The new paradigm of systemic therapies for metastatic melanoma

BCKDHA contributes to melanoma progression by promoting the expressions of lipogenic enzymes FASN and ACLY

The dysregulation of branched-chain amino acid (BCAA) metabolism and related enzymes has been greatly implicated in the progression of multiple types of cancer, whereas remains far from understood in melanoma. Here, we explored the role of the BCAA metabolism enzyme BCKDHA in melanoma pathogenesis and elucidated the underlying mechanisms. In vitro cell biology experiments and in vivo pre-clinical mice model experiments were performed to investigate the role of BCKDHA in melanoma progression. RNA sequencing, immunohistochemical/immunofluorescence staining and bioinformatics analysis were used to examine the underlying mechanism. BCKDHA expression was prominently increased in both melanoma tissues and cell lines. The up-regulation of BCKDHA promoted long-term tumour cell proliferation, invasion and migration in vitro and tumour growth in vivo. Through RNA-sequencing technology, it was found that BCKDHA regulated the expressions of lipogenic fatty acid synthase (FASN) and ATP-citrate lyase (ACLY), which was thereafter proved to mediate the oncogenic role of BCKDHA in melanoma. Our results demonstrate that BCKDHA promotes melanoma progression by regulating FASN and ACLY expressions. Targeting BCKDHA could be exploited as a promising strategy to restrain tumour progression in melanoma.

ETS transcription factor ELK3 in human cancers: An emerging therapeutic target

Cancer is a genetic and complex disorder, resulting from several events associated with onset, development, and metastasis. Tumor suppressors and oncogenes are among the main regulators of tumor progression, contributing to various cancer-related behaviors like cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), cell cycle, and apoptosis. Transcription factors (TFs) could act as tumor suppressors or oncogenes in cancer progression. E-twenty-six/E26 (ETS) family of TFs have a winged helix-turn-helix (HLH) motif, which interacted with specific DNA regions with high levels of purines and GGA core. ETS proteins act as transcriptional repressors or activators to modulate the expression of target genes. ETS transcription factor ELK3 (ELK3), as a type of ETS protein, was shown to enhance in various cancers, suggesting that it may have an oncogenic role. These studies indicated that ELK3 promoted invasion, migration, cell cycle, proliferation, and EMT, and suppressed cell apoptosis. In addition, these studies demonstrated that ELK3 could be a promising diagnostic and prognostic biomarker in human cancer. Moreover, accumulating data proved that ELK3 could be a novel chemoresistance mediator in human cancer. Here, we aimed to explore the overall change of ELK3 and its underlying molecular mechanism in human cancers. Moreover, we aimed to investigate the potential role of ELK3 as a prognostic and diagnostic biomarker as well as its capability as a chemoresistance mediator in cancer.

Advances in Stigmasterol on its anti-tumor effect and mechanism of action

Stigmasterol is a phytosterol derived from multiple herbaceous plants such as herbs, soybean and tobacco, and it has received much attention for its various pharmacological effects including anti-inflammation, anti-diabetes, anti-oxidization, and lowering blood cholesterol. Multiple studies have revealed that stigmasterol holds promise as a potentially beneficial therapeutic agent for malignant tumors because of its significant anti-tumor bioactivity. It is reported that stigmasterol has anti-tumor effect in a variety of malignancies (e.g., breast, lung, liver and ovarian cancers) by promoting apoptosis, inhibiting proliferation, metastasis and invasion, and inducing autophagy in tumor cells. Mechanistic study shows that stigmasterol triggers apoptosis in tumor cells by regulating the PI3K/Akt signaling pathway and the generation of mitochondrial reactive oxygen species, while its anti-proliferative activity is mainly dependent on its modulatory effect on cyclin proteins and cyclin-dependent kinase (CDK). There have been multiple mechanisms underlying the anti-tumor effect of stigmasterol, which make stigmasterol promising as a new anti-tumor agent and provide insights into research on its anti-tumor role. Presently, stigmasterol has been poorly understood, and there is a paucity of systemic review on the mechanism underlying its anti-tumor effect. The current study attempts to conduct a literature review on stigmasterol for its anti-tumor effect to provide reference for researchers and clinical workers.

