A new era: melanoma genetics and therapeutics

Targeted Therapy and Immunotherapy for Advanced Malignant Conjunctival Tumors: Systematic Review

PURPOSE

To review the outcomes of targeted therapy and immunotherapy in advanced conjunctival tumors, including conjunctival squamous cell carcinoma, conjunctival melanoma, and conjunctival lymphoma.

METHODS

A Pubmed database systematic search was performed between January 1999 and December 2022. The literature search was limited to studies published in English.

RESULTS

This review included 142 patients with advanced malignant conjunctival tumors from 42 articles. In the conjunctival squamous cell carcinoma group, 2 cases of advanced conjunctival squamous cell carcinoma treated with epidermal growth factor receptor inhibitors showed significant tumor size improvement after 7.5 months of follow-up. Among 7 cases treated with systemic immunotherapy, 5 cases (72%) had complete response (CR), 1 case (14%) showed partial response (PR), and 1 case (14%) had stable disease (SD) after 16 months. In the conjunctival melanoma group, among 18 cases treated with combined v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated extracellular signal-regulated kinase inhibitors, 6 (33%) had CR, 5 (28%) had PR, 2 (11%) had SD, and 5 (28%) had progressive disease after 24.8 months of follow-up. Of 44 conjunctival melanoma cases treated with immunotherapy, 12 (28%) had CR, 9 (20%) had PR, 7(16%) had SD, and 16 (36%) had progressive disease after 14.2 months. Systemic Rituximab treatment for conjunctival lymphoma cases resulted in CR in 21 patients (63%), PR in 11 patients (33%), and SD in 1 patient (3%) after 20.5 months of follow-up. Intralesional Rituximab injections in 38 conjunctival lymphoma cases showed CR in 28 patients (75%), PR in 7 patients (19%), SD in 1 patient (2%), and progressive disease in 2 patients (4%) after 20.4 months of follow-up.

CONCLUSIONS

Despite limited clinical case reports and short-term follow-ups, targeted therapy and immunotherapy have shown promising results for advanced malignant conjunctival tumors.

Genetic Concordance in Primary Cutaneous Melanoma and Matched Metastasis: A Systematic Review and Meta-Analysis

Studying primary melanoma and its corresponding metastasis has twofold benefits. Firstly, to better understand tumor biology, and secondly, to determine which sample should be examined in assessing drug targets. This study systematically analyzed all the literature on primary melanoma and its matched metastasis. Following PRISMA guidelines, we searched multiple medical databases for relevant publications from January 2000 to December 2022, assessed the quality of the primary-level studies using the QUIPS tool, and summarized the concordance rate of the most reported genes using the random-effects model. Finally, we evaluated the inter-study heterogeneity using the subgroup analysis. Thirty-one studies investigated the concordance of BRAF and NRAS in 1220 and 629 patients, respectively. The pooled concordance rate was 89.4% [95% CI: 84.5; 93.5] for BRAF and 97.8% [95% CI: 95.8; 99.4] for NRAS. When high-quality studies were considered, only BRAF mutation status consistency increased. Five studies reported the concordance status of c-KIT (93%, 44 patients) and TERT promoter (64%, 53 patients). Lastly, three studies analyzed the concordance of cancer genes involved in the signaling pathways, apoptosis, and proliferation, such as CDKN2A (25%, four patients), TP53 (44%, nine patients), and PIK3CA (20%, five patients). Our study found that the concordance of known drug targets (mainly BRAF) during melanoma progression is higher than in previous meta-analyses, likely due to advances in molecular techniques. Furthermore, significant heterogeneity exists in the genes involved in the melanoma genetic makeup; although our results are based on small patient samples, more research is necessary for validation.

PTEN phosphatase inhibits metastasis by negatively regulating the Entpd5/IGF1R pathway through ATF6

PTEN encodes a tumor suppressor with lipid and protein phosphatase activities whose dysfunction has been implicated in melanomagenesis; less is known about how its phosphatases regulate melanoma metastasis. We demonstrate that PTEN expression negatively correlates with metastatic progression in human melanoma samples and a PTEN-deficient mouse melanoma model. Wildtype PTEN expression inhibited melanoma cell invasiveness and metastasis in a dose-dependent manner, behaviors that specifically required PTEN protein phosphatase activity. PTEN phosphatase activity regulated metastasis through Entpd5. Entpd5 knockdown reduced metastasis and IGF1R levels while promoting ER stress. In contrast, Entpd5 overexpression promoted metastasis and enhanced IGF1R levels while reducing ER stress. Moreover, Entpd5 expression was regulated by the ER stress sensor ATF6. Altogether, our data indicate that PTEN phosphatase activity inhibits metastasis by negatively regulating the Entpd5/IGF1R pathway through ATF6, thereby identifying novel candidate therapeutic targets for the treatment of PTEN mutant melanoma.

PTEN Dual Lipid- and Protein-Phosphatase Function in Tumor Progression

Simple Summary

Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a multifunctional tumor suppressor with protein- and lipid-phosphatase activities. The inactivation of PTEN is commonly found in all human cancers and is correlated with tumor progression. PTEN-lipid-phosphatase activity has been well documented to dephosphorylate phosphatidylinositol-3, 4, 5-phosphate (PIP3), which hinders cell growth and survival by dampening the PI3K and AKT signaling activity. PTEN-protein-phosphatase activity is less well studied and understood. Recent studies have reported that PTEN-protein-phosphatase activity dephosphorylates the different proteins and acts in various cell functions. We here review the PTEN mutations and protein-phosphatase substrates in tumor progression. We aim to address the gap in our understanding as to how PTEN protein phosphatase contributes to its tumor-suppression functions.

Abstract

PTEN is the second most highly mutated tumor suppressor in cancer, following only p53. The PTEN protein functions as a phosphatase with lipid- and protein-phosphatase activity. PTEN-lipid-phosphatase activity dephosphorylates PIP3 to form PIP2, and it then antagonizes PI3K and blocks the activation of AKT, while its protein-phosphatase activity dephosphorylates different protein substrates and plays various roles in tumorigenesis. Here, we review the PTEN mutations and protein-phosphatase substrates in tumorigenesis and metastasis. Our purpose is to clarify how PTEN protein phosphatase contributes to its tumor-suppressive functions through PI3K-independent activities.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2022

A unique collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO), and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on the systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with one to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumor thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("tumor board"). Adjuvant therapies can be proposed in stage III/completely resected stage IV patients and are primarily anti-PD-1, independent of mutational status, or alternatively dabrafenib plus trametinib for BRAF mutant patients. In distant metastases (stage IV), either resected or not, systemic treatment is always indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In stage IV melanoma with a BRAF-V600  E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harboring a BRAF-V600  E/K mutation, this therapy shall be offered as second-line therapy. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Advancing human disease research with fish evolutionary mutant models

