A375 human malignant melanoma cells through apoptosis induction, DNA damage, cell invasion inhibition and downregulation of the mTOR/PI3K/Akt signalling pathway

INTRODUCTION

The main purpose of the present research was to study the anticancer effects of methylwogonin in A375 human malignant melanoma cells by evaluating its effects on apoptosis, DNA fragmentation, cancer cell invasion and the mTOR/PI3K/AKT signalling pathway.

MATERIAL AND METHODS

Effects on cell cytotoxicity were evaluated by MTT assay while a clonogenic assay determined the effects of methylwogonin on colony formation. Fluorescence microscopy evaluated apoptotic effects of methylwogonin in these cells using acridine orange/propidium iodide and Hoechst 33342 staining dyes. Gel electrophoresis evaluated the effects of methylwogonin on DNA fragmentation while the Matrigel invasion assay evaluated the effects of the drug on cancer cell invasion. Effects of methylwogonin on the mTOR/PI3K/AKT signalling pathway were evaluated by western blot assay.

RESULTS

Methylwogonin induces concentration-dependent as well as time-dependent growth inhibitory effects inducing significant cytotoxicity in these cancer cells. Methylwogonin led to dose-dependent inhibition of colony formation in A375 human malignant melanoma cells. The number of cell colonies decreased significantly as the methylwogonin dose increased from 0, 50, 150, to 300 μM. Methylwogonin treatment of cells at lower doses led to yellow fluorescence (early apoptosis), which changed to red/orange fluorescence, indicating late apoptosis at higher doses. Similar results were obtained using Hoechst 33342 staining, revealing that 50, 150 and 300 μM doses of methylwogonin led to significant morphological changes including chromatin condensation, fragmented nuclei and cellular shrinkage. DNA ladder formation was also observed, and this effect increased with increasing doses of methylwogonin. Methylwogonin also inhibited cancer cell invasion in a dose-dependent manner.

CONCLUSIONS

Different doses of methylwogonin led to concentration-dependent downregulation of phosphorylated PI3K, AKT and mTOR.

Serum S100B Levels in Melanoma

Malignant melanoma is a cancer with increasing incidence worldwide with relevant socioeconomic impact. Despite progress in prevention and early detection, it is one of the most lethal forms of skin cancer. Therefore it is urgent need to identify suitable biomarkers in order to improve early diagnosis, precise staging, and prognosis, as well as for therapy selection and monitoring. In this book chapter, we are focusing on S100B and discuss its clinical relevance in melanoma.

Bullfrog oil (Rana catesbeiana Shaw) induces apoptosis, in A2058 human melanoma cells by mitochondrial dysfunction triggered by oxidative stress

Bullfrog oil, an animal oil extracted from the adipose tissue of Rana catesbeiana Shaw, showed promising cytotoxic activity against melanoma cells and, therefore, has the potential to become a pharmaceutical active compound. However, there is a lack of information regarding the pathways involved in its pharmacological activity. Thus, the aim of this study was to investigate and elucidate the cytotoxic effect of this oil against A2058 human melanoma cells. The cytotoxic potential was evaluated by the MTT assay, the cell cycle analysis and the cell death assay. In addition, the apoptotic potential was investigated by (i) the DNA fragmentation using propidium iodide staining analysis, (ii) the evaluation of mitochondrial membrane potential and (iii) the determination of intracellular Reactive Oxygen Species (ROS) level. The results showed that the bullfrog oil was able to promote a time-dependent cytotoxic effect, decreasing cell viability to 38% after 72 h of treatment without affecting the cell cycle. Additionally, the bullfrog oil induced the apoptosis in A2058 cells, increasing up to 50 ± 13% of the intracellular ROS level, maintaining the DNA integrity and promoting an approximate decrease of 35 ± 5% in the mitochondrial membrane potential. It can be concluded that the in vitro cytotoxic effect of the bullfrog oil in A2058 human melanoma cells is mediated by oxidative stress that induces mitochondrial dysfunction, triggering the apoptosis. These unprecedented results highlight the pharmacological potential of bullfrog oil and provide important information to support studies on the development of new pharmaceutical products for complementary and alternative treatments for melanoma.