Melanoma: An update on systemic therapies

Despite advances in early detection as described in part 1 of this continuing medical education series, melanoma continues to be a large contributor to cutaneous cancer-related mortality. In a subset of patients with unresectable or metastatic disease, surgical clearance is often not possible; therefore, systemic and local therapies are considered. The second article in this series provides dermatologists with an up-to-date working knowledge of the treatment options that may be prescribed by oncologists for patients with unresectable stage III, stage IV, and recurrent melanoma.

The Effects of Hedgehog Signaling Pathway on the Proliferation and Apoptosis of Melanoma Cells

Background

Studies have found that the abnormality of the Hedgehog signaling pathway is related to the occurrence and development of a variety of tumors, but the effect of this signaling pathway on melanoma cells is still unclear.

Methods

This study aimed to discuss the effect of Hedgehog signaling pathway on the proliferation and apoptosis of human malignant melanoma A375 cells and explore its possible mechanism in the proliferation and apoptosis of melanoma cells. Different concentrations of Hedgehog signaling pathway inhibitor cyclopamine (5, 10, 20 and 40 μM) were used to treat human melanoma A375 cells for 24, 48, and 72 h, and set a blank control group (0 μM). Trypan blue cell counting method was used to detect cell viability. MTT method was used to detect the inhibition rate of cell proliferation. Transwell was used to detect cell invasion, and flow cytometry was used to detect cell apoptosis.

Results

Through the trypan blue cell counting method and MTT experiment, it was found that the Hedgehog signaling pathway inhibitor cyclopamine has an inhibitory effect on the proliferation and viability of melanoma A375 cells (P < 0.05), and the proliferation inhibitory effect is enhanced with prolonged action time in a dose- and time-dependent manner. Transwell experiment showed that compared with the blank control group, the invasion and migration ability of the treated melanoma A375 cells are significantly reduced, and the difference is statistically significant (P < 0.05). Cell apoptosis experiment showed that compared with the blank control group, the apoptosis rate of A375 cells is significantly higher after treated by 40 μM cyclopamine for 24 h, and the difference is statistically significant (P < 0.05). Gli1 and Bcl-2 protein are highly expressed in melanoma A375 cells, and their expressions show a downward trend (P < 0.05) after being treated by cyclopamine.

Conclusion

Cyclopamine inhibits cell proliferation and induces cell apoptosis by downregulating Gli1. Hedgehog signaling pathway can be used as a new target for the treatment of malignant melanoma, and multiple measures can be used to inhibit the signaling pathway to achieve a therapeutic effect.

Liquid biopsy-based analysis by ddPCR and CAPP-Seq in melanoma patients

BACKGROUND

The development of BRAF/MEK inhibitors in patients with metastatic melanoma harboring BRAF mutations has garnered attention for liquid biopsy to detect BRAF mutations in cell-free DNA (cfDNA) using droplet digital PCR (ddPCR) or next-generation sequencing methods.

OBJECTIVE

To investigate gene mutations in tumor DNA and cfDNA collected from 43 melanoma patients and evaluate their potential as biomarkers.

METHODS

ddPCR and CAncer Personalized Profiling by deep Sequencing (CAPP-Seq) techniques were performed to detect gene mutations in plasma cfDNA obtained from patients with metastatic melanoma.

RESULTS

Gene variants, including BRAF, NRAS, TP53, GNAS, and MET, were detectable in the plasma cfDNA, and the results were partially consistent with the results of those identified in the tissues. Among the variants examined, copy numbers of MET mutations were consistent with the disease status in two melanoma patients.

CONCLUSION

Liquid biopsy using CAPP-Seq and ddPCR has the potential to detect tumor presence and mutations, especially when tissue biopsies are unavailable. MET mutations in cfDNA may be a potential biomarker in patients with metastatic melanoma.

Journey of the Patient With Melanoma: Understanding Resource Use and Bridging the Gap Between Dermatologist, Surgeon, and Oncologist in Different Health Care Systems

PURPOSE

New scientific evidence has led to modifications in the clinical practice of handling melanoma. In health care systems, there is currently a wide variety of clinical procedures to treat cancer, and the various routes have different effects on the survival of patients with cancer. Thus, this article aimed to evaluate the journey of patients with melanoma in the public and private health care systems in Brazil from the viewpoint of different medical professionals involved in the diagnosis and treatment of the disease. The study also considers the resources used for the complete delivery cycle of health care at different stages of the evolution of melanoma.