Model organism research is essential to understand disease mechanisms. However, laboratory-induced genetic models can lack genetic variation and often fail to mimic the spectrum of disease severity. Evolutionary mutant models (EMMs) are species with evolved phenotypes that mimic human disease. EMMs complement traditional laboratory models by providing unique avenues to study gene-by-environment interactions, modular mutations in noncoding regions, and their evolved compensations. EMMs have improved our understanding of complex diseases, including cancer, diabetes, and aging, and illuminated mechanisms in many organs. Rapid advancements of sequencing and genome-editing technologies have catapulted the utility of EMMs, particularly in fish. Fish are the most diverse group of vertebrates, exhibiting a kaleidoscope of specialized phenotypes, many that would be pathogenic in humans but are adaptive in the species' specialized habitat. Importantly, evolved compensations can suggest avenues for novel disease therapies. This review summarizes current research using fish EMMs to advance our understanding of human disease.

Reduced WNT5A signaling in melanoma cells favors an amoeboid mode of invasion

Tumor cells invade and spread via either a mesenchymal or an amoeboid mode of migration. Amoeboid tumor cells have a rounded morphology and pronounced RhoA activity. Here, we investigate how WNT5A signaling, a tumor promotor in melanoma, relates to Rho GTPase activity and amoeboid migration. We compared melanoma cells with low (HTB63 cells) and high (WM852 cells) WNT5A expression. HTB63 cells exhibited an amoeboid morphology and had higher RhoA activity but lower invasiveness than WM852 cells in a three‐dimensional (3D) collagen matrix. We next explored the relationships between WNT5A, morphology, and invasive behavior. WNT5A knockdown impaired Rho GTPase Cdc42 activity, resulting in reduced invasion of amoeboid and mesenchymal melanoma cells. Interestingly, knockdown of WNT5A or inhibition of its secretion in WM852 cells expressing wild‐type BRAF also led to increased RhoA activity via decreased RND3 expression, resulting in predominantly amoeboid morphology. In contrast, such treatments had the opposite effects on RND3 expression and RhoA activity in HTB63 cells expressing the active BRAF^V600 mutation. However, treatment of HTB63 cells with a BRAF inhibitor made them respond to WNT5A knockdown in a similar manner as WM852 cells expressing wild‐type BRAF. We next found that dual targeting of WNT5A and RhoA more effectively reduced melanoma cell invasion than targeting either protein individually. Taken together, our results suggest that low WNT5A signaling in melanoma cells promotes a rounded amoeboid type of invasion, which quite likely serves as a compensatory response to decreased WNT5A/Cdc42‐driven invasion. This phenomenon partially explains the enduring melanoma cell invasion observed after impaired WNT5A signaling and has therapeutic implications. Our results suggest that dual targeting of WNT5A and RhoA signaling is a more effective strategy for controlling the invasion of BRAF wild‐type and BRAF^V600 mutated melanomas treated with a BRAF inhibitor than targeting either of the proteins individually.

Survivin Promoter-Driven DFF40 Gene Expression Sensitizes Melanoma Cancer Cells to Chemotherapy

Downregulation of the apoptotic protein DNA fragmentation factor 40 (DFF40) is correlated with poor overall survival in some malignancies, including melanoma. In this study, DFF40 gene expression driven by survivin promoter, a tumor-specific promoter, was used to selectively induce cytotoxicity in melanoma cells. The activity and strength of survivin promoter were examined in B16F10 murine melanoma, and L929 murine normal fibroblast cell lines using enhanced green fluorescent protein reporter assay and reverse transcription polymerase chain reaction. The effect of expression of DFF40 under the control of cytomegalovirus (CMV) or survivin promoter on viability of cancerous and normal cells was determined by MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. Apoptosis induction by expression of DFF40 was evaluated using Annexin-V/propidium iodide staining. Our findings showed high activity of survivin promoter comparable to the control promoter (ie, CMV) in melanoma cells, while survivin activity in normal cells was negligible. Survivin promoter-derived DFF40 gene expression led to selective inhibition of cell viability and induction of apoptosis in cancerous cells. Low and sublethal concentrations of a chemotherapeutic drug, dacarbazine, significantly enhanced the growth inhibitory effect of DFF40 gene therapy. Combination of survivin-driven gene therapy and chemotherapy could be considered as a potential therapeutic treatment for melanoma and possibly other malignancies with similar features.

Bcl-xL: A Focus on Melanoma Pathobiology

Apoptosis is the main mechanism by which multicellular organisms eliminate damaged or unwanted cells. To regulate this process, a balance between pro-survival and pro-apoptotic proteins is necessary in order to avoid impaired apoptosis, which is the cause of several pathologies, including cancer. Among the anti-apoptotic proteins, Bcl-xL exhibits a high conformational flexibility, whose regulation is strictly controlled by alternative splicing and post-transcriptional regulation mediated by transcription factors or microRNAs. It shows relevant functions in different forms of cancer, including melanoma. In melanoma, Bcl-xL contributes to both canonical roles, such as pro-survival, protection from apoptosis and induction of drug resistance, and non-canonical functions, including promotion of cell migration and invasion, and angiogenesis. Growing evidence indicates that Bcl-xL inhibition can be helpful for cancer patients, but at present, effective and safe therapies targeting Bcl-xL are lacking due to toxicity to platelets. In this review, we summarized findings describing the mechanisms of Bcl-xL regulation, and the role that Bcl-xL plays in melanoma pathobiology and response to therapy. From these findings, it emerged that even if Bcl-xL plays a crucial role in melanoma pathobiology, we need further studies aimed at evaluating the involvement of Bcl-xL and other members of the Bcl-2 family in the progression of melanoma and at identifying new non-toxic Bcl-xL inhibitors.

Pharmacologically induced uveitis

Treatments of numerous systemic and local diseases of different etiologies may be accompanied by an unwanted side effect in the form of uveitis. We inform readers about medications that have the potential to cause uveitis and analyze the strength of association of these medications with uveitis. Subsequently, cessation of medication or appropriate treatment can be individualized for each patient for the purpose of preventing further damage to tissue structure and function. Being aware of these associations, physicians may readily identify medications that may cause uveitis and avoid expensive and unnecessary clinical and laboratory testing.

