Oncogenic ras induces gastrin/CCKB receptor gene expression in human colon cancer cell lines LoVo and Colo320HSR.
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.
Hori
Hiroyuki
H
Department of Biosignal Pathophysiology, Graduate School of Medicine and Medical Center for Student Health, Kobe, Japan.
Nakata
Hirohisa
H
Iguchi
Genzo
G
Yamada
Hajime
H
Chihara
Kazuo
K
Baba
Hisamitsu
H
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
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