冬凌草甲素对K562细胞端粒酶活性调控及细胞周期的影响

Regulation of telomerase activity and cell cycle of K562 cells by oridonin

目的 研究冬凌草甲素 (ORI)对K5 6 2细胞端粒酶活性及其细胞周期的影响。方法 免疫细胞化学法测定K5 6 2细胞中hTERT和C myc蛋白的表达 ;TRAP PCR ELISA法检测了端粒酶活性变化 ;流式细胞仪测定细胞周期各时相百分比。结果 用 3 4 3μmol·L- 1 ORI作用于K5 6 2细胞 4 8h后 ,hTERT和C myc蛋白的表达降低 ;在一定的浓度范围内 ,ORI可下调K5 6 2细胞端粒酶活性。同时细胞周期各时相分布发生变化 ,G0 G1 期或G2 M期细胞增多 ,S期细胞减少。结论 ORI可下调K5 6 2细胞的端粒酶活性 ,其机制可能与其细胞周期阻滞作用及抑制hTERT和C myc蛋白的表达有关。

Aim To investigate the effect of oridonin (ORI) on telomerase activity and cell cycle of human leukemic cell line K562 cells. Methods Immunohistochemistry (IHC) technique was used to determine the expression of hTERT or C-myc. Telomerase activity was detected with TRAP-PCR-ELISA assay. In addition, the percentages of K562 cells in different cell cycle were determined by flow cytometry (FCM) at 24th and 48th hours separately after adding the different concentrations of ORI. Results After the K562 cells were treated with ORI at 3.43 μmol·L -1 for 48 h, the expression of hTERT and C-myc decreased obviously. There was statistical significant (P<0.05) difference between experimental groups and the normal controls. In addition, the telomerase activity of K562 cells was significantly inhibited by ORI at the dose of 3.43 μmol·L -1 for 48 h. At the same time, the cell cycle distribution changed, the percentage of G 0/G 1 or G 2/M stages cells increased and that of the S stage cells decreased after ORI was added. Conclusion ORI can effectively inhibit telomerase activity in K562 cells. Arresting cell cycle and decreasing the expression of hTERT and C-myc may be the mechanism of action.