亚硒酸钠对K562/ADR多药耐药的逆转作用及其机制

Reversal Effect of Sodium Selenite on Multidrug Resistance in K562/ADR Cell Line and Its Mechanisms

本研究探讨亚硒酸钠对白血病耐药细胞株K562/ADR细胞的多药耐药性的逆转作用及其逆转机制。用噻唑蓝(MTT)法检测亚硒酸钠对K562/ADR细胞的生长抑制作用及其对K562/ADR细胞耐药性的逆转作用;应用流式细胞仪检测亚硒酸钠对K562及K562/ADR细胞凋亡率的影响;用半定量RT-PCR法检测K562/ADR细胞中mdr1和bcl-2基因的表达情况。结果表明,10μmol/L亚硒酸钠可以明显增加K562/ADR细胞对阿霉素敏感性,其耐药逆转倍数为2.31;早期凋亡率在10μmol/L亚硒酸钠作用于K562细胞48小时是升高的;而中、晚期凋亡率在亚硒酸钠5、10μmol/L作用48、72小时时均明显升高;两种浓度亚硒酸钠在作用48小时可使K562/ADR细胞早期凋亡率增加,作用48、72小时可使K562/ADR的细胞中、晚期凋亡率增高,10μmol/L的亚硒酸钠所致凋亡率高于5μmol/L,作用72小时的凋亡率高于48小时;亚硒酸钠可使K562/ADR细胞mdr1 mRNA及bcl-2mRNA表达下降。结论:亚硒酸钠可部分逆转K562/ADR细胞的耐药性,其机制可能是增加K562/ADR细胞凋亡率,下调mdr1 mR-NA和bcl-2 mRNA的表达。

This study was purposed to investigate the reversal effect of sodium selenite on multidrug resistance in adriamycin-resistant leukemic cell line K562/ADR and its mechanisms. The cytotoxicity and the reversal effect of sodium selenite on K562/ADR cells were assayed by MTT method; the apoptosis rate of K562 and K562/ADR cells were detected by flow cytometery, the mRNA expressions of mdrl and bcl-2 were measured by semi-quantitative reverse transcriptase polymerase chain reaction （RT-PCR）. The results showed that 10 μmol/L sodium selenite significantly increased the cytotoxicity of adriamycin to K562/ADR cell and the reverse index（RI） was 2.31 ; the early apoptosis rate of K562 cells was elevated after treatment with 5 μmol/L Na2 SeO3 for 48 hours;and the medium-term and late apoptosis rate was elevated after treatment with both 5 and 10 μmol/L Na2SeO3 for 48 and 72 hours. Both doses of 5 and 10 μmol/L Na2SeO3 increased the early apoptosis rate of K562/ADR at 48 hours, and also increased the medium-term and late apoptosis rate after treating for 48 and 72 hours. The apoptosis rate was higher at dose of 10 μmol/L than that at 5 μmol/L, the apoptosis rate at 72 hours also was higher than that at 48 hours. The expressions of mdrl mRNA and bcl-2 mRNA were decreased significantly by 10 μmol/L sodium selenite. It is concluded that sodium selenite can reverse the multidrug resistance in K562/ADR partially by down-regulating the expressions of mdrl mRNA and bcl-2 mRNA, and increasing apoptosis rate of K562/ADR cells.