Study of the relationship between mdrl gene expression and resistance to chemotherapy in leukemia

Objective To study the relationship between mdrl gene expression and clinical treatment. Methods We analysed forty four leukemic patients and five normal controls by RT PCR to determine mdrl gene expression. Results 78.9% of newly diagnosed patients, 55.6% of remission patients and 93.3% of refractory relapsed pateints expressed mdrl gene, while none of the normal controls had this gene expression. 82.4% of mdrl negative and low expressed patients reached CR, while CR rate was only 34% in mdrl intermediate and highly expressed patients ( P =0.003).Conclusion These data indicate that high level of mdrl gene expression may lead to resistance of tumor cells to chemotherapy. So the mdrl gene expression can serve as a supplementary marker to monitor the patients' condition and determine the prognosis of the disease. (Shanghai Med J, 2000,23:34 37)