METHODS

We conducted a behavioral study by applying a questionnaire to a group of medical professionals. A nonprobabilistic sampling method for convenience was used, justified by the heterogeneous national incidence and the limited availability of medical professionals who diagnose and treat melanoma.

RESULTS

The questionnaire was answered by 138 doctors, including doctors from the Brazilian states with the highest concentration of medical specialists and regions with a higher melanoma incidence. The results of this study have the potential to enrich our understanding of the reality of Brazilian health care systems and, at the same time, allow us to discuss the multiple ways in which professionals from diverse specialist fields understand and explain decision making in health care.

CONCLUSION

Health care decision making is complex and, among other factors, depends on the diversity of available health resources and the knowledge of which treatments provide the greatest benefit to patients and greatest value to the system as a whole. This work can inform debates and reflection that are applicable not only in Brazil, but also in various other countries with similar realities.

The Evolution of Care of Cancers of the Head and Neck Region: State of the Science in 2020

Cancers that arise in the head and neck region are comprised of a heterogeneous group of malignancies that include carcinogen- and human papillomavirus (HPV)-driven mucosal squamous cell carcinoma as well as skin cancers such as cutaneous squamous cell carcinoma, basal cell carcinoma, melanoma, and Merkel cell carcinoma. These malignancies develop in critical areas for eating, talking, and breathing and are associated with substantial morbidity and mortality despite advances in treatment. Understanding of advances in the management of these various cancers is important for all multidisciplinary providers who care for patients across the cancer care continuum. Additionally, the recent Coronavirus Disease 2019 (COVID-19) pandemic has necessitated adaptations to head and neck cancer care to accommodate the mitigation of COVID-19 risk and ensure timely treatment. This review explores advances in diagnostic criteria, prognostic factors, and management for subsites including head and neck squamous cell carcinoma and the various forms of skin cancer (basal cell carcinoma, cutaneous squamous cell carcinoma, Merkel cell carcinoma, and melanoma). Then, this review summarizes emerging developments in immunotherapy, radiation therapy, cancer survivorship, and the delivery of care during the COVID-19 era.

Cancer stem cells, epigenetics, tumor microenvironment and future therapeutics in cutaneous malignant melanoma: a review

This review provides an overview of the current understanding of the ontogeny and biology of melanoma stem cells in cutaneous malignant melanoma. This article also summarizes and evaluates the current knowledge of the underlying epigenetic mechanisms, the regulation of melanoma progress by the tumor microenvironment as well as the therapeutic implications and applications of these novel insights, in the setting of personalized medicine. Unraveling the complex ecosystem of cutaneous malignant melanoma and the interplay between its components, aims to provide novel insights into the establishment of efficient therapeutic strategies.

Neutrophil-predominant bullous pemphigoid induced by checkpoint inhibitors: A case series

Checkpoint inhibitors have been revolutionary in the treatment of metastatic melanoma, non-small-cell lung cancer, and renal cell carcinoma. By restricting negative feedback of T-cells, checkpoint inhibitors allow the immune system to identify and destroy malignant cells. This enhanced immune response is efficacious in the treatment of the aforementioned malignancies; however, it may lead to immune-related adverse events. Bullous pemphigoid (BP) is a well-documented cutaneous adverse reaction of checkpoint inhibitors, with a majority of cases reporting an eosinophil-predominant or mixed inflammatory infiltrate. We report two cases of neutrophil-predominant BP presenting in patients on checkpoint inhibitors.

