Open AccessHyperactivation of MEK–ERK1/2 signaling and resistance to apoptosis induced by the oncogenic B-RAF inhibitor, PLX4720, in mutant N-RAS melanoma cells
Author(s) -
Fred M. Kaplan,
Yongping Shao,
Melanie M. Mayberry,
Andrew E. Aplin
Publication year - 2010
Publication title -
oncogene
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.395
H-Index - 342
eISSN - 1476-5594
pISSN - 0950-9232
DOI - 10.1038/onc.2010.408
Subject(s) - melanoma , hyperactivation , biology , cancer research , mutant , mek inhibitor , apoptosis , mutation , signal transduction , mapk/erk pathway , cell cycle , microbiology and biotechnology , genetics , gene
Activating mutations in B-RAF and N-RAS occur in ∼60 and ∼15% of melanomas, respectively. The most common mutation in B-RAF is V600E, which activates B-RAF and the downstream MEK-ERK1/2 pathway. Thus, B-RAF(V600E) is a viable therapeutic target. PLX4720 is a selective inhibitor of mutant B-RAF and its analog, PLX4032, is currently undergoing clinical trials in melanoma. However, the effects of PLX4720 across the genotypic spectrum in melanoma remain unclear. Here, we describe that PLX4720 treatment rapidly induces hyperactivation of the MEK-ERK1/2 pathway in mutant N-RAS melanoma cells. Furthermore, we demonstrate that C-RAF is the major RAF isoform involved in this process. Importantly, PLX4720-induced hyperactivation of the MEK-ERK1/2 pathway promotes resistance to apoptosis in both non-invasive and invasive mutant N-RAS melanoma cells but does not enhance cell cycle properties. These findings underscore the need to genotypically stratify melanoma patients before enrollment on a mutant B-RAF inhibitor trial.