title: Inhibition of growth and invasive ability of melanoma by inactivation of mutated BRAF with lentivirus-mediated RNA interference.
abstract: Oncogenic mutations of molecules involved in the mitogen-activated protein kinase (MAPK) pathways provide signals mediating both tumor growth and invasion in various cancers including melanomas. BRAF somatic mutations, found in 66% of melanomas, have NIH3T3 transforming ability with the elevated kinase activity in vitro. We attempted to mediate RNA interference (RNAi) with HIV lentiviral vectors specific for either wild type or the most frequently mutated form of BRAF (V599E) in 10 melanoma cell lines, and found that RNAi inhibited the growth of most melanoma cell lines in vitro as well as in vivo, which was accompanied by decrease of both BRAF protein and ERK phosphorylation. Interestingly, the mutated BRAF (V599E)-specific siRNA inhibited the growth and MAPK activity of only melanoma cell lines with this mutation. Furthermore, BRAF RNAi inhibited matrigel invasion of melanoma cells accompanied with a decrease of matrix metalloproteinase activity and beta(1) integrin expression. These results clarify that the mutated BRAF (V599E) is essentially involved in malignant phenotype of melanoma cells through the MAPK activation and is an attractive molecular target for melanoma treatment. The lentivirus-mediated RNAi specific for oncogenic mutations may be a powerful technique for gene therapy of cancer.
authors.affiliation: Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Sumimoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Miyagishi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Shizuko
authors.initials: S
authors.lastname: Yamagata
authors.forename: Ayako
authors.initials: A
authors.lastname: Shimizu
authors.forename: Kazunari
authors.initials: K
authors.lastname: Taira
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D002455:Cell Division; D045744:Cell Line, Tumor; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D008545:Melanoma / Q000201:enzymology / Q000473:pathology / Q000628:therapy*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D009154:Mutation; D009361:Neoplasm Invasiveness; D048491:Proto-Oncogene Proteins A-raf / Q000378:metabolism; D048493:Proto-Oncogene Proteins B-raf / Q000037:antagonists & inhibitors* / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism
chemical_list: D034741:RNA, Small Interfering; D048491:Proto-Oncogene Proteins A-raf; D048493:Proto-Oncogene Proteins B-raf; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human