TERT Promoter Mutations Differently Correlate with the Clinical Outcome of MAPK Inhibitor-Treated Melanoma Patients

Resistance is a major challenge in the management of mitogen-activated protein kinase inhibitor (MAPKi)-treated metastatic melanoma. Tumor genetic alterations can cause MAPK pathway reactivation, leading to lack of response and poor outcome. Characterization of the mutational profile in patients with melanoma might be crucial for patient-tailored treatment choices. Mutations in the promoter region of the telomerase reverse transcriptase gene (TERTprom) lead to increased TERT expression and telomerase activity and are frequent in BRAF^V600 mutant melanoma. Reportedly, TERTprom, and BRAF^V600 mutations cooperate in driving cancer progression and aggressiveness. We evaluated the effect of the TERTprom status on the clinical outcome in 97 MAPKi-treated melanoma patients. We observed that patients with the c.-146C > T mutation showed a significantly worse progression-free survival (PFS) compared to those carrying the c.-124C > T mutation and a two-fold increased risk of progression (median 5.4 vs. 9.5 months; hazard ratio (HR) 1.9; 95% confidence interval (CI) 1.2–3.2; p = 0.013). This trend was also observed for the overall survival (OS); melanoma patients with the c.-146C > T mutation showed a poorer prognosis compared to those with the c.-124C > T mutation (median 13.3 vs. 25.5 months; HR 1.9, 95% CI 1.1–3.3, p = 0.023). Our results disclose a different correlation of the two TERTprom mutations with MAPKi-treated melanoma patient outcome, highlighting a different impact of the pathway blockade.

Long-Term Vemurafenib Exposure Induced Alterations of Cell Phenotypes in Melanoma: Increased Cell Migration and Its Association with EGFR Expression

Acquired resistance during BRAF inhibitor therapy remains a major challenge for melanoma treatment. Accordingly, we evaluated the phenotypical and molecular changes of isogeneic human V600E BRAF-mutant melanoma cell line pairs pre- and post-treatment with vemurafenib. Three treatment naïve lines were subjected to in vitro long-term vemurafenib treatment while three pairs were pre- and post-treatment patient-derived lines. Molecular and phenotypical changes were assessed by Sulforhodamine-B (SRB) assay, quantitative RT-PCR (q-RT-PCR), immunoblot, and time-lapse microscopy. We found that five out of six post-treatment cells had higher migration activity than pretreatment cells. However, no unequivocal correlation between increased migration and classic epithelial–mesenchymal transition (EMT) markers could be identified. In fast migrating cells, the microphthalmia-associated transcription factor (MITF) and epidermal growth factor receptor (EGFR) mRNA levels were considerably lower and significantly higher, respectively. Interestingly, high EGFR expression was associated with elevated migration but not with proliferation. Cells with high EGFR expression showed significantly decreased sensitivity to vemurafenib treatment, and had higher Erk activation and FRA-1 expression. Importantly, melanoma cells with higher EGFR expression were more resistant to the EGFR inhibitor erlotinib treatment than cells with lower expression, with respect to both proliferation and migration inhibition. Finally, EGFR-high melanoma cells were characterized by higher PD-L1 expression, which might in turn indicate that immunotherapy may be an effective approach in these cases.

Joint action of miR-126 and MAPK/PI3K inhibitors against metastatic melanoma

Emerging data support the rationale of combined therapies in advanced melanoma. Specifically, the combined use of drugs with different mechanisms of action can reduce the probability of selecting resistant clones. To identify agents active against melanoma cells, we screened a library of 349 anti‐cancer compounds, currently in clinical use or trials, and selected PIK‐75, an inhibitor of the phosphatidylinositol 3‐kinase/protein kinase B (PI3K/AKT) pathway, as the ‘top active’ drug. PIK‐75 was then used alone or in combination with vemurafenib, the first BRAF inhibitor approved for patients with melanoma harboring BRAF mutations. We identified a combined dose of PIK‐75 and vemurafenib that inhibited both the PI3K/AKT and mitogen‐activated protein kinase pathways, thereby overcoming any compensatory activation. In view of the important tumor suppressor function induced by restoring expression of microRNA (miR)‐126 in metastatic melanoma cells, we examined whether miR‐126 has a synergistic role when included in a triple combination alongside PIK‐75 and vemurafenib. We found that enforced expression of miR‐126 (which alone can reduce tumorigenicity) significantly increased PIK‐75 activity when used as either a single agent or in combination with vemurafenib. Interestingly, PIK‐75 proved to be effective against early passage cell lines derived from patients’ biopsies and on melanoma cell lines resistant to either vemurafenib or dabrafenib, thus suggesting that it potentially has the capability to overcome drug resistance. Finally, the synergistic role played by miR‐126 in combination with vemurafenib and/or PIK‐75 was demonstrated in vivo in mouse xenograft models, in which tumor growth inhibition was associated with increased apoptosis. These results not only show the efficacy of PIK‐75 and vemurafenib co‐treatment but also indicate that restoration of miR‐126 expression in advanced melanoma can enhance their antitumor activity, which may possibly allow dose reduction to decrease adverse events without reducing the therapeutic benefits.

