Submitted on December 6, 2002
Accepted on February 17, 2003
GASTRIN INDUCED GASTRIC ADENOCARCINOMA GROWTH IS MEDIATED THROUGH CYCLIN D1
Diane H. Song1, Basabi Rana2, Jessica R. Wolfe1, Geoffrey Crimmins1, Caroline Choi1, Chris Albanese3, Timothy C. Wang4, Richard G. Pestell3, and M. Michael Wolfe1*
1 Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
2 Section of Gastroenterology, Boston University School of Medicine, Boston Medical Center, Boston, MA, USA; Division of Molecular Cardiology, Texas A&M University System Health Science Center, College of Medicine, Temple, TX, USA
3 Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
4 Gastrointestinal Division, University of Massachusetts Medical School, Worcester, MA, USA
* To whom correspondence should be addressed. E-mail: michael.wolfe{at}bmc.org.
Gastrin is a gastrointestinal (GI) peptide that possesses potent trophic effects on most of the normal and neoplastic mucosa of the GI tract. Despite abundant evidence for these properties, the mechanisms governing gastrin-induced proliferation are still largely unknown. To elucidate the mechanisms by which gastrin might influence mitogenesis in gastric adenocarcinoma, we analyzed its effects on the human cell line AGS-B. Amidated gastrin-17 (G-17), one of the major circulating forms of gastrin, induced a concentration-dependent increase in 3H-thymidine incorporation of cells in culture, with the maximum effective concentration occurring with 20 nM G-17. This effect was significantly attenuated by the gastrin-specific receptor antagonist, L365,260. In addition, we found that G-17 induced a significant increase in the levels of cyclin D1 transcripts, protein, and promoter activity. The results of these studies indicate that gastrin appears to exert its mitogenic effects on gastric adenocarcinoma, at least in part, through changes in cyclin D1 expression.