Identification of lncRNA-mRNA Regulatory Module to Explore the Pathogenesis and Prognosis of Melanoma

Skin cutaneous melanoma (SKCM) is an aggressive form of skin cancer that results in high mortality rate worldwide. It is vital to discover effective prognostic biomarkers and therapeutic targets for the treatment of melanoma. Long non-coding RNA (lncRNA) has been verified to play an essential role in the regulation of gene expression in diseases and tumors. Therefore, it is significant to explore the function of lncRNAs in the development and progression of SKCM. In this paper, a set of differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were first screened out using 471 cutaneous melanoma samples and 813 normal skin samples. Gene Ontology and KEGG pathway enrichment analysis were performed to obtain the significant function annotations and pathways of DEmRNAs. We also ran survival analysis on both DElncRNAs and DEmRNAs to identify prognostic-related lncRNAs and mRNAs. Next, a set of hub genes derived from protein-protein interaction (PPI) network analysis and lncRNA target genes screened from starbase-ENCORI database were integrated to construct a lncRNA-mRNA regulatory module, which includes 6 lncRNAs 4 target mRNAs. We further checked the capacity of these lncRNA and mRNA in the diagnosis of melanoma, and found that single lncRNA can effectively distinguish tumor and normal tissue. Moreover, we ran CMap analysis to select a list of small molecule drugs for SKCM, such as EGFR inhibitor AG-490, growth factor receptor inhibitor GW-441756 and apoptosis stimulant betulinic-acid, which have shown therapeutic effect in the treatment of melanoma.

Functional Characterization of Cholinergic Receptors in Melanoma Cells

In the last two decades, the scientific community has come to terms with the importance of non-neural acetylcholine in light of its multiple biological and pathological functions within and outside the nervous system. Apart from its well-known physiological role both in the central and peripheral nervous systems, in the autonomic nervous system, and in the neuromuscular junction, the expression of the acetylcholine receptors has been detected in different peripheral organs. This evidence has contributed to highlight new roles for acetylcholine in various biological processes, (e.g., cell viability, proliferation, differentiation, migration, secretion). In addition, growing evidence in recent years has also demonstrated new roles for acetylcholine and its receptors in cancer, where they are involved in the modulation of cell proliferation, apoptosis, angiogenesis, and epithelial mesenchymal transition. In this review, we describe the functional characterization of acetylcholine receptors in different tumor types, placing attention on melanoma. The latest set of data accessible through literature, albeit limited, highlights how cholinergic receptors both of muscarinic and nicotinic type can play a relevant role in the migratory processes of melanoma cells, suggesting their possible involvement in invasion and metastasis.

Protein Expression in Metastatic Melanoma and the Link to Disease Presentation in a Range of Tumor Phenotypes

Malignant melanoma is among the most aggressive skin cancers and it has among the highest metastatic potentials. Although surgery to remove the primary tumor is the gold standard treatment, once melanoma progresses and metastasizes to the lymph nodes and distal organs, i.e., metastatic melanoma (MM), the usual outcome is decreased survival. To improve survival rates and life span, advanced treatments have focused on the success of targeted therapies in the MAPK pathway that are based on BRAF (BRAF V600E) and MEK. The majority of patients with tumors that have higher expression of BRAF V600E show poorer prognosis than patients with a lower level of the mutated protein. Based on the molecular basis of melanoma, these findings are supported by distinct tumor phenotypes determined from differences in tumor heterogeneity and protein expression profiles. With these aspects in mind, continued challenges are to: (1) deconvolute the complexity and heterogeneity of MM; (2) identify the signaling pathways involved; and (3) determine protein expression to develop targeted therapies. Here, we provide an overview of the results from protein expression in MM and the link to disease presentation in a variety of tumor phenotypes and how these will overcome the challenges of clinical problems and suggest new promising approaches in metastatic melanoma and cancer therapy.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2019

A unique collaboration of multidisciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organization for Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with 1- to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumour thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("Tumor Board"). Adjuvant therapies in stage III/IV patients are primarily anti-PD-1, independent of mutational status, or dabrafenib plus trametinib for BRAF-mutant patients. In distant metastasis, either resected or not, systemic treatment is indicated. For first-line treatment, particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In particular scenarios for patients with stage IV melanoma and a BRAF-V600 E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harbouring a BRAF-V600 E/K mutation, this therapy shall be offered in second-line. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Circular RNA ITCH downregulates GLUT1 and suppresses glucose uptake in melanoma to inhibit cancer cell proliferation

BACKGROUND

Circular RNA ITCH has been proved as a tumor suppressor in several types of cancer. Genetic alterations are known to play important roles in melanoma development. However, the function of circular RNAs and the role of ITCH in melanoma are still hardly known.

METHODS

We investigated the expression levels of ITCH and the correlation between ITCH expression and GLUT1 expression, which showed that ITCH was downregulated in melanoma tissues and inversely correlated with GLUT1.

RESULTS

ITCH overexpression resulted in the downregulation of GLUT1 and suppressed glucose uptake in melanoma. GLUT1 overexpression promoted glucose uptake but failed to affect ITCH. ITCH overexpression resulted in increased, while GLUT1 overexpression resulted in decreased rate of melanoma cell proliferation. In addition, GLUT1 overexpression reduced the effects of ITCH overexpression on cell proliferation.

CONCLUSIONS

We concluded that ITCH may downregulate GLUT1 and suppresses glucose uptake in melanoma to inhibit cancer cell proliferation.

SHARPIN Promotes Melanoma Progression via Rap1 Signaling Pathway

SHARPIN, as a tumor-associated gene, is involved in the metastatic process of many kinds of tumors. Herein, we studied the function of Shank-associated RH domain interacting protein (SHARPIN) in melanoma metastasis and the relevant molecular mechanisms. We found that SHARPIN expression was increased in melanoma tissues and activated the process of proliferation, migration, and invasion in vitro and in vivo, resulting in a poor prognosis of the disease. Functional analysis demonstrated that SHARPIN promoted melanoma migration and invasion by regulating Ras-associated protein-1(Rap1) and its downstream pathways, including p38 and JNK/c-Jun. Rap1 activator (8-pCPT-2'-O-Me-cAMP) and inhibitor (ESI-09 and farnesylthiosalicylic acid-amide) treatments could partially rescue invasion and migration of tumor cells. Additionally, SHARPIN expression in cell lines and public datasets also indicated that molecules other than BRAF and N-RAS may contribute to SHARPIN activation. In conclusion, our broad-in-depth work suggests that SHARPIN promotes melanoma development via p38 and JNK/c-Jun pathways through upregulation of Rap1 expression.

