二烯丙基二硫对人胃癌MGC803细胞G_2/M期的阻滞作用

目的　探讨二烯丙基二硫 (DADS)对人胃癌MGC80 3细胞G2 /M期的阻滞作用及分子机制。方法　体外培养MGC80 3细胞 ,采用MTT比色实验、细胞计数法 ,流式细胞光度术和Westernblot分析DADS对MGC80 3细胞的抑制增殖作用 ,细胞周期分布的影响及细胞周期相关蛋白的表达。结果　MTT法显示 ,2 0mg·L-1DADS、30mg·L-1DADS作用MGC80 3细胞 72h后 ,生长抑制率分别达2 5 7%、5 8 6 %。细胞计数法表明常规培养MGC80 3细胞群体倍增时间为 2 9 92h ,30mg·L-1DADS作用MGC80 3细胞后 ,其细胞群体倍增时间延长到 5 5 5 8h。流式细胞仪分析结果显示DADS呈浓度依赖性将MGC80 3细胞阻滞在G2 /M期。 30mg·L-1DADS作用MGC80 3细胞 36h ,与对照组相比 ,可使G2 /M期细胞增加到 4倍多。Westernblot分析表明在G2 /M期阻滞同时有Cdc2 5C蛋白表达下降 ,但CDK1蛋白表达不受DADS作用的影响。结论　DADS对MGC80 3细胞的抑制增殖作用与G2 /M期阻滞有关 ,DADS对MGC80 3细胞G2 /M期阻滞的分子机制可能与降低Cdc2 5C蛋白水平有关

Effect of diallyl disulfide on G2/M arrest in human gastric cancer cell

AIM To explore whether DADS treatment resulted in a block in the cell cycle of human gastric cancer MGC803 cells and its molecular mechanisms. METHOND MGC803 cells growth inhibition were measured by MTT assay and cell counting. Phase distribution of cell cycle was analyzed by flow cytometry. Expression of Cdc25C, CDK1 was determined by western blot analysis. RESULTS MTT assay showed that DADS significantly inhibited MGC803 cells and exhibited a dose dependent modal. Adding 20 mg·L -1 and 30 mg·L -1 DADS for 72 h suppressed MGC803 growth by 25 7%, 58 6%,respectively. Cell counting showed that average doubling time retarded from 29 92 h in normal cultured MGC803 cells to 58 58 h in 30 mg·L -1 DADS experimented MGC803 cells ( P <0 05). Flow cytometry analysis revealed that treating MGC803 cells with increasing quantities of DADS increased the percentage of cells in the G 2/M phase. The proportion of cells in the G 2/M phase after treatment with 30 mg·L -1 DADS for 36 h was 53 7%, more than four times that occurring in untreated cells (13 8%). Western blot analysis revealed that 30 mg·L -1 DADS didnot influence the quantity of CDK1 protein expressed. But decreased the amount associated with Cdc25C by 85% at 48 hours. CONCLUSION The antiproliferation property of diallyl disulfide (DADS) in cultured human gastric carcinoma MGC803 cell line relates to its ability to arrest G 2/M. G 2/M arrest of MGC803 cells by DADS may be related to the decrease of the expression of Cdc25C phosphatase protein. But DADS do not influence the quantity of CDK1 protein expressed.