叶酸对卵巢癌细胞的增殖抑制作用

目的 探讨叶酸对卵巢癌细胞增殖的影响及作用机制.方法 体外培养人卵巢癌细胞株HO-8910,采用MTT法检测不同叶酸浓度（0～160 nmol/L）作用48 h后的细胞抑制率.叶酸组采用120 nmol/L（细胞抑制达50%的浓度,即IC_（50））叶酸处理细胞48 h;常规培养的细胞作为对照组;加人二甲基亚砜（DMSO）溶剂培养的细胞作为DMSO组.分别采用Real-time PCR和Western blotting检测叶酸受体（FR-a）、二氢叶酸还原酶（DHFR）和5,10-亚甲基四氢叶酸还原酶（MTHFR）mRNA和蛋白的表达;流式细胞术检测细胞周期的变化;MTT法检测叶酸与顺铂、紫杉醇或表阿霉素联合作用时,对卵巢癌细胞增殖的影响.结果 随着叶酸浓度升高,卵巢癌细胞抑制率逐渐升高;IC_（50）为120 nmol/L.叶酸组卵巢癌细胞（120 nmol/L叶酸处理）的FR-a、DHFR 和MTHFR的mRNA和蛋白表达均低于对照组和DMSO组（P〈0.05或P〈0.01）.与对照组比较,叶酸组卵巢癌细胞G_2/M期细胞百分数降低（P〈0.05）,S期细胞百分数升高（P〈0.05）,G_0/G_1期无明显变化（P〉0.05）.120 nmol/L叶酸分别联合40 μmol/L顺铂、10 μmol/L紫杉醇或15 μmol/L表阿霉素作用48 h后,其细胞抑制率显著高于单纯化疗药物作用下的细胞抑制率（P〈0.05）.结论 一定浓度的叶酸可能通过影响叶酸代谢而抑制卵巢癌细胞的生长;叶酸可能增强化疗药物对卵巢癌的细胞毒性作用,从而增强卵巢癌化疗敏感性.

Proliferation inhibiting effects of folate on ovarian cancer cells

Objective To investigate the antiproliferative effects of folate on ovarian cancer cells. Methods Ovarian cancer cells HO-8910 were cultured in vitro, and cell inhibition rates were detected by MTT assay after treatment of ovarian cancer cells with 0 to 160 nmol/L folate for 48 h. Ovarian cancer cells in folate group were treated with 120 nmol/L (50% inhibiting concentration, IC_(50)) folate for 48 h, cells with routine culture were served as control group, and cells in dimethyl sulfoxide (DMSO) group were treated with DMSO. Real-time PCR and Western blotting were performed to observe the mRNA and protein expression of folate receptor ( FR-a), dihydrofolate reductase ( DHFR) and 5, 10-methylenetetra-hydrofolate reductase (MTHFR) in the ovarian cancer cells, and flow cytometry was employed to observe the changes of cell cycles. The effects of folate combined with Cisplatin, Paclitaxol or Epirubicin on ovarian cancer cells were detected by MTT. Results The cell inhibition rates increased with the concentrations of folate, and IC_(so)was 120 nmol/L. The mRNA and protein expression of FR-a, DHFR and MTHFR was lower than that of control group and DMSO group (P <0.05 or P < 0.01). Compared with control group, the cell percentage of G_2/M phase in folate group decreased (P < 0. 05), the cell percentage of S phase increased (P <0.05), and there was no significant change in G_0/G_1 phase ( P >0. 05) . The inhibition rates on ovarian cancer cells of Cisplatin (40 μ mol/L), Paclitaxo (10 μ mol/L) and Epirubicin (15 μ mol/L) combined with 120 nmol/L folate was significantly higher than that of chemotherapeutics lonely (P< 0. 05). Conclusion The antiproliferative effects of folate on ovarian cancer cells may be achieved by influencing folate metabolism. Folic acid may increase the cytotoxic effect of chemotherapy drugs on ovarian cancer, and increase the chemosensitivity of ovarian cancer.