Expresslon and clinical significance of multidrug resistance gene MDR1 and P-gp protein in breast cancer

OBJECTIVE:To detect the expressionis of multidrug resistance gene 1(MDR1) and P-gp protein in breast cancer and to study the relationship between the expression and clinicopathology parameters and the correlation between MDR1 and P-gp. METHODS: Expression of MDR1 gene was measured with the fluoregenic quantitative RT-PCR method in 61 cases of breast cancer and 22 cases of the control group (including 11 cases of benign breast lesions and 11 cases of adjacent breast tissues). In addition, immunohistochemical analysis was used to detect the expression of P-gp protein in above mentioned tissues. RESULTS: The amplification rate of MDR1 gene and the expression rate of P-gp protein in breast cancer group were 50.82%(31/61) and 42.62%(26/61) respectively, which had significient difference compared with the control group. The expression of P-gp was independent of age, tumor size, lymphnode metastasis, estrogen receptor, progesteron receptor status and menopause status. The amplification of MDR1 gene was higher than the expression of P-gp protein, and there was a close correlation between them but no complete correspondence. CONCLUSIONS: Multidrug resistance gene1 (MDR1) and P-gp protein are co-expressed in breast cancer, and their expressions are positively related. To detect the expressions of MDR1 gene and its protein may predict the multidrug resistance in breast cancer.