Fibronectin 1 promotes melanoma proliferation and metastasis by inhibiting apoptosis and regulating EMT

Background and aims: The complex process of cancer metastasis remains the least understood. Tumor cells alter their protein expression profile to survive from the tumor metastasis. Fibronectin 1 (FN1 gene coding protein) is a member of the glycoprotein family that has been shown to play an important role in cancer metastasis. However, its effects on melanoma metastasis are still unclear. Methods: We detected the FN1 expression between metastatic cells and primary cells by using Western blot and RT-qPCR assays. And, we analyzed the expressed feature of FN1 in different tissues and examined the clinical relevance of upregulated FN1 in melanoma progression by bioinformatic analysis. Furthermore, we downregulated the expression of FN1 by small interfering RNA technique to reveal the effect of FN1 on melanoma phenotype and expression of related genes. Finally, we used bioinformatics to reveal the possible mechanism of FN1 regulating melanoma progression. Results: We reported that the expression of FN1 was changed during melanoma metastasis. In this study, we established two metastatic cell lines of melanoma through mouse model, and found that metastatic cells exhibited stronger mesenchyme phenotype and possessed higher FN1 expression level compared to primary cells. Besides, we examined the clinical relevance of upregulated FN1 in tumor progression. Small interfering RNA (siRNA)-mediated downregulation of FN1 suppressed the migration, invasion, adhesion, proliferation capabilities and induced apoptosis of melanoma cells. We detected a diminished EMT-related gene signature including increased expression of E-cadherin and decreased expression of N-cadherin and Vimentin. Downregulation of FN1 also increased Bax/Bcl-2 ratio which might result in apoptosis of melanoma cells. Bioinformatics analysis revealed that FN1 most likely involved in focal adhesion and PI3K-Akt signaling pathway to regulate EMT process and apoptosis. Conclusions: Taken together, these findings demonstrated a role of FN1 in promoting melanoma metastasis by inhibiting apoptosis and regulating EMT.

MicroRNA-203 reinforces stemness properties in melanoma and augments tumorigenesis in vivo

One of the challenges encountered in microRNA (miRNA) studies is to observe their dual role in different conditions and cells. This leads to a tougher prediction of their behavior as gene expression regulators. miR-203 has been identified to play a negative role in the progression of malignant melanoma; however, it has been reported, with dual effect, as both an oncomiR and tumor suppressor miRNA in some malignancies, such as breast cancer, meanwhile, the role of miR-203 in melanoma stem cells or even metastatic cells is unclear. In the present study, after observation of upregulation of miR-203 in melanoma patient's serum and also melanospheres as cancer stem cells model, we examined its overexpression on the stemness potential and migration ability of melanoma cells. Our data demonstrated that the increased miR-203 level was significantly associated with significant increase in the ability of proliferation, colony and spheres formation, migration, and tumorigenesis in A375 and NA8 cells. All of these changes were associated with enhancement of BRAF, several epithelial to mesenchymal transition factors, and stemness genes. In conclusion, our results clearly determined that miR-203 could be down-regulateddownregulated in melanoma tissues but be overexpressed in melanoma stem cells. It has an important role as oncomiR and promote repopulation, tumorigenicity, self-renewal, and migration. Therefore, we suggested overexpression of miR-203 as biomarker for early detection of metastasis. However, more studies are needed to validate our data.

Weighted correlation network and differential expression analyses identify candidate genes associated with BRAF gene in melanoma

BACKGROUND

Primary cutaneous malignant melanoma is a cancer of the pigment cells of the skin, some of which are accompanied by BRAF mutation. Melanoma incidence and mortality rates have been rising around the world. As the current knowledge about pathogenesis, clinical and genetic features of cutaneous melanoma is not very clear, we aim to use bioinformatics to identify the potential key genes involved in the expression and mutation status of BRAF.

