Treatment implications of the emerging molecular classification system for melanoma

Photosensitive Hybrid γδ-T Exosomes for Targeted Cancer Photoimmunotherapy

Melanoma is the most aggressive type of skin cancers. Traditional chemotherapy and radiotherapy have limited effectiveness and can lead to systemic side effects. Photodynamic therapy (PDT) is a photoresponsive cancer therapy based on photosensitizers to generate reactive oxygen species (ROS) to eradicate tumor cells. Our previous study showed that exosomes derived from human γδ-T cells (γδ-T exosomes) could control Epstein-Barr virus-associated tumors. Here, we combined γδ-T exosomes and PDT for targeted photoimmunotherapy by membrane fusion of γδ-T exosomes and Chlorin e6 (Ce6)-loaded liposomes. The functional surface proteins, such as CCR5 and PD-1, on the hybrid exosomes mediated the specific binding of hybrid exosomes toward melanoma tissues. The cytolytic molecules, such as granzyme A, granzyme B, perforin, and granulysin from γδ-T exosomes, induced specific apoptosis of cancer cells without harming normal cells. In response to light irradiation, ROS generation inside melanoma cells synergized with cytolytic molecules to induce apoptosis and promote immunogenic cancer cell death (ICD). The subsequently released damage-associated molecular patterns (DAMPs) could stimulate human dendritic cell maturation and induce melanoma antigen-specific CD4+ and CD8+ T-cell responses, thereby enhancing antitumor immunity. This study provides a promising strategy by combining γδ-T exosomes and PDT for photoimmunotherapy, thereby expanding the clinical applications of γδ-T exosome therapy for cancer patients.

Triazole-Estradiol Analogs Induce Apoptosis and Inhibit EGFR and Its Downstream Pathways in Triple Negative Breast Cancer

Triple negative breast cancer, TNBC, is a difficult disease to treat due to relapse and resistance to known therapies. Epidermal growth factor receptor (EGFR), a tyrosine kinase responsible for downstream signaling leading to cell growth and survival, is typically overexpressed in TNBC. Our previous work has detailed the synthesis of triazole-estradiol derivatives as inhibitors of EGFR and downstream receptors, and this work continues that discussion by evaluating them in EGFR-dependent TNBC cell models MDA-MB-231 and MDA-MB-468. Compound Fz25 was cytotoxic against both MDA-MB-231 and MDA-MB-468 cell lines, yielding IC50 values of 8.12 ± 0.85 and 25.43 ± 3.68 µM, respectively. However, compounds Fz57 and Fz200 were potent against only MDA-MB-231 cells, generating IC50 values of 21.18 ± 0.23 and 10.86 ± 0.69 µM, respectively. Pathway analyses revealed that Fz25, Fz57 and Fz200 arrested the G0/G1 phase of the cell cycle and concomitantly suppressed cell cycle regulators, cyclin D1, cyclin E and Dyrk1B in MDA-MB-231 cells. Additionally, all compounds inhibited EGFR and its downstream signaling pathways-extracellular receptor kinase (ERK) and the mammalian target of rapamycin (mTOR)-in a dose-dependent manner. Furthermore, Fz25, Fz57 and Fz200 induced apoptosis in MDA-MB-231 cells by modulating morphological changes, including chromatin condensation, and attenuating the levels of cytochrome c, APAF1, caspases-3 and -9 as well as cleaved PARP. Of these compounds, only Fz25 showed overall satisfactory ADMET properties in silico. Similarly, Fz25 showed suitable binding parameters explored using molecular dynamic simulations in silico. These findings suggest that Fz25 warrants further preclinical and clinical investigations as a new generation of triazole congeners with significant potency in EFGR-dependent TNBC.

Global trends in melanoma burden: A comprehensive analysis from the Global Burden of Disease Study, 1990-2021

BACKGROUND

Melanoma, a significant global health concern, has shown evolving epidemiologic trends. Accurate estimation of melanoma's burden is essential for public health strategies and interventions.

OBJECTIVES

This study aims to estimate the incidence, mortality, and disability-adjusted life years for melanoma, stratified by region, gender, and age group, from 1990 to 2021.

METHODS

Using data from the Global Burden of Disease 2021, we analyzed melanoma incidence, mortality rates, and disability-adjusted life years in 204 countries from 1990 to 2021. These metrics were age-standardized and stratified by age, sex, Socio-Demographic Index, region, and country. The estimated annual percentage change was calculated to track temporal trends.

RESULTS

Our study shows a substantial global increase in melanoma incidence, with significant disparities between genders and age groups. Higher Socio-Demographic Index regions had increased incidence rates, while global mortality declined, likely due to improved detection and treatment.

LIMITATIONS

The reliance on estimates and models may introduce bias due to variability in disease definitions, diagnostic criteria, and data collection methods.

CONCLUSION

This study underscores the dynamic nature of melanoma's burden and the need for targeted, age-specific, and gender-specific interventions. Continued research is essential to address the growing challenges posed by melanoma.

Strongly ROS-Correlated, Time-Dependent, and Selective Antiproliferative Effects of Synthesized Nano Vesicles on BRAF Mutant Melanoma Cells and Their Hyaluronic Acid-Based Hydrogel Formulation

Cutaneous metastatic melanoma (CMM) is the most aggressive form of skin cancer with a poor prognosis. Drug-induced secondary tumorigenesis and the emergency of drug resistance worsen an already worrying scenario, thus rendering urgent the development of new treatments not dealing with mutable cellular processes. Triphenyl phosphonium salts (TPPSs), in addiction to acting as cytoplasmic membrane disruptors, are reported to be mitochondria-targeting compounds, exerting anticancer effects mainly by damaging their membranes and causing depolarization, impairing mitochondria functions and their DNA, triggering oxidative stress (OS), and priming primarily apoptotic cell death. TPP-based bola amphiphiles are capable of self-forming nanoparticles (NPs) with enhanced biological properties, as commonly observed for nanomaterials. Already employed in several other biomedical applications, the per se selective potent antibacterial effects of a TPP bola amphiphile have only recently been demonstrated on 50 multidrug resistant (MDR) clinical superbugs, as well as its exceptional and selective anticancer properties on sensitive and MDR neuroblastoma cells. Here, aiming at finding new molecules possibly developable as new treatments for counteracting CMM, the effects of this TPP-based bola amphiphile (BPPB) have been investigated against two BRAF mutants CMM cell lines (MeOV and MeTRAV) with excellent results (even IC50 = 49 nM on MeOV after 72 h treatment). With these findings and considering the low cytotoxicity of BPPB against different mammalian non-tumoral cell lines and red blood cells (RBCs, selectivity indexes up to 299 on MeOV after 72 h treatment), the possible future development of BPPB as topical treatment for CMM lesions was presumed. With this aim, a biodegradable hyaluronic acid (HA)-based hydrogel formulation (HA-BPPB-HG) was prepared without using any potentially toxic crosslinking agents simply by dispersing suitable amounts of the two ingredients in water and sonicating under gentle heating. HA-BPPB-HA was completely characterized, with promising outcomes such as high swelling capability, high porosity, and viscous elastic rheological behavior.

