RESUMO
OBJECTIVE: To study whether gastrin/cholecystokinin-B (CCK-B) receptor autocrine loop exists in human gastric cancer cells and the effects of gastrin/CCK-B receptor autocrine loop on the growth and apoptosis of human gastric cancer cells. METHODS: Human gastric cancer cells of the line SGC-7901 were cultured. The expression of gastrin and CCK-B was detected by RT-PCR, immunocytochemistry and radioimmunoassay. Antibody against gastrin was added so as to block the autocrine loop to observe the growth rate, cell cycle and apoptosis by 3-(4.5-dimethylthiazol-z-yl) -2, 5-diphenyl tertrazolium blue (MMT) colorimetric assay and flow cytometry (FCM). RESULTS: The SGC-7901 cells co-expressed gastrin and CCK-B receptor mRNAs, confirmed by sequencing, thus forming gastrin/the CCK-B receptor autocrine loop. After the blocking of the autocrine loop by antibody against gastrin, the cell growth rate and the number of cells residing in the S-phase of the cell cycle decreased and the apoptotic rate increased in an antibody concentration-dependent manner. CONCLUSION: Human gastric cancer SGC-7901 cells possess the gastrin/the CCK-B receptor autocrine loop. Blocking the autocrine loop inhibits the cell proliferation and promotes the cell apoptosis.