The molecular pathology of cancer: from pan-genomics to post-genomics

As the cancer genomics of most major cancer types have been comprehensively catalogued over the past decade through a variety of national and international efforts, the delineation of cancer subtypes has been refined, and our understanding of critical cancer drivers and of the potentially targetable vulnerabilities that they create has grown tremendously. The 2018 Annual Review Issue of the Journal of Pathology provides in-depth assessments of how these pan-genomic approaches have enabled advances in cancer classification, targeted therapy selection, and assessment of cancer progression, all of which are now genomically informed, using several cancer types as examples. Beyond these areas of by now conventional pan-genomic tumour analysis, there are also reviews of diverse 'post-genomic' areas, such as the analysis of circulating free tumour DNA in plasma, concurrent germline cancer predisposition profiling in the setting of apparently sporadic cancer, genetic alterations in epigenetic control and DNA repair, proteomics of tumour heterogeneity, computational pathology, and the roles of the cellular stress response and the microbiome in human cancers. As we are able to derive more and more biologically useful information from diverse human biospecimens, these many advances are informing and transforming the practice of cancer pathology. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Role of Isothiocyanates as Cancer Chemo-Preventive, Chemo-Therapeutic and Anti-Melanoma Agents

Many studies have shown evidence in support of the beneficial effects of phytochemicals in preventing chronic diseases, including cancer. Among such phytochemicals, sulphur-containing compounds (e.g., isothiocyanates (ITCs)) have raised scientific interest by exerting unique chemo-preventive properties against cancer pathogenesis. ITCs are the major biologically active compounds capable of mediating the anticancer effect of cruciferous vegetables. Recently, many studies have shown that a higher intake of cruciferous vegetables is associated with reduced risk of developing various forms of cancers primarily due to a plurality of effects, including (i) metabolic activation and detoxification, (ii) inflammation, (iii) angiogenesis, (iv) metastasis and (v) regulation of the epigenetic machinery. In the context of human malignant melanoma, a number of studies suggest that ITCs can cause cell cycle growth arrest and also induce apoptosis in human malignant melanoma cells. On such basis, ITCs could serve as promising chemo-therapeutic agents that could be used in the clinical setting to potentiate the efficacy of existing therapies.

Metastatic Cutaneous Melanoma Presenting with Choroidal Metastasis Simulating Primary Uveal Melanoma

PURPOSE

To report a case of metastatic cutaneous melanoma presenting with choroidal metastasis simulating primary uveal melanoma.

DESIGN

Case report.

METHOD

Presentation of clinical, radiographic, histopathologic, and tumor genetic findings in a patient with cutaneous melanoma with choroidal metastasis.

RESULTS

A 50-year-old man with a remote history of stage 1A cutaneous melanoma presented with eye pain, peripheral vision loss, floaters, red eye, and choroidal mass that was originally diagnosed as a primary uveal melanoma at an outside institution; however, subsequent imaging and clinical evaluation demonstrated that this choroidal mass was the first manifestation of widely metastatic cutaneous melanoma (liver, pancreas, lung, bone, brain, and orbit lesions). Histopathologic analysis of the tumor after enucleation was consistent with cutaneous melanoma, and tumor genetic testing was positive for BRAF V600E mutation, confirming the choroidal lesion to be a cutaneous melanoma metastasis rather than a primary choroidal melanoma.

CONCLUSIONS

Metastatic cutaneous melanoma to the orbit or globe occurs rarely. Tumor genetic testing may help differentiate metastatic cutaneous melanoma from primary uveal melanoma in cases where the diagnosis is uncertain, and can also inform therapy and prognostic counseling.

Dabrafenib-trametinib combination in 'field-practice': an Italian experience

AIM

This observational study investigates the effectiveness and safety of dabrafenib/trametinib combination in patients with metastatic melanoma.

PATIENTS & METHODS

Seventy-six patients treated with dabrafenib/trametinib (150 mg twice daily/2 mg once daily) were included.

RESULTS

Median progression-free survival was 9 months (95% CI: 7-11) and median overall survival was 14 months (11-16); disease control rate was 72%. Nine patients (12%) experienced a complete response. Of these, seven presented one metastatic site, none had lung or CNS metastasis, and none had elevated baseline lactate dehydrogenase (LDH) levels. Overall, subgroup analysis for patients with adverse prognostic features led to similar results. No new safety signals were reported.

CONCLUSION

Dabrafenib/trametinib combination can be effective and well-tolerated also in a heterogeneous 'real life' population comprising patients with adverse prognostic features.

Melanoma treatment in review

Melanoma represents the most aggressive and the deadliest form of skin cancer. Current therapeutic approaches include surgical resection, chemotherapy, photodynamic therapy, immunotherapy, biochemotherapy, and targeted therapy. The therapeutic strategy can include single agents or combined therapies, depending on the patient’s health, stage, and location of the tumor. The efficiency of these treatments can be decreased due to the development of diverse resistance mechanisms. New therapeutic targets have emerged from studies of the genetic profile of melanocytes and from the identification of molecular factors involved in the pathogenesis of the malignant transformation. In this review, we aim to survey therapies approved and under evaluation for melanoma treatment and relevant research on the molecular mechanisms underlying melanomagenesis.

Treatment with combined dabrafenib and trametinib in BRAFV600E-mutated metastatic malignant melanoma: a case of long-term complete response after treatment cessation

Here, we report the case of a patient, diagnosed with BRAF^V600E-mutated metastatic malignant melanoma M1a, who achieved a complete metabolic response after 7 months of treatment with the combination of dabrafenib and trametinib. After 31 months, the treatment was interrupted for patient’s decision. To date October 2017, 18 months after the interruption of the treatment with the combination of dabrafenib and trametinib, follow-up Positron Emission Tomography (PET) scans are still documenting complete metabolic response.

Identification of epigenetically altered genes and potential gene targets in melanoma using bioinformatic methods

This study aimed to analyze epigenetically and genetically altered genes in melanoma to get a better understanding of the molecular circuitry of melanoma and identify potential gene targets for the treatment of melanoma. The microarray data of GSE31879, including mRNA expression profiles (seven melanoma and four melanocyte samples) and DNA methylation profiles (seven melanoma and five melanocyte samples), were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and differentially methylated positions (DMPs) were screened using the linear models for microarray data (limma) package in melanoma compared with melanocyte samples. Gene ontology (GO) and pathway enrichment analysis of the DEGs were carried out using the Database for Annotation, Visualization, and Integrated Discovery. Moreover, differentially methylated genes (DMGs) were identified, and a transcriptional regulatory network was constructed using the University of California Santa Cruz genome browser database. A total of 1,215 DEGs (199 upregulated and 1,016 downregulated) and 14,094 DMPs (10,450 upregulated and 3,644 downregulated) were identified in melanoma compared with melanocyte samples. Additionally, the upregulated and downregulated DEGs were significantly associated with different GO terms and pathways, such as pigment cell differentiation, biosynthesis, and metabolism. Furthermore, the transcriptional regulatory network showed that DMGs such as Aristaless-related homeobox (ARX), damage-specific DNA binding protein 2 (DDB2), and myelin basic protein (MBP) had higher node degrees. Our results showed that several methylated genes (ARX, DDB2, and MBP) may be involved in melanoma progression.