The treatment of advanced melanoma: Current approaches and new challenges

In recent years, advances in melanoma treatment have renewed patient hope. This comprehensive review emphasizes the evolving treatment landscape, particularly highlighting first-line strategies and the interplay between immune-checkpoint inhibitors (ICIs) and targeted therapies. Ipilimumab plus nivolumab has achieved the best median overall survival, exceeding 70 months. However, the introduction of new ICIs, like relatlimab, has added complexity to first-line therapy decisions. Our aim is to guide clinicians in making personalized treatment decisions. Various features, including brain metastases, PD-L1 expression, BRAF mutation, performance status, and prior adjuvant therapy, significantly impact the direction of advanced melanoma treatment. We also provide the latest insights into the treatment of rare melanoma subtypes, such as uveal melanoma, where tebentafusp has shown promising improvements in overall survival for metastatic uveal melanoma patients. This review provides invaluable insights for clinicians, enabling informed treatment choices and deepening our understanding of the multifaceted challenges associated with advanced melanoma management.

Antiproliferation and apoptosis studies of estrone pharmacophores in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that shows high metastatic capability and poor prognosis. The aggressive behavior of TNBC may involve amplified EGFR expression. Currently, no targeted therapy has been approved for treating TNBC, which urgently needs novel treatment options. In this study, we report that estrone analogs with novel pharmacophores exhibited high potency toward TNBC cells through multiple mechanisms, inhibition of cell proliferation via EGFR receptor, and induction of mitochondrial apoptosis. Molecular docking studies revealed that hit analogs MMA307 and MMA321 were potent against the EGFR receptor (pdb code: 1M17) in silico and were over 10-fold more potent than sorafenib (positive control) when dosed against MDA-MB-468 cells in vitro. MMA307 and MMA321 induced mitochondrial apoptosis as characterized by condensed nuclei with fragmented chromatin, phosphatidylserine flip and modulated expressions of Apaf1, cytochrome c, and caspases 3 and 9. MMA307 and MMA321 inhibited TNBC proliferation through suppression of EGFR and activated EGFR (Y1068) expressions. Similarly, EGFR signaling pathways, RAF/ERK and AKT/mTOR, were inhibited as pARaf, pERK1/2 (characterizes RAF/ERK pathway) and pAKT, pmTOR, p70S6Kα (characterizes AKT/mTOR pathway) were all suppressed. Moreover, MMA307 and MMA321 inhibited TNBC cell growth through downregulation of cyclin D1 expression and arresting TNBC cells in the G1 phase of cell cycle. This study reports for the first time that estrone congeners with novel pharmacophores may be an effective therapy for TNBC. Findings from this research provide a solid foundation for further preclinical and clinical studies in developing estrone derivatives as novel TNBC therapeutics.

Regulation of melanoma malignancy by the RP11-705C15.3/miR-145-5p/NRAS/MAPK signaling axis

Melanoma is a common lethal skin cancer. Dissecting molecular mechanisms driving the malignancy of melanoma may uncover potential therapeutic targets. We previously identified miR-145-5p as an important tumor-suppressive microRNA in melanoma. Here, we further investigated the roles of long non-coding RNAs (lncRNAs) in melanoma. We identified RP11-705C15.3, a regulator of miR-145-5p, as an oncogenic lncRNA in melanoma. RP11-705C15.3 competitively bound miR-145-5p, relieved the repressive roles of miR-145-5p on its target NRAS, upregulated NRAS expression, and activated MAPK signaling. In vitro functional assays revealed that ectopic expression of RP11-705C15.3 promoted melanoma cell proliferation, inhibited apoptosis, and promoted migration and invasion. Silencing of RP11-705C15.3 repressed melanoma cell proliferation, induced apoptosis, and repressed migration and invasion. Notably, the roles of RP11-705C15.3 in melanoma cell proliferation, apoptosis, migration and invasion are reversed by miR-145-5p overexpression. In vivo functional assays revealed that RP11-705C15.3 promoted melanoma tumor growth and metastasis, which were also reversed by miR-145-5p overexpression. Furthermore, we investigated the expression of RP11-705C15.3 in clinical melanoma tissues and found that RP11-705C15.3 was increased in melanoma tissues. High expression of RP11-705C15.3 was positively correlated with thickness, ulceration, metastasis, and inferior overall survival. Taken together, our findings suggest RP11-705C15.3 as a novel oncogene in melanoma, and highlight that the RP11-705C15.3/miR-145-5p/NRAS/MAPK signaling axis may be potential therapeutic targets for melanoma.

An 89Zr-HDL PET Tracer Monitors Response to a CSF1R Inhibitor

The immune function within the tumor microenvironment has become a prominent therapeutic target, with tumor-associated macrophages (TAMs) playing a critical role in immune suppression. We propose an 89Zr-labeled high-density lipoprotein (89Zr-HDL) nanotracer as a means of monitoring response to immunotherapy. Methods: Female MMTV-PyMT mice were treated with pexidartinib, a colony-stimulating factor 1 receptor (CSF1R) inhibitor, to reduce TAM density. The accumulation of 89Zr-HDL within the tumor was assessed using PET/CT imaging and autoradiography, whereas TAM burden was determined using immunofluorescence. Results: A significant reduction in 89Zr-HDL accumulation was observed in PET/CT images, with 2.9% ± 0.3% and 3.7% ± 0.2% injected dose/g for the pexidartinib- and vehicle-treated mice, respectively. This reduction was corroborated ex vivo and correlated with decreased TAM density. Conclusion: These results support the potential use of 89Zr-HDL nanoparticles as a PET tracer to quickly monitor the response to CSF1R inhibitors and other therapeutic strategies targeting TAMs.

Acral Lentiginous Melanomas Harbour Intratumor Heterogeneity in BRAF Exon 15, With Mutations Distinct From V600E/V600K

The choice of appropriate therapeutic strategies may be influenced by intratumor heterogeneity and makes cancer treatment considerably more challenging. We aimed to evaluate the heterogeneity of BRAF exon 15 mutations in different areas of acral lentiginous melanoma (ALM). The entire exon 15 was sequenced in 4 different areas of paraffin-embedded samples from 26 patients with ALM. A total of 26 of 49 cases of ≥1 mm in depth of ALM identified by clinical, anatomical, and pathological data fulfilled the inclusion and exclusion criteria for this study. Tumors had a mean Breslow depth of 7.2 mm and an average mitotic index of 3 mitosis/mm. Mutations distinct from the common V600E and V600K were detected in 31%, and intratumor heterogeneity was observed in 31% of samples. Interestingly, 63.5% of all mutations had been previously associated with cancer. Most (62.5%) of the missense BRAF exon 15 mutations found in the ALM samples examined here were deemed "detrimental" for protein function according to at least 2 functional prediction programs, and 3 mutations (37.5%) were predicted to be "neutral," with no effect on protein function. BRAF exon 15 mutations were detected frequently in ALM and displayed heterogeneity, a finding to be further investigated.

