Camp regulates gastrin gene expression.
Shiotani, Akiko, and Juanita L. Merchant.
Juanita L. Merchant, M.D., Ph.D., 1150 West Medical Drive, MSRB I,
3510, Ann Arbor, MI 48109-0650, Phone: 313-747-2944, Fax: 313-936
-1400
APStracts 2:0080G, 1995.
Gastrin is one of the most potent regulators of acid secretion and
gastrointestinal cell growth. A variety of signals regulate gastrin
release from the antral G cell. However whether these secretagogues
also stimulate gastrin gene expression has not been established.
Dramatic increases in gastrin gene expression occur in the stomach
after birth and in response to chronic achlorhydria. Moreover,
gastrin gene expression in malignant islet cell tumors (gastrinomas)
appears to represent reactivation of the fetal pattern of expression
in the pancreas. Thus, differential expression of the gastrin gene is
a reflection of differences in transcriptional control. Since various
luminal and humoral factors stimulate the production of cAMP and
gastrin secretion in both gastrinoma and antral G cells, we studied
the effect of cAMP on gastrin gene expression. Using stable and
transient transformants of a pituitary cell line containing the human
gastrin gene, we found that cAMP stimulates a 3-fold increase in
gastrin mRNA levels and that the response maps to elements located
between -148 and -40 bp upstream from the cap site. Collectively,
these studies link an important regulator of gastrin secretion to
regulation of gastrin gene expression.
Received 3 January 1995; accepted in final form 25 April 1995.
APS Manuscript Number G3-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 2 May 1995.