The activation of the G protein-coupled estrogen receptor (GPER) inhibits the proliferation of mouse melanoma K1735-M2 cells

The activation of the G protein-coupled estrogen receptor (GPER) by its specific agonist G-1 inhibits prostate cancer and 17β-estradiol-stimulated breast cancer cell proliferation. Tamoxifen (TAM), which also activates the GPER, decreases melanoma cell proliferation, but its action mechanism remains controversial. Here we investigated the expression and the effects of GPER activation by G-1, TAM and its key metabolite endoxifen (EDX) on melanoma cells. Mouse melanoma K1735-M2 cells expressed GPER and G-1 reduced cell biomass, and the number of viable cells, without increasing cell death. Rather, G-1 decreased cell division by blocking cell cycle progression in G2. Likewise, TAM and EDX exhibited an antiproliferative activity in melanoma cells due to decreased cell division. Both G-1 and the antiestrogens showed a trend to decrease the levels of phosphorylated ERK 1/2 after 1 h treatment, although only EDX, the most potent antiproliferative antiestrogen, induced significant effects. Importantly, the targeting of GPER with siRNA abolished the cytostatic activity of both G-1 and antiestrogens, suggesting that the antitumor actions of antiestrogens in melanoma cells involve GPER activation. Our results unveil a new target for melanoma therapy and identify GPER as a key mediator of antiestrogen antiproliferative effects, which may contribute to select the patients that benefit from an antiestrogen-containing regimen.

Mitogen-Activated Protein Kinase Signaling Pathway in Cutaneous Melanoma: An Updated Review

The mitogen-activated protein kinase (MAPK) signaling pathway is a cascade of protein kinases that act in a sequential and predominantly linear fashion, albeit displaying some cross talk with other signaling cascades. Mutations in proteins integral to the MAPK signaling pathway are present in more than 50% of cutaneous melanomas. The most frequently mutated protein is v-raf murine sarcoma viral oncogene homolog B (BRAF), followed by neuroblastoma Ras viral oncogene homolog (NRAS). Recently, the development of targeted drugs for the treatment of BRAF-mutant melanoma has led to the widespread implementation of molecular assays for the detection of specific BRAF mutations. There have been some attempts to standardize testing of BRAF mutations, but this has not been achieved so far. Here we provide an updated review on the role of the MAPK signaling pathway in the pathogenesis of cutaneous melanoma, focusing on several different BRAF mutations and their diagnostic and therapeutic implications.

SOCS1 favors the epithelial-mesenchymal transition in melanoma, promotes tumor progression and prevents antitumor immunity by PD-L1 expression

Silencing of SOCS1 protein with shRNAi lentivirus (shR-SOCS1) led to partial reversion of the tumorigenic phenotype of B16F10-Nex2 melanoma cells. SOCS1 silencing inhibited cell migration and invasion as well as in vitro growth by cell cycle arrest at S phase with increased cell size and nuclei. Down-regulation of SOCS1 decreased the expression of epidermal growth factor receptor, Ins-Rα, and fibroblast growth factor receptors. The present work aimed at analyzing the SOCS1 cell signaling and expression of proteins relevant to tumor development. An RNA microarray analysis of B16F10-Nex2 melanoma cells with SOCS1 silenced by shRNAi-SOCS1 was undertaken in comparison with cells transduced with the empty vector. Among 609 differentially expressed genes, c-Kit, Met and EphA3 cytokine/tyrosine-kinase (TK) receptors were down regulated. A significant decrease in the expression of TK receptors, the phosphorylation of mediators of ERK1/2 and p38 pathways and STAT3 (S727) were observed. Subcutaneous immunization with shR-SOCS1-transduced viable tumor cells rendered protection against melanoma in a syngeneic model, with decreased expression of PD-L1 and of matrix metallo-proteinases (MMPs) and CD-10 in those cells. The present work shows the role of SOCS1 in murine melanoma development and the potential of SOCS1-silenced tumor cells in raising an effective anti-melanoma immune response.

A case report of a patient with metastatic ocular melanoma who experienced a response to treatment with the BRAF inhibitor vemurafenib

BACKGROUND

Conjunctival malignant melanoma (CMM) is a rare malignancy and in the advanced setting there is no effective treatment. In contrast, half of cutaneous melanomas have BRAF mutations and treatment with BRAF inhibitors is established for patients with disseminated disease. The most common form of ocular melanoma, uveal melanoma, lacks these mutations, however, their presence has been reported for CMM.

CASE PRESENTATION

We used the BRAF inhibitor vemurafenib to treat a 53 year-old female suffering from a BRAF(V600E) mutated metastatic CMM. The patient benefited from the treatment, a response was evident within a week and she experienced a progression free survival of four months.

CONCLUSIONS

To our knowledge, this is the first described case of response to vemurafenib treatment in a patient with ocular melanoma.

Diagnosis and treatment of melanoma. European consensus-based interdisciplinary guideline - Update 2016

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumour and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organisation of Research and Treatment of Cancer was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. Diagnosis is made clinically using dermoscopy and staging is based upon the AJCC system. CMs are excised with 1-2 cm safety margins. Sentinel lymph node dissection is routinely offered as a staging procedure in patients with tumours >1 mm in thickness, although there is as yet no clear survival benefit for this approach. Interferon-α treatment may be offered to patients with stage II and III melanoma as an adjuvant therapy, as this treatment increases at least the disease-free survival and less clear the overall survival (OS) time. The treatment is however associated with significant toxicity. In distant metastasis, all options of surgical therapy have to be considered thoroughly. In the absence of surgical options, systemic treatment is indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies should be considered. BRAF inhibitors like dabrafenib and vemurafenib in combination with the MEK inhibitors trametinib and cobimetinib for BRAF mutated patients should be offered as first or second line treatment. Therapeutic decisions in stage IV patients should be primarily made by an interdisciplinary oncology team ('Tumour Board').

