Quantitative and Functional Assay of MDR1/P170-mediated MDR in Ascites Cells of Patients with Ovarian Cancer

Abstract

Background: MDR1-associated P-glycoproteindependent multidrug resistance is a common cause of chemotherapy failure in patients with advanced ovarian cancer. Here, we describe a clinical method for simultaneously assessing the expression and function of the MDR1/Pgp in tumour cells from ascites of patients with malignant ovarian carcinoma. Materials and Methods: Cells from ascites from 35 patients were collected. The expression and function of Pgp were detected by flow cytometry. For functional study, rhodamine 123 was used. Results: Using the Pgp- specific UIC2 and MM6.15 antibodies, we demonstrated the presence of Pgp in 10-79 % (38.9±20, 7; n=35) of the CA125-positive cell subpopulations. The results of the functional assay showed strong correlation with the level of Pgp expression (r=0.976; p=3.2×10^-5). Conclusion: Direct detection of the expression level and function of MDR1/Pgp in the ascites provide useful information for the more efficient treatment of malignant diseases by proper adjustment of the chemotherapeutic protocol.