The expression and significance of MDR1 ,BCRP,LRP mRNA and protein in breast cancer / 中华检验医学杂志

ABSTRACT

Objective To investigate the expression and the significance of the MDR1, breast cancer resistance protein, lung cancer resistance protein mRNA and corresponding proteins P-gp, BCRP and LRP in breast cancer tissues and adjacent breast tissues. Methods RT-PCR was used to exam the expression of MDR1, BCRP, LRP mRNA in 42 breast cancer tissues and 42 adjacent tissues. IHC was used to exam the expression of P-gp, BCRP and LRP in 126 breast cancer tissues and 42 adjacent tissues, and theirs relationships with clinicopathological parameters in breast cancer, axillary lymph node status and 5-year recurrence and metastasis. Results The relative expression levels of MDR1, BCRP and LRP mRNA were 0.81 ±0.17,0.78 ±0.14,0.79 ±0.13 in breast cancer tissues and 0.33 ±0.11,0.45 ±0.09,0.36 ±0.10 in adjacent tissues respectively. There were significant differences between cancer tissues and adjacent tissues ( t = 4.613, 4.850 and 8. 089, P < 0.01 ). The positivities of P-gp, BCRP and LRP were 41% ( 52/126) ,39% (49/126) and 66% (83/126) in breast cancer tissues. There were significant differences between cancer tissues and adjacent tissues (x2 = 10.147, 7.020, 27.820, P < 0.01 ). The expression of MDR1 mRNA/P-gp was significantly associated with tumor stage and lymph node metastasis ( r = 0.369,0.398, P < 0.05 ). The expression of BCRP (mRNA/protein) was significantly associated with lymph node metastasis (r = 0.355, P < 0.05 ) . The positivities of P-gp were significantly different between 39 recurrence/metastasis patients occurred in 5 years and 32 unrecurrence/nonmetastasis patients in 5 years (x2 = 11.771, P < 0.01 ). The positivities of BCRP and LRP were not significantly different in these two groups(x2 =2.261,0.078,P >0.05). The coincidence rates for expression of MDR1 ,BCRP,LRP mRNA and their proteins in breast cancer tissues were 90.48% ,92.85% and 85.71% respectively (the Kappa values were 0.806,0.751 and 0.697, P < 0.01 ). Conclusions Multidrug resistance is common in breast cancer. The three drug resistance genes and proteins are involved in the formation of multidrug resistance of breast cancer. Detection of multidrng resistance genes in breast cancer may be useful to choose chemotherapy,especially patients with P-gp positive expression are not advised to use the CAF chemotherapy.