RIN1-Ras-ERK pathway plays an important role in carcinogenesis in colon cancer cell line LoVo.
The RIN1 protein has SH2, three domains, and H-Ras binding domains; thus, it is presumed to be an important molecule in an intracellular signaling pathway. We examined the effect of the introduction of a membrane protein-encoding, mutated (S351A)RIN1 gene into a colon cancer. In the LoVo colon cancer cell line, endogenous RIN1 protein was strongly expressed in the cytoplasmic fraction, and the RIN1 protein in the cytoplasmic fraction was strongly bound to the 14-3-3 protein. In the mutated (S351A)RIN1-transfected LoVo cells, the mutated (S351A)RIN1 protein was identified in the cell membrane, and was bound to HRas protein. Also, in vitro the proliferative capacity of the mutated (S351A)RIN1-transfected LoVo cells was significantly inhibited, compared with that of their empty vector-transfected counterparts. In the mutated (S351A)RIN1-transfected LoVo cells, the phosphorylation of ERK1/2 proteins downstream of the H-Ras molecule was inhibited, compared with the counterparts. This study is the first to show that the localization of RIN1 protein plays an important role in the carcinogenesis in colon cancer cells LoVo (i.e., signal transduction in the Ras-ERK pathway).
First Department of Surgery, Faculty of Medicine, University of Fukui, Fukui, Japan.
Takeshi
T
Inoue
Takanori
T
Goi
Yasuo
Y
Hirono
Kanji
K
Katayama
Akio
A
Yamaguchi
D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology*; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D003593:Cytoplasm / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D011485:Protein Binding; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D048948:14-3-3 Proteins; D047908:Intracellular Signaling Peptides and Proteins; C092117:RIN1 protein, human; D012333:RNA, Messenger; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)