RESUMO
We have cloned full-length MDR1 cDNA from human normal liver tissue in previous study. Using this MDR1 cDNA as probe, we observed the MDR1 gene expression in human hepatocellular carcinoma treated with and without chemotherapy by Northern blot. The results showed that expression of MDR1 gene in hepatocellular carcinoma tissues was higher than that in their adjacent normal liver tissues; and enhanced MDR1 gene expression was also observed in hepatocellular carcinoma treated with chemotherapic agents. We also explored a method for quantitative analysis of MDR1 gene expression in hepatocellular carcinoma by polymerase chain reaction. This study suggests that overexpression of MDR1 gene may be responsible for the intrinsic and acquired drug resistance of human hepatocellular carcinoma, and PCR is a preferable method for quantitative analysis of MDR1 gene expression in hepatocellular carcinoma.