Effects of gastrin, proglumide, loxiglumide and L-365,260 on growth of human colon carcinoma cells.

Gastrin-17 stimulated growth of the human colon carcinoma cell line HT29 but not of the human colon carcinoma cell lines T84, HCT116 and the mouse fibroblast cell line 3T3-L1. Correspondingly, specific gastrin binding sites were only found on HT29-cells. Proglumide, loxiglumide and L-365,260 inhibited gastrin-17 stimulated growth of HT29-cells at doses which did not influence cell growth when given without gastrin. At higher concentrations proglumide and loxiglumide reduced cell proliferation in all cell lines investigated. Gastrin-17 could not reverse these effects. This growth inhibition was therefore considered as not gastrin receptor mediated. The results demonstrate that only some human colon carcinoma cell lines are stimulated by gastrin. This stimulation can be inhibited by gastrin/CCK-antagonists.