[Detection of expression of multidrug resistance gene in breast cancer by RT-PCR]

Using RT-PCR technique, we established a method for measuring expression of mdr-1 gene in breast cancer and the conditions affecting PCR results. Expression of mdr-1 gene was detected in 74 breast cancer samples. The results showed that 34.3%(12/35) untreated primary lesions and 59.0%(23/39) relapsed metastatic lesions had positive expression of mdr-1 gene (P < 0.05). In 32 patients, the overall correlation of mdr-1 gene expression with clinical drug sensitivity was 78.1%. The results validate that RT-PCR assay is highly sensitive, relatively quantitative and reliable for measuring levels of mdr-1 gene expression in clinical samples.