KIT, NRAS, BRAF and FMNL2 mutations in oral mucosal melanoma and a systematic review of the literature

Oral mucosal melanoma (OMM) is an aggressive malignant tumor derived from melanocytes in the oral cavity. The genetic etiology of OMM has not been extensively investigated to date. In the present study, the aim was to detect novel gene mutations in patients with OMM. Mutation analysis of KIT, BRAF and NRAS was conducted by polymerase chain reaction. In addition, the relevant literature was searched using the PubMed database, and previous findings were compared with the results of the present study. Among the 9 patients with OMM examined, KIT, BRAF and NRAS mutations were detected, and these mutations were all observed at a frequency of 11.1% (1/9 patients). Notably, a novel FMNL2 mutation in 2 patients with OMM was identified by exome sequencing. In conclusion, the current study observed KIT, BRAF, NRAS and FMNL2 mutations in patients with OMM, which may be of benefit for elucidating the underlying mechanism of OMM pathogenesis.

Adjuvant Therapy for Resected Stage III Melanoma Patients: High-Dose Interferon-Alpha versus Ipilimumab Combined with Kinases Inhibitors

High-dose interferon-alpha remains the first-line treatment in the adjuvant therapy of metastatic melanoma. More recently, high-dose pegylated interferon-alpha-2b has been approved by the US Food and Drug Administration. Actually, an adjuvant therapy alternative to high-dose interferon-alpha is represented by ipilimumab. Moreover, combination therapy of IFN-alpha or ipilimumab with tyrosine kinase inhibitors has been proved in patients with specific mutations. It is mandatory to understand what the best adjuvant treatment is for resected metastatic melanoma patients, particularly at stage III-N1, in terms of overall survival rather than recurrence-free survival. The ECOG 1609 clinical trial compared high-dose interferon-alpha and ipilimumab alone or combined with tyrosine kinase inhibitors for the treatment of early metastatic melanoma. In the past, ECOG 1684, 1690 and 1694 trials showed improvement in recurrence-free survival more than overall survival for high-risk melanoma patients (stage IIB-III) treated with high-dose interferon-alpha, whereas more recently the EORTC 18991 trial reported successful therapeutic results in terms of recurrence-free survival rather than overall survival for stage III-N1 melanoma patients treated with high-dose pegylated interferon-alpha-2b. Toxicity was more acceptable within one year of treatment. Randomized trials have demonstrated that ipilimumab as second-line therapy is able to increase dose-dependent overall survival rates in advanced melanoma patients despite severe but reversible immune-related adverse events. Old tyrosine kinase inhibitors have been used in combination with interferon for the treatment of advanced melanoma patients with moderate benefits and increased toxicity, but new selective drugs seem to be more efficacious. Early metastatic melanoma patients (stage III-N1) should be the principal subset to be treated with the most suitable adjuvant therapy to achieve the best overall survival. New schedules have to be tested with high-dose interferon-alpha and ipilimumab alone or combined with tyrosine kinase inhibitors while waiting for results from ECOG 1609.

Genome-Wide Analysis on the Landscape of Transcriptomes and Their Relationship With DNA Methylomes in the Hypothalamus Reveals Genes Related to Sexual Precocity in Jining Gray Goats

The Jining Gray goat is famous for its sexual precocity; however, the exact regulatory mechanism is still unknown. The hypothalamus is the key centrum in the process of animal reproduction, especially in signal transduction, and the initiation of puberty. The identification of potential genes and pathways in the hypothalamus of Jining Gray goat is critical to understanding the regulatory mechanism of sexual precocity in these goats. In this study, mRNA transcriptome analysis of the hypothalamus of juvenile and pubertal goats revealed eight genes (NTS, ADORA1, CRH, UCN3, E2F2, PDGFRB, GNRH1, and CACNA1C) and three pathways [neuroactive ligand-receptor interaction; gonadotropin-releasing hormone (GnRH) signal; melanoma] that are involved in this regulation. Subsequent methylation analysis on differentially methylated region (DMR) genes revealed the potential regulation network that influences pubertal onset. Correlation analysis verified the methylation level of some DMR genes correlates negatively with expression level. Integrated analysis between transcriptomes and methylomes identified 80 candidate genes involved in GnRH and neuroactive ligand signal pathways, of which CACNA1C and CRH were differentially expressed genes (DEGs) influenced by methylation level. The GnRH gene was the only DEG not affected by its methylation level. In summary, in this study, we identified eight genes and three pathways that are related to pubertal onset in Jining Gray goats, and the expression of CACNA1C and CRH genes of the GnRH and neuroactive ligand signal pathways were influenced by DNA methylation, while that of the GnRH gene was not affected.

An integrated tool for determining the primary origin site of metastatic tumours

Aims

Cancers of unknown primary sites account for 3%–5% of all malignant neoplasms. Current diagnostic workflows based on immunohistochemistry and imaging tests have low accuracy and are highly subjective. We aim to develop and validate a gene-expression classifier to identify potential primary sites for metastatic cancers more accurately.

Methods

We built the largest Reference Database (RefDB) reported to date, composed of microarray data from 4429 known tumour samples obtained from 100 different sources and divided into 25 cancer superclasses formed by 58 cancer subclass. Based on specific profiles generated by 95 genes, we developed a gene-expression classifier which was first trained and tested by a cross-validation. Then, we performed a double-blinded retrospective validation study using a real-time PCR-based assay on a set of 105 metastatic formalin-fixed, paraffin-embedded (FFPE) samples. A histopathological review performed by two independent pathologists served as a reference diagnosis.

Results

The gene-expression classifier correctly identified, by a cross-validation, 86.6% of the expected cancer superclasses of 4429 samples from the RefDB, with a specificity of 99.43%. Next, the performance of the algorithm for classifying the validation set of metastatic FFPE samples was 83.81%, with 99.04% specificity. The overall reproducibility of our gene-expression-classifier system was 97.22% of precision, with a coefficient of variation for inter-assays and intra-assays and intra-lots <4.1%.

Conclusion

We developed a complete integrated workflow for the classification of metastatic tumour samples which may help on tumour primary site definition.

Therapeutic and Prognostic Implications of BRAF V600E in Pediatric Low-Grade Gliomas

Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510). Clinical and treatment data of patients with BRAF V600E mutated PLGG (n = 99) were compared with a large international independent cohort of patients with BRAF V600E mutated-PLGG (n = 180). Results BRAF V600E mutation was detected in 69 of 405 patients (17%) with PLGG across a broad spectrum of histologies and sites, including midline locations, which are not often routinely biopsied in clinical practice. Patients with BRAF V600E PLGG exhibited poor outcomes after chemotherapy and radiation therapies that resulted in a 10-year progression-free survival of 27% (95% CI, 12.1% to 41.9%) and 60.2% (95% CI, 53.3% to 67.1%) for BRAF V600E and wild-type PLGG, respectively ( P < .001). Additional multivariable clinical and molecular stratification revealed that the extent of resection and CDKN2A deletion contributed independently to poor outcome in BRAF V600E PLGG. A similar independent role for CDKN2A and resection on outcome were observed in the independent cohort. Quantitative imaging analysis revealed progressive disease and a lack of response to conventional chemotherapy in most patients with BRAF V600E PLGG. Conclusion BRAF V600E PLGG constitutes a distinct entity with poor prognosis when treated with current adjuvant therapy.