METHODS

Firstly, we used UCSC public hub datasets of melanoma (Lin et al., Cancer Res 68(3):664, 2008) to perform weighted genes co-expression network analysis (WGCNA) and differentially expressed genes analysis (DEGs), respectively. Secondly, overlapping genes between significant gene modules and DEGs were screened and validated at transcriptional levels and overall survival in TCGA and GTEx datasets. Lastly, the functional enrichment analysis was accomplished to find biological functions on the web-server database.

RESULTS

We performed weighted correlation network and differential expression analyses, using gene expression data in melanoma samples. We identified 20 genes whose expression was correlated with the mutation status of BRAF. For further validation, three of these genes (CYR61, DUSP1, and RNASE4) were found to have similar expression patterns in skin tumors from TCGA compared with normal skin samples from GTEx. We also found that weak expression of these three genes was associated with worse overall survival in the TCGA data. These three genes were involved in the nucleic acid metabolic process.

CONCLUSION

In this study, CYR61, DUSP1, and RNASE4 were identified as potential genes of interest for future molecular studies in melanoma, which would improve our understanding of its causes and underlying molecular events. These candidate genes may provide a promising avenue of future research for therapeutic targets in melanoma.

Self-detection frequency and recognition patterns in medium to high-risk cutaneous melanoma patients

BACKGROUND AND OBJECTIVES

The question of how frequently patients with medium to high-risk melanomas become aware of their tumors and which self-detection patterns exist remains unanswered.

PATIENTS AND METHODS

We conducted a retrospective survey of melanoma patients who had undergone sentinel node biopsy between 2004 and 2008. One hundred twenty-seven out of a total of 133 patients completed the questionnaire.

RESULTS

Twenty-five percent of patients had not noticed their tumors at all. The remaining 75 % showed three different self-detection patterns, with 25 % of individuals seeking medical advice within 0-12 weeks and another 25 % within 3-6 months. The remaining 25 % had waited for more than six months prior to tumor excision. Age, gender, and melanoma location were comparable in all self-detection subgroups. The most frequent subtypes were: SSM (59), NMM (31), ALM (9), UCM (9) and LMM (4). Rare subtypes occurred in 15 individuals. Patients with lesions previously noticed for 3-6 months revealed the highest average tumor thickness and the significantly highest number of pT4 tumors. Sixty percent of NMM patients had a disease history < 6 months. Rare subtypes such as amelanotic, spindle cell, or spitzoid melanoma were self-detected in only 50 % of cases.

CONCLUSIONS

Even advanced melanoma lesions remained undetected in 25 % of patients; rare melanoma subtypes, in 50 % of cases. Thus, self-examination frequency, increased awareness of rare melanoma subtypes, and rapid referral to a specialist ought to be at the center of future awareness campaigns.

Anticancer activities of Zanthoxylum bungeanum seed oil on malignant melanoma

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum Maxim. (ZBM), a Chinese herb medicine and food additive, has been shown to have broad-spectrum beneficial effects. However, the anticancer activities of its seed have not been reported.

AIM OF THE STUDY

for the first time investigated the anti-proliferation activity of seed oil of ZBM (ZBSO) on melanoma A375 cells as well as the underlying mechanisms.

MATERIALS AND METHODS

The chemical composition of ZBSO was analyzed by Ultra Performance Liquid Chromatography. A375 cells exposure at different concentrations of ZBSO to examine the selectivity versus normal skin cells, invasion, apoptosis and cell cycle arrest. Furthermore, transcriptome analysis was employed to investigate potential anticancer mechanisms of ZBSO.