Fibroblast Growth Factor Receptor Signaling in Skin Cancers

Fibroblast growth factor (FGF)/Fibroblast growth factor receptor (FGFR) signaling regulates various cellular processes during the embryonic development and in the adult organism. In the skin, fibroblasts and keratinocytes control proliferation and survival of melanocytes in a paracrine manner via several signaling molecules, including FGFs. FGF/FGFR signaling contributes to the skin surface expansion in childhood or during wound healing, and skin protection from UV light damage. Aberrant FGF/FGFR signaling has been implicated in many disorders, including cancer. In melanoma cells, the FGFR expression is low, probably because of the strong endogenous mutation-driven constitutive activation of the downstream mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK-ERK) signaling pathway. FGFR1 is exceptional as it is expressed in the majority of melanomas at a high level. Melanoma cells that acquired the capacity to synthesize FGFs can influence the neighboring cells in the tumor niche, such as endothelial cells, fibroblasts, or other melanoma cells. In this way, FGF/FGFR signaling contributes to intratumoral angiogenesis, melanoma cell survival, and development of resistance to therapeutics. Therefore, inhibitors of aberrant FGF/FGFR signaling are considered as drugs in combination treatment. The ongoing LOGIC-2 phase II clinical trial aims to find out whether targeting the FGF/FGFR signaling pathway with BGJ398 may be a good therapeutic strategy in melanoma patients who develop resistance to v-Raf murine sarcoma viral oncogene homolog B (BRAF)/MEK inhibitors.

Human Epididymis Secretory Protein 4 (HE4) Compromises Cytotoxic Mononuclear Cells via Inducing Dual Specificity Phosphatase 6

While selective overexpression of serum clinical biomarker Human epididymis secretory protein 4 (HE4) is indicative of ovarian cancer tumorigenesis, much is still known about the mechanistic role of the HE4 gene or gene product. Here, we examine the role of the secretory glycoprotein HE4 in ovarian cancer immune evasion. Through modified subtractive hybridization analyses of human peripheral blood mononuclear cells (PBMCs), we have characterized gene targets of HE4 and established a preliminary mechanism of HE4-mediated immune failure in ovarian tumors. Dual specificity phosphatase 6 (DUSP6) emerged as the most upregulated gene in PBMCs upon in vitro exposure to HE4. DUSP6 was found to be upregulated in CD8⁺ cells and CD56⁺ cells. HE4 exposure reduced Erk1/2 phosphorylation specifically in these cell populations and the effect was erased by co-incubation with a DUSP6 inhibitor, (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI). In co-culture with PBMCs, HE4-silenced SKOV3 human ovarian cancer cells exhibited enhanced proliferation upon exposure to external HE4, while this effect was partially attenuated by adding BCI to the culture. Additionally, the reversal effects of BCI were erased in the co-culture with CD8⁺ / CD56⁺ cell deprived PBMCs. Taken together, these findings show that HE4 enhances tumorigenesis of ovarian cancer by compromising cytotoxic CD8⁺ and CD56⁺ cells through upregulation of self-produced DUSP6.

Patient preferences for treatment of metastatic melanoma

AIM

To investigate patient preferences for clinical attributes of first-line metastatic melanoma treatments.

MATERIALS & METHODS

A discrete-choice experiment and best-worst scaling exercise were used to assess relative preferences for treatment attributes.

