Inhibition of vemurafenib-resistant melanoma by interference with pre-mRNA splicing

Nat Commun. 2015 May 14;6:7103. doi: 10.1038/ncomms8103.

Abstract

Mutations in the serine/threonine kinase BRAF are found in more than 60% of melanomas. The most prevalent melanoma mutation is BRAF(V600E), which constitutively activates downstream MAPK signalling. Vemurafenib is a potent RAF kinase inhibitor with remarkable clinical activity in BRAF(V600E)-positive melanoma tumours. However, patients rapidly develop resistance to vemurafenib treatment. One resistance mechanism is the emergence of BRAF alternative splicing isoforms leading to elimination of the RAS-binding domain. Here we identify interference with pre-mRNA splicing as a mechanism to combat vemurafenib resistance. We find that small-molecule pre-mRNA splicing modulators reduce BRAF3-9 production and limit in-vitro cell growth of vemurafenib-resistant cells. In xenograft models, interference with pre-mRNA splicing prevents tumour formation and slows growth of vemurafenib-resistant tumours. Our results identify an intronic mutation as the molecular basis for a RNA splicing-mediated RAF inhibitor resistance mechanism and we identify pre-mRNA splicing interference as a potential therapeutic strategy for drug resistance in BRAF melanoma.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Alternative Splicing
  • Animals
  • Cell Line, Tumor
  • Cell Proliferation
  • Drug Resistance, Neoplasm / genetics*
  • Genes, Reporter
  • Humans
  • Indoles / pharmacology*
  • Introns
  • Male
  • Melanoma / drug therapy*
  • Melanoma / genetics
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasm Transplantation
  • Point Mutation
  • Protein Isoforms
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins B-raf / chemistry
  • Proto-Oncogene Proteins B-raf / genetics*
  • RNA Precursors / genetics
  • RNA Splicing*
  • RNA, Messenger / metabolism
  • Skin Neoplasms / drug therapy*
  • Skin Neoplasms / genetics
  • Sulfonamides / pharmacology*
  • Vemurafenib

Substances

  • Indoles
  • Protein Isoforms
  • RNA Precursors
  • RNA, Messenger
  • Sulfonamides
  • Vemurafenib
  • BRAF protein, human
  • Braf protein, mouse
  • Proto-Oncogene Proteins B-raf