RESULTS

Major compounds of ZBSO were identified and unsaturated fatty acid made up the major compound. ZBSO-treated A375 cells showed more typical apoptotic morphologic features than normal cells. ZBSO can significantly inhibit invasion and proliferation of A375 cells by G1 phase arrest and induction of apoptosis. Transcriptome analysis showed that ZBSO may affect cell cycle and MAPK signaling pathway of A375 cells.

CONCLUSION

ZBSO possessed anticancer activities that were selectively effective to A375 cells. This study support the hypothesis that ZBSO is a capable candidate for anti-melanoma agent, and provide new insights for future work on investigating the utilization of ZBSO in malignant melanoma treatment.

cAMP-mediated regulation of melanocyte genomic instability: A melanoma-preventive strategy

Malignant melanoma of the skin is the leading cause of death from skin cancer and ranks fifth in cancer incidence among all cancers in the United States. While melanoma mortality has remained steady for the past several decades, melanoma incidence has been increasing, particularly among fair-skinned individuals. According to the American Cancer Society, nearly 10,000 people in the United States will die from melanoma this year. Individuals with dark skin complexion are protected damage generated by UV-light due to the high content of UV-blocking melanin pigment in their epidermis as well as better capacity for melanocytes to cope with UV damage. There is now ample evidence that suggests that the melanocortin 1 receptor (MC1R) is a major melanoma risk factor. Inherited loss-of-function mutations in MC1R are common in melanoma-prone persons, correlating with a less melanized skin complexion and poorer recovery from mutagenic photodamage. We and others are interested in the MC1R signaling pathway in melanocytes, its mechanisms of enhancing genomic stability and pharmacologic opportunities to reduce melanoma risk based on those insights. In this chapter, we review melanoma risk factors, the MC1R signaling pathway, and the relationship between MC1R signaling and DNA repair.

NPS - 2143 (hydrochloride) inhibits melanoma cancer cell proliferation and induces autophagy and apoptosis

Melanoma is a common and aggressive skin cancer caused by the oncogenic transformation of melanocytes. NPS-2143 (hydrochloride) is a calcification drug that acts as an antagonist of the calcium-sensing receptor (CaSR) and consequently stimulates the release of parathyroid hormone. In the present work, we treated cells from the human melanoma cell line M14 to investigate the effects of NPS-2143 on melanoma cells and elucidate their underlying mechanisms. We observed that NPS-2143 inhibits the survival and proliferation of M14 cells and suppresses the migration and proliferation of M14 cells by inducing apoptosis. The Bax/Bcl‑2 ratio in M14 cells was enhanced by the NPS-2143 treatment, suggesting that the mitochondrial apoptotic pathway was activated. The expression and phosphorylation of proteins involved in the PI3K signaling pathway were altered by NPS-2143 treatment. Our data show that NPS-2143 impacts the viability and induces the apoptosis of melanoma M14 cells through its impact on the PI3K signaling pathway. It suggests that NPS-2143 could represent a promising candidate for melanoma treatment.

Biobank integration of large-scale clinical and histopathology melanoma studies within the European Cancer Moonshot Lund Center

We present the Cancer Moonshot clinical project located at the European center in Lund. Here, tissue and blood samples have been collected and stored in a large-scale biobank. Multiple clinical centers around the world are participating and tissue and blood samples are sent to the European Cancer Moonshot Lund Center that acts as the clinical hub. Our center has been developed to generate and build large-scale biostorage archives of patient melanoma samples, which is then combined with a histopathological capability to characterize the patient tumours. Such a large-scale clinical sample processing initiative has begun with the aim of creating high-end histopathology indexing with database computational power and including proteogenomic analysis. The biobank at Lund has become an important resource in clinical research worldwide. Following suite, several national health programs are being initiated with the aim of also building large-scale biobank storages with a wealth of high-quality patient samples. In our Cancer Moonshot R&D activities, samples in the biobanks and the data derived from these samples are being used to build an understanding of disease presentation and using this information to move towards 'Big Data' proteogenomic and mass spectrometry imaging studies. Additionally, we report here a sample processing workflow that has been adapted to a fully-automated biobank processing strategy for large-scale studies.

