Abstract: Objective To explore the effects of gastrin-17 and its antagonist PGL on cell proliferation and the expression of HB-EGF in human gastric cancer line MKN-45. Methods MKN45 cells were incubated in the medium with gastrin-17 (10-6～10-10 mol/L)，proglumide(10-2～10-4 mol/L) or combination of two agents (10-8 mol/L gastrin-17 and 10-2～10-4 mol/L proglumide).Cell growth and proliferation of MKN45 were analyzed by MTT assay，and expression of HB-EGF by Western blot. Results MTT showed gastrin-17 significantly promoted cell proliferation at the concentration of 10-6～10-9 mol/L (P<0.05)，PGL at the concentration of 10-2～10-3 mol/L significantly inhibited the proliferation of MKN45 cells (P<0.05).In the combination of two agents，PGL (10-2～10-3 mol/L) significantly inhibite the proliferation of MKN-45 cells induced by gastrin-17 (P<0.05).Meanwhile，MKN45 had the expression of HB-EGF protein which significantly up-regulated by Gastrin-17 at the concertration of 10-6～10-9 mol/L.In the combination of two agents，PGL (10-2～10-3 mol/L) significantly inhibited the expression of HB-EGF stimulated by gastrin-17(P<0.05). Conclusion Gastrin-17 could promote cell proliferation of MKN45 cells in human gastric cancer，which strongly down-regulated by its antagonist PGL.Gastrin-17 significantly promoted the expression of HB-EGF，contrastly and inhibited an antagonist PGL.