Ghrelin inhibits 5-fluorouracil-induced apoptosis in colonic cancer cells

Abstract

Background and Aim: The aim of the present study was to investigate if ghrelin inhibits apoptosis in colonic cancer cells. Methods: Cell viability in HT-29 cells was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was measured using 4',6-diamidino-2-phenylindole staining and flow cytometry. The protein expression of Bcl-2, Bax, and caspase-3 activation was examined using Western blotting. Results: Ghrelin dose dependently decreased the growth inhibition of HT-29 cells induced by 5-fluorouracil (5-FU). Cells treated with 5-FU displayed chromatin condensation and nuclear fragmentation, which are typical changes of apoptosis. However, co-treatment with ghrelin reduced these changes. Flow cytometry after staining with Annexin V and propidium iodide showed that ghrelin decreased the apoptotic rate of HT-29 cells induced by 5-FU. Caspase-3 activation was significantly lower in the co-treated group than in the group treated with 5-FU alone. In addition, ghrelin reversed the 5-FU-induced Bcl-2/Bax protein ratio. Conclusion: Ghrelin inhibits 5-FU-induced apoptosis in colon cancer cells through the regulation of the Bcl-2/Bax protein ratio. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.