RESULTS

The 200 survey respondents had distinct preferences. Avoiding a 30% risk of colitis or hormone gland problems and avoiding severe fever were more important to respondents than avoiding a 20% risk of extreme sun sensitivity (p < 0.05). Patients preferred taking pills to receiving intravenous infusions in a clinic. When attributes were combined, approximately 85% of respondents preferred a risk profile similar to targeted therapy over a profile similar to immunotherapy, holding efficacy constant.

CONCLUSION

Taking patient preferences into account can help patients get the full benefit from metastatic melanoma therapies.

HGF/c-MET Signaling in Melanocytes and Melanoma

Hepatocyte growth factor (HGF)/ mesenchymal-epithelial transition factor (c-MET) signaling is involved in complex cellular programs that are important for embryonic development and tissue regeneration, but its activity is also utilized by cancer cells during tumor progression. HGF and c-MET usually mediate heterotypic cell–cell interactions, such as epithelial–mesenchymal, including tumor–stroma interactions. In the skin, dermal fibroblasts are the main source of HGF. The presence of c-MET on keratinocytes is crucial for wound healing in the skin. HGF is not released by normal melanocytes, but as melanocytes express c-MET, they are receptive to HGF, which protects them from apoptosis and stimulates their proliferation and motility. Dissimilar to melanocytes, melanoma cells not only express c-MET, but also release HGF, thus activating c-MET in an autocrine manner. Stimulation of the HGF/c-MET pathways contributes to several processes that are crucial for melanoma development, such as proliferation, survival, motility, and invasiveness, including distant metastatic niche formation. HGF might be a factor in the innate and acquired resistance of melanoma to oncoprotein-targeted drugs. It is not entirely clear whether elevated serum HGF level is associated with low progression-free survival and overall survival after treatment with targeted therapies. This review focuses on the role of HGF/c-MET signaling in melanoma with some introductory information on its function in skin and melanocytes.

Lycorine inhibits melanoma A375 cell growth and metastasis through the inactivation of the PI3K/AKT signaling pathway

Malignant melanoma, one of the most aggressive skin cancers, has a very high mortality rate. Currently, the number of drugs to treat melanoma is low. Although new immunotherapeutic approaches based on the use of antibodies against immune checkpoints have shown long term responses, it is urgent to develop novel anti-melanoma drugs with a high efficiency and a low toxicity in a large number of patients. Lycorine, a natural product, has been reported to exert antitumor effects on some cancers. However, the impact of lycorine on melanoma cells is still unknown. Using the CCK8 assay, we found that lycorine can suppress the proliferation of melanoma A375 cells in a dose-time-dependent manner. Moreover, a transwell assay showed that lycorine inhibited the migration and invasion of A375 cells significantly. Further, lycorine treatment could induce the apoptosis of the A375 cells. Biochemical analyses showed that the expression level of the anti-apoptosis Bcl-2 protein decreased, while the expression of the pro-apoptosis protein Bax and active caspase-3 increased after lycorine treatment. Finally, using western blot assay, we found that the antitumor effects of lycorine on A375 cells might be through the inactivation of the PI3K/Akt signaling pathway. Based on these observations, we suggest that lycorine may be an interesting candidate for further studies on its ability to represent a novel antitumor drug for human melanoma treatment in the future.

Acquisition of resistance to vemurafenib leads to interleukin-10 production through an aberrant activation of Akt in a melanoma cell line

Serine/threonine-protein kinase B-Raf (BRAF) inhibitors are very effective in treating melanoma with BRAF mutations. BRAF inhibitors suppress aberrant growth of melanoma cells caused by BRAF mutations. BRAF mutations reportedly result in melanoma cells releasing immunosuppressive factors, and BRAF inhibitors elicit anti-melanoma immune responses by reducing such factors. However, immunological characteristics of tumor cells that acquire resistance to BRAF inhibitors remain unknown. Here, we compared immunological characteristics between a melanoma cell line and its vemurafenib-resistant subline. No differences were observed in the status of BRAF mutations, expression of surface molecules related to antitumor T-cell responses or recognition by human leukocyte antigen-A*0201-matched melanoma-specific cytotoxic T lymphocytes in a short-term co-culture assay. However, resistant tumor cells released high amounts of interleukin-10 depending on aberrant activation of Akt signaling, and dendritic cell functions were considerably suppressed by culture supernatants of the resistant cells. Our findings demonstrated a novel immunological mechanism contributing to tumor growth owing to drug resistance to BRAF inhibitors.