[Primary intramedullary melanoma: Case report and literature review]

A dark pigmented intramedullary mass is very rarely encountered in daily practice, and poses a diagnostic challenge. Several entities have to be considered, including melanin-containing tumours (melanotic ependymoma and melanotic schwannoma) and melanocyte-containing tumours (melanocytoma, primary melanoma and melanoma metastases). The case is presented of a 47 year-old male with a pigmented intramedullary tumour located at T7-T8 level. Magnetic resonance images (MRI) revealed a tumour with hyperintensity on T1 and hypointensity on T2. The tumour was resected partially and treated with adjuvant radiotherapy. The diagnosis of primary intramedullary melanoma (PIM) was established based on histology and the absence of other lesions outside of the CNS. A literature review is presented on the other 26 PIM cases reported. PIM are extremely rare tumours, but are the most frequent cause of pigmented intramedullary tumour. Complete surgical resection is the treatment of choice whenever possible, followed by radiotherapy.

Future of circulating tumor cells in the melanoma clinical and research laboratory settings

Circulating tumor cells (CTC) have become a field of interest for oncologists based on the premise that they constitute the underpinning for metastatic dissemination. The lethal nature of cancer is no longer attributed to solid tumor formation, but rather to the process of metastasis; shifting the focus of current studies towards the isolation and identification of metastatic progenitors, such as CTCs. CTCs originate from primary tumor masses that undergo morphologic and genetic alterations, which involve the release of mesenchymal-like cancer cells into the bloodstream, capable of invading nearby tissues for secondary tumor development. Cancerous cells contained in the primary tumor mass acquire the motile mesenchymal phenotype as a result of the Epithelial-to-Mesenchymal Transition, where substantial variations in protein expression and signaling pathways take place. CTCs that migrate from the primary tumor, intravasate into the systemic vasculature, are transported through the bloodstream, and invade tissues and organs suitable for secondary tumor development. While only a limited number of CTCs are viable in the bloodstream, their ability to elude the immune system, evade apoptosis and successfully metastasize at secondary tumor sites, makes CTCs promising candidates for unraveling the triggers that initiates the metastatic process. In this article, these subjects are explored in greater depth to elucidate the potential use of CTCs in the detection, disease staging and management of metastatic melanoma.

Melanoma in Mexico: Clinicopathologic Features in a Population with Predominance of Acral Lentiginous Subtype

BACKGROUND

The aim of this study was to analyze the clinicopathologic features of melanoma in México as the demographics of melanoma are not well known in Mexican and Latin American people.

MATERIALS AND METHODS

A total of 1219 patients with cutaneous melanoma were analyzed through a retrospective database collected from a cancer referral institute, and the results were compared with developed countries.

RESULTS

Median age was 57 years, and 713 (58.5 %) were females. The most common melanoma subtype was acral lentiginous melanoma (ALM), which was observed in 538 (44.1 %) patients. Median Breslow thickness was 5.2 mm. Among 837 patients with complete data, the 5-year disease-specific survival (DSS) was 52.3 %. Factors associated with worse DSS on univariate analysis were Breslow thickness (p < 0.001), recurrence (p < 0.001), ulceration (p < 0.001), positive margin (p < 0.001), ALM (p = 0.001), and male sex (p = 0.001). Multivariate analysis demonstrated Breslow thickness [hazard ratio (HR) 1.45, 95 % confidence interval (CI) 1.27-1.65; p < 0.001], positive margin (HR 1.25, 95 % CI 1.03-1.57; p = 0.018), recurrence (HR 9.56, 95 % CI 6.89-9.87; p = 0.002), ALM (HR 8.07, 95 % CI 6.77-8.95; p = 0.004), and male sex (HR 1.33, 95 % CI 1.06-1.68; p = 0.013) as independent risk factors for DSS.

CONCLUSION

Our patients had worse prognosis compared with data from the US Surveillance, Epidemiology, and End Results database. We found male sex and ALM as independent risk factors for worse survival, in addition to known risk factors.

Development and validation of an ultra-high sensitive next-generation sequencing assay for molecular diagnosis of clinical oncology

Dramatic improvements in the understanding of oncogenes have spurred the development of molecular target therapies, which created an exigent need for comprehensive and rapid clinical genotyping. Next-generation sequencing (NGS) assay with increased performance and decreased cost is becoming more widely used in clinical diagnosis. However, the optimization and validation of NGS assay remain a challenge, especially for the detection of somatic variants at low mutant allele fraction (MAF). In the present study, we developed and validated the Novogene Comprehensive Panel (NCP) based on targeted capture for NGS analysis. Due to the high correlation between SNV/INDEL detection performance and target coverage, here we focused on these two types of variants for our deep sequencing strategy. To validate the capability of NCP in single-nucleotide variant (SNV) and small insert and deletion (INDEL) detection, we implemented a practical validation strategy with pooled cell lines, deep sequencing of pooled samples (>2000X average unique coverage across target region) achieving >99% sensitivity and high specificity (positive predictive value, PPV >99%) for all types of variations with expected MAF >5%. Furthermore, given the high sensitivity and that false positive may exist in this assay, we confirmed its accuracy of variants with MAF <5% using 35 formalin-fixed and paraffin-embedded (FFPE) tumor specimens by Quantstudio 3D Digital PCR (dPCR; Life Technologies) and obtained a high consistency (32 of 35 mutations detected by NGS were verified). We also used the amplification refractory mutation system (ARMS) to verify the variants with a MAF in a broad range of 2-63% detected in 33 FFPE samples and reached a 100% PPV for this assay. As a potential clinical diagnosis tool, NCP can robustly and comprehensively analyze clinical-related genes with high sensitivity and low cost.

Signal Sequence Receptor 2 is required for survival of human melanoma cells as part of an unfolded protein response to endoplasmic reticulum stress

Current therapy approaches in melanoma targeting have met with the development of resistance and tumour recurrence with a more aggressive phenotype. In a quest for alternative therapy targets, we had previously identified Signal Sequence Receptor 2 (SSR2) as a gene with high expression in a subgroup of human primary melanomas. Now we show that SSR2 exerts a prosurvival functionality in human melanoma cells and that high expression levels of SSR2 are associated with an unfavourable disease outcome in primary melanoma patients. Consistent with SSR's role in translocation of proteins from the ribosome across the endoplasmic reticulum (ER) membrane, our data supports induction of SSR2 as a part of the ER stress response. This response included SSR2 upregulation upon development of therapy resistance to BRAF inhibitors, as well as the dependency of cell survival of BRAF inhibitor-resistant melanoma cells on SSR2. Complementary gain and loss of function data showed the Unfolded Protein Response (UPR) to ER stress as an inducer of SSR2 via transcriptional regulation through X-Box Binding Protein 1s (XBP1s) and support an ER stress-UPR-Transcription Factor XBP1s-SSR2 response axis in human melanocytic cells. Together with its dispensability for survival in normal human cells, these data propose SSR2 as a potential therapeutic target in (therapy-resistant) human melanoma.

