Zhang Ru-Gang, Guo Li-Xia, Wang Xing-Wang, Xie Hong
Department of Biotherapy, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai 200031, China.
World J Gastroenterol. 2002 Oct;8(5):827-31. doi: 10.3748/wjg.v8.i5.827.
To study the effects of doxorubicin on telomerase activity and telomere length in hepatocellular carcinoma.
Telomerase activity was assayed with a non-radioisotopic quantitative telomerase repeat amplification protocol-based method. The effect of doxorubicin (DOX) on the growth of BEL-7404 human hepatoma cells was determined by microculture tetrazolium assay. Mean telomere length (terminal restriction fragment) was detected by Southern blot method. The expression of telomerase subunits genes was investigated by RT-PCR. Cell apoptosis and cell cycle distribution were evaluated by flow cytometry.
Telomerase activity was inhibited in a dose and time-dependent manner in BEL-7404 human hepatoma cells treated with DOX for 24, 48 or 72 h in concentrations from 0.156 to 2.5 microM which was correlated with the inhibition of cell growth. No changes were found in the mRNA expression of three telomerase subunits (hTERT, hTR and TP1) after drug exposure for 72 h with indicated concentrations. The cells treated with DOX showed shortened mean telomere length and accumulated at the G(2)/M phase. However, there was almost no effects on cell apoptosis by DOX.
The telomerase inhibition and the telomere shortening by DOX may contribute to its efficiency in the treatment in hepatocellular carcinoma.
研究阿霉素对肝癌细胞端粒酶活性及端粒长度的影响。
采用基于非放射性定量端粒酶重复序列扩增法检测端粒酶活性。用微量培养四氮唑蓝法测定阿霉素（DOX）对人肝癌BEL-7404细胞生长的影响。采用Southern印迹法检测平均端粒长度（末端限制片段）。通过逆转录聚合酶链反应研究端粒酶亚基基因的表达。用流式细胞术评估细胞凋亡和细胞周期分布。
用浓度为0.156至2.5微摩尔的DOX处理人肝癌BEL-7404细胞24、48或72小时，端粒酶活性呈剂量和时间依赖性抑制，这与细胞生长抑制相关。在指定浓度下用药物处理72小时后，三种端粒酶亚基（hTERT、hTR和TP1）的mRNA表达未发现变化。用DOX处理的细胞平均端粒长度缩短，并在G(2)/M期积累。然而，DOX对细胞凋亡几乎没有影响。
DOX抑制端粒酶活性和缩短端粒长度可能有助于其治疗肝癌的疗效。
