Genetics of metastasis: melanoma and other cancers

Extracellular vesicles promote migration despite BRAF inhibitor treatment in malignant melanoma cells

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.

Current knowledge about immunotherapy resistance for melanoma and potential predictive and prognostic biomarkers

Melanoma still reaches thousands of new diagnoses per year, and its aggressiveness makes recovery challenging, especially for those with stage III/IV unresectable melanoma. Immunotherapy, emerging as a beacon of hope, stands at the forefront of treatments for advanced melanoma. This review delves into the various immunotherapeutic strategies, prominently featuring cytokine immunotherapy, adoptive cell therapy, immune checkpoint inhibitors, and vaccinations. Among these, immune checkpoint inhibitors, notably anti-programmed cell death-1 (PD-1) and anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) antibodies, emerge as the leading strategy. However, a significant subset of melanoma patients remains unresponsive to these inhibitors, underscoring the need for potent biomarkers. Efficient biomarkers have the potential to revolutionize the therapeutic landscape by facilitating the design of personalized treatments for patients with melanoma. This comprehensive review highlights the latest advancements in melanoma immunotherapy and potential biomarkers at the epicenter of recent research endeavors.

Integrated in vivo functional screens and multi-omics analyses identify α-2,3-sialylation as essential for melanoma maintenance

Glycosylation is a hallmark of cancer biology, and altered glycosylation influences multiple facets of melanoma growth and progression. To identify glycosyltransferases, glycans, and glycoproteins essential for melanoma maintenance, we conducted an in vivo growth screen with a pooled shRNA library of glycosyltransferases, lectin microarray profiling of benign nevi and melanoma patient samples, and mass spectrometry-based glycoproteomics. We found that α-2,3 sialyltransferases ST3GAL1 and ST3GAL2 and corresponding α-2,3-linked sialosides are upregulated in melanoma compared to nevi and are essential for melanoma growth in vivo and in vitro. Glycoproteomics revealed that glycoprotein targets of ST3GAL1 and ST3GAL2 are enriched in transmembrane proteins involved in growth signaling, including the amino acid transporter Solute Carrier Family 3 Member 2 (SLC3A2/CD98hc). CD98hc suppression mimicked the effect of ST3GAL1 and ST3GAL2 silencing, inhibiting melanoma cell proliferation. We found that both CD98hc protein stability and its pro-survival effect in melanoma are dependent upon α-2,3 sialylation mediated by ST3GAL1 and ST3GAL2. In summary, our studies reveal that α-2,3-sialosides functionally contribute to melanoma maintenance, supporting ST3GAL1 and ST3GAL2 as novel therapeutic targets in these tumors.

DLL4/Notch3/WNT5B axis mediates bidirectional prometastatic crosstalk between melanoma and lymphatic endothelial cells

Despite strong indications that interactions between melanoma and lymphatic vessels actively promote melanoma progression, the molecular mechanisms are not yet completely understood. To characterize molecular factors of this crosstalk, we established human primary lymphatic endothelial cell (LEC) cocultures with human melanoma cell lines. Here, we show that coculture with melanoma cells induced transcriptomic changes in LECs and led to multiple changes in their function. WNT5B, a paracrine signaling molecule upregulated in melanoma cells upon LEC interaction, was found to contribute to the functional changes in LECs. Moreover, WNT5B transcription was regulated by Notch3 in melanoma cells following the coculture with LECs, and Notch3 and WNT5B were coexpressed in melanoma patient primary tumor and metastasis samples. Moreover, melanoma cells derived from LEC coculture escaped efficiently from the primary site to the proximal tumor-draining lymph nodes, which was impaired upon WNT5B depletion. This supported the role of WNT5B in promoting the metastatic potential of melanoma cells through its effects on LECs. Finally, DLL4, a Notch ligand expressed in LECs, was identified as an upstream inducer of the Notch3/WNT5B axis in melanoma. This study elucidated WNT5B as a key molecular factor mediating bidirectional crosstalk between melanoma cells and lymphatic endothelium and promoting melanoma metastasis.

Indoloquinazoline alkaloids suppress angiogenesis and inhibit metastasis of melanoma cells

Metastasis is the leading cause of cancer-related mortality, targeting angiogenesis emerges as a therapeutic strategy for the treatment of melanoma metastasis. Discovery of new antiangiogenic compounds with specific mechanism of action is still desired. In present study, a bioassay-guidance uncovers the EtOAc extract of a marine-derived fungus Aspergillus clavutus LZD32-24 with significant inhibitory activity against the angiogenesis in Tg (fli1a: EGFP) zebrafish model. Extensive chromatographic fractionation led to the isolation of 48 indoloquinazoline alkaloids, including 21 new analogues namely clavutoines A-U (1-21). Their structures were determined by the spectroscopic data, including the ECD, single crystal X-ray diffraction and quantum chemical calculation for the configurational assignments. Among the bioactive analogues, quinadoline B (QB) showed the most efficacy to suppress the zebrafish vascular outgrowth in zebrafish embryos. QB markedly inhibited the migration, invasion and tube formation with weak cytotoxicity in human umbilical vein endothelial cells (HUVECs). Investigation of the mode of action revealed QB suppressed the ROCK/MYPT1/MLC2/coffin and FAK /Src signaling pathways, and subsequently disrupted actin cytoskeletal organization. In addition, QB reduced the number of new vessels sprouting from the ex vivo chick chorioallantoic membrane (CAM), and inhibited the metastasis of B16F10 melanoma cells in lung of C57BL/6 mice through suppressing angiogenesis. These findings suggest that QB is a potential lead for the development of new antiangiogenic agent to inhibit melanoma metastasis.

OTUD4 regulates metastasis and chemoresistance in melanoma by stabilizing Snail1

Melanoma is the most aggressive form of skin cancer with rapidly increased incidence worldwide especially in the Caucasian population. Surgical excision represents the curative treatment choice in patients with early-stage disease. However, the therapeutic outcomes in patients with metastatic melanoma remains unsatisfactory. Thus, understanding molecular mechanisms contributing to metastasis and chemoresistance is critical for new improved therapies of melanoma. Snail1, an important epithelial-mesenchymal transition transcription factors (EMT-TFs), is critical to induce the EMT process, thereby contributing to cancer metastasis. However, the involvement of Snail1 in melanoma metastasis remains elusive and the underlying mechanism to regulate Snail1 in melanoma needs to be further investigated. Here, we identified OTUD4 as a novel deubiquitinase of Snail1 in melanoma. Moreover, the depletion of OTUD4 in melanoma cells markedly inhibited Snail1 stability and Snail1-driven malignant phenotypes both in vitro and in vivo. Overall, our study establishes OTUD4 as a novel therapeutic target in metastasis and chemoresistance of melanoma by stabilizing Snail1 and provides a rationale for potential therapeutic strategies of melanoma.

Second Cancer Affecting the Central Nervous System: Systematic Literature Review Exploring the Link Between Malignant Melanoma and Glioblastoma

BACKGROUND

Glioblastoma (GBM) is a malignant primary brain cancer, among the most devastating and lethal diseases of the central nervous system. Similarly, malignant melanoma (MM) is responsible for most skin cancer-related deaths. A link between those 2 aggressive cancers has not yet been established. We present here a systematic review of the literature and an exemplificative case.

METHODS

A systematic review of the literature was conducted to assess possible commonalities between MM and GBM. An exemplificative surgical vignette of a 73-year-old patient with the occurrence of a frontobasal GBM after surgical removal of a metastasis of MM in the same location was then detailed.

RESULTS

Fifteen studies published in the English international literature support a link between MM and GBM, both based on epidemiologic and pathophysiologic/genetic aspects. This theory is reinforced by our surgical vignette of a collision tumor with the occurrence of both tumors in the same location several years apart.

