中文摘要：

目的：探讨抗凋亡蛋白Bcl-2低表达后对人乳腺癌细胞米托蒽醌（mitoxantrone，MX）敏感性的影响。方法：分别用MTr法和流式细胞仪PI单染、AnnexinV／PI双染法、彗星实验检测Bcl-2低表达后，MX对乳腺癌MDA—MB-435S和MDA～MB-231细胞生存率、细胞周期、凋亡和DNA损伤的影响。结果：Bcl-2表达降低后MX对乳腺癌MDA—MB-435S和MDA—MB-231细胞的增殖抑制、S期阻滞、凋亡诱导、DNA损伤均明显增加，具有统计学意义。结论：抑制Bcl-2表达可以增加乳腺癌细胞对MX的敏感性。

英文摘要：

Objective：To investigate the effect of Bcl -2 protein low expression on resistance of mitoxantrone （MX） to human breast cancer cell. Methods： MTT assay, PI staining, Annexin V/PI double staining, Comet assay were used to detect the cell survival and apoptosis of breast cancer MDA -MB -435S cell and MDA -MB -231 cell after treated with Bcl -2 inhibitor and MX. Results： After reducing the expression of Bcl -2 in MDA -MB -435S and MDA -MB -231 cell, MX significantly inhibited breast cancer cell survival and increased S phase arrest, apoptosis and DNA damage. Conclusion： Inhibiting the expression of Bcl -2 can increase the sensitivity of breast cancer cells to MX.