Molecular profiling, including TERT promoter mutations, of acral lentiginous melanomas

Abstract

Acral lentiginous melanoma (ALM) is the less common subtype with singular characterization. TERT (human telomerase reverse transcriptase) promoter mutations have being described as recurrent in melanomas and infrequent in ALM, but their real incidence and clinical relevance is unclear. The objectives of this study were to describe the prevalence of TERT promoter mutations in ALM, and correlate with the molecular profile of other drive genes and clinical features. Sixty-one samples from 48 patients with ALM were analyzed. After DNA isolation, the mutation profiles of the hotspot region of BRAF, NRAS, KIT, PDGFRA, and TERT genes were determined by PCR amplification followed by direct Sanger sequencing. KIT, PDGFRA, and VEGFR2 gene amplification was performed by quantitative PCR. Clinical information such as survival, clinical stage, and Breslow tumor classification were obtained from medical records. TERT promoter mutations were found in 9.3% of the cases, BRAF in 10.3%, NRAS in 7.5%, KIT in 20.7%, and PDGFRA in 14.8% of ALM. None of the cases showed KIT, PDGFRA, or VEGFR2 gene amplification. We found an association between KIT mutations and advanced Clark level (IV and V, P=0.043) and TERT promoter mutations with low mitotic index. No other significant associations were observed between mutation profile and patients' clinical features nor survival rates. Oncogenic TERT promoter mutations are present in a fraction of ALMs. No relevant associations were found between TERT mutation status and clinical/molecular features nor survival. Mutations of KIT and PDGFRA are the most common genetic alterations, and they can be therapeutic targets for these patients.

Mutational profiling of acral melanomas in Korean populations

“…Only the mutations confirmed via digital droplet PCR or mutations in BRAF, KIT and NRAS , the most frequently altered cancer genes in cutaneous melanoma, were considered as positive . Well‐known driver mutations in melanoma ( BRAF V600E , KIT and NRAS ), which were evaluated using NGS in this study, were manually reviewed in the catalogue of Somatic Mutations in Cancer (COSMIC, http://cancer.sanger.ac.uk/cancergenome/projects/cosmic).…”

“…In the current study, we molecularly analysed a homogenous cohort of 47 AM patients. Although the mutational profile of AM has been reported in previous studies, previous reports focused on Caucasian populations and only a few studies have described the molecular profile in Asian populations (Table ). In Korea, there is limited molecular data on AM (two Korean studies).…”

“…Therefore, studies of frequent recurrent genetic alterations in melanomas were crucial for new treatment strategies . However, previous studies regarding melanoma‐associated mutation profiles have been conducted in Caucasian populations, and data on genetic alterations in AM are limited in Asian populations . In this study, we aimed to identify mutational status of AM patients in Korean populations using next‐generation sequencing (NGS)‐based methods.…”

The metabolic microenvironment of melanomas: Prognostic value of MCT1 and MCT4

“…47,48 The specific primers designed to include the regions of interest were as follows: 5 0 -ATGACTGAGTACAAACTGGT-3 0 (forward) and 5 0 -CTCTATGGTGGGATCATATT-3 0 (reverse) for codon 12/13, and 5 0 -TCTTACAGAAAACAAGTGGT-3 0 (forward) and 5 0 -GTAGAGGTTAATATCCGCAA-3 0 (reverse) for codon 61. The PCR cycling conditions were as follows: initial denaturation at 95 C for 15 minutes, followed by 40 cycles of 95 C denaturation for 45 seconds, annealing at 56.…”

“…47,48 PCR primers were as follows: 5 0 -AGTG-GATTCGCGGGCACAGA-3 0 (forward) and 5 0 -CAGCGCTGCCTGAAACTC-3 0 (reverse). PCR cycling conditions were as follows: initial denaturation at 96 C for 15 minutes, followed by 40 cycles of 96 C denaturation for 45 seconds, annealing temperature at 55.5 C for 45 seconds and 72 C elongation for 45 seconds, and 72 C final elongation for 10 minutes, in a Verity PCR machine (Applied Biosystems).…”