CONCLUSIONS

The evidence reported in the literature, as well as our surgical vignette, support a likely link between the pathogenesis of GBM and MM.

Exploring and validating the prognostic value of pathomics signatures and genomics in patients with cutaneous melanoma based on bioinformatics and deep learning

BACKGROUND

Cutaneous melanoma (CM) is the most common malignant tumor of the skin. Our study aimed to investigate the prognostic value of pathomics signatures for CM by combining pathomics and genomics.

PURPOSE

The purpose of this study was to explore the potential application value of pathomics signatures.

METHODS

Pathology full scans, clinical information, and genomics data for CM patients were downloaded from The Cancer Genome Atlas (TCGA) database. Exploratory data analysis (EDA) was used to visualize patient characteristics. Genes related to a poorer prognosis were screened through differential analysis. Survival analysis was performed to assess the prognostic value of gene and pathomics signatures. Artificial neural network (ANN) models predicted prognosis using signatures and genes. Correlation analysis was used to explore signature-gene links.

RESULTS

The clinical traits for 468 CM samples and the genomic data and pathology images for 471 CM samples were obtained from the TCGA database. The EDA results combined with multiple machine learning (ML) models suggested that the top 5 clinical traits in terms of importance were age, biopsy site, T stage, N stage and overall disease stage, and the eight ML models had a precision lower than 0.56. A total of 60 differentially expressed genes were obtained by comparing sequencing data. A total of 413 available quantitative signatures of each pathomics image were obtained with CellProfile software. The precision of the binary classification model based on pathomics signatures was 0.99, with a loss value of 1.7119e-04. The precision of the binary classification model based on differentially expressed genes was 0.98, with a loss value of 0.1101. The precision of the binary classification model based on pathomics signatures and differentially expressed genes was 0.97, with a loss value of 0.2088. The survival analyses showed that the survival rate of the high-risk group based on gene expression and pathomics signatures was significantly lower than that of the low-risk group. A total of 222 pathomics signatures and 51 differentially expressed genes were analyzed for survival with p-values of less than 0.05. There was a certain correlation between some pathomics signatures and differential gene expression involving ANO2, LINC00158, NDNF, ADAMTS15, and ADGRB3, etc. CONCLUSION: This study evaluated the prognostic significance of pathomics signatures and differentially expressed genes in CM patients. Three ANN models were developed, and all achieved accuracy rates higher than 97%. Specifically, the pathomics signature-based ANN model maintained a remarkable accuracy of 99%. These findings highlight the CellProfile + ANN model as an excellent choice for prognostic prediction in CM patients. Furthermore, our correlation analysis experimentally demonstrated a preliminary link between disease quantification and qualitative changes. Among various features, including M stage and treatments received, special attention should be given to age, biopsy site, T stage, N stage, and overall disease stage in CM patients.

LncRNA NEAT1 antagonizes the inhibition of melanoma proliferation, migration, invasion and EMT by Polyphyllin B

Polyphyllin B (PPB) is a compound with anti-tumor effects. Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long-stranded noncoding RNA that induces epithelial-mesenchymal transition (EMT) of tumor cells and promotes tumor growth and metastasis. However, the role and mechanism of PPB on melanoma and the correlation between them remain unclear. In this study we screened NEAT1 by using LncRNA transcriptomic sequencing, and then transfected B16F10 cells using OVER-NEAT1 lentivirus. Next, we found that PPB had significant proliferation inhibition of melanoma and B16F10 cells through MTT assay and establishment of mouse subcutaneous transplantation tumor model; in addition, through wound healing assay, transwell assay and establishment of mouse melanoma lung metastasis model, we found that PPB significantly inhibited the invasion and migration of B16F10 cells in vitro, and inhibited the metastasis of melanoma to lung, bone and liver in vivo. Finally, changes in the expression levels of EMT-related proteins were assessed by western blot (WB) and immunohistochemistry, and PPB significantly downregulated the expression levels of MMP-9, N-cadherin, etc., and upregulated E-cadherin. While overexpressed NEAT1 showed the ability to promote melanoma proliferation, migration and invasion, in addition to partially reversed the inhibition of proliferation, migration and invasion of melanoma by PPB mentioned above.

Advances in the expression and function of Fyn in different human tumors

The tyrosine kinase Fyn is a member of the SRC family of kinases, and its sustained activation is closely linked to tumor cell migration, proliferation, and cell metabolism. Recently, Fyn has been found to be expressed in various tumor tissues, and the expression and function of Fyn vary between tumors, with Fyn acting as an oncogene to promote proliferation and metastasis in some tumors. This article summarizes the recent studies on the role of Fyn in different human tumors, focusing on the role of Fyn in melanoma, breast cancer, glioma, lung cancer, and peripheral T-cell lymphoma in order to provide a basis for future research and targeted therapy in different human tumors.

A practical nomogram and risk stratification system predicting the cancer-specific survival for patients aged >50 with advanced melanoma

Objective

To investigate risk factors for advanced melanoma over 50 years of age and to develop and validate a new line chart and classification system.

Methods

The SEER database was screened for patients diagnosed with advanced melanoma from 2010 to 2019 and Cox regression analysis was applied to select variables affecting patient prognosis. The area under curve (AUC), relative operating characteristic curve (ROC), Consistency index (C-index), decision curve analysis (DCA), and survival calibration curves were used to verify the accuracy and utility of the model and to compare it with traditional AJCC tumor staging. The Kaplan-Meier curve was applied to compare the risk stratification between the model and traditional AJCC tumor staging.

Results

A total of 5166 patients were included in the study. Surgery, age, gender, tumor thickness, ulceration, the number of primary melanomas, M stage and N stage were the independent prognostic factors of CSS in patients with advanced melanoma (P<0.05). The predictive nomogram model was constructed and validated. The C-index values obtained from the training and validation cohorts were 0.732 (95%CI: 0.717-0.742) and 0.741 (95%CI: 0.732-0.751). Based on the observation and analysis results of the ROC curve, survival calibration curve, NRI, and IDI, the constructed prognosis model can accurately predict the prognosis of advanced melanoma and performs well in internal verification. The DCA curve verifies the practicability of the model. Compared with the traditional AJCC staging, the risk stratification in the model has a better identification ability for patients in different risk groups.

Conclusion

The nomogram of advanced melanoma and the new classification system were successfully established and verified, which can provide a practical tool for individualized clinical management of patients.

Activity and Selectivity of Novel Chemical Metallic Complexes with Potential Anticancer Effects on Melanoma Cells

Human malignant melanoma cells from lymph node metastatic site (MeWo) were selected for testing several synthesized and purified silver(I) and gold(I) complexes stabilized by unsymmetrically substituted N-heterocyclic carbene (NHC) ligands, called L20 (N-methyl, N'-[2-hydroxy ethylphenyl]imidazol-2-ylide) and M1 (4,5-dichloro, N-methyl, N'-[2-hydroxy ethylphenyl]imidazol-2-ylide), having halogenide (Cl^- or I^-) or aminoacyl (Gly=N-(tert-Butoxycarbonyl)glycinate or Phe=(S)-N-(tert-Butoxycarbonyl)phenylalaninate) counterion. For AgL20, AuL20, AgM1 and AuM1, the Half-Maximal Inhibitory Concentration (IC₅₀) values were measured, and all complexes seemed to reduce cell viability more effectively than Cisplatin, selected as control. The complex named AuM1 was the most active just after 8 h of treatment at 5 μM, identified as effective growth inhibition concentration. AuM1 also showed a linear dose and time-dependent effect. Moreover, AuM1 and AgM1 modified the phosphorylation levels of proteins associated with DNA lesions (H2AX) and cell cycle progression (ERK). Further screening of complex aminoacyl derivatives indicated that the most powerful were those indicated with the acronyms: GlyAg, PheAg, AgL20Gly, AgM1Gly, AuM1Gly, AgL20Phe, AgM1Phe, AuM1Phe. Indeed, the presence of Boc-Glycine (Gly) and Boc-L-Phenylalanine (Phe) showed an improved efficacy of Ag main complexes, as well as that of AuM1 derivatives. Selectivity was further checked on a non-cancerous cell line, a spontaneously transformed aneuploid immortal keratinocyte from adult human skin (HaCaT). In such a case, AuM1 and PheAg complexes resulted as the most selective allowing HaCaT viability at 70 and 40%, respectively, after 48 h of treatment at 5 μM. The same complexes tested on 3D MeWo static culture induced partial spheroid disaggregation after 24 h of culture, with almost half of the cells dead.

