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CCK B /gastrin receptor mediates synergistic stimulation of DNA synthesis and cyclin D1, D3, and E expression in Swiss 3T3 cells
Author(s) -
Zhukova Elena,
SinnettSmith James,
Wong Helen,
Chiu Terence,
Rozengurt Enrique
Publication year - 2001
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.10018
Subject(s) - gastrin , bombesin , cholecystokinin , cholecystokinin b receptor , cholecystokinin receptor , signal transduction , 3t3 cells , transfection , receptor , hyperphosphorylation , microbiology and biotechnology , dna synthesis , biology , chemistry , medicine , endocrinology , kinase , cell culture , biochemistry , secretion , neuropeptide , genetics , in vitro
Abstract In order to develop a model system for identifying signaling pathways and cell cycle events involved in gastrin‐mediated mitogenesis, we have used high efficiency retroviral‐mediated transfection of cholecystokinin (CCK) B /gastrin receptor into Swiss 3T3 cells. The retrovirally‐transfected CCK B /gastrin receptor binds 125 I‐CCK‐8 with high affinity (Kd = 1.1 nM) and is functionally coupled to intracellular signaling pathways including rapid and transient increase in Ca 2+ fluxes, protein kinase C‐dependent protein kinase D activation, and MEK‐dependent ERK1/2 activation. In the presence of insulin, CCK‐8 or gastrin induced a 66.5 ± 8.8‐fold (mean ± SEM, n = 24 in eight independent experiments) increase in cellular DNA synthesis, reaching a level similar to that achieved by stimulation with a saturating concentration of fresh serum, and much greater than the response to each agonist added alone. CCK‐8 also induced a striking increase in the expression of cyclins D1, D3, and E and hyperphosphorylation of Rb acting synergistically with insulin. Similar effects were observed when CCK B /gastrin receptor was activated in the presence of EGF or bombesin. Our results demonstrate that activation of CCK B /gastrin receptor retrovirally‐transfected into Swiss 3T3 induces a potent synergistic effect on DNA synthesis, accumulation of cyclins D1, D3, and E and hyperphosphorylation of Rb in combination with insulin, EGF, or bombesin. Thus, the CCK B /gastrin receptor transfected into Swiss 3T3 cells provides a novel model system to elucidate mitogenic signal transduction pathways and cell cycle events activated via this receptor. © 2001 Wiley‐Liss, Inc.