Reduction in the expression of the anti-survival BH3-only proteins PUMA and Bim is associated with the pathogenesis of melanoma. However, we have found that the expression of the other BH3-only protein Noxa is commonly upregulated in melanoma cells, and that this is driven by oncogenic activation of MEK/ERK. Immunohistochemistry studies showed that Noxa was expressed at higher levels in melanomas than nevi. Moreover, the expression of Noxa was increased in metastatic compared to primary melanomas, and in thick primaries compared to thin primaries. Inhibition of oncogenic BRAFV600E or MEK downregulated Noxa, whereas activation of MEK/ERK caused its upregulation. In addition, introduction of BRAFV600E increased Noxa expression in melanocytes. Upregulation of Noxa was due to a transcriptional increase mediated by cAMP responsive element binding protein, activation of which was also increased by MEK/ERK signaling in melanoma cells. Significantly, Noxa appeared necessary for constitutive activation of autophagy, albeit at low levels, by MEK/ERK in melanoma cells. Furthermore, it was required for autophagy activation that delayed apoptosis in melanoma cells undergoing nutrient deprivation. These results reveal that oncogenic activation of MEK/ERK drives Noxa expression to promote autophagy, and suggest that Noxa has an indirect anti-apoptosis role in melanoma cells under nutrient starvation conditions.

The Data Safety Monitoring Committee (DSMC) recommended the trial continue recruitment after reviewing the unblinded data. The data provision and quality to date indicates that a reliable outcome will be obtained when the final analysis is performed. Accrual is ongoing with 156 out of 200 patients randomised to date (26(th) November 2014).

Unprecedented clinical responses have been reported in advanced stage metastatic melanoma patients treated with targeted inhibitors of constitutively activated mutant BRAF, which is present in approximately half of all melanomas. We and others have previously observed an association of elevated nuclear β-catenin with improved survival in molecularly-unselected melanoma patients. This study sought to determine whether levels of Wnt/β-catenin signaling in melanoma tumors prior to treatment might predict patient responses to BRAF inhibitors (BRAFi). We performed automated quantification of β-catenin immunohistochemical expression in pretreatment BRAF-mutant tumors from 32 BRAFi-treated melanoma patients. Unexpectedly, patients with higher nuclear β-catenin in their tumors did not exhibit the survival advantage previously observed in molecularly-unselected melanoma patients who did not receive BRAFi. In cultured melanoma cells treated with long-term BRAFi, activation of Wnt/β-catenin signaling is markedly inhibited, coinciding with a loss of the enhancement of BRAFi-induced apoptosis by WNT3A observed in BRAFi-naïve cells. Together, these observations suggest that long-term treatment with BRAFi can impact the interaction between BRAF/MAPK and Wnt/β-catenin signaling to affect patient outcomes. Studies with larger patient cohorts are required to determine whether nuclear β-catenin expression correlates with clinical responses to BRAFi and to specific mechanisms of acquired resistance to BRAFi. Understanding these pathway interactions will be necessary to facilitate efforts to individualize therapies for melanoma patients.

High-throughput sequencing technologies are providing new insights into the genetic alterations involved in melanomagenesis. It appears likely that most genetic events important in the pathogenesis of melanoma will be discovered over the next few years. Genetic analysis is also increasingly being used to direct patient care. In parallel with the discovery of new genes and the elucidation of molecular pathways important in the development of melanoma, therapies targeting these pathways are becoming available. In other words, the age of personalized medicine has arrived, characterized by molecular profiling of melanoma to identify the relevant genetic alterations and the abnormal signaling mechanisms involved, followed by selection of optimal, individualized therapies. In this review, we summarize the key genetic alterations in melanoma and the development of targeted agents against melanomas bearing specific mutations. These developments in melanoma serve as a model for the implementation of personalized medicine for patients with all cancers.

BRAF inhibitor (BRAFi) therapy leads to remarkable anti melanoma responses, but the initial tumor shrinkage is commonly incomplete, providing a nidus for subsequent disease progression. Adaptive signaling may underlie early BRAFi resistance and influence the selection pattern for genetic variants, causing late, acquired resistance. We show here that BRAFi (or BRAFi + MEKi) therapy in patients frequently led to rebound phosphorylated AKT (p-AKT) levels in their melanomas early on-treatment. In cell lines, BRAFi treatment led to rebound levels of receptor tyrosine kinases (RTK; including PDGFRβ), phosphatidyl (3,4,5)-triphosphate (PIP3), pleckstrin homology domain recruitment, and p-AKT. PTEN expression limited this BRAFi-elicited PI3K-AKT signaling, which could be rescued by the introduction of a mutant AKT1 (Q79K) known to confer acquired BRAFi resistance. Functionally, AKT1(Q79K) conferred BRAFi resistance via amplification of BRAFi-elicited PI3K-AKT signaling. In addition, mitogen-activated protein kinase pathway inhibition enhanced clonogenic growth dependency on PI3K or AKT. Thus, adaptive or genetic upregulation of AKT critically participates in melanoma survival during BRAFi therapy.