Malignant melanoma resection and reconstruction with the first manifestation of lumbar metastasis: A case report

BACKGROUND

Malignant melanoma (MM) has shown an increasing incidence worldwide, and a potential to metastasize to almost any part of the body. Clinically, MM with bone metastasis as the initial manifestation is extremely rare. Spinal metastatic MM can cause spinal cord or nerve root compression, resulting in severe pain and paralysis. Currently, the primary clinical treatments for MM are surgical resection in conjunction with chemotherapy, radiotherapy, and immunotherapy.

CASE SUMMARY

Here, we report the case of a 52-year-old male who presented to the clinic with progressive low back pain and limited nerve function. No primary lesion or spinal cord compression was detected from computed tomography and magnetic resonance imaging of the lumbar vertebrae and positron emission tomography scan. A lumbar puncture biopsy confirmed the diagnosis of lumbar spine metastatic MM. Following surgical resection, the patient’s quality of life improved, symptoms were relieved, and comprehensive treatment was initiated, which prevented recurrence.

CONCLUSION

Spinal metastatic MM is clinically rare, and may cause neurological symptoms, including paraplegia. Currently, the clinical treatment plan consists of surgical resection in combination with chemotherapy, radiotherapy, and immunotherapy.

Age-related increases in IGFBP2 increase melanoma cell invasion and lipid synthesis

Aged melanoma patients (>65 years old) have more aggressive disease relative to young patients (<55 years old) for reasons that are not completely understood. Analysis of the young and aged secretome from human dermal fibroblasts identified >5-fold levels of insulin-like growth factor binding protein 2 (IGFBP2) in the aged fibroblast secretome. IGFBP2 functionally triggers upregulation of the PI3K-dependent fatty acid biosynthesis program in melanoma cells through increases in FASN. Melanoma cells co-cultured with aged dermal fibroblasts have higher levels of lipids relative to young dermal fibroblasts, which can be lowered by silencing IGFBP2 expression in fibroblasts, prior to treating with conditioned media. Conversely, ectopically treating melanoma cells with recombinant IGFBP2 in the presence of conditioned media from young fibroblasts, promoted lipid synthesis and accumulation in the melanoma cells. Neutralizing IGFBP2 in vitro reduces migration and invasion in melanoma cells, and in vivo studies demonstrate that neutralizing IGFBP2 in syngeneic aged mice, ablates tumor growth as well as metastasis. Conversely, ectopic treatment of young mice with IGFBP2 in young mice increases tumor growth and metastasis. Our data reveal that aged dermal fibroblasts increase melanoma cell aggressiveness through increased secretion of IGFBP2, stressing the importance of considering age when designing studies and treatment.

Significance

The aged microenvironment drives metastasis in melanoma cells. This study reports that IGFBP2 secretion by aged fibroblasts induces FASN in melanoma cells and drives metastasis. Neutralizing IGFBP2 decreases melanoma tumor growth and metastasis.

Safety and rapid response of dabrafenib and trametinib therapy during hyperbilirubinemia in metastatic melanoma

This case report describes the occurrence of hyperbilirubinemia as a complication of metastatic melanoma. A 72-year-old male patient was diagnosed with BRAF V600E-mutated melanoma with metastases in the liver, lymph nodes, lungs, pancreas, and stomach. Due to a lack of clinical data and specific guidelines for the treatment of mutated metastatic melanoma patients with hyperbilirubinemia, a conference of specialists debated between initiating treatment or providing supportive care. Ultimately, the patient was started on the combination therapy of dabrafenib and trametinib. This treatment resulted in a significant therapeutic response via normalization of bilirubin levels and an impressive radiological response of metastases just one month post-treatment initiation.

Two unique cases of metastatic malignant melanoma of the gastrointestinal tract

INTRODUCTION AND IMPORTANCE

Gastrointestinal tract (GIT) is a common site for malignant melanoma metastasis, with small bowel being the most common. It is usually difficult to diagnose at an early stage because of the anatomical location of the disease. It is also challenging for pathologists to diagnose due to the small amount of biopsy samples. Survival rates of melanoma patients with distant metastasis are very poor.

CASE PRESENTATION

This study presents two males, aged 67 and 69 years old, who have metastatic melanoma within the GIT. One was metastasis to the esophagus and another with metastasis to the jejunum presenting as intraluminal masses. Their clinical history and pathologic features of the metastasis are evaluated to give an insight into this disease.

CLINICAL DISCUSSION

Gastrointestinal melanoma is hard to detect due to its anatomical location and limited ability to biopsy. Typically, they present at an advanced stage when diagnosed. Approximately 60 % of patients with cutaneous melanoma will have GIT metastasis at the time of autopsy. The small bowel was found to have an affinity for malignant melanoma due to the expression of the CCR9 ligand, CCL25. BRAF mutations are much less observed in GIT mucosal melanomas as compared to cutaneous melanomas. Furthermore, AKAP13-NTRK3 fusion has been reported specifically in the GIT mucosal melanomas. NTRK fusions in general can be observed in metastatic melanomas and have been reported in GIT metastatic melanomas.

CONCLUSION

GIT malignant melanomas are difficult to detect due to their anatomical location, with poor prognosis, and have a unique genetic profile.

Bottom-Up Strategy to Forecast the Drug Location and Release Kinetics in Antitumoral Electrospun Drug Delivery Systems

Electrospun systems are becoming promising devices usable for topical treatments. They are eligible to deliver different therapies, from anti-inflammatory to antitumoral. In the current research, polycaprolactone electrospun membranes loaded with synthetic and commercial antitumoral active substances were produced, underlining how the matrix-filler affinity is a crucial parameter for designing drug delivery devices. Nanofibrous membranes loaded with different percentages of Dacarbazine (the drug of choice for melanoma) and a synthetic derivative of Dacarbazine were produced and compared to membranes loaded with AuM1, a highly active Au-complex with low affinity to the matrix. AFM morphologies showed that the surface profile of nanofibers loaded with affine substances is similar to one of the unloaded systems, thanks to the nature of the matrix-filler interaction. FTIR analyses proved the efficacy of the interaction between the amidic group of the Dacarbazine and the polycaprolactone. In AuM1-loaded membranes, because of the weak matrix-filler interaction, the complex is mainly aggregated in nanometric domains on the nanofiber surface, which manifests a nanometric roughness. Consequently, the release profiles follow a Fickian behavior for the Dacarbazine-based systems, whereas a two-step with a highly prominent burst effect was observed for AuM1 systems. The performed antitumoral tests evidence the high-cytotoxic activity of the electrospun systems against melanoma cell lines, proving that the synthetic substances are more active than the commercial dacarbazine.

