title: Inhibition of vemurafenib-resistant melanoma by interference with pre-mRNA splicing.
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.
authors.affiliation: National Cancer Institute, NIH, Cell Biology of Genomes Group, Bethesda, Maryland 20892, USA.
authors.forename: Maayan
authors.initials: M
authors.lastname: Salton
authors.affiliation: Leidos Biomedical Research, Inc., Basic Science Program, Frederick National Laboratory, Frederick, Maryland 21702 USA.
authors.forename: Wojciech K
authors.initials: WK
authors.lastname: Kasprzak
authors.affiliation: National Cancer Institute, NIH, Cell Biology of Genomes Group, Bethesda, Maryland 20892, USA.
authors.forename: Ty
authors.initials: T
authors.lastname: Voss
authors.affiliation: National Cancer Institute, NIH, Frederick, RNA Structure and Design Section, Maryland 21702, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Shapiro
authors.affiliation: Icahn School of Medicine at Mount Sinai, Department of Oncological Sciences and Department of Dermatology, The Tisch Cancer Institute, New York, New York 10029, USA.
authors.forename: Poulikos I
authors.initials: PI
authors.lastname: Poulikakos
authors.affiliation: National Cancer Institute, NIH, Cell Biology of Genomes Group, Bethesda, Maryland 20892, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Misteli
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D017930:Genes, Reporter; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D007438:Introns; D008297:Male; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D017354:Point Mutation; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D048493:Proto-Oncogene Proteins B-raf / Q000737:chemistry / Q000235:genetics*; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000235:genetics; D013449:Sulfonamides / Q000494:pharmacology*; D000077484:Vemurafenib
chemical_list: D007211:Indoles; D020033:Protein Isoforms; D012322:RNA Precursors; D012333:RNA, Messenger; D013449:Sulfonamides; D000077484:Vemurafenib; C482119:BRAF protein, human; C482120:Braf protein, mouse; D048493:Proto-Oncogene Proteins B-raf