Effect Of Combination Curcumin With 5-FU Inhibited Proliferation And Induced Apoptosis In Gastric Carcinoma

ObjectiveCurcumin is a natural yellow pigment isolated from the rhizome of curcuma longa L.And it has been widely accepted that curcumin could inhibit the proliferation and induce the apoptosis of many tumor cells.The drug of 5-fluorouracil(5-FU)is a basal drug of chemotherapy for the gastric cancer treatment.Therefore it is a region attractive to researchers whether curcumin can enhance the anti-carcinogenic effect of 5-FU.In order to explore the possible mechanism and offer experimental evidence of anti-cancer effect of curcumin combined with 5-FU,we investigated the anti-proliferation effect of curcumin combined with 5-FU on human SGC-7901 gastric adenocarcinoma cells and its impact with the expression of apoptosis related genes.MethodsMTT assay,plate colony formation test was used to detect drug effect. The combination effect was quantitatively determined by using the method of median-effect principle and the combination index.Apoptotic rates of human SGC-7901 gastric adenocarcinoma cells were determined by flow cytometry(FCM).The AO/EB staining and DNA ladder were used for SGC-7901 cells to detect the morphological and biochemical character changes of apoptotic cells under the action of curcumin combined with 5-FU.The expressions of Bcl-2 and Bax protein were determined by the immunohistochemical method.Results1.Curcumin inhibited the growth of human SGC-7901 gastric adenocarcinoma cells and the forming of SGC-7901 cells clone in a dose- dependent manner(P＜0.01).The effect of the individual drugs were enhanced as drug concentration increased.The median concentration of curcumin was 25.159μmol/L and that of 5-fluorouracil was 704.275μmol/L.The median concentration of combination two drugs was 268.338((4.399+263.989)μmol/L.The interaction of two drugs was synergistic at higher concentration(CI＜1)and antagonistic at lower concentration(CI＞1).2.The Cells could be classifies ted into:early apoptotic cells,laet apoptotic cells,alive cells and dead cells under the fluorescence microscopy.Curcumin could lead to characteristic morphological changes of apoptosis in human SGC-7901 gastric adenocarcinoma cells after 24 hours. 3.Curcumin compared with fluorouracil either curcumin or fluorouracil alone could arrest the cell cycle of SGC-7901 cells at S phase.4.The ratios of apoptosis cell were significantly higher than that of controls(P＜0.05)after curcumin influence the SGC-7901 cells.After exposure to RPMI 1640 medium(control),300μmol/L fluorouracil,600μmol/L fluorouracil,5μmol/L curcumin,10μmol/L curcumin,300μmol/L fluorouracil combinced with 5μmol/L curcumin,300μmol/L fluorouracil combinced with 5μmol/L curcumin for 24h,the apoptotic rates of SGC-7901 cells were 6.01±0.22%,12.32±1.2%,25.0±0.41%,8.64±0.61%,21.4±0.11%,43.99±0.8%,respectively.The apoptotic rate of SGC-7901 cells is the highest after treatment with curcumin compared with fluorouracil.5.After curcumin compared with fluorouracil influence SGC-7901 cells, DNA ladder in agarose gel,were observed.6.Bax protein was remarkably elevated after curcumin compared with fluorouracil either curcumin or fluorouracil alone influence the SGC-7901 cells for 24h.However the expression level of Bcl-2 decreased.Conclusion1.Curcumin could significantly inhibit the growth of human SGC-7901 gastric adenocarcinoma cells,which enhance dsensitivity of fluorouracil on SGC-7901 cells. 2.The curcumin and fluorouracil can all induce human SGC-7901 gastric adenocarcinoma cells apoptosis.When the two drugs combined,the inductive effect for cell apoptosis became more obvious.3.These data suggest a possible underlying molecular mechanism whereby curcumin could induce the apoptosis signaling pathway in human SGC-7901 gastric adenocarcinoma ceils by Bax activation and by the regulation of Bcl-2 protein.