Oxidative Stress and Immune Response in Melanoma: Ion Channels as Targets of Therapy

Oxidative stress and immune response play an important role in the development of several cancers, including melanoma. Ion channels are aberrantly expressed in tumour cells and regulate neoplastic transformation, malignant progression, and resistance to therapy. Ion channels are localized in the plasma membrane or other cellular membranes and are targets of oxidative stress, which is particularly elevated in melanoma. At the same time, ion channels are crucial for normal and cancer cell physiology and are subject to multiple layers of regulation, and therefore represent promising targets for therapeutic intervention. In this review, we analyzed the effects of oxidative stress on ion channels on a molecular and cellular level and in the context of melanoma progression and immune evasion. The possible role of ion channels as targets of alternative therapeutic strategies in melanoma was discussed.

Phytochemical Constituents and Derivatives of Cannabis sativa; Bridging the Gap in Melanoma Treatment

Melanoma is deadly, physically impairing, and has ongoing treatment deficiencies. Current treatment regimens include surgery, targeted kinase inhibitors, immunotherapy, and combined approaches. Each of these treatments face pitfalls, with diminutive five-year survival in patients with advanced metastatic invasion of lymph and secondary organ tissues. Polyphenolic compounds, including cannabinoids, terpenoids, and flavonoids; both natural and synthetic, have emerging evidence of nutraceutical, cosmetic and pharmacological potential, including specific anti-cancer, anti-inflammatory, and palliative utility. Cannabis sativa is a wellspring of medicinal compounds whose direct and adjunctive application may offer considerable relief for melanoma suffers worldwide. This review aims to address the diverse applications of C. sativa's biocompounds in the scope of melanoma and suggest it as a strong candidate for ongoing pharmacological evaluation.

Alantolactone Inhibits Melanoma Cell Culture Viability and Migration and Promotes Apoptosis by Inhibiting Wnt/β-Catenin Signaling

BACKGROUND

Melanoma is a highly invasive and metastatic malignant tumor originating from melanocytes and is associated with a poor prognosis. Surgical resection and chemotherapy are currently the main therapeutic options for malignant melanoma; however, their efficacy is poor, highlighting the need for the development of new, safe, and effective drugs for the treatment of this cancer.

OBJECTIVE

To investigate the effects of alantolactone (ALT) on the proliferative, migratory, invasive, and apoptotic ability of malignant melanoma cells and explore its potential anticancer mechanism.

METHODS

Melanoma cells (A375 and B16) were treated with different concentrations (4, 6, 8, and 10 μmol/L) of ALT, with DMSO and no treatment serving as controls. The effects of the different concentrations of the drug on cell proliferation were assessed by crystal violet staining and CCK-8 assay. The effects on cell migration and invasion were detected by wound healing and Transwell assays, respectively. Flow cytometry was used to evaluate the effects of the drug on apoptosis and the cell cycle. ALT target genes in melanoma were screened using network pharmacology. Western blotting was used to measure the expression levels of the proliferation-related protein PCNA; the apoptosisrelated proteins Bax, Bcl-2, and caspase-3; the invasion and metastasis-related proteins MMP-2, MMP-7, MMP-9, vimentin, E-cadherin, and N-cadherin; and the canonical Wnt signaling pathway-related proteins β-catenin, c-Myc, and p-GSK3β. In addition, an l model of melanoma was established by the subcutaneous injection of A375 melanoma cells into nude mice, following which the effects of ALT treatment on malignant melanoma were determined in vivo.

RESULTS

Compared with the controls, the proliferative, migratory, and invasive capacity of ALT-treated melanoma cells was significantly inhibited, whereas apoptosis was enhanced (P<0.01), showing effects that were exerted in a dose-dependent manner. The expression levels of the pro-apoptotic proteins Bax and caspase-3, as well as those of the interstitial marker E-cadherin, were upregulated in melanoma cells irrespective of the ALT concentration (P<0.05). In contrast, the expression levels of the anti-apoptotic protein Bcl-2, the proliferation-related protein PCNA, and the invasion and metastasis-related proteins MMP-2, MMP-7, MMP-9, N-cadherin, and vimentin were downregulated (P<0.05). The network pharmacology results indicated that GSK3β may be a key ALT target in melanoma. Meanwhile, western blotting assays showed that ALT treatment markedly suppressed the expression of β-catenin as well as that of its downstream effector c-Myc, and could also inhibit GSK3β phosphorylation.

CONCLUSION

ALT can effectively inhibit the culture viability, migration, and invasion of A375 and B16 melanoma cells while also promoting their apoptosis. ALT may exert its anti-melanoma effects by inhibiting the Wnt/β-catenin signaling pathway. Combined, our data indicate that ALT has the potential as an effective and safe therapeutic drug for the treatment of melanoma.

METTL3 Promotes the Growth and Invasion of Melanoma Cells by Regulating the lncRNA SNHG3/miR-330-5p Axis

Accumulating evidence indicates that m6A methyltransferase 3 (METTL3) plays a pivotal role in different malignancies including melanoma. However, the function and underlying mechanisms by which METTL3 contributes to the tumorigenesis of melanoma remain undocumented. The association of METTL3 and long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) with clinicopathological characteristics and prognosis in patients with melanoma was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and The Cancer Genome Atlas data sets. The role of METTL3 in melanoma cells was assessed by in vitro and in vivo experiments. The m6A dot blot, methylated RNA immunoprecipitation (MeRIP), and RT-qPCR were used to verify METTL3-mediated m6A modification of lncRNA SNHG3. The effect of METTL3 on lncRNA SNHG3 was determined by luciferase gene reporter assay, RT-qPCR, and Western blotting. We found that METTL3 was upregulated in melanoma tissue samples and associated with poor survival in patients with melanoma. Knockdown of METTL3 suppressed the growth and invasion of melanoma cells in vitro and in vivo, whereas restored expression of METTL3 promoted these effects. Mechanistic investigations showed that knockdown of METTL3 reduced SNHG3 m6A levels and its messenger ribonucleic acid (mRNA) expression levels. SNHG3 could act as a sponge of microRNA (miR)-330-5p to upregulate the expression of CCHC-type zinc finger nucleic acid binding protein (CNBP). SNHG3 overexpression reversed METTL3-knockdown-caused antitumor effects, miR-330-5p upregulation and CNBP downregulation. SNHG3 had a positive correlation with METTL3 expression but a negative correlation with miR-330-5p expression in melanoma tissue samples. In conclusion, our findings demonstrated that METTL3-mediated m6A modification of lncRNA SNHG3 promoted the growth and invasion of melanoma cells by regulating the miR-330-5p/CNBP axis.

TRPV4 Promotes Metastasis in Melanoma by Regulating Cell Motility through Cytoskeletal Rearrangement

The abnormal expression of Transient Receptor Potential cation channel subfamily V member 4 (TRPV4) is closely related to the progression of multiple tumors. In addition, TRPV4 is increasingly being considered a potential target for cancer therapy, especially in tumor metastasis prevention. However, the biological correlation between TRPV4 and tumor metastasis, as well as the specific role of TRPV4 in malignant melanoma metastasis, is poorly understood. In this study, we aimed to examine the role of TRPV4 in melanoma metastasis through experiments and clinical data analysis, and the underlying anticancer mechanism of Baicalin, a natural compound, and its inhibitory effect on TRPV4 with in vivo and in vitro experiments. Our findings suggested that TRPV4 promotes metastasis in melanoma by regulating cell motility via rearranging the cytoskeletal, and Baicalin can inhibit cancer metastasis, whose mechanisms reverse the recruitment of activated cofilin to leading-edge protrusion and the increasing phosphorylation level of cortactin, which is provoked by TRPV4 activation.

