title: Oncogenic ras induces gastrin/CCKB receptor gene expression in human colon cancer cell lines LoVo and Colo320HSR.
abstract: Gastrin has the ability to stimulate cell growth in some colorectal cancer cells and some of these cells also express gastrin/CCKB receptors, suggesting that gastrin and its autocrine loop are involved in their proliferation. We previously reported that oncogenic ras induced gastrin gene expression in colon cancer cells. The aim of this study was to investigate whether oncogenic ras also induces gastrin/CCKB receptor gene expression. A transiently transfected activated ras vector stimulated gastrin/CCKB receptor transcriptional activities in both Colo320HSR and LoVo cells, but these ras-increased activities were inhibited by a specific MEK inhibitor, PD98059. An RPA demonstrated that activated ras increased endogenous gastrin/CCKB receptor mRNA levels and PD98059 decreased them in LoVo cells. These findings suggest that oncogenic ras induces gastrin/CCKB receptor gene expression through some intracellular signaling pathways, including MEK, in colon cancer cell lines.
authors.affiliation: Department of Biosignal Pathophysiology, Graduate School of Medicine and Medical Center for Student Health, Kobe, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hori
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Nakata
authors.forename: Genzo
authors.initials: G
authors.lastname: Iguchi
authors.forename: Hajime
authors.initials: H
authors.lastname: Yamada
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chihara
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Baba
mesh_terms: D001483:Base Sequence; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D017931:DNA Primers; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D011905:Genes, ras; D012333:RNA, Messenger / Q000235:genetics; D011949:Receptors, Cholecystokinin / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D017931:DNA Primers; D004791:Enzyme Inhibitors; D005419:Flavonoids; D012333:RNA, Messenger; D011949:Receptors, Cholecystokinin; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one