Tissue-engineered 3D melanoma model with blood and lymphatic capillaries for drug development

While being the rarest skin cancer, melanoma is also the deadliest. To further drug discovery and improve clinical translation, new human cell-based in vitro models are needed. Our work strives to mimic the melanoma microenvironment in vitro as an alternative to animal testing. We used the self-assembly method to produce a 3D human melanoma model exempt of exogenous biomaterial. This model is based on primary human skin cells and melanoma cell lines while including a key feature for tumor progression: blood and lymphatic capillaries. Major components of the tumor microenvironment such as capillaries, human extracellular matrix, a stratified epidermis (involucrin, filaggrin) and basement membrane (laminin 332) are recapitulated in vitro. We demonstrate the persistence of CD31+ blood and podoplanin+/LYVE-1+ lymphatic capillaries in the engineered tissue. Chronic treatment with vemurafenib was applied to the model and elicited a dose-dependent response on proliferation and apoptosis, making it a promising tool to test new compounds in a human-like environment.

Copper Chelation as Targeted Therapy in a Mouse Model of Oncogenic BRAF-Driven Papillary Thyroid Cancer

Purpose: Sixty percent of papillary thyroid cancers (PTC) have an oncogenic (V600E) BRAF mutation. Inhibitors of BRAF and its substrates MEK1/2 are showing clinical promise in BRAFV600E PTC. PTC progression can be decades long, which is challenging in terms of toxicity and cost. We previously found that MEK1/2 require copper (Cu) for kinase activity and can be inhibited with the well-tolerated and economical Cu chelator tetrathiomolybdate (TM). We therefore tested TM for antineoplastic activity in BRAFV600E -positive PTC.Experimental Design: The efficacy of TM alone and in combination with current standard-of-care lenvatinib and sorafenib or BRAF and MEK1/2 inhibitors vemurafenib and trametinib was examined in BRAFV600E-positive human PTC cell lines and a genetically engineered mouse PTC model.Results: TM inhibited MEK1/2 kinase activity and transformed growth of PTC cells. TM was as or more potent than lenvatinib and sorafenib and enhanced the antineoplastic activity of sorafenib and vemurafenib. Activated ERK2, a substrate of MEK1/2, overcame this effect, consistent with TM deriving its antineoplastic activity by inhibiting MEK1/2. Oral TM reduced tumor burden and vemurafenib in a BrafV600E -positive mouse model of PTC. This effect was ascribed to a reduction of Cu in the tumors. TM reduced P-Erk1/2 in mouse PTC tumors, whereas genetic reduction of Cu in developing tumors trended towards a survival advantage. Finally, TM as a maintenance therapy after cessation of vemurafenib reduced tumor volume in the aforementioned PTC mouse model.Conclusions: TM inhibits BRAFV600E -driven PTC through inhibition of MEK1/2, supporting clinical evaluation of chronic TM therapy for this disease. Clin Cancer Res; 24(17); 4271-81. ©2018 AACR.

Breslow Density Is a Novel Prognostic Feature That Adds Value to Melanoma Staging

Histomorphologic prognostic biomarkers that can be measured using only an hematoxylin and eosin stain are very attractive because they are simple and cheap. We conceived an entirely novel biomarker of this type, the Breslow density (BD), which measures invasive melanoma cell density at the site where Breslow thickness (BT) is measured. This study assessed BD's prognostic value. In this study, BD was measured in 1329 melanoma patients. Measurement accuracy and precision was assessed using intraclass correlation coefficient (ICC). Survival was assessed with a primary end-point of melanoma-specific survival (MSS) and also overall survival and metastasis-free survival. We found that BD measurement was accurate compared with gold standard image analysis (ICC, 0.84). Precision was excellent for 3 observers with different experience (ICC, 0.93) and for an observer using only written instructions (ICC, 0.93). BD was a highly significant predictor in multivariable analysis for overall survival, MSS, and metastasis-free survival (each, P<0.001) and it explained MSS better than BT, but BT and BD together had best explanatory capability. A BD cut point of ≥65% was trained in 970 melanomas and validated in 359. This cut point showed promise as a novel way to upstage melanoma from T stage "a" to "b." BD was combined with BT to create a targeted burden score. This was a validated as an adjunct to American Joint Committee on Cancer stage. In summary, BD can be measured accurately and precisely. It demonstrated independent prognostic value and explained MSS better than BT alone. Notably, we demonstrated ways that BD could be used with American Joint Committee on Cancer version 8 staging.