A novel endoplasmic reticulum stress-related lncRNA prognostic risk model for cutaneous melanoma

OBJECTIVE

Endoplasmic reticulum stress (ERS) and long non-coding RNAs (lncRNAs) are important in melanoma development and progression. This study aimed to explore the prognostic value of ERS-associated lncRNA profiles in cutaneous melanoma (CM).

METHODS

The Cancer Genome Atlas (TCGA) provides the raw data of CM. GSEA website was used to obtain ERS-related genes, and mRNA and LncRNA co-expression network were used to obtain ERS-related lncRNAs. A Lasso regression analysis was used to identify a prognostic risk model for the composition of ERS-related lncRNAs. Patients were divided into high- and low-risk groups based on the model's risk score. The researchers then compared the two groups' survival rates, immune infiltration, chemotherapeutic drug sensitivity, and immune checkpoint gene expression.

RESULTS

Thirty-nine ERS-related lncRNAs were discovered to be prognostic. A prognostic risk model made up of ten ERS-related lncRNAs was discovered. Patients in the low-risk group had a better prognosis than those in the high-risk group. An examination of tumor microenvironment revealed that risk scores correlated with immune cell infiltration in eight cases. Dacarbazine, paclitaxel, and cisplatin, three chemotherapy drugs, were more sensitive in the low-risk group than in the high-risk group.

CONCLUSION

This study identified a risk model of ten ERS-related lncRNAs that have significant prognostic value in CM and could help guide clinical treatment.

Artificial intelligence in melanoma: A systematic review

BACKGROUND

Melanoma accounts for the majority of skin cancer deaths. Artificial intelligence has been applied in many types of cancers, and in melanoma in recent years. However, no systematic review summarized the application of artificial intelligence in melanoma.

AIMS

This study aims to systematically review previously published articles to explore the application of artificial intelligence in melanoma.

MATERIALS & METHODS

PubMed database was used to search the eligible publications on August 1, 2020. The query term was "artificial intelligence" and "melanoma."

RESULTS

A total of 51 articles were included in this review. Artificial intelligence technique is mainly used in the evaluation of dermoscopic images, other image segmentation and processing, and artificial intelligence diagnosis system.

DISCUSSION

Artificial intelligence is also applied in metastasis prediction, drug response prediction, and prognosis of melanoma. Besides, patients' perspectives of artificial intelligence and collaboration of human and artificial intelligence in melanoma also attracted attention. The query term might not include all articles, and we could not examine the algorithms that were built without publication.

CONCLUSION

The performance of artificial intelligence in melanoma is satisfactory and the future for potential applications is enormous.

Olive leaf extract inhibits metastatic melanoma spread through suppression of epithelial to mesenchymal transition

Olive tree leaves are an abundant source of bioactive compounds with several beneficial effects for human health, including a protective role against many types of cancer. In this study, we investigated the effect of an extract, obtained from olive tree (Olea europaea L.) leaves (OLE), on proliferation, invasion, and epithelial to mesenchymal transition (EMT) on metastatic melanoma, the highly aggressive form of skin cancer and the deadliest diseases. Our results demonstrated that OLE inhibited melanoma cells proliferation through cell cycle arrest and induction of apoptotic cell death. Moreover, OLE suppressed the migration, invasion, and colonies formation of human melanoma cells. Similar to our in vitro findings, we demonstrated that the oral administration of OLE inhibited cutaneous tumor growth and lung metastasis formation in vivo by modulating the expression of EMT related factors. In addition, the anti-proliferative and anti-invasive effects of OLE against melanoma were also related to a simultaneous targeting of mitogen-activated protein kinase and PI3K pathways, both in vitro and in vivo. In conclusion, our findings suggest that OLE has the potential to inhibit the metastatic spread of melanoma cells thanks to its multifaceted mechanistic effects, and may represent a new add-on therapy for the management of metastatic melanoma.

Gain of Chromosome 1q Perturbs a Competitive Endogenous RNA Network to Promote Melanoma Metastasis

Somatic copy-number alterations (CNA) promote cancer, but the underlying driver genes may not be comprehensively identified if only the functions of the encoded proteins are considered. mRNAs can act as competitive endogenous RNAs (ceRNA), which sponge miRNAs to posttranscriptionally regulate gene expression in a protein coding-independent manner. We investigated the contribution of ceRNAs to the oncogenic effects of CNAs. Chromosome 1q gains promoted melanoma progression and metastasis at least in part through overexpression of three mRNAs with ceRNA activity: CEP170, NUCKS1, and ZC3H11A. These ceRNAs enhanced melanoma metastasis by sequestering tumor suppressor miRNAs. Orthogonal genetic assays with miRNA inhibitors and target site blockers, along with rescue experiments, demonstrated that miRNA sequestration is critical for the oncogenic effects of CEP170, NUCKS1, and ZC3H11A mRNAs. Furthermore, chromosome 1q ceRNA-mediated miRNA sequestration alleviated the repression of several prometastatic target genes. This regulatory RNA network was evident in other cancer types, suggesting chromosome 1q ceRNA deregulation as a common driver of cancer progression. Taken together, this work demonstrates that ceRNAs mediate the oncogenicity of somatic CNAs.

SIGNIFICANCE

The function of CEP170, NUCKS1, and ZC3H11A mRNAs as competitive endogenous RNAs that sequester tumor suppressor microRNAs underlies the oncogenic activity of chromosome 1q gains.

Differential Gene Expression and Methylation Analysis of Melanoma in TCGA Database to Further Study the Expression Pattern of KYNU in Melanoma

Background: The aim of this study was to analyze and compare melanoma gene expression profiles in TCGA database through the application of different genes to explore the pathogenesis of melanoma. Furthermore, we confirmed the extent of the role of KYNU in melanoma and whether it can be a potential target for the diagnosis and treatment of melanoma. Methods: The gene expression profiles of melanoma samples were downloaded from TCGA database, and matrix files were synthesized to screen differential genes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analysis and GCDA broad institute were used to analyze common gene locus mutations and expression changes in melanoma, as well as methylation. In addition, the expression patterns of KYNU in melanoma were quantified by immunohistochemistry, Western blotting, qRT-PCR, software such as GEO DataSets and the Human Protein Atlas, and meta-analysis of skin diseases. KYNU was overexpressed in keratinocytes (HaCaT and HEKα) and melanoma cells (A375 and H1205-lu). CFDA-SE, Annexin V–PI double staining, and PI single staining were used to investigate the mechanism of KYNU in melanoma and its effects on melanoma proliferation, apoptosis, invasion, and migration. Results: The main signaling pathways involved in melanoma were EGF/EGFR–RAS–BRAF–MEK–ERK–CyclinD1/CDK4, Ras–PI3K–PTEN–PKB/AKT, and p14/p16 (CDKN2A)–MDM2–p53–p21–cyclinD1/CDK4/6–Rb/E2F. Moreover, MITF, KIT, CDH1. NRAS, AKT1, EGFR, TP53, KIT, and CDK4 were elevated in melanoma, whereas PTEN, cAMP, and BCL2 were reduced in melanoma. The copy number of tumor-promoting genes increased, while the copy number of tumor suppressor genes decreased. Changes in the copy number of the above tumor genes enriched in chromosomes were found through SNP gene mutations. The genes whose expression was negatively regulated by DNA methylation in melanoma included KRT18, CDK2, JAK3, BCL2, MITF, MET, CXCL10, EGF, SOX10, SOCS3, and KIT. The mutation rate of KYNU was high according to TCGA database. The KYNU level was decreased in melanoma. Overexpression of KYNU can promote changes in apoptotic BCL-2, metabolic KYN, 3-HAA, invasion and migration MMP9, E-cadherin, and other related proteins in melanoma. Fluorescence staining and flow analysis showed that a slower proliferation rate led to a stronger fluorescence intensity. In melanoma tumor cells with a low expression of KYNU, overexpression of KYNU could promote tumor cell apoptosis. IL-10 induced immunoregulatory changes in melanoma. The expression of MMP9 and AMPK decreased in A375, but the change in BCL-2 was not obvious. The expression of BCL-2 decreased significantly in H1205-lu. A375 showed cell-cycle arrest, indicating that IL-10 could slow down the cell cycle of melanoma. Conclusions: These results provide insights into the pathologic mechanisms of melanoma target genes and KYNU as a biomarker and potential therapeutic factor for melanoma.