Enhancing the treatment effect on melanoma by heat shock protein 70-peptide complexes purified from human melanoma cell lines

Dendritic cell (DC) vaccines are currently one of the most effective approaches to treat melanoma. The immunogenicity of antigens loaded into DCs determines the treatment effects. Patients treated with autologous antigen-loaded DC vaccines achieve the best therapeutic effects. In China, most melanoma patients cannot access their autologous antigens because of formalin treatment of tumor tissue after surgery. In the present study, we purified heat shock protein 70 (HSP70)-peptide complexes (PCs) from human melanoma cell lines A375, A875, M21, M14, WM‑35, and SK‑HEL‑1. We named the purified product as M‑HSP70‑PCs, and determined its immunological activities. Autologous HSP70‑PCs purified from primary tumor cells of melanoma patients (nine cases) were used as controls. These two kinds of tumor antigenic complexes loaded into DCs were used to stimulate an antitumor response against tumor cells in the corresponding patients. Mature DCs pulsed with M‑HSP70‑PCs stimulated autologous T cells to secrete the same levels of type I cytokines compared with the autologous HSP70‑PCs. Moreover, DCs pulsed with M‑HSP70‑PCs induced CD8+ T cells with an equal ability to kill melanoma cells from patients compared with autologous HSP70‑PCs. Next, we used these PC‑pulsed autologous DCs and induced autologous specific CD8+ T cells to treat one patient with melanoma of the nasal skin and lung metastasis. The treatment achieved a good effect after six cycles. These findings provide a new direction for DC-based immunotherapy for melanoma patients who cannot access autologous antigens.

Interaction of extracellular S100A4 with RAGE prompts prometastatic activation of A375 melanoma cells

S100A4, a member of the S100 protein family of EF-hand calcium-binding proteins, is overexpressed in various tumour entities, including melanoma, and plays an important role in tumour progression. Several studies in epithelial and mesenchymal tumours revealed a correlation between extracellular S100A4 and metastasis. However, exact mechanisms how S100A4 stimulates metastasis in melanoma are still unknown. From a pilot experiment on baseline synthesis and secretion of S100A4 in human melanoma cell lines, which are in broad laboratory use, A375 wild-type cells and, additionally, newly generated A375 cell lines stably transfected with human S100A4 (A375-hS100A4) or human receptor for advanced glycation endproducts (A375-hRAGE), were selected to investigate the influence of extracellular S100A4 on cell motility, adhesion, migration and invasion in more detail. We demonstrated that A375 cells actively secrete S100A4 in the extracellular space via an endoplasmic reticulum-Golgi-dependent pathway. S100A4 overexpression and secretion resulted in prometastatic activation of A375 cells. Moreover, we determined the influence of S100A4-RAGE interaction and its blockade on A375, A375-hS100A4, A375-hRAGE cells, and showed that interaction of RAGE with extracellular S100A4 contributes to the observed activation of A375 cells. This investigation reveals additional molecular targets for therapeutic approaches aiming at blockade of ligand binding to RAGE or RAGE signalling to inhibit melanoma metastasis.

Clinicopathological characteristics and mutation profiling in primary cutaneous melanoma

BACKGROUND

The incidence of mutations in malignant melanoma varies remarkably according to the subtype of melanoma, and this in itself is affected by racial and geographical factors. Studies screening melanoma case series for different types of mutations are relatively rare.

METHOD

The authors analyzed the frequency of various somatic point mutations of 10 genes in 106 primary cutaneous melanoma cases. The mutations (BRAF, NRAS, KIT, CDKN2A, KRAS, HRAS, PIK3CA, STK11, GNAQ, CTNNB1) were evaluated with real-time PCR-based PCR-Array through allele-specific amplification, and the results were correlated with various clinicopathological characteristics.

RESULTS

Mutations were found in 64.2% of the melanomas overall. BRAF (42.5%), NRAS (15.1%), and CDKN2A (13.2%) were the 3 most common mutations. BRAF and NRAS mutations were more frequent in nodular and superficial spreading melanomas (P < 0.001). Associations with BRAF mutation were as follows: male gender [odds ratio (OR) = 2.4], younger age (OR = 2.7), superficial spreading (OR = 15.6) and nodular melanoma (OR = 9.5), trunk localization (OR = 6.3), and intermittent sun exposure (OR = 4.6). A considerable percentage of V600K (44.4%) mutations were found among the BRAF mutations, whereas KIT mutations (3.8%) were less frequent. Multiple mutations were detected in 13.2% of the melanomas. The most common co-occurrences were in the BRAF, NRAS, and CDKN2A genes.

CONCLUSIONS

The authors analyzed 10 somatic mutations in the main subtypes of primary cutaneous melanomas from the western region of Turkey. Mutations were found in 64.2% of the melanomas overall. The most common mutations were in the BRAF and NRAS genes. In addition to other less common mutations, a notable number of multiple mutations were encountered. The multiplicity and concurrence of mutations in this study may provide further study areas for personalized targeted therapy.

Adoptive Cell Therapy of Melanoma with Cytokine-induced Killer Cells

Melanoma is the most aggressive skin cancer and its incidence is gradually increasing worldwide. Patients with metastatic melanoma have a very poor prognosis (estimated 5-year survival rate of <16%). In the last few years, several drugs have been approved for malignant melanoma, such as tyrosine kinase inhibitors and immune checkpoint blockades. Although new therapeutic agents have improved progression-free and overall survival, their use is limited by drug resistance and drug-related toxicity. At the same time, adoptive cell therapy of metastatic melanoma with tumor-infiltrating lymphocytes has shown promising results in preclinical and clinical studies. In this review, we summarize the currently available drugs for treatment of malignant melanoma. In addition, we suggest cytokine-induced killer (CIK) cells as another candidate approach for adoptive cell therapy of melanoma. Our preclinical study and several previous studies have shown that CIK cells have potent anti-tumor activity against melanomas in vitro and in an in vivo human tumor xenograft model without any toxicity.

Emerging clinical applications of selected biomarkers in melanoma

Melanoma is a lethal skin disease with a mostly predictable clinical course according to a known constellation of clinical and pathologic features. The distinction of melanoma from benign melanocytic nevus is typically unequivocol; however, there is a subset of tumors known for its diagnostic challenges, development of late metastases, and difficulties in treatment. Several melanocytic tissue biomarkers are available that can facilitate the histopathologic interpretation of melanoma as well as provide insight into the biologic potential and mutational status of this disease. This review describes the clinical application of some of these established and emerging tissue biomarkers available to assess melanocytic differentiation, vascular invasion, mitotic capacity, and mutation status. The selected tissue biomarkers in this review include MiTF, Sox10, D2-40, PHH3, H3KT (anti-H3K79me3T80ph), anti-BRAFV600E, and anti-BAP-1.