Estrogen Receptor β in Melanoma: From Molecular Insights to Potential Clinical Utility

Cutaneous melanoma is an aggressive tumor; its incidence has been reported to increase fast in the past decades. Melanoma is a heterogeneous tumor, with most patients harboring mutations in the BRAF or NRAS oncogenes, leading to the overactivation of the MAPK/ERK and PI3K/Akt pathways. The current therapeutic approaches are based on therapies targeting mutated BRAF and the downstream pathway, and on monoclonal antibodies against the immune checkpoint blockade. However, treatment resistance and side effects are common events of these therapeutic strategies. Increasing evidence supports that melanoma is a hormone-related cancer. Melanoma incidence is higher in males than in females, and females have a significant survival advantage over men. Estrogens exert their effects through estrogen receptors (ERα and ERβ) that affect cancer growth in an opposite way: ERα is associated with a proliferative action and ERβ with an anticancer effect. ERβ is the predominant ER in melanoma, and its expression decreases in melanoma progression, supporting its role as a tumor suppressor. Thus, ERβ is now considered as an effective molecular target for melanoma treatment. 17β-estradiol was reported to inhibit melanoma cells proliferation; however, clinical trials did not provide the expected survival benefits. In vitro studies demonstrate that ERβ ligands inhibit the proliferation of melanoma cells harboring the NRAS (but not the BRAF) mutation, suggesting that ERβ activation might impair melanoma development through the inhibition of the PI3K/Akt pathway. These data suggest that ERβ agonists might be considered as an effective treatment strategy, in combination with MAPK inhibitors, for NRAS mutant melanomas. In an era of personalized medicine, pretreatment evaluation of the expression of ER isoforms together with the concurrent oncogenic mutations should be considered before selecting the most appropriate therapeutic intervention. Natural compounds that specifically bind to ERβ have been identified. These phytoestrogens decrease the proliferation of melanoma cells. Importantly, these effects are unrelated to the oncogenic mutations of melanomas, suggesting that, in addition to their ERβ activating function, these compounds might impair melanoma development through additional mechanisms. A better identification of the role of ERβ in melanoma development will help increase the therapeutic options for this aggressive pathology.

BRAF Mutation (V600E) Prevalence in Mexican Patients Diagnosed with Melanoma

BACKGROUND

B-Raf is a serine/threonine protein kinase activating the MAP kinase/ERK-signaling pathway. It has been shown that 50% of melanomas harbor activating BRAF mutations, with over 90% being the V600E mutation.

OBJECTIVE

The goal of this research was to determine the prevalence of the BRAF V600E mutation in patients from Central Mexico diagnosed with primary melanoma.

METHODS

Skin biopsies from 47 patients with melanoma were obtained from the dermatology department of the Hospital General 'Dr. Manuel Gea González' in Mexico City. For BRAF mutation determination, after DNA isolation, the gene region where the mutation occurs was amplified by PCR. Subsequently, the presence or absence of the V600E mutation was detected by Sanger sequencing performed at the private molecular diagnostic laboratory Vitagénesis in Monterrey, Mexico.

RESULTS

Of the 47 patients sampled, 6.4% harbored the V600E mutation. No statistical significance was found between mutations and the type of tumor.

Targeting mitosis-regulating genes in cisplatin-sensitive and -resistant melanoma cells: A live-cell RNAi screen displays differential nucleus-derived phenotypes

Chemoresistance in malignant melanoma remains an unresolved clinical issue. In the search for novel molecular targets, a live-cell high-content RNAi screen based on gene expression data was performed in cisplatin-sensitive and cisplatin-resistant MeWo melanoma cells, Mel-28 cells and a melanocyte cell line. Cells were exposed to 91 siRNAs and distinct nucleus-derived phenotypes such as cell division, cell death and migration phenotypes were detected by time-lapse microscopy over 60 h. Using this approach, cisplatin-sensitive and cisplatin-resistant melanoma cells were compared by automated image analysis and visual inspection. In cisplatin-sensitive MeWo melanoma cells, 14 genes were identified that showed distinct phenotype abnormalities after exposure to gene-specific siRNAs. In cisplatin-resistant MeWo cells, five genes were detected. Nine genes were detected whose knock-down led to differential nuclear phenotypes in cisplatin-sensitive and -resistant cells. In Mel-28 cells, nine genes were identified which induced nuclear phenotypes including all eight genes which were identified in cisplatin-resistant MeWo cells. An analogous RNAi screen on melanocytes revealed no detectable phenotype abnormalities after RNAi. Pathway analysis showed in cisplatin-sensitive MeWo cells and Mel-28 cells an enrichment of at least three genes in major mitotic pathways. We hereby show that siRNA screening may help to identify tumor-specific genes leading to phenotype abnormalities. These genes may serve as potential therapeutic targets in the treatment of melanoma.

Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT): A Hybridization Capture-Based Next-Generation Sequencing Clinical Assay for Solid Tumor Molecular Oncology

The identification of specific genetic alterations as key oncogenic drivers and the development of targeted therapies are together transforming clinical oncology and creating a pressing need for increased breadth and throughput of clinical genotyping. Next-generation sequencing assays allow the efficient and unbiased detection of clinically actionable mutations. To enable precision oncology in patients with solid tumors, we developed Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT), a hybridization capture-based next-generation sequencing assay for targeted deep sequencing of all exons and selected introns of 341 key cancer genes in formalin-fixed, paraffin-embedded tumors. Barcoded libraries from patient-matched tumor and normal samples were captured, sequenced, and subjected to a custom analysis pipeline to identify somatic mutations. Sensitivity, specificity, reproducibility of MSK-IMPACT were assessed through extensive analytical validation. We tested 284 tumor samples with previously known point mutations and insertions/deletions in 47 exons of 19 cancer genes. All known variants were accurately detected, and there was high reproducibility of inter- and intrarun replicates. The detection limit for low-frequency variants was approximately 2% for hotspot mutations and 5% for nonhotspot mutations. Copy number alterations and structural rearrangements were also reliably detected. MSK-IMPACT profiles oncogenic DNA alterations in clinical solid tumor samples with high accuracy and sensitivity. Paired analysis of tumors and patient-matched normal samples enables unambiguous detection of somatic mutations to guide treatment decisions.

Lysosomes and unfolded protein response, determinants of differential resistance of melanoma cells to vinca alkaloids

On account of its strong ability to become chemoresistant after a primary response to drugs, malignant melanoma (MM) remains a therapeutic challenge. This study focuses on acquired resistance to vinca alkaloids (VAs) using VA-resistant MM cell lines (CAL1R-VCR, CAL1R-VDS, and CAL1R-VRB), established by long-term continuous exposure of parental CAL1-wt cells to vincristine (VCR), vindesine (VDS), or vinorelbine (VRB), respectively. Transcriptomic profiling using rma and rdam methods led to distinguish two cell groups: CAL1R-VCR and CAL1R-VDS, CAL1R-VRB, and CAL1-wt. mgsa of the specifically altered genes in the first group evidenced the GO terms 'lysosomal lumen' and 'vacuolar lumen' linked to underexpressed genes, and 'endoplasmic reticulum (ER) stress response' associated with overexpressed genes. A specific reduction of lysosomal enzymes, independent of acidic vacuole organelle (AVO) turnover, was observed (LTG probe) in CAL1R-VCR and CAL1R-VDS cells. It was associated with the specific lowering of cathepsin B and L, known to be involved in the lysosomal pathway of apoptosis. Confirming gene profiling, the same groups (CAL1R-VCR and CAL1R-VDS, CAL1-wt and CAL1R-VRB) could be distinguished regarding the VA-mediated changes on mean size areas and on acidic compartment volumes. These two parameters were reduced in CAL1R-VCR and CAL1R-VDS cells, suggesting a smaller AVO accumulation and thus a reduced sensitivity to lysosomal membrane permeabilization-mediated apoptosis. In addition, 'ER stress response' inhibition by tauroursodeoxycholic acid induced a higher VA sensitization of the first cell group. In conclusion, lysosomes and unfolded protein response could be key determinants of the differential resistance of MM to VAs.