Cilengitide, an αvβ3-integrin inhibitor, enhances the efficacy of anti-programmed cell death-1 therapy in a murine melanoma model

Integrins play an important role in multiple stages of tumor progression and metastasis. Previous studies have shown synergistic effects of combined αvβ6-integrin and αvβ8-integrin inhibitors with immunotherapy. However, the role of αvβ3-integrin inhibitor in tumor immunity is still unclear. In this study, we aimed to elucidate the impact of the αvβ3-integrin inhibitor on PD-L1 expression and sensitivity to immune checkpoint blockade in melanoma. We investigated the effects of cilengitide, an αvβ3-integrin inhibitor, on cell viability and apoptosis of melanoma cell lines. And we explored how cilengitide regulated the expression of PD-L1 in melanoma cells in vitro and in vivo, using immunofluorescence, flow cytometry, Western blotting, and immunohistochemistry. A subcutaneous B16 murine melanoma model was utilized to determine whether combining cilengitide with anti-PD1 therapy inhibited tumor growth and positively regulated tumor microenvironment (TME). Our results showed that cilengitide inhibited cell viability and induced apoptosis in B16 and A375 cell lines. Furthermore, cilengitide decreased PD-L1 expression by reducing STAT3 phosphorylation in two melanoma cell lines. Cilengitide also reduced subcutaneous tumor PD-L1 expression in the B16 murine melanoma model. Accordingly, cilengitide positively regulated antitumor immune responses and provided durable therapy when combined with anti-PD1 monoclonal antibody in the murine melanoma model. This combination therapy reduced tumor growth and extended survival. Our study highlights that cilengitide enhances the efficacy of anti-PD1 therapy and produces a stronger antitumor immune response. This combination therefore represents a novel therapeutic regimen that may improve immunotherapy treratment.

Upregulation of REV7 correlates with progression of malignant melanoma

REV7 is a multifunctional protein implicated in DNA damage tolerance, cell cycle control, and gene expression, and is involved in the carcinogenesis of various human tumors. It has been reported that REV7 expression is associated with ultraviolet-induced mutagenesis; however, the role of REV7 expression in skin cancers, including malignant melanomas, remains unclear. In the present study, we investigated the clinical and biological significance of REV7 in malignant melanoma. Levels of REV7 expression in human skin cancers were evaluated immunohistochemically. Positive expression of REV7 was frequently observed in malignant melanomas, as well as in squamous cell carcinomas and basal cell carcinomas. Enhanced immunoreactivity to REV7 was closely linked with cell proliferation assessed by Ki-67 labeling indexes in the three skin cancers, and was related with tumor thickness in malignant melanomas. REV7 depletion in malignant melanoma cells MEWO and G361 suppressed cell proliferation, migration, and invasion abilities. REV7 depletion also affected the expression of intracellular signaling molecules AKT and ERK in MEWO cells, resulting in downregulation of ERK signal activation. In addition, REV7 depletion facilitated sensitivity to cisplatin, but not to dacarbazine, in MEWO cells. Our results suggest that REV7 expression correlates with disease progression of malignant melanoma.

Genomic and Transcriptomic Underpinnings of Melanoma Genesis, Progression, and Metastasis

Melanoma is a deadly skin cancer with rapidly increasing incidence worldwide. The discovery of the genetic drivers of melanomagenesis in the last decade has led the World Health Organization to reclassify melanoma subtypes by their molecular pathways rather than traditional clinical and histopathologic features. Despite this significant advance, the genomic and transcriptomic drivers of metastatic progression are less well characterized. This review describes the known molecular pathways of cutaneous and uveal melanoma progression, highlights recently identified pathways and mediators of metastasis, and touches on the influence of the tumor microenvironment on metastatic progression and treatment resistance. While targeted therapies and immune checkpoint blockade have significantly aided in the treatment of advanced disease, acquired drug resistance remains an unfortunately common problem, and there is still a great need to identify potential prognostic markers and novel therapeutic targets to aid in such cases.

Treating Metastatic Brain Cancers With Stem Cells

Stem cell therapy may present an effective treatment for metastatic brain cancer and glioblastoma. Here we posit the critical role of a leaky blood-brain barrier (BBB) as a key element for the development of brain metastases, specifically melanoma. By reviewing the immunological and inflammatory responses associated with BBB damage secondary to tumoral activity, we identify the involvement of this pathological process in the growth and formation of metastatic brain cancers. Likewise, we evaluate the hypothesis of regenerating impaired endothelial cells of the BBB and alleviating the damaged neurovascular unit to attenuate brain metastasis, using the endothelial progenitor cell (EPC) phenotype of bone marrow-derived mesenchymal stem cells. Specifically, there is a need to evaluate the efficacy for stem cell therapy to repair disruptions in the BBB and reduce inflammation in the brain, thereby causing attenuation of metastatic brain cancers. To establish the viability of stem cell therapy for the prevention and treatment of metastatic brain tumors, it is crucial to demonstrate BBB repair through augmentation of vasculogenesis and angiogenesis. BBB disruption is strongly linked to metastatic melanoma, worsens neuroinflammation during metastasis, and negatively influences the prognosis of metastatic brain cancer. Using stem cell therapy to interrupt inflammation secondary to this leaky BBB represents a paradigm-shifting approach for brain cancer treatment. In this review article, we critically assess the advantages and disadvantages of using stem cell therapy for brain metastases and glioblastoma.

Organ Specific Copy Number Variations in Visceral Metastases of Human Melanoma

Malignant melanoma is one of the most aggressive skin cancers with high potential of visceral dissemination. Since the information about melanoma genomics is mainly based on primary tumors and lymphatic or skin metastases, an autopsy-based visceral metastasis biobank was established. We used copy number variation arrays (N = 38 samples) to reveal organ specific alterations. Results were partly completed by proteomic analysis. A significant increase of high-copy number gains was found in an organ-specific manner, whereas copy number losses were predominant in brain metastases, including the loss of numerous DNA damage response genes. Amplification of many immune genes was also observed, several of them are novel in melanoma, suggesting that their ectopic expression is possibly underestimated. This "immunogenic mimicry" was exclusive for lung metastasis. We also provided evidence for the possible autocrine activation of c-MET, especially in brain and lung metastases. Furthermore, frequent loss of 9p21 locus in brain metastases may predict higher metastatic potential to this organ. Finally, a significant correlation was observed between BRAF gene copy number and mutant allele frequency, mainly in lung metastases. All of these events may influence therapy efficacy in an organ specific manner, which knowledge may help in alleviating difficulties caused by resistance.