MiR-203 inhibits melanoma invasive and proliferative abilities by targeting the polycomb group gene BMI1

Metastasis is the major problem in malignant melanoma, posing a therapeutic challenge to clinicians. The investigation of the underlying mechanism driving this progress remains a large unmet need. In this study, we revealed a miR-203-BMI1 axis that regulated melanoma metastasis. We found significantly deregulation of miR-203 and up-regulation of BMI1 in melanoma, particularly in metastatic melanoma. An inverse correlation between the levels of miR-203 and BMI1 was further observed in melanoma tissues and cell lines. We also identified BMI1 as a downstream target gene of miR-203, which bound to the 3'UTR of BMI1. Overexpression of miR-203 was associated with decreased BMI1 expression and impaired cell invasion and tumor sphere formation activities. Re-expression of BMI1 markedly rescued miR-203-mediated suppression of these events. Taken together, our results demonstrated that miR-203 regulated melanoma invasive and proliferative abilities in part by targeting BMI1, providing new insights into potential mechanisms of melanoma metastasis.

Melanoma: clinical features and genomic insights

Recent efforts in genomic research have enabled the characterization of molecular mechanisms underlying many types of cancers, ushering novel approaches for diagnosis and therapeutics. Melanoma is a molecularly heterogeneous disease, as many genetic alterations have been identified and the clinical features can vary. Although discoveries of frequent mutations including BRAF have already made clinically significant impact on patient care, there is a growing body of literature suggesting a role for additional mutations, driver and passenger types, in disease pathophysiology. Although some mutations have been strongly associated with clinical phenotypes of melanomas (such as physical distribution or morphologic subtype), the function or implications of many of the recently identified mutations remains less clear. The phenotypic and clinical impact of genomic mutations in melanoma remains a promising opportunity for progress in the care of melanoma patients.

Molecular pathology of skin neoplasms of the head and neck

CONTEXT

Skin neoplasms include the most common malignancies affecting humans. Many show an ultraviolet (UV)-induced pathogenesis and often affect the head and neck region.

OBJECTIVE

To review literature on cutaneous neoplasms that show a predilection for the head and neck region and that are associated with molecular alterations.

DATA SOURCES

Literature review.

CONCLUSIONS

Common nonmelanoma skin cancers, such as basal and squamous cell carcinomas, show a UV-induced pathogenesis. Basal cell carcinomas are characterized by molecular alterations of the Hedgehog pathway, affecting patched and smoothened genes. While squamous cell carcinomas show UV-induced mutations in several genes, driver mutations are only beginning to be identified. In addition, certain adnexal neoplasms also predominantly affect the head and neck region and show interesting, recently discovered molecular abnormalities, or are associated with hereditary conditions whose molecular genetic pathogenesis is well understood. Furthermore, recent advances have led to an increased understanding of the molecular pathogenesis of melanoma. Certain melanoma subtypes, such as lentigo maligna melanoma and desmoplastic melanoma, which are more often seen on the chronically sun-damaged skin of the head and neck, show differences in their molecular signature when compared to the other more common subtypes, such as superficial spreading melanoma, which are more prone to occur at sites with acute intermittent sun damage. In summary, molecular alterations in cutaneous neoplasms of the head and neck are often related to UV exposure. Their molecular footprint often reflects the histologic tumor type, and familiarity with these changes will be increasingly necessary for diagnostic and therapeutic considerations.

Epigenetics of human melanoma: promises and challenges

Melanoma is the deadliest form of skin cancer with rising incidence and mortality rates. Although early-stage melanoma is highly curable, advanced-stage melanoma is refractory to treatment. This underscores the importance of prevention and early detection as well as the need to improve treatment and prognostication of human melanoma. Elucidating the underlying mechanisms of the initiation and progression of human melanoma can help identify potential targets of intervention for prevention, diagnosis, therapy, and prognosis of this disease. Aberrant DNA methylation and histone modifications are the best-established epigenetic mechanisms of carcinogenesis. The occurrence of epigenetic changes prior to clinical diagnosis of cancer and their reversibility through pharmacologic/genetic approaches offer a promising avenue for basic and translational research on human melanoma. Candidate gene(s) or genome-wide aberrant DNA methylation and histone modifications have been observed in human melanoma tumor tissues and cell lines, and correlated to cellular and functional characteristics and/or clinicopathological features of this malignancy. The present review summarizes the published researches on aberrant DNA methylation and histone modifications in connection with human melanoma. Representative studies are highlighted to set forth the current state of knowledge, gaps in the knowledgebase, and future directions in these epigenetic fields of research. Examples of epigenetic therapy applied for human melanoma in vitro, and the challenges of its in vivo application for clinical treatment of solid tumors are discussed.

Management of conjunctival malignant melanoma: a review and update

Conjunctival malignant melanoma is a pigmented lesion of the ocular surface. It is an uncommon but potentially devastating tumor that may invade the local tissues of the eye, spread systemically through lymphatic drainage and hematogenous spread, and recur in spite of treatment. Despite its severity, the rarity of available cases has limited the evidence for diagnosis and management. This review will provide an overview of the epidemiology, presentation, diagnosis, management, and surveillance of conjunctival melanoma, with an emphasis on recent advances in biological therapies to treat this disease.

A meta analysis of pancreatic microarray datasets yields new targets as cancer genes and biomarkers

The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a five year survival rate of less than 5%. Improved screening for earlier diagnosis, through the detection of diagnostic and prognostic biomarkers provides the best hope of increasing the rate of curatively resectable carcinomas. Though many serum markers have been reported to be elevated in patients with PC, so far, most of these markers have not been implemented into clinical routine due to low sensitivity or specificity. In this study, we have identified genes that are significantly upregulated in PC, through a meta-analysis of large number of microarray datasets. We demonstrate that the biological functions ascribed to these genes are clearly associated with PC and metastasis, and that that these genes exhibit a strong link to pathways involved with inflammation and the immune response. This investigation has yielded new targets for cancer genes, and potential biomarkers for pancreatic cancer. The candidate list of cancer genes includes protein kinase genes, new members of gene families currently associated with PC, as well as genes not previously linked to PC. In this study, we are also able to move towards developing a signature for hypomethylated genes, which could be useful for early detection of PC. We also show that the significantly upregulated 800+ genes in our analysis can serve as an enriched pool for tissue and serum protein biomarkers in pancreatic cancer.

Paradigm Shift in Dendritic Cell-Based Immunotherapy: From in vitro Generated Monocyte-Derived DCs to Naturally Circulating DC Subsets

Dendritic cell (DC)-based immunotherapy employs the patients’ immune system to fight neoplastic lesions spread over the entire body. This makes it an important therapy option for patients suffering from metastatic melanoma, which is often resistant to chemotherapy. However, conventional cellular vaccination approaches, based on monocyte-derived DCs (moDCs), only achieved modest response rates despite continued optimization of various vaccination parameters. In addition, the generation of moDCs requires extensive ex vivo culturing conceivably hampering the immunogenicity of the vaccine. Recent studies, thus, focused on vaccines that make use of primary DCs. Though rare in the blood, these naturally circulating DCs can be readily isolated and activated thereby circumventing lengthy ex vivo culture periods. The first clinical trials not only showed increased survival rates but also the induction of diversified anti-cancer immune responses. Upcoming treatment paradigms aim to include several primary DC subsets in a single vaccine as pre-clinical studies identified synergistic effects between various antigen-presenting cells.

