辛伐他汀对K562细胞端粒酶活性及人端粒酶逆转录酶表达的影响

Effects of simvastatin on telomerase activity and expression of human telomerase reverse transcriptase in K562 cells

目的探讨辛伐他汀治疗慢性粒细胞白血病可能的作用机制。方法辛伐他汀10和20μmol.L-1与K562细胞作用48或72 h后,用流式细胞术AnnexinⅤ-FITC/PI双染法检测细胞凋亡百分率;提取细胞端粒酶,用PCR-ELISA检测端粒酶活性;实时荧光定量PCR检测人端粒酶逆转录酶(hTERT),c-myc和bcl2-mRNA表达。结果辛伐他汀10和20μmo.lL-1与K562细胞作用48 h后,细胞凋亡率分别为(6.24±0.18)%和(9.41±0.22)%,与对照组(1.88±0.14)%比较明显增加;作用72 h后细胞凋亡率分别为(12.41±0.32)%和(19.08±0.26)%,与对照组(4.20±0.19)%比较明显增加。辛伐他汀10和20μmo.lL-1与K562细胞作用48或72 h后,端粒酶活性,hTERT,c-myc和bcl-2 mRNA表达明显低于对照组。结论辛伐他汀可使K562细胞端粒酶活性降低,其机制可能与下调hTERT mRNA表达有关。

AIM To explore the possible mechanism of simvastatin on chronic myelogemous leukemia. METHODS K562 cells were treated with simvastatin 10 and 20μmol·L^-1 for 48 or 72 h. Cell apoptosis was confirmed by Annexin V-FITC/PI double staining. Telomerase activity was determined by polymerase chain reaction-enzyme-linked immunosorbent assay （PCR-ELISA）. The expressions of hu- man telomerase reverse transcriptase （hTERT）, c-myc and bcl-2 mRNA were analyzed by RT-PCR. RESULTS K562 cells could be induced to undergo apoptosis after simvastatin 10 and 20μmol·L^-1 treatment for 48 h, and the apoptotic rate was （6. 24± 0.18 ） % and （ 9.41±0.22 ） % , respectively, and significantly higher than that of control group （ 1.88 ± 0.14） %. At 72 h, the apoptotic rates was （12.41±0.32）% and （19.08 ±0.26） %, respectively, and markedly higher than that of control group （4.20 ± 0.19）%. The telomerase activity, hTERT, c-myc and bcl-2 mRNA expression of K562 cells incubated with simvastatin 10 and 20μmol·L^-1 for 48 or 72 h decreased compared with that of control. CONCLUSION Simvastatin can decrease telomerase activity in K562 ceils. The underlying mechanism might be related to downregulation of hTERT mRNA expression.