Death due to melanoma in childhood (up to 20 y of age) is a rare event, with an average of 18 cases reported annually in the United States. In this study we evaluated 2 subgroups of high-risk melanocytic neoplasms in childhood, specifically atypical Spitz tumors (ASTs) with chromosomal copy number changes and conventional melanomas. We analyzed the clinical, histologic, and molecular features of all cases and performed the Fisher exact test, logistic regression, and multivariate analysis to evaluate features associated with aggressive clinical behavior in these cases. Among the ASTs, all of which had 1 or more chromosomal copy number aberrations, the presence of homozygous 9p21 deletions and a positive sentinel lymph node were each found to be correlated with tumor extension beyond the sentinel lymph node, with P-values of 0.046 and 0.01, respectively. Two patients with ASTs that had homozygous 9p21 deletions developed brain metastasis, one of whom died of disease. Among the 21 conventional melanomas, 3 patients developed distant metastasis and died of disease. Chromosomal copy number aberrations evaluated by fluorescence in situ hybridization were present in the majority of the cases (16/18). Among conventional melanomas, we did not identify any clinical, histologic, or molecular features associated with aggressive behavior. The presence of 8q24 gains was seen almost exclusively in 6 amelanotic small cell melanomas in children of whom 1 died of disease. Characteristic chromosomal copy number aberrations may occur in specific subtypes of melanocytic neoplasms in children and may help with the classification and prognostication of these rare tumors.

8548 Background: Drugs selectively targeting oncogenic mutant (mut) BRAF show activity against metastatic melanoma (MM) carrying these mutations. Distinguishing clinico-pathologic features of mut BRAF MM may influence patient (pt) selection and stratification in trials of these drugs, but no large studies have comprehensively examined this possibility. Our aim was to identify clinico-pathologic correlates of the BRAF mutation status in pts with MM. Methods: Consecutive BRAF tested pts with MM were followed prospectively. Tumor sections were screened by high resolution melt curve analysis of BRAF exon 15 and abnormal results confirmed by DNA sequencing. Data were collected on demographics, details of the primary melanoma (PM) and diagnostic, prognostic and treatment details from date of first distant metastasis (DM). Chi-square and Mann Whitney U tests were used to assess the association of clinico-pathologic features with BRAF status. Multivariate analysis was performed using a logistic regression model. Results: 97/207 pts (47%) had a mutation in exon 15 of the BRAF gene. Of these 72 (74%) were V600E, 19 (20%) V600K, and 6(6%) another mutation or combination. Pt age at diagnosis of DM was significantly different for mut (median age 56, n = 73) and wt (median age 62, n = 81: p < 0.005) tumours. There was no difference between mut/wt in disease free interval from diagnosis of PM to date of DM, sex, site of metastases at diagnosis of DM, regional lymph node involvement ever, resection of DM with intent to cure, response to chemotherapy (CT) or length of response to CT. ECOG status was not significantly different between mut/wt when adjusted for age. Features of the PM significantly associated (p < 0.05) with BRAF mut were: age at PM ≤ 50 yrs (OR = 3.16, 95%CI: 1.28-7.80); superficial spreading or nodular histopathologic subtype (OR = 3.96, 95%CI: 1.32-11.86); and truncal location (OR = 2.66, 95%CI: 1.09-6.47). Conclusions: The BRAF mutation rate in an Australian MM cohort was 47% and non-V600E activating mutations were more common than previously reported. Characteristics of the preceding PM and age at diagnosis differed in BRAF mut and wt MM pts. Clinical features of metastatic disease were essentially indistinguishable. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration GlaxoSmithKline GlaxoSmithKline, Roche

Melanoma cells that colonize the brain harbor numerous genetically and epigenetically altered genes. This study presents an integrated genomic and epigenomic analysis that reveals MBM-specific molecular alterations and mutually exclusive molecular subtypes.