Predictive value of excision repair cross-complementing group 2 gene Lys751Gln and Asp312Asn polymorphisms in melanoma risk

Epidemiological studies have assessed the association between excision repair cross-complementing group 2 (ERCC2) Lys751Gln and Asp312Asn polymorphisms and melanoma risk with conflicting results. Relevant articles were searched from PubMed, Embase, and Web of Science with a time limit of 3 September 2016. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the association. We performed this meta-analysis with 12 studies including 6157 cases and 8873 controls for Lys751Gln and nine studies including 5037 cases and 7542 controls for Asp312Asn polymorphism. Overall, no significant associations were found under all the models for Lys751Gln polymorphism, and significant associations were found for Asp312Asn polymorphism for AA versus GG (OR=1.12, 95% CI=1.00-1.26) and for the recessive model (OR=1.11, 95% CI=1.00-1.24). In the stratification analyses by source of control: for Lys751Gln polymorphism, significant associations were found for CC versus AA (OR=1.19, 95% CI=1.04-1.36) and the recessive model (OR=1.15, 95% CI=1.02-1.30); for Asp312Asn polymorphism, significant associations were found for AA versus GG (OR=1.31, 95% CI=1.11-1.53) and the recessive model (OR=1.29, 95% CI=1.11-1.50). This meta-analysis suggested that both the Lys751Gln and Asp312Asn polymorphisms were risk factors for melanoma risk in population-based subgroup.

Downregulation of lncRNA H19 inhibits the migration and invasion of melanoma cells by inactivating the NF‑κB and PI3K/Akt signaling pathways

As the most aggressive type of skin cancer, melanoma seriously affects human health. Long noncoding (lncRNA) 19 has been demonstrated to be involved in the progression of a number of different types of human cancers. However, the involvement of lncRNA H19 in melanoma remains unknown. Therefore, the present study was performed to investigate the roles of H19 in the development and progression of melanoma. In the present study, 49 patients with melanoma were included. Expression of lncRNA H19 in tumor tissue, adjacent healthy tissue and various cell lines with different treatments was measured by reverse transcription‑quantitative polymerase chain reaction. The effects of H19 knockdown on melanoma cell proliferation, migration and invasion were detected by cell counting kit‑8, wound‑healing and transwell invasion assays, respectively. In addition, the effects of H19 knockdown on the expression of nuclear factor (NF)‑κB pathway‑associated proteins were investigated by western blotting. The results revealed that the expression level of H19 was significantly higher in tumor tissue than in the adjacent healthy tissue of 47 out of 49 patients. H19 knockdown significantly reduced the proliferation, migration and invasion ability of melanoma cells. H19 knockdown also inactivated the phosphoinositide 3‑kinase (PI3K)/protein kinase B (Akt) pathway, which in turn inhibited the activation of the NF‑κB signaling pathway. Thus, downregulation of lncRNA H19 may inhibit the migration and invasion of melanoma cells by inactivating the NF‑κB signaling pathway via the inactivation of the PI3K/Akt signaling pathway. The present study provided references for future studies on the pathogenesis of melanoma and the clinical treatment of this disease.

Metastatic primary pulmonary melanoma successfully treated with checkpoint inhibitors

Our patient is a 69-year-old man who presented to the emergency department with left-sided hemiparesis that started 4 hours prior to presentation. Brain CT showed right basal ganglia and internal capsule haemorrhagic strokes. MRI revealed multiple brain lesions suspicious for metastases. Further workup revealed a 5 cm lung mass and a 1 cm pancreatic nodule. Biopsy of both pulmonary and pancreatic lesions was consistent with melanoma and was similar histologically. The patient underwent cyberknife stereotactic radiosurgery to the brain metastases followed by immunotherapy with pembrolizumab, and then by nivolumab and ipilimumab. The patient remains free of disease progression 2 years after treatment.