Relationship analysis between the expression of multidrug resistant glycoprotein P and tumor chemotherapy resistance in breast cancer

Abstract

Objective To explore the relationship between the expression of multidrug resistant glycoprotein P(P-gp) and tumor chemotherapy resistance in breast cancer. Methods One hundred and ninety-five cases patients with breast cancer who were treated in the Central Hospital of Huanggang from January 2012 to June 2015 were selected as observation group.Thirty cases patients with breast adenosis at the same period were selected as control group.MDR1 mRNA level of the two group were determined by real-time quantitative PCR.P-gp protein level were analyzed by immunohistochemistry.According to P-gp level, 195 cases patients were divided into drug-resistant group and non-resistant group.Patients in two group were given CFM chemotherapy regimen in the treatment of cyclophosphamide(C, 600 mg/m2), methotrexate(M, 40m/m2), 5-fluorouracil(F, 500 mg/m2), 28 days as a course, a total of 6 courses.The relationship between the P-gp expression levels and clinical effectiveness was analyzed. Results (1)RT-PCR showed that MDR1 mRNA levels of breast cancer tissues in observation group significantly enhanced than of control group((7.5±2.1) vs.(1.2±0.4), t=5.139, P<0.05). Immunohistochemistry revealed that MDR1 coded product P-gp was brown, mainly expressed in the cells cytoplasm and cell surface of breast cancer cells.There was no the expression of P-gp protein the control group patients.There were 64 cases P-gp protein-negative patients(non-resistance group) and 131 cases positive patients(resistance group). (2)Clinical effectiveness in non-resistance group was 73.44%(47/64), significantly higher than that of resistance group(42.75%(56/131)), the difference was significant(x03C7;2=2.184, P<0.05). (3)The 1-year and 2-year cumulative survival rates of resistance group were 53.44% and 26.72% respectively, significantly higher than that of non-resistance group(78.13% and 43.75%), the difference was significant(x03C7;2=5.836, 4.183, P<0.05). Conclusion Abnormal expression of MDR1 encoding product P-gp in breast cancer, which associated with cancer chemotherapy drug resistance.It is helpful to the medication guide in breast cancer chemotherapy by detecting P-gp level. Key words: Breast cancer; Multidrug resistant glycoprotein P; MDR1; Chemotherapy resistance; Survival rate