Gastrin and cholecystokinin (CCK) have trophic action on cells expressing wild type A or B CCK receptors. Potential relevance to pancreatic and colonic cancers was raised by the demonstration of a misspliced type B CCK receptor that, when expressed in Balb3T3 cells, had constitutive activity to stimulate intracellular calcium. We attempted to confirm and extend this observation in CHO cells by establishing lines expressing similar densities of variant or wild type B CCK receptor. While both were capable of normal binding and agonist-induced signaling, neither expressed constitutive signaling and both had similar basal growth. Agonist stimulation of cells expressing misspliced receptor had greater increases in calcium and greater growth rates than control cells despite similar MAP kinase phosphorylation responses. Thus, this variant receptor can potentate peptide-stimulated signaling and trophic action and may contribute to the proliferation of neoplasms expressing it.
|Original language||English (US)|
|Number of pages||11|
|State||Published - May 10 2005|
- G protein-coupled receptor
- Peptide hormone
ASJC Scopus subject areas
- Cancer Research