LncRNA BASP1-AS1 interacts with YBX1 to regulate Notch transcription and drives the malignancy of melanoma

Melanoma is a fatal skin malignant tumor with a poor prognosis. We found that long noncoding RNA BASP1-AS1 is essential for the development and prognosis of melanoma. The methylation, RNA sequencing, copy number variation, mutation data, and sample follow-up information of melanoma from The Cancer Genome Atlas (TCGA) were analyzed using weighted gene co-expression network analysis and 366 samples common to the three omics were selected for multigroup clustering analysis. A four-gene prognostic model (BASP1-AS1, LOC100506098, ARHGAP27P1, and LINC01532) was constructed in the TCGA cohort and validated using the GSE65904 series. The expression of BASP1-AS1 was upregulated in melanoma tissues and various melanoma cell lines. Functionally, the ectopic expression of BASP1-AS1 promoted cell proliferation, migration, and invasion in both A375 and SK-MEL-2 cells. Mechanically, BASP1-AS1 interacted with YBX1 and recruited it to the promoter of NOTCH3, initiating its transcription process. The activation of the Notch signaling then resulted in the transcription of multiple oncogenes, including c-MYC, PCNA, and CDK4, which contributed to melanoma progression. Thus, BASP1-AS1 could act as a potential biomarker for cutaneous malignant melanoma.

High regional mortality due to malignant melanoma in Eastern Finland may be explained by the increase in aggressive melanoma types

Background

A regional skin cancer prevention program in Eastern Finland revealed a relatively high age-standardized mortality due to malignant melanoma during 2013–2017. An explanation for this is needed.

Purpose

To analyse the 543 melanoma samples in 524 subjects collected during 2000–2013 at Kuopio University Hospital and reposited in the Biobank of Eastern Finland. A focus was directed to factors related to metastasis.

Methods

The samples were analysed anonymously by examining the histopathological report, referral text and the list of diagnoses. A possible state of immunosuppression was evaluated.

Results

The mean age at the diagnosis of malignant melanoma (MM), lentigo maligna (LM) and melanoma in situ was relatively high, i.e., 66.2, 72.1 and 63.3, respectively. Especially the MM type increased markedly during 2000–2013. In further analyses of a representative cohort of 337 samples, the proportion of nodular melanoma and LM/LMM melanoma was relatively high, 35.6 and 22.0%, respectively, but that from superficial spreading melanoma relatively low (33.8%). Metastasis correlated with immunosuppression, male gender, Clark level, Breslow thickness, ulceration, mitosis count, invasion into vessels and/or perineural area, microsatellites, melanoma subtype, body site, recidivism, and the absence of dysplastic nevus cells.

Conclusion

The marked increase in aggressive melanomas with associated metastasis, and the relatively high age at diagnosis, can partially explain the mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08879-1.

Squaring the circle: circRNAs in melanoma

Non-coding RNAs are emerging as critical molecules in the genesis, progression, and therapy resistance of cutaneous melanoma. This includes circular RNAs (circRNAs), a class of non-coding RNAs with distinct characteristics that forms through non-canonical back-splicing. In this review, we summarize the features and functions of circRNAs and introduce the current knowledge of the roles of circRNAs in melanoma. We also highlight the various mechanisms of action of the well-studied circRNA CDR1as and describe how it acts as a melanoma tumor suppressor. We further discuss the utility of circRNAs as biomarkers, therapeutic targets, and therapeutic agents in melanoma and outline challenges that must be overcome to comprehensively characterize circRNA functions.

Effect of piceatannol against malignant melanoma in vivo and in vitro

OBJECTIVES

To study the antitumor effect of piceatannol (PIC) on malignant melanoma in vitro and in vivo.

METHODS

B16F10 cells were cultured in vitro and treated with gradient concentrations of PIC. Cell viability was detected with methyl thiazolyl tetrazolium (MTT) assay; matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF), spleen tyrosine kinase (Syk), and p-Syk were detected with Western blot; migration ability was detected with wound healing assay; invasion ability was detected with Transwell assay. Syk expression was suppressed through RNA interference for the detection of the possible mechanism of PIC in melanoma. An in vivo study was established by creating B16F10-bearing mice with intraperitoneal injection of PIC.

RESULTS

The cell viability of B16F10 decreased with increasing PIC concentration. The results of the Transwell assay showed that invasion ability decreased with increasing PIC concentration, and healing time was prolonged at increased PIC concentration in the wound healing assay. Western blot results showed that PIC mainly inhibited the phosphorylation of Syk and inhibited the expression of MMP-2, MMP-9, and VEGF. RNA interference pointed out that blocking the expression of Syk can reveal the same inhibition effect on B16F10 cells as PIC. In vivo study revealed that different concentrations of PIC cangreatly inhibit melanoma progression.

CONCLUSIONS

PIC might block the progression of malignant melanoma by inhibiting spleen tyrosine kinase.

TGF-β Increases MFGE8 Production in Myeloid-Derived Suppressor Cells to Promote B16F10 Melanoma Metastasis

There is growing evidence that myeloid-derived suppressor cells (MDSCs) are directly involved in all stages leading to metastasis. Many mechanisms for this effect have been proposed, but mechanisms of coregulation between tumor cells and MDSCs remain poorly understood. In this study, we demonstrate that MDSCs are a source of milk fat globule-epidermal growth factor (EGF) factor 8 (MFGE8), which is known to be involved in tumor metastasis. Interestingly, TGF-β, an abundant cytokine in the tumor microenvironment (TME), increased MFGE8 production by MDSCs. In addition, co-culturing MDSCs with B16F10 melanoma cells increased B16F10 cell migration, while MFGE8 neutralization decreased their migration. Taken together, these findings suggest that MFGE8 is an important effector molecule through which MDSCs promote tumor metastasis, and the TME positively regulates MFGE8 production by MDSCs through TGF-β.

The Research on the Treatment of Metastatic Skin Cutaneous Melanoma by Huanglian Jiedu Decoction Based on the Analysis of Immune Infiltration Analysis

Objective

To explore the potential mechanism of Huanglian Jiedu Decoction (HJD) treatment and prevention of metastatic Cutaneous Melanoma (CM) occurrence and metastasis based on network pharmacological methods and immune infiltration analysis.

Methods

The GEO database was used to obtain metastatic CM disease targets, the TCMSP database and the HERB database were used to obtain HJD action targets, core genes were screened by protein interaction network, and the potential mechanism of HJD in the treatment of metastatic CM was explored by enrichment analysis, prognostic analysis and immune infiltration analysis.

Results

HJD treatment of metastatic CM involved 60 targets, enrichment analysis showed that HJD treatment of metastatic CM involved Chemokine signaling pathway, NF-kappa B signaling pathway, and Fluid shear stress and atherosclerosis, etc. Prognostic analysis revealed that HJD had a certain ability to improve the prognosis of metastatic CM patients. Immune infiltration analysis showed that HJD could inhibit the immune cell infiltration of metastatic CM patients by acting on related targets.

Conclusions

Our study identified the potential mechanism of HJD in the treatment of metastatic CM through network pharmacology, and revealed the mechanism of HJD in the prevention of Skin Cutaneous Melanoma metastasis through immune infiltration analysis and prognostic analysis.

Intravenously Infused Stem Cells for Cancer Treatment

Despite the recent influx of immunotherapies and small molecule drugs to treat tumors, cancer remains a leading cause of death in the United States, in large part due to the difficulties of treating metastatic cancer. Stem cells, which are inherently tumoritropic, provide a useful drug delivery vehicle to target both primary and metastatic tumors. Intravenous infusions of stem cells carrying or secreting therapeutic payloads show significant promise in the treatment of cancer. Stem cells may be engineered to secrete cytotoxic products, loaded with oncolytic viruses or nanoparticles containing small molecule drugs, or conjugated with immunotherapies. Herein we describe these preclinical and clinical studies, discuss the distribution and migration of stem cells following intravenous infusion, and examine both the limitations of and the methods to improve the migration and therapeutic efficacy of tumoritropic, therapeutic stem cells.

