Expression of ATP-binding Cassette Proteins Pgp, MRP1, and MRP3 in Malignant and Benign Ovarian Lesions

This study was designed to compare the expression of PgP (P-glycoprotein), MRP1 (multidrug related protein), and MRP3 in ovarian cancer patients, patients with benign ovarian tumors, and healthy women, and to evaluate the correlation between the expression of ATP-binding cassette proteins Pgp, MRP1, and MRP3 with stage, grade, and histological type. Tissue specimens from 212 women who underwent surgery at the Department of Obstetrics and Gynecology at University Hospital Hradec Králové were subjected to immunohistochemical staining for Pgp, MRP1, and MRP3. The expression of Pgp and MRP1 was higher in ovarian tumor cells than in the cells lining the ovarian cyst. The lowest level of expression was found in normal ovarian tissue (p < 0.001). Histological subtype of epithelial ovarian cancer correlated with the expression of PgP, MRP1, and MRP3. The lowest level of Pgp and MRP1 expression was found in endometrioid ovarian cancers (p = 0.151; p = 0.013). Patients with advanced ovarian cancer (FIGO III + IV) had higher MRP1 expression than those with early stage ovarian cancer (median MRP1 FIGO I + II 80%; CI 60-100; FIGO III + IV 100%; CI