中文摘要：

目的本研究旨在观察N-甲基化嘌吟DNA糖基化酶在小细胞肺癌多药耐药细胞系H446／CDDP中的表达情况。方法以本所前期诱导成功的小细胞肺癌多药耐药细胞系H446／CDDP为研究对象，H446亲代细胞为对照，采用半定量RT—PCR法检测MPG基因mRNA的转录水平，免疫细胞化学法检测其蛋白表达。结果半定量RT—PCR显示，H446细胞MPG基因mRNA的转录量为0．19±0．15，H446／CDDP细胞为0．75±0．08；免疫细胞化学显示，H446／CDDP、H446细胞MPG蛋白表达呈阳性，均表达于细胞核。结论MPG的高表达可能同人小细胞肺癌多药耐药的产生有关。

英文摘要：

Objective To investigate the expression of N-methylpurine-DNA-Glycosylase in lung cancer H446/CDDP multidrugresistanee cell line. Methods MPG mRNA transcription in H446/CDDP multidrug-resistance cell line and H446 parental cell line were examined by reverse transcription polymerase chain reaction （RT-PCR）, The expression and intracellular localization of MPG protein was determined by immunocytochemistry, Results The mRNA level of MPG was much higher in H446/CDDP multidrugresistance cell line than that in H446 parental cell llne. MPG protein was detected only in the nucleus of H446/CDDP multidrug-resistance cell line and H446 parental cell line. Conclusion Overexpression of MPG could be associated with the rise of multidrug resistance of small-cell-lung-cancer.