反义寡核苷酸对K562细胞增殖和端粒酶活性的影响

 目的　研究靶向封闭端粒酶反转录酶（hTERT）mRNA的反义硫代寡核苷酸（ASPSODN）对K562细胞目的基因的抑制及其对端粒酶活性及细胞增殖周期和凋亡的影响 。方法　ASPSODN转染到人类红白血病细胞株K562，采用MTT法、酶联免疫吸附（ELISA）法和流式细胞术（FCM）检测K562细胞的增殖、端粒酶活性、细胞凋亡和细胞周期的改变，RT-PCR检测hTERT mRNA的表达。结果　0.6 μmol／L的ASPSODN（0.42±0.16）能明显下调hTERT表达（P＜0.05），端粒酶相对活性降至52 %；MTT法检测显示明显抑制K562细胞增殖活性；FCM显示细胞凋亡率为10.31 %，PI染色显示细胞被阻止在G1／G0期，S期及G2／M期的细胞减少，但无特征性的凋亡峰。结论　ASPSODN靶向 hTERT 能特异性抑制K562细胞hTERT mRNA的表达，明显下调端粒酶活性，抑制K562细胞增殖，并通过降低细胞的端粒酶活性而诱发细胞凋亡。

Effect of antisense oligodeoxynucleotide on cell proliferation and telomerase activity in K562 cell line

Objective To observe anti-sense phosphorothioate oligonucletide (ASPSODN) targeted directly to hTERT mRNA to its inhibiting effect on aimed gene and the influence on the telomerase activity, cellular proliferation, cell apoptosis of K562 cells. Methods Human leukemia cell line K562 was transfected with anti-sense oligonucleotide ASPSODN by liposome. The proliferation activity of K562 cell line was determined by using methyl thiazolyl tetrazolium assay, and telomerase activity was detected by TRAP-PCR-ELISA. Flow cytometry was adopted to examine apoptotic rate and cell cycle. RT-PCR was used to detect the expression of target gene hTERT mRNA. Results 0.6 μmol/L ASPSODN (0.42 ±0.16) was remarkably decreased the expression of hTERT mRNA, Telomerase relative activation was decreased by 52 %. According to 0.6 (μmol/L ASPSODN caused significant the inhibition of K562 cell growth. Apoptotic rate and cell cycle was examined by 0.6 μmol/L ASPSODN with flow cytometry. The cell apoptosis rate of 0.6μmol/L ASPSODN were 10.31 %. It showed the cells treated with 0.6 uU PSASODN arrested in G_1/C_0. The ratio of cells in G_2/M and S period was reduced. But there was no characteristic apoptosis peak. Conclusion ASPSODN targeted hTERT can inhibit the expression of target gene hTERT mRNA, and decrease the telomerase activity of K562 cells. ASPSODN can inhibit strongly the proliferation of K562 cell and induce cell apoptosis by decreasing telomerase activity.