中文摘要：

目的：检测小细胞肺癌多药耐药细胞H446/CDDP差异表达片段I-2^PP2A在多种肿瘤细胞中的表达情况,以了解I-2^PP2A基因的表达分布特点及功能特征,为进一步相关研究奠定基础。方法：利用Northern杂交与半定量RT-PCR相结合的方法检测I-2^PP2A在H446、H446/CDDP、A549、A549/CDDP、SK-HEP-1、Na-malwa、SGC7901等7种肿瘤细胞中的表达。结果：I-2^PP2A在H446细胞、H446/CDDP细胞及Namalwa细胞中均有表达,经进一步图像分析及统计学处理表明I-2^PP2A在H446/CDDP细胞中的表达量明显高于在H446细胞中的表达量（P〈0.01）,在H446/CDDP与Namalwa间的表达量无明显差异（P〉0.05）。结论：相对于H446细胞来说,I-2^PP2A在其耐药细胞株H446/CDDP中有差异高表达。I-2^PP2A可能参与了H446/CDDP多药耐药性的形成,其参与途径可能与细胞凋亡有关。

英文摘要：

Objective：To detect the expression of I -2^PP2A, one of the differentially expressed cDNA fragments of the human small -cell lung cancer （SCLC） multi -drug resistance cell H446/CDDP, in SCLC MDR cell and various other tumour cells and to investigate the distributional and functional characteristics of the I - 2^PP2A expression. Meth- ods： Semi - quantitative RT - PCR and Northern blot were used to detect the expressions of I - 2^PP2A in seven tumour cells including H446, H446/CDDP, A549, A549/CDDP, SK - HEP - 1, Namalwa and SGC7901. Results： Semi - quantitative RT - PCR and Northern blot results showed that I - 2^PP2A had expression in H446, H446/CDDP, and Namalwa. I-2^PP2A expression in H446/CDDP was significantly higher than that in H446 （P 〈0.01 ） and that I -2^PP2A expression in H446/CDDP is not significantly different from that in Namalwa （P 〉 0.05）. Conclusion：I -2^PP2A has higher expression in H446/CDDP than in H446 ; I - 2^PP2A has the possibility to act in the formation of the MDR in H446/CDDP and this involvement might relate to cell apoptosis.