Cutaneous Metastases from Primary Liver Cancers: The Need for Knowledge and Differential Diagnosis

Primary skin tumors are certainly more frequent than metastatic tumors, but the latter can sometimes be the first sign of otherwise unrecognized neoplastic pathology and always correspond to an advanced stage of the disease. Among the various neoplasms that can metastasize in cutaneous districts, skin metastases from primary malignant neoplasms from the liver and biliary tract are infrequent, and when they do occur they can pose differential diagnosis problems to the pathologist. Here we present two cases of metastatic skin lesions, respectively originating from the liver and the intrahepatic biliary tract, and we conduct a brief review of the current literature.

Circ_0013359 facilitates the tumorigenicity of melanoma by regulating miR-136-5p/RAB9A axis

Background

Circular RNAs play crucial roles in tumor occurrence and progression. This research aimed to explore the role and potential mechanism of hsa_circ_0013359 (circ_0013359) in melanoma.

Methods

The levels of circ_0013359, microRNA-136-5p (miR-136-5p), and member RAS oncogene family (RAB9A) in melanoma tissues and cells were detected using quantitative reverse transcriptase-polymerase chain reaction or western blot. Cell proliferation, apoptosis, cell cycle, cell migration, and invasion were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, colony formation assay, flow cytometry, and transwell assay. Glycolysis was determined by detecting glucose consumption, lactate production, and extracellular acidification rate. The levels of hexokinase 2 and lactate dehydrogenase A were examined by western blot. The targeting relationship between miR-136-5p and circ_0013359 or RAB9A was confirmed by dual-luciferase reporter assay. Xenograft experiments were used to analyze tumor growth in vivo.

Results

Circ_0013359 and RAB9A levels were increased, while the miR-136-5p level was reduced in melanoma tissues and cells. Circ_0013359 knockdown inhibited proliferation, migration, invasion, and glycolysis and promoted apoptosis and cycle arrest in A875 and SK-MEL-1 cells. Circ_0013359 sponged miR-136-5p to regulate melanoma progression. In addition, miR-136-5p suppressed melanoma progression by targeting RAB9A. Besides, circ_0013359 silencing inhibited tumor growth in vivo.

Conclusion

Depletion of circ_0013359 hindered melanoma progression by regulating miR-136-5p/RAB9A axis.

Tetrahydrocannabinol and Skin Cancer: Analysis of YouTube Videos

BACKGROUND

Cannabis oil is being used topically by patients with skin cancer as a homeopathic remedy, and has been promoted and popularized on social media, including YouTube. Although topical cannabinoids, especially tetrahydrocannabinol (THC), may have antitumor effects, results from a sparse number of clinical trials and peer-reviewed studies detailing safety and efficacy are still under investigation.

OBJECTIVE

We sought to assess the accuracy, quality, and reliability of THC oil and skin cancer information available on YouTube.

METHODS

The 10 most-viewed videos on THC oil and skin cancer were analyzed with the Global Quality Scale (GQS), DISCERN score, and useful/misleading criteria based on presentation of erroneous and scientifically unproven information. The videos were also inspected for source, length, and audience likes/dislikes. Top comments were additionally examined based on whether they were favorable, unfavorable, or neutral regarding the video content.

RESULTS

All analyzed videos (10/10, 100%) received a GQS score of 1, corresponding to poor quality of content, and 9/10 (90%) videos received a DISCERN score of 0, indicating poor reliability of information presented. All 10 videos were also found to be misleading and not useful according to established criteria. Top comments were largely either favorable (13/27, 48%) or neutral (13/27, 48%) toward the content of the videos, compared to unfavorable (1/27, 4%).

CONCLUSIONS

Dermatologists should be aware that the spread of inaccurate information on skin cancer treatment currently exists on popular social media platforms and may lead to detrimental consequences for patients interested in pursuing alternative or homeopathic approaches.

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.

Cul4b Promotes Progression of Malignant Cutaneous Melanoma Patients by Regulating CDKN2A

Although several molecular targeted therapy and immunotherapy have been developed, cutaneous melanoma prognosis is still not satisfying. Cul4b promotes the progression of several malignant tumors by regulating cell proliferation. However, its prognostic role in malignant cutaneous melanoma has not been evaluated. In this study, immunohistochemistry was performed to assess the expression of Cul4b in a consecutive patient cohort. The prognostic role of Cul4b was estimated with univariate and multivariate analysis. Cul4b was knocked down in melanoma cell line to evaluate its role in promoting cell proliferation. The results revealed that Cul4b was highly expressed in some of the cutaneous malignant melanoma patients and high expression of Cul4b was associated with poor melanoma-specific overall survival and poor disease-free survival. Cul4b expression was associated with Breslow categories, Clark level, and Ki67 expression. Univariate and multivariate analysis revealed that Cul4b is an independent prognosis risk factor of cutaneous melanoma. Downregulation of Cul4b inhibited the proliferation ability of melanoma cells and downregulated the expression of CDKN2A. These results suggest that Cul4b plays an essential role in cutaneous melanoma progression and may serve as a promising treatment target.

Cardiac Melanoma Metastasis with ERBB2 Gene Amplification: A Potential for Future Targeted Therapy

Cardiac tumors are rare, and their treatment differs interindividually regarding the histopathological proprieties and the stage of disease. Authors present a case of symptomatic cardiac melanoma metastasis that expressed an ERBB2 (HER2) gene amplification in a course of the disease that has not yet been reported. The frail patient with a history of pulmonary and renal carcinoma, was admitted to the hospital due to a symptomatic left atrial tumor mass. The patient underwent a tumor-resecting cardiac surgery. At first mistaken for myxoma on echocardiography, the histopathological examination of the tumor revealed a melanoma of acral or mucosal origin. The melanoma metastasis was negative for common genetic mutations in BRAF, NRAS or KIT genes, and for the presence of NTRK genes fusions, but carried ERBB2 (HER2) gene amplification. The absence of standard gene mutations rendered it unresponsive to treatment with BRAF and MEK inhibitors. This molecular finding is rare in melanomas and represented a therapeutic target for off-label systemic treatment with drugs, primarily aimed at ERBB2 positive breast, gastric, and gastroesophageal junction cancers. A rare finding like this justifies molecular genetic analysis of unusual tumor specimen and guarantees optimal treatment for uncommon types of cardiac metastatic tumors.

Silencing Osteopontin Expression Inhibits Proliferation, Invasion and Induce Altered Protein Expression in Melanoma Cells

Osteopontin (OPN) is a multifunctional phosphoprotein that is expressed in different types of cancers, including melanoma. OPN overexpression is associated with tumor progression and metastasis formation; however, the role of OPN in cell invasion and metastasis formation is not completely understood. In this study we aimed to define OPN expression in melanoma tissues and cell lines and investigate the effect of OPN expression on cell proliferation and invasion after inhibiting OPN expression with small interfering RNA (siRNA). OPN gene expression was determined by qRT-PCR, while protein expression was examined using a Proteome Profiler Oncology Array. siRNA-mediated OPN knockdown led to decreased OPN expression in melanoma cell lines, which was associated with decreased cell proliferation and invasion. Proteome profile analysis revealed significantly different protein expression between the original and transfected cell lines. The altered expression of the differently expressed proteins was validated at the mRNA level. Furthermore, OPN-specific siRNA was able to reduce OPN expression and inhibit the invasiveness of melanoma cells. Our results revealed for the first time that silencing the OPN gene influences proliferation and invasion of melanoma cells by effecting EGFR, tenascin C, survivin, galectin-3 and enolase 2 expression. To predict protein-protein interactions along with putative pathways we used STRING analysis for the differentially expressed proteins. These proteins formed multiple clusters, including extracellular matrix organization, regulation of angiogenesis, cell death and cell migration, PI3K-Akt, MAPK and focal adhesion signaling pathways. Taken together these data suggest that OPN might be an ideal target for drug development and therapies.