Melanoma of the lower genital tract: Prognostic factors and treatment modalities

Primary melanomas originating from the gynecological tract are rare and aggressive cancers. The vulva is the most frequent site (70%), followed by vagina and more rarely by cervix. The clinical outcome of patients with female genital tract melanoma is very poor, with a 5-year overall survival (OS) of 37-50% for vulvar, 13-32% for vaginal, and approximately 10% for cervical melanoma. In this systematic review, we analyzed the pathogenesis and the different factors influencing the prognosis of melanomas of the lower genital tract, with particular emphasis on biologic variables that may influence new therapeutic approaches. We evaluated the different treatment modalities described in the literature, in order to offer a possible algorithm that may help the clinicians in diagnosing and treating patients with these uncommon malignancies.

Melanoma and Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

Prognosis of patients with advanced melanoma is dismal with a median overall survival of about 8 months and 5-year overall survival from a diagnosis of metastatic disease of roughly 10%. However, immune checkpoint inhibitors have brought indispensable benefits to melanoma patients. Here we will review the recent clinical efficacy and adverse events of immune checkpoint inhibitors for melanoma patients.

RECENT FINDINGS

The immune checkpoint inhibitors increase confirmed objective response and prolong progression-free and overall survival of the afflicted patients in association with maintaining their quality of life. Although diverse immune-related adverse events occur, most of them are manageable by appropriate immunomodulating agents. Clinical efficacy of immune checkpoint inhibitors continues even after discontinuation of drugs. Compared with conventional therapeutic options, the immune checkpoint inhibitors appear to prolong the survival of patients with advanced melanoma. Further clinical trials are warranted to determine whether their combinatory use with other treatment options may augment benefits or not.

Long Noncoding RNA Taurine-Upregulated Gene1 (TUG1) Promotes Tumor Growth and Metastasis Through TUG1/Mir-129-5p/Astrocyte-Elevated Gene-1 (AEG-1) Axis in Malignant Melanoma

BACKGROUND Malignant melanoma is a class of malignant tumors derived from melanocytes. lncRNAs have been considered as pro-/anti-tumor factors in progression of cancers. The function of lncRNA TUG1 on growth of melanoma was investigated in this study. MATERIAL AND METHODS The TUG1 and miR-129-5p expression were examined via qRT-PCR. The protein expression was investigated by Western blotting assay. Luciferase reporter assay was used to assess if lncRNA TUG1 can bind to miR-129-5p and if miR-129-5p can target AEG1 mRNA. CCK-8 and apoptosis assay were used to detect cell growth and apoptosis. The metastasis of melanoma cells was detected by wound-healing and Transwell assays. The effects of TUG1 on growth of melanoma in vivo and cell chemoresistance were investigated via xenograft animal experiment and CCK-8 assay. RESULTS The expression of TUG1 and AEG1 was elevated and the miR-129-5p level was decreased in melanoma specimens and cell lines. Downregulation of either TUG1 or AEG1 suppressed cell growth and metastasis. miR-129-5p can bind directly to AEG1 and TUG1 can directly sponge miR-129-5p. Inhibition of TUG1 expression suppressed the expression of Bcl-2, MMP-9, and cyclin D1, and raised the level of cleaved caspase3 by modulating AEG1 level in melanoma cells. Inhibition of TUG1 reduced the growth of tumors in vivo and improved the chemosensitivity of A375 cells to cisplatin and 5-FU. CONCLUSIONS Reduction of TUG1 level suppressed cell growth and metastasis by regulating AEG1 expression mediated by targeting miR-129-5p. Suppression of lnc TUG1 may be a promising therapeutic strategy in the treatment of malignant melanoma.