Prognostic molecular biomarkers for cutaneous malignant melanoma

Recent Developments of Circulating Tumor Cell Analysis for Monitoring Cutaneous Melanoma Patients

Simple Summary

Circulating tumor cells (CTCs) originating from cutaneous melanoma patients have been studied for several decades as surrogates for real-time clinical status and disease outcomes. Here, we will review clinical studies from the last 15 years that assessed CTCs and disease outcomes for melanoma patients. Assessment of multiple molecular melanoma-associated antigen (MAA) markers by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was the most common assay allowing for the improvement of assay sensitivity, to address tumor heterogeneity, and to predict patient outcomes. Multicenter studies demonstrate the utility of CTC assays reducing the bias observed in single-center trials. Recent development of CTC enrichment platforms has provided reproducible methods. CTC assessment enables both multiple mRNAs and DNAs genomic profiling. CTC provides specific important translational information on tumor progression, prediction of treatment response, and survival outcomes for cutaneous melanoma patients.

Abstract

Circulating tumor cells (CTCs) have been studied using multiple technical approaches for interrogating various cancers, as they allow for the real-time assessment of tumor progression, disease recurrence, treatment response, and tumor molecular profiling without the need for a tumor tissue biopsy. Here, we will review studies from the last 15 years on the assessment of CTCs in cutaneous melanoma patients in relation to different clinical outcomes. The focus will be on CTC detection in blood samples obtained from cutaneous melanoma patients of different clinical stages and treatments utilizing multiple platforms. Assessment of multiple molecular melanoma-associated antigen (MAA) markers by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was the most common assay allowing for the improvement of assay sensitivity, tumor heterogeneity, and to predict patient outcomes. Multicenter studies demonstrate the utility of CTC assays reducing the bias observed in single- center trials. The recent development of CTC enrichment platforms has provided reproducible methods. CTC assessment enables both multiple mRNAs and DNAs genomic aberration profiling. CTC provides specific important translational information on tumor progression, prediction of treatment response, and survival outcomes for cutaneous melanoma patients. The molecular studies on melanoma CTCs have provided and may set standards for other solid tumor CTC analyses.

Current Achievements and Applications of Transcriptomics in Personalized Cancer Medicine

Over the last decades, transcriptome profiling emerged as one of the most powerful approaches in oncology, providing prognostic and predictive utility for cancer management. The development of novel technologies, such as revolutionary next-generation sequencing, enables the identification of cancer biomarkers, gene signatures, and their aberrant expression affecting oncogenesis, as well as the discovery of molecular targets for anticancer therapies. Transcriptomics contribute to a change in the holistic understanding of cancer, from histopathological and organic to molecular classifications, opening a more personalized perspective for tumor diagnostics and therapy. The further advancement on transcriptome profiling may allow standardization and cost reduction of its analysis, which will be the next step for transcriptomics to become a canon of contemporary cancer medicine.

Energy metabolism in skin cancers: A therapeutic perspective

Skin cancers are the most common cancers worldwide. The incidence of common skin cancers, including basal cell carcinomas (BCCs), squamous cell carcinomas (SCCs) and melanomas, continues to rise by 5 to 7% per year, mainly due to ultraviolet (UV) exposure and partly because of aging. This suggests an urgent necessity to improve the level of prevention and protection for skin cancers as well as developing new prognostic and diagnostic markers of skin cancers. Moreover, despite innovative therapies especially in the fields of melanoma and carcinomas, new therapeutic options are needed to bypass resistance to targeted therapies or treatment's side effects. Since reprogramming of cellular metabolism is now considered as a hallmark of cancer, some of the recent findings on the role of energy metabolism in skin cancer initiation and progression as well as its effect on the response to targeted therapies are discussed in this review. This article is part of a Special Issue entitled Mitochondria in cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux.

Transcription factor LSF (TFCP2) inhibits melanoma growth

Late SV40 factor 3 (LSF), a transcription factor, contributes to human hepatocellular carcinoma (HCC). However, decreased expression level of LSF in skin melanoma compared to that in benign melanocytic tumors and nevi in mice and humans was found in this study. Anchorage-dependent and -independent growth of melanoma cells was suppressed by LSF overexpression through an increased percentage of G1 phase cells and an increased p21^CIP1 expression level in vitro and in vivo. Anchorage-dependent growth in LSF-overexpressed melanoma cells was promoted by depletion of LSF in the LSF-overexpressed cells. Integrated results of our EMSA and chromatin immunoprecipitation assays showed binding of LSF within a 150-bp upstream region of the transcription start site of p21CIP1 in melanoma cells. Taken together, our results suggest potential roles of LSF as a growth regulator through control of the transcription of p21^CIP1 in melanocytes and melanoma cells as well as a biomarker for nevus.

The Prognostic Value of Circulating Cell-Free DNA in Colorectal Cancer: A Meta-Analysis

BACKGROUND

Circulating cell-free DNA (cfDNA) is a promising candidate biomarker for detection, monitoring and survival prediction of colorectal cancer (CRC). However, its prognostic significance for patients with CRC remains controversial. To derive a precise estimation of the prognostic significance of cfDNA, a meta-analysis was performed.

METHODS

We made a systematic search in data base of the Science Citation Index Embase and Pubmed for studies reporting prognostic data of cfDNA in CRC patients. The data of cfDNA on recurrences-free survival (RFS) and overall survival (OS) were extracted and measured in hazard rates (HRs) and 95% confident intervals (CIs). Subgroup analyses were carried out as well. Finally, the meta-analysis is accompanied with nine studies including 19 subunits.

RESULTS

The pooled HRs with 95% CIs revealed strong associations between cfDNA and RFS (HR [95%CI]=2.78[2.08-3.72], I(2)=32.23%, n=7) along with OS (HR [95%CI]=3.03[2.51-3.66], I(2)=29.24%, n=12) in patients with CRC. Entire subgroup analyses indicated strong prognostic value of cfDNA irrespective tumor stage, study size, tumor markers, detection methods and marker origin.

CONCLUSIONS

All the results exhibits that appearance of cfDNA in blood is an indicator for adverse RFS and OS in CRC patients.

The Role of CTCs as Tumor Biomarkers

Detection of Circulating Tumor Cells (CTCs) in peripheral blood can serve as a "liquid biopsy" approach and as a source of valuable tumor markers. CTCs are rare, and thus their detection, enumeration and molecular characterization are very challenging. CTCs have the unique characteristic to be non-invasively isolated from blood and used to follow patients over time, since these cells can provide significant information for better understanding tumour biology and tumour cell dissemination. CTCs molecular characterization offers the unique potential to understand better the biology of metastasis and resistance to established therapies and their analysis presents nowadays a promising field for both advanced and early stage patients. In this chapter we focus on the latest findings concerning the clinical relevance of CTC detection and enumeration, and discuss their potential as tumor biomarkers in various types of solid cancers. We also highlight the importance of performing comparison studies between these different methodologies and external quality control systems for establishing CTCs as tumor biomarkers in the routine clinical setting.

High Expression of miR-532-5p, a Tumor Suppressor, Leads to Better Prognosis in Ovarian Cancer Both In Vivo and In Vitro

Ovarian cancer is the leading cause of death for gynecologic cancers, ranking fifth overall for cancer-related death among women. The identification of biomarkers and the elucidation of molecular mechanisms for improving treatment options have received extensive efforts in ovarian cancer research. miRNAs have high potential to act as both ovarian cancer biomarkers and as critical regulators of ovarian tumor behavior. We comprehensively analyzed global mRNA, miRNA expression, and survival data for ovarian cancer from The Cancer Genome Atlas (TCGA) to pinpoint miRNAs that play critical roles in ovarian cancer survival through their effect on mRNA expression. We performed miRNA overexpression and gene knockdown experiments to confirm mechanisms predicted in our bioinformatics approach. We established that overexpression of miR-532-5p in OVCAR-3 cells resulted in a significant decrease in cell viability over a 96-hour time period. In the TCGA ovarian cancer dataset, we found 67 genes whose expression levels were negatively correlated with miR-532-5p expression and correlated with patient survival, such as WNT9A, CSNK2A2, CHD4, and SH3PXD2A The potential miR-532-5p-regulated gene targets were found to be enriched in the Wnt pathway. Overexpression of miR-532-5p through miRNA mimic caused downregulation of CSNK2A2, CHD4, and SH3PXD2A in the OVCAR-3 cell line. We have discovered and validated the tumor-suppressing capabilities of miR-532-5p both in vivo through TCGA analysis and in vitro through ovarian cancer cell lines. Our work highlights the potential clinical importance of miR-532-5p expression in ovarian cancer patients. Mol Cancer Ther; 15(5); 1123-31. ©2016 AACR.

Novel DNA methylation markers with potential prognostic relevance in advanced malignant melanoma identified using COBRA assays

Aberrant methylation of promoter regions involved in silencing of tumor suppressor genes is a key feature of many human cancers including melanoma. These DNA methylation events occur early in cancer development, increase with progression, and may therefore serve as biomarkers for the detection and staging of cancer. In our study, we used an epigenomic reactivation screening approach including Combined Bisulfite Restriction Analyses (COBRA) assays to identify novel methylation markers in late-stage melanoma. Two human xenograft melanoma models have been used to identify genes methylated in cancer and reactivated upon treatment with a histone deacetylase inhibitor. Gene expression analysis and promoter scanning for DNA methylation by COBRA assays and bisulfite sequencing were used to identify candidate genes. The methylation status of the CpG island promoter region of genes related to melanoma pathophysiology in skin, lymph node, and visceral metastatic metastases in 28 patients (samples n=35) were assessed. These methylation markers have been evaluated in melanoma metastasis tissue and in control samples from normal skin. The screening in in-vitro and in-vivo systems for methylated genes in melanoma samples showed 10 candidate genes. Using COBRA assays, we detected a methylation pattern in the promoter region of 10 genes with two genes (BASP1, CDH11), together with the patient's age and the log-S100B-level at biopsy, constructing a descriptor with a trend to correlate with shorter time to death.

Xanthoceraside induces apoptosis in melanoma cells through the activation of caspases and the suppression of the IGF-1R/Raf/MEK/ERK signaling pathway

Xanthoceraside, a saponin extracted from the husks of Xanthoceras sorbifolia Bunge, suppresses inflammation and oxidative stress. However, the antitumor properties of xanthoceraside as well as its mechanism of action remain unclear. Therefore, we proposed to investigate its potential anticancer property. In this study, the viability of cells was measured by the MTT assay. Cell cycle and mitochondrial membrane potential were measured by flow cytometry, and the expressions of procaspase-9, procaspase-3, Cyto.c, Apaf-1, Bcl-2, Bcl-xL, Bad, p53, and IGF-1R/Raf/MEK/ERK were tested by Western blotting. Xanthoceraside significantly inhibited the proliferation of human melanoma A375.S2 cells in a concentration- and time-dependent manner but did not impair the viability of normal cells (peripheral blood mononuclear cells). Further analysis revealed that xanthoceraside induced apoptosis by activating caspase-3 and caspase-9 in a time-dependent manner through the mitochondrial pathway but did not activate caspase-8 in the cells. In addition, xanthoceraside inhibited the expression of the insulin-like growth factor-1 receptor (IGF-1R), which is an important prosurvival, antiapoptotic signaling growth factor receptor that is frequently overexpressed in cancer cells and used as a therapeutic target for multiple cancers. Interestingly, xanthoceraside also decreased the expression of Raf, p-MEK, and p-ERK, the downstream effectors of IGF-1R. Taken together, these findings indicate that xanthoceraside induces apoptosis through a mitochondria-mediated apoptotic pathway, which is induced by the downregulation of IGF-1R/Raf/MEK/ERK cascades in A375.S2 cells.

Neuropilin-2 gene expression correlates with malignant progression in cutaneous melanoma

BACKGROUND

It is currently not possible to predict the metastatic potential of early-stage melanoma lesions by histological examination alone; however, a significant number of thin melanomas will progress over time to advanced disease. Molecular biomarkers that could identify patients with melanoma at high risk at the time of original diagnosis would contribute significantly to improved patient outcomes and increased survival. Neuropilin-2 (NRP2), a cell surface receptor involved in tumour-associated angiogenesis and lymphangiogenesis, has recently been shown to be expressed in melanoma.

OBJECTIVES

To evaluate the potential value of NRP2 gene transcript levels as biomarkers for malignant melanoma progression.

METHODS

We measured NRP2 gene expression in a panel of formalin-fixed paraffin-embedded tissue specimens consisting of naevi, primary melanomas and metastatic melanomas using quantitative reverse transcriptase-polymerase chain reaction technique.

RESULTS

NRP2 levels are clearly segregated among the groups of naevi, primary and metastatic melanoma samples with a statistical trend towards increasing NRP2 gene expression correlating with disease progression. Logistic regression analysis reveals that the probability of malignant progression increases with elevated levels of NRP2 (odds ratio of 2·60 with confidence interval 1·29-5·21). Within the group of primary melanomas, there is a positive correlation (r = 0·823) between NRP2 expression and Breslow depth. This correlation was validated in an independent sample set of patients with melanoma.

CONCLUSIONS

This preliminary study strongly supports the significance of NRP2 as a useful biomarker for malignant progression of melanoma, which may be useful for early identification of patients with melanoma at high risk.

Contemporary controversies and perspectives in the staging and treatment of patients with lymph node metastasis from melanoma, especially with regards positive sentinel lymph node biopsy

The management of melanoma lymph node metastasis particularly when detected by sentinel lymph node biopsy (SLNB) is still controversial. Results of the only randomized trial conducted to assess the therapeutic value of SLNB, the Multicenter Selective Lymphadenectomy Trial (MSLT-1), have not conclusively proven the effectiveness of this procedure but are interpreted by the authors and guidelines as indicating SLNB is standard of care. After surgery, interferon alpha had a small survival benefit and radiotherapy has limited effectiveness for patient at high-risk of regional recurrence. New drugs, including immune modulating agents and targeted therapies, already shown to be effective in patients with distant metastasis, are being evaluated in the adjuvant setting. In this regard, ensuring high quality of surgery through the identification of reliable quality assurance indicators and improving the homogeneity of prognostic stratification of patients entered onto clinical trials is paramount. Here, we review the controversial issues regarding the staging and treatment of melanoma patients with lymph node metastasis, present a summary of important and potentially practice changing ongoing research and provide a commentary on what it all means at this point in time.

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.

Pathways and therapeutic targets in melanoma

This review aims to summarize the current knowledge of molecular pathways and their clinical relevance in melanoma. Metastatic melanoma was a grim diagnosis, but in recent years tremendous advances have been made in treatments. Chemotherapy provided little benefit in these patients, but development of targeted and new immune approaches made radical changes in prognosis. This would not have happened without remarkable advances in understanding the biology of disease and tremendous progress in the genomic (and other "omics") scale analyses of tumors. The big problems facing the field are no longer focused exclusively on the development of new treatment modalities, though this is a very busy area of clinical research. The focus shifted now to understanding and overcoming resistance to targeted therapies, and understanding the underlying causes of the heterogeneous responses to immune therapy.

Circulating tumor cells as promising novel biomarkers in solid cancers

The presence of circulating tumor cells (CTCs) in peripheral blood can serve as a "liquid biopsy" approach and has thus emerged lately as one of the hottest fields in cancer research. CTCs can be isolated from blood in a non-invasive approach, and can be used to follow patients over time since these cells can provide significant information for a better understanding of tumor biology and tumor cell dissemination. CTC molecular characterization offers the unique potential to better understand the biology of metastasis and resistance to established therapies, and analysis of these cells presents a promising field for both advanced and early-stage patients. CTC detection, enumeration, and molecular characterization are very challenging since CTCs are rare, and the amount of available sample is very limited. Since detection of CTCs has been shown to be of considerable utility in the clinical management of patients with solid cancers, various analytical systems for their isolation and detection have been developed. New areas of research are directed towards developing novel assays for single-CTC isolation and molecular characterization. The clinical significance of CTCs has been evaluated in many types of solid cancers, and the CTC enumeration test in metastatic breast, colorectal, and prostate cancer was cleared by the FDA almost a decade ago. This review is mainly focused on the clinical potential of CTCs as novel biomarkers in 10 different types of solid cancers: breast, ovarian, prostate, lung, colorectal, hepatocellular carcinoma, pancreatic, head and neck, bladder cancer and melanoma.

Biological properties of acidic cosmetic water from seawater

This current work was to investigate the biological effects of acidic cosmetic water (ACW) on various biological assays. ACW was isolated from seawater and demonstrated several bio-functions at various concentration ranges. ACW showed a satisfactory effect against Staphylococcus aureus, which reduced 90% of bacterial growth after a 5-second exposure. We used cultured human peripheral blood mononuclear cells (PBMCs) to test the properties of ACW in inflammatory cytokine release, and it did not induce inflammatory cytokine release from un-stimulated, normal PBMCs. However, ACW was able to inhibit bacterial lipopolysaccharide (LPS)-induced inflammatory cytokine TNF-α released from PBMCs, showing an anti-inflammation potential. Furthermore, ACW did not stimulate the rat basophilic leukemia cell (RBL-2H3) related allergy response on de-granulation. Our data presented ACW with a strong anti-oxidative ability in a superoxide anion radical scavenging assay. In mass spectrometry information, magnesium and zinc ions demonstrated bio-functional detections for anti-inflammation as well as other metal ions such as potassium and calcium were observed. ACW also had minor tyrosinase and melanin decreasing activities in human epidermal melanocytes (HEMn-MP) without apparent cytotoxicity. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects of ACW on human skin melanoma cells (A375.S2) indicating that it exerted the anti-cancer potential against skin cancer. The results obtained from biological assays showed that ACW possessed multiple bioactivities, including anti-microorganism, anti-inflammation, allergy-free, antioxidant, anti-melanin and anticancer properties. To our knowledge, this was the first report presenting these bioactivities on ACW.

Epigenetic biomarkers in skin cancer

Epigenetic aberrations have been associated with cutaneous melanoma tumorigenesis and progression including dysregulated DNA gene promoter region methylation, histone modification, and microRNA. Several of these major epigenetic aberrations have been developed into biomarkers. Epigenetic biomarkers can be detected in tissue and in blood as circulating DNA in melanoma patients. There is strong evidence that biomarkers in cutaneous melanoma will have an important role as companions to therapeutics and overall patient management. Important progress has been made in epigenetic melanoma biomarker development and verification of clinical utility, and this review discusses some of the key current developments and existing challenges.