中文摘要：

肿瘤细胞对多种化疗药物产生交叉耐药性称为多药耐药（multidrug resistance，MDR），是造成肿瘤耐药化疗失败的主要原因。经过20余年国内外诸多实验室通过诱导耐药细胞株及对动物模型耐药表型的研究，发现多药耐药的发生存在多机制，多环节。针对不同耐药机制，已经发现一系列逆转剂。因此，对MDR机制研究和逆转MDR成为肿瘤治疗亟待解决的问题。

英文摘要：

Muhidrug resistance （ MDR）, which is defined as cross resistance of tumor cells to many chemotherapy drugs, is the main cause for failure in tumors chemotherapy. Using muhidrug resistant tumor cell lines and animal models, many studies revealed numbers of mechanisms involved in multidrug resistance. A series of reversal drugs with different mechanisms have been discovered.