促肝再生磷酸酶-3拮抗剂原钒酸钠对大肠癌细胞增殖凋亡影响

目的 探讨原钒酸钠(SoV)通过对促肝再生磷酸酶-3(PRL-3)抑制,观察对大肠癌细胞株Colo-320增殖凋亡影响.方法 应用Western blot方法检测PRL-3在7株大肠癌细胞中表达情况,筛选出表达最强的一株做下一步抑制实验.选择PRL-3拮抗剂SoV,通过噻唑蓝(MTT)实验观察其在0.1～0.5 μmol/L浓度范围对癌细胞增殖影响;通过流式细胞术计算增殖指数(PI),观察其对癌细胞周期和凋亡影响.结果 Western blot方法筛选出表达PRL-3最强结肠癌细胞株Colo-320,MTT实验显示SoV能显著抑制Colo-320细胞生长能力,呈量-效(0.1～0.5 μmol/L)、时-效(0～120 h)相关性.0.5 μmol/L SoV作用48 h后,s期细胞比例为(17.5±0.6)%,与对照组S期所占比例(28.0±1.1)%比较明显下降(P<0.01),细胞分裂阻滞在s期,PI值亦明显降低(P<0.01),没有发现细胞凋亡.结论 SoV能显著抑制Colo-320细胞增殖,其机制与抑制PRL-3酶活性以及参与细胞周期调控有关,而与细胞凋亡过程无关.

The effects of phosphatase of regeneration liver-3 Inhibitor sodium orthovanadate on proliferation and apoptosis of Colo-320 cells

Objective To elucidate the effects of sodium orthovanadate (SoV), an inhibitor of PRL-3 phosphatase ,on proliferation and apoptosis of Colo-320 celia through blocking the catalytical activity of PRL-3 phosphatase. Methods The expression levels of PRL-3 in 7 colorectal cancer cell lines were ex-amined by Western blot in order to screen out which cell line expressed the highest level of PRL-3 protein. Then this cell line was employed in the next experiments of drug intervention. Mar assay was used to ana- lyze the effects of SoV on proliferation of cancer cells after the cells were exposed to SoV at various concen- trations of 0.1,0.2,0.3,0.4,0.5 μmol/L, respectively, for 0 to 120 h. The optimal concentration and time were chosen to test the effects of SoV on the cancer cell cycle and apoptosis by flow cytometry. Results The expression of PRL-3 was clearly detected in 5 of 7 (71.4%) colorectal cancer cell lines by Western blot. The colonic cancer cell line Colo-320 was screened as the target cell for its highest expression level of PRL-3. Mar assay showed that SoV inhibited the proliferation of cancer cells in a dose- and time-depend- ent manner. After exposure to SoV at a concentration of 0.5 μmol/L for 48 h, the percentage of cells, (17.5±0.6) %, in S-phase was significantly decreased as compared to that of (28.0±1.1) % in control cells (P <0.01) ,indicating that the cell division was blocked in S-phase. No obvious signs of apoptosis were observed.. Conclusion SoV shows good inhibition efficacy to colonic cancer cell growth, which may be yielded through restraining catalytical activity of PRL-3 phosphatase and then blocking the cell cycle in S-phase.