Liver X receptor activation induces apoptosis of melanoma cell through caspase pathway

Liver X receptors (LXRs) are nuclear receptors that function as ligand-activated transcription factors regulating lipid metabolism and inflammation. Recent discoveries found LXRs could regulate tumor growth in a variety of cancer cell lines. In this study, we investigated the effect of LXR activation on melanoma cell proliferation and apoptosis both in vitro and in vivo. Treatment of B16F10 and A-375 melanoma cells with synthetic LXR agonist T0901317 significantly inhibited the proliferation of melanoma cells in vitro. Meanwhile, T0901317 induced the apoptosis of B16F10 melanoma cells in a dose-dependent manner. Furthermore, western blot assay showed that the pro-apoptotic effect of T0901317 on B16F10 melanoma cells was mediated through caspase-3 pathway. Oral administration of T0901317 inhibited the growth of B16F10 melanoma in C56BL/6 mice. Altogether, this study demonstrates the critical role of LXRs in the regulation of melanoma growth and presents the LXR agonist T0901317 as a potential anti-melanoma agent.

UVB-irradiated keratinocytes induce melanoma-associated ganglioside GD3 synthase gene in melanocytes via secretion of tumor necrosis factor α and interleukin 6

Although expression of gangliosides and their synthetic enzyme genes in malignant melanomas has been well studied, that in normal melanocytes has been scarcely analyzed. In particular, changes in expression levels of glycosyltransferase genes responsible for ganglioside synthesis during evolution of melanomas from melanocytes are very important to understand roles of gangliosides in melanomas. Here, expression of glycosyltransferase genes related to the ganglioside synthesis was analyzed using RNAs from cultured melanocytes and melanoma cell lines. Quantitative RT-PCR revealed that melanomas expressed high levels of mRNA of GD3 synthase and GM2/GD2 synthase genes and low levels of GM1/GD1b synthase genes compared with melanocytes. As a representative exogenous stimulation, effects of ultraviolet B (UVB) on the expression levels of 3 major ganglioside synthase genes in melanocytes were analyzed. Although direct UVB irradiation of melanocytes caused no marked changes, culture supernatants of UVB-irradiated keratinocytes (HaCaT cells) induced definite up-regulation of GD3 synthase and GM2/GD2 synthase genes. Detailed examination of the supernatants revealed that inflammatory cytokines such as TNFα and IL-6 enhanced GD3 synthase gene expression. These results suggest that inflammatory cytokines secreted from UVB-irradiated keratinocytes induced melanoma-associated ganglioside synthase genes, proposing roles of skin microenvironment in the promotion of melanoma-like ganglioside profiles in melanocytes.

The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

Recent reports suggest that N-methyl-d-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination.

Expression of IL-27 by tumor cells in invasive cutaneous and metastatic melanomas [corrected]

Interleukin (IL)-27 is a cytokine of the IL-12 family that displays either immunostimulatory or immunosuppressive functions depending on the context. In various murine tumor models including melanoma models, ectopic expression of IL-27 has been shown to play an anti-tumoral role and to favor tumor regression. In this study, we investigated whether IL-27 might play a role in the development of melanoma in humans. We analyzed the in situ expression of IL-27 in melanocytic lesions (n = 82) representative of different stages of tumor progression. IL-27 expression was not observed in nevus (n = 8) nor in in situ melanoma (n = 9), but was detected in 28/46 (61%) cases of invasive cutaneous melanoma, notably in advanced stages (19/23 cases of stages 3 and 4). In most cases, the main source of IL-27 was tumor cells. Of note, when IL-27 was detected in primary cutaneous melanomas, its expression was maintained in metastatic lesions. These in situ data suggested that the immunosuppressive functions of IL-27 may dominate in human melanoma. Consistent with this hypothesis, we found that IL-27 could induce suppressive molecules such as PD-L1, and to a lesser extent IL-10, in melanoma cells, and that the in situ expression of IL-27 in melanoma correlated with those of PD-L1 and IL-10.

MicroRNAs induced in melanoma treated with combination targeted therapy of Temsirolimus and Bevacizumab

Background

Targeted therapies directed at commonly overexpressed pathways in melanoma have clinical activity in numerous trials. Little is known about how these therapies influence microRNA (miRNA) expression, particularly with combination regimens. Knowledge of miRNAs altered with treatment may contribute to understanding mechanisms of therapeutic effects, as well as mechanisms of tumor escape from therapy. We analyzed miRNA expression in metastatic melanoma tissue samples treated with a novel combination regimen of Temsirolimus and Bevacizumab. Given the preliminary clinical activity observed with this combination regimen, we hypothesized that we would see significant changes in miRNA expression with combination treatment.

Methods

Using microarray analysis we analyzed miRNA expression levels in melanoma samples from a Cancer Therapy Evaluation Program-sponsored phase II trial of combination Temsirolimus and Bevacizumab in advanced melanoma, which elicited clinical benefit in a subset of patients. Pre-treatment and post-treatment miRNA levels were compared using paired t-tests between sample groups (patients), using a p-value < 0.01 for significance.

Results

microRNA expression remained unchanged with Temsirolimus alone; however, expression of 15 microRNAs was significantly upregulated (1.4 to 2.5-fold) with combination treatment, compared to pre-treatment levels. Interestingly, twelve of these fifteen miRNAs possess tumor suppressor capabilities. We identified 15 putative oncogenes as potential targets of the 12 tumor suppressor miRNAs, based on published experimental evidence. For 15 of 25 miRNA-target mRNA pairings, changes in gene expression from pre-treatment to post-combination treatment samples were inversely correlated with changes in miRNA expression, supporting a functional effect of those miRNA changes. Clustering analyses based on selected miRNAs suggest preliminary signatures characteristic of clinical response to combination treatment and of tumor BRAF mutational status.

Conclusions

To our knowledge, this is the first study analyzing miRNA expression in pre-treatment and post-treatment human metastatic melanoma tissue samples. This preliminary investigation suggests miRNAs that may be involved in the mechanism of action of combination Temsirolimus and Bevacizumab in metastatic melanoma, possibly through inhibition of oncogenic pathways, and provides the preliminary basis for further functional studies of these miRNAs.