Functional significance of gastrin gene expression in human cancer cells.
The gastrointestinal peptide, gastrin, stimulates the growth of human pancreatic cancer. A receptor for gastrin activity, the cholecystokinin-C (CCK-C) receptor, has been identified in binding assays, cloned and sequenced, and is a splice variant of the CCK-B receptor. The relationship of gastrin and the CCK-C receptor to the growth of cancer cells was examined in vitro and in vivo. Stable transfection of the sense cDNA of gastrin into human MDA Amp-7 ampullary cancer cells, which normally lack gastrin gene expression but possess CCK-C receptors, increased cell growth up to 10-fold over wild type (WT) and vector-transfected (VT) cells. MDA Amp-7 tumors of gastrin-transfected cells reduced latency time for a visible tumor by 35%, decreased the timetable of tumor incidence, and increased tumor size by at least 2-fold in comparison to WT and VT groups. Transfection of human BxPC-3 pancreatic cancer cells, which normally express gastrin and possess CCK-C receptors, with the antisense cDNA to human gastrin decreased cell number by 30% in culture and tumor size by 53% compared to the WT and VT groups. Transfection of sense gastrin cDNA to monkey COS-1 cells, which normally lack both the gastrin and the CCK-C receptor genes, had no effect on growth. These studies demonstrate that gastrin and the CCK-C receptor form an autocrine loop in human pancreatic cancer that plays a role in regulating growth.
Smith
Jill P
JP
Department of Medicine, Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center, Hershey, PA 17033, USA. jsmith2@psu.edu
Verderame
Michael F
MF
Ballard
Elizabeth N
EN
Zagon
Ian S
IS
D000818:Animals; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D016373:DNA, Antisense / Q000494:pharmacology; D018076:DNA, Complementary; D005755:Gastrins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D051379:Mice; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011949:Receptors, Cholecystokinin / Q000502:physiology; D014162:Transfection
D016373:DNA, Antisense; D018076:DNA, Complementary; D005755:Gastrins; D011949:Receptors, Cholecystokinin