Methylation-dependent SOX9 expression mediates invasion in human melanoma cells and is a negative prognostic factor in advanced melanoma

Background

Melanoma is the most fatal skin cancer displaying a high degree of molecular heterogeneity. Phenotype switching is a mechanism that contributes to melanoma heterogeneity by altering transcription profiles for the transition between states of proliferation/differentiation and invasion/stemness. As phenotype switching is reversible, epigenetic mechanisms, like DNA methylation, could contribute to the changes in gene expression.

Results

Integrative analysis of methylation and gene expression datasets of five proliferative and five invasion melanoma cell cultures reveal two distinct clusters. SOX9 is methylated and lowly expressed in the highly proliferative group. SOX9 overexpression results in decreased proliferation but increased invasion in vitro. In a B16 mouse model, sox9 overexpression increases the number of lung metastases. Transcriptional analysis of SOX9-overexpressing melanoma cells reveals enrichment in epithelial to mesenchymal transition (EMT) pathways. Survival analysis of The Cancer Genome Atlas melanoma dataset shows that metastatic patients with high expression levels of SOX9 have significantly worse survival rates. Additional survival analysis on the targets of SOX9 reveals that most SOX9 downregulated genes have survival benefit for metastatic patients.

Conclusions

Our genome-wide DNA methylation and gene expression study of 10 early passage melanoma cell cultures reveals two phenotypically distinct groups. One of the genes regulated by DNA methylation between the two groups is SOX9. SOX9 induces melanoma cell invasion and metastasis and decreases patient survival. A number of genes downregulated by SOX9 have a negative impact on patient survival. In conclusion, SOX9 is an important gene involved in melanoma invasion and negatively impacts melanoma patient survival.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0594-4) contains supplementary material, which is available to authorized users.

A new generation of companion diagnostics: cobas BRAF, KRAS and EGFR mutation detection tests

The cobas(®) (Roche) portfolio of companion diagnostics in oncology currently has three assays CE-marked for in vitro diagnostics. Two of these (EGFR and BRAF) are also US FDA-approved. These assays detect clinically relevant mutations that are correlated with response (BRAF, EGFR) or lack of response (KRAS) to targeted therapies such as selective mutant BRAF inhibitors in malignant melanoma, tyrosine kinases inhibitor in non-small cell lung cancer and anti-EGFR monoclonal antibodies in colorectal cancer, respectively. All these assays are run on a single platform using DNA extracted from a single 5 µm section of a formalin-fixed paraffin-embedded tissue block. The assays provide an 'end-to-end' solution from extraction of DNA to automated analysis and report on the cobas z 480. The cobas tests have shown robust and reproducible performance, with high sensitivity and specificity and low limit of detection, making them suitable as companion diagnostics for clinical use.

Circulating melanoma cells in the diagnosis and monitoring of melanoma: an appraisal of clinical potential

Circulating melanoma cells (CMCs) are thought to be the foundation for metastatic disease, which makes this cancer especially lethal. Cancer cells contained in the primary tumor undergo genotypic and phenotypic changes leading to an epithelial-to-mesenchymal transition, during which numerous changes occur in signaling pathways and proteins in the cells. CMCs are then shed off or migrate from the primary tumor and intravasate the vasculature system. A few CMCs are able to survive in the circulation through expression of a variety of genes and also by evading immune system recognition to establish metastases at distant sites after extravasating from the vessels. The presence of CMCs in the blood of a melanoma patient can be used for disease staging, predicting metastasis development, and evaluating the efficacy of therapeutic agents. Overall survival and disease-free duration can also be correlated with the presence of CMCs. Finally, analysis of CMCs for druggable therapeutic gene targets could lead to the development of personalized treatment regimens to prevent metastasis. Thus, the study of CMCs shows promise for the detection, staging, and monitoring of disease treatment, as well as for determination of prognosis and predicting overall disease-free survival. These are the areas reviewed in this article.

Discovery of new membrane-associated proteins overexpressed in small-cell lung cancer

INTRODUCTION

Small-cell lung cancer (SCLC) is the most aggressive subtype of lung cancer, with no early detection strategy or targeted therapy currently available. We hypothesized that difference gel electrophoresis (DIGE) may identify membrane-associated proteins (MAPs) specific to SCLC, advance our understanding of SCLC biology, and discover new biomarkers of SCLC.

METHODS

MAP lysates were prepared from three SCLCs, three non-small-cell lung cancers, and three immortalized normal bronchial epithelial cell lines and coanalyzed by DIGE. Subsequent protein identification was performed by mass spectrometry. Proteins were submitted to Ingenuity Pathway Analysis. Candidate biomarkers were validated by Western blotting (WB) and immunohistochemistry (IHC).

RESULTS

Principal component analysis on the global DIGE data set demonstrated that the four replicates derived from each of the nine cell lines clustered closely, as did samples within the same histological group. One hundred thirty-seven proteins were differentially expressed in SCLC compared with non-small-cell lung cancer and immortalized normal bronchial epithelial cells. These proteins were overrepresented in cellular/tissue morphology networks. Dihydropyrimidinase-related protein 2, guanine nucleotide-binding protein alpha-q, laminin receptor 1, pontin, and stathmin 1 were selected as candidate biomarkers among MAPs overexpressed in SCLC. Overexpression of all candidates but RSSA in SCLC was verified by WB and/or IHC on tissue microarrays. These proteins were significantly associated with SCLC histology and survival in univariables analyses.

CONCLUSION

DIGE analysis of a membrane-associated subproteome discovered overexpression of dihydropyrimidinase-related protein 2, guanine nucleotide-binding protein alpha-q, RUVB1, and stathmin 1 in SCLC. Results were verified by WB and/or IHC in primary tumors, suggesting that investigating their functional relevance in SCLC progression is warranted. Association with survival requires further validation in larger clinical data sets.

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.

Is it a primary or metastatic melanocytic neoplasm of the central nervous system?: A molecular based approach

Primary melanocytic neoplasms of the central nervous system (CNS) are uncommon and must be distinguished from metastatic lesions as patients with metastatic disease carry a worse prognosis. Therefore, tools to aid in the diagnosis of a primary CNS melanocytic neoplasm would be of clinical utility. Primary CNS melanocytic neoplasms, including uveal melanomas have frequent mutations in GNAQ and GNA11, but are rare in cutaneous and mucosal melanomas. Additionally, primary uveal melanomas often exhibit monosomy 3 conferring an elevated risk of metastasis. We present a 63 year-old male with a melanocytic neoplasm in the thoracic spinal cord. Molecular studies revealed the tumor contained a GNAQ mutation and four-color fluorescent in situ hybridization (FISH) composed of chromosome enumeration probes for 3, 7, 17 and a locus specific probe for 9p21/CDKN2A yielded a normal result (i.e. two copies per cell), favoring a primary versus metastatic melanocytic neoplasm of the CNS. We report a case in which the combination of mutational analysis and FISH aided in identifying the origin of the neoplasm.

Tumor genetic analyses of patients with metastatic renal cell carcinoma and extended benefit from mTOR inhibitor therapy

PURPOSE

Rapalogs are allosteric mTOR inhibitors and approved agents for advanced kidney cancer. Reports of clonal heterogeneity in this disease challenge the concept of targeted monotherapy, yet a small subset of patients derives extended benefit. Our aim was to analyze such outliers and explore the genomic background of extreme rapalog sensitivity in the context of intratumor heterogeneity.

EXPERIMENTAL DESIGN

We analyzed archived tumor tissue of 5 patients with renal cell carcinoma, who previously achieved durable disease control with rapalogs (median duration, 28 months). DNA was extracted from spatially separate areas of primary tumors and metastases. Custom target capture and ultradeep sequencing was used to identify alterations across 230 target genes. Whole-exome sequence analysis was added to investigate genes beyond this original target list.

RESULTS

Five long-term responders contributed 14 specimens to explore clonal heterogeneity. Genomic alterations with activating effect on mTOR signaling were detected in 11 of 14 specimens, offering plausible explanation for exceptional treatment response through alterations in two genes (TSC1 and MTOR). In two subjects, distinct yet functionally convergent alterations activated the mTOR pathway in spatially separate sites. In 1 patient, concurrent genomic events occurred in two separate pathway components across different tumor regions.

CONCLUSIONS

Analysis of outlier cases can facilitate identification of potential biomarkers for targeted agents, and we implicate two genes as candidates for further study in this class of drugs. The previously reported phenomenon of clonal convergence can occur within a targetable pathway which might have implications for biomarker development beyond this disease and this class of agents.

Estimating the cure proportion of malignant melanoma, an alternative approach to assess long term survival: a population-based study

OBJECTIVES

A large proportion of patients with cutaneous malignant melanoma (CMM) do not experience excess mortality due to their disease. This group of patients is referred to as the cure proportion. Few studies have examined the possibility of cure for CMM. The aim of this study was to estimate the cure proportion of patients with CMM in a Swedish population.

METHODS

We undertook a population-based study of 5850 CMM patients in two Swedish health care regions during 1996-2005. We used flexible parametric cure models to estimate cure proportions and median survival times (MSTs) of uncured by stage, sex, age and anatomical site.

RESULTS

Disease stage at diagnosis was the most important factor for the probability of cure, with a cure proportion of approximately 1.0 for stage IA. While the probability of cure decreased with older age, the influence of age was smaller on the MST of uncured. Differences in prognosis between males and females were mainly attributed to differences in cure as opposed to differences in MST of uncured.

CONCLUSIONS

This population-based study showed approximately 100% cure among stage IA disease. Almost 50% of patients had stage IA disease and the high cure proportion for this large patient group is reassuring.

Identification of multiple mechanisms of resistance to vemurafenib in a patient with BRAFV600E-mutated cutaneous melanoma successfully rechallenged after progression

PURPOSE

To investigate the mechanism(s) of resistance to the RAF-inhibitor vemurafenib, we conducted a comprehensive analysis of the genetic alterations occurring in metastatic lesions from a patient with a BRAF(V600E)-mutant cutaneous melanoma who, after a first response, underwent subsequent rechallenge with this drug.

EXPERIMENTAL DESIGN

We obtained blood and tissue samples from a patient diagnosed with a BRAF(V600E)-mutant cutaneous melanoma that was treated with vemurafenib and achieved a near-complete response. At progression, he received additional lines of chemo/immunotherapy and was successfully rechallenged with vemurafenib. Exome and RNA sequencing were conducted on a pretreatment tumor and two subcutaneous resistant metastases, one that was present at baseline and previously responded to vemurafenib (PV1) and one that occurred de novo after reintroduction of the drug (PV2). A culture established from PV1 was also analyzed.

RESULTS

We identified two NRAS-activating somatic mutations, Q61R and Q61K, affecting two main subpopulations in the metastasis PV1 and a BRAF alternative splicing, involving exons 4-10, in the metastasis PV2. These alterations, known to confer resistance to RAF inhibitors, were tumor-specific, mutually exclusive, and were not detected in pretreatment tumor samples. In addition, the oncogenic PIK3CA(H1047R) mutation was detected in a subpopulation of PV1, but this mutation did not seem to play a major role in vemurafenib resistance in this metastasis.

CONCLUSIONS

This work describes the coexistence within the same patient of different molecular mechanisms of resistance to vemurafenib affecting different metastatic sites. These findings have direct implications for the clinical management of BRAF-mutant melanoma.

Systemic treatment of metastatic uveal melanoma: review of literature and future perspectives

Up to 50% of patients with uveal melanoma develop metastatic disease with poor prognosis. Regional, mainly liver-directed, therapies may induce limited tumor responses but do not improve overall survival. Response rates of metastatic uveal melanoma (MUM) to systemic chemotherapy are poor. Insights into the molecular biology of MUM recently led to investigation of new drugs. In this study, to compare response rates of systemic treatment for MUM we searched Pubmed/Web of Knowledge databases and ASCO website (1980-2013) for "metastatic/uveal/melanoma" and "melanoma/eye." Forty studies (one case series, three phase I, five pilot, 22 nonrandomized, and two randomized phase II, one randomized phase III study, data of three expanded access programs, three retrospective studies) with 841 evaluable patients were included in the numeric outcome analysis. Complete or partial remissions were observed in 39/841 patients (overall response rate [ORR] 4.6%; 95% confidence intervals [CI] 3.3-6.3%), no responses were observed in 22/40 studies. Progression-free survival ranged from 1.8 to 7.2, median overall survival from 5.2 to 19.0 months as reported in 21/40 and 26/40 studies, respectively. Best responses were seen for chemoimmunotherapy (ORR 10.3%; 95% CI 4.8-18.7%) though mainly in first-line patients. Immunotherapy with ipilimumab, antiangiogenetic approaches, and kinase inhibitors have not yet proven to be superior to chemotherapy. MEK inhibitors are currently investigated in a phase II trial with promising preliminary data. Despite new insights into genetic and molecular background of MUM, satisfying systemic treatment approaches are currently lacking. Study results of innovative treatment strategies are urgently awaited.

Somatic mutations in MAP3K5 attenuate its proapoptotic function in melanoma through increased binding to thioredoxin

Patients with advanced metastatic melanoma have poor prognosis and the genetics underlying its pathogenesis are poorly understood. High throughput sequencing has allowed comprehensive discovery of somatic mutations in cancer samples. Here, upon analysis of our whole-genome and whole-exome sequencing data of 29 melanoma samples we identified several genes that harbor recurrent non-synonymous mutations. These included MAP3K5, which in a prevalence screen of 288 melanomas was found to harbor a R256C substitution in 5 cases. All MAP3K5 mutated samples were wild-type for BRAF, suggesting a mutual exclusivity for these mutations. Functional analysis of the MAP3K5 R256C mutation revealed attenuation of MKK4 activation through increased binding of the inhibitory protein thioredoxin (TXN/TRX-1/Trx); resulting in increased proliferation and anchorage-independent growth of melanoma cells. This mutation represents a potential target for the design of new therapies to treat melanoma.

Targets, structures, and recent approaches in malignant melanoma chemotherapy

Malignant metastatic melanoma is one of the oncologic diseases with the worst clinical prognosis, due primarily to resistance phenomena against chemotherapeutic agents in current use. However, over the last few years, characterization of the molecular mechanisms involved in the development and progression of the disease has contributed to elucidation of the main pathways by which tissue invasion and metastasis can occur. More importantly, the identification of abnormalities in signaling cascades in melanoma cells has facilitated new therapeutic approaches against malignant melanoma through the design of highly potent and selective drugs with low associated toxicity. Ultimately, recognition of the restricted applicability of new chemotherapies in certain genetic contexts has led to significant improvements in the results of clinical trials, anticipating the existing need for investment in personalized therapies, and taking into account the molecular alterations observed in tumors. Although significant advances have been made in terms of extending the median overall survival rate and improving the quality of life for patients, the mechanisms that compromise in vivo drug efficacy remain poorly understood, particularly those concerning therapeutic resistance phenomena. This review summarizes recently validated targets from the perspective of the medicinal chemistry carried out in the design of the most promising structures.

The development and validation of a decision-analytic model representing the full disease course of acute myeloid leukemia

BACKGROUND

The treatment of acute myeloid leukemia (AML) is moving towards personalized medicine. However, due to the low incidence of AML, it is not always feasible to evaluate the cost-effectiveness of personalized medicine using clinical trials. Decision analytic models provide an alternative data source.

OBJECTIVE

The aim of this study was to develop and validate a decision analytic model that represents the full disease course of AML.

METHODS

We used a micro simulation with discrete event components to incorporate both patient and disease heterogeneity. Input parameters were calculated from patient-level data. Two hematologists critically evaluated the model to ensure face validity. Internal and external validity was tested by comparing complete remission (CR) rates and survival outcomes of the model with original data, other clinical trials and a population-based study.

RESULTS

No significant differences in patient and treatment characteristics, CR rate, 5-year overall and disease-free survival were found between the simulated and original data. External validation showed no significant differences in survival between simulated data and other clinical trials. However, differences existed between the simulated data and a population-based study.

CONCLUSIONS

The model developed in this study is proved to be valid for analysis of an AML population participating in a clinical trial. The generalizability of the model to a broader patient population has not been proven yet. Further research is needed to identify differences between the clinical trial population and other AML patients and to incorporate these differences in the model.

BRAF and GNAQ mutations in melanocytic tumors of the oral cavity

OBJECTIVE

The genetic factors participating in oral melanoma evolution have not been studied extensively. We aimed to analyze the prevalence of BRAF and GNAQ mutations in a series of oral melanocytic tumors, nevi, and melanomas.

STUDY DESIGN

The study group consisted of 4 melanomas and 10 nevi (6 intramucosal, 4 blue nevi). DNA was extracted from paraffin-embedded tissue sections, and mutations in GNAQ and BRAF were analyzed with the use of mass spectrometery.

RESULTS

V600E point mutation was identified in the BRAF gene in 3 intramucosal nevi and in 2 melanomas. Only 1 blue nevus harbored the GNAQ209 mutation. None of the BRAF-positive samples harbored GNAQ mutations.

CONCLUSIONS

The finding of BRAF mutations in oral benign and malignant melanocytic lesions points to a potential initiating role of BRAF in malignant transformation, which may have important therapeutic implications as those with BRAF mutations may benefit from specific treatment using RAF inhibitors.

Microbiopsy engineered for minimally invasive and suture-free sub-millimetre skin sampling

We describe the development of a sub-millimetre skin punch biopsy device for minimally invasive and suture-free skin sampling for molecular diagnosis and research. Conventional skin punch biopsies range from 2-4 mm in diameter. Local anaesthesia is required and sutures are usually used to close the wound. Our microbiopsy is 0.50 mm wide and 0.20 mm thick. The microbiopsy device is fabricated from three stacked medical grade stainless steel plates tapered to a point and contains a chamber within the centre plate to collect the skin sample. We observed that the application of this device resulted in a 0.21 ± 0.04 mm wide puncture site in volunteer skin using reflectance confocal microscopy. Histological sections from microbiopsied skin revealed 0.22 ± 0.12 mm wide and 0.26 ± 0.09 mm deep puncture sites. Longitudinal observation in microbiopsied volunteers showed that the wound closed within 1 day and was not visible after 7 days. Reflectance confocal microscope images from these same sites showed the formation of a tiny crust that resolved by 3 weeks and was completely undetectable by the naked eye. The design parameters of the device were optimised for molecular analysis using sampled DNA mass as the primary end point in volunteer studies. Finally, total RNA was characterized. The optimised device extracted 5.9 ± 3.4 ng DNA and 9.0 ± 10.1 ng RNA. We foresee that minimally invasive molecular sampling will play an increasingly significant role in diagnostic dermatology and skin research.

Multicolor FISH with improved sensitivity and specificity in the diagnosis of malignant melanoma

The diagnosis of malignant melanoma remains a challenging aspect in the field of pathology. In the last years, FISH has become an important tool for the diagnosis of melanocytic tumors in addition to conventional microscopy. Benign and malignant melanomas can be discriminated using a four-probe FISH assay targeting 6p25, 6q23, Cep6 and 11q13. Gerami et al. proposed to refine this current probe set with the incorporation of chromosome 8q24 and 9p21 probes into the FISH assay, and hereby increase sensitivity and specificity for distinguishing between benign and malignant melanoma and improve the detection of spitzoid melanomas. In this article, the authors evaluate this newly-defined multicolor FISH probe set for the diagnosis of malignant melanoma. Optimizing diagnostic tests in malignant melanoma are important for current and future management of patients with melanocytic proliferations.

Comprehensive assessment of the association of ERCC2 Lys751Gln polymorphism with susceptibility to cutaneous melanoma

Previous studies evaluating the association between excision repair cross-complimentary group 2 (ERCC2) Lys751Gln polymorphism and susceptibility to cutaneous melanoma reported conflicting findings. We searched PubMed and Wangfang Medical databases up to October 16, 2012 to identify eligible studies. A total of 8 case-control studies including 3,492 cases and 5,381 controls were included in the meta-analysis. Statistical analysis was performed with Review Manage version 5.1. Odds ratios (ORs) with 95 % confidence intervals (95 %CIs) were used to assess the strength of the association. There was no obvious between-study heterogeneity among those eight studies under all four comparison models. Overall, there was a significant association between ERCC2 Lys751Gln polymorphism and susceptibility to cutaneous melanoma under three genetic models (for Gln versus Lys: OR = 1.08, 95 % CI = 1.01-1.15, P = 0.02; for GlnGln versus LysLys: OR = 1.16, 95 % CI = 1.01-1.33, P = 0.03; for GlnGln/LysGln versus LysLys: OR = 1.10, 95 % CI = 1.01-1.21, P = 0.04). Sensitivity analysis by omitting one study a time showed the significance of the pooled ORs was stable under all those three genetic models above. Therefore, the meta-analysis suggests that there is a significant association between ERCC2 Lys751Gln polymorphism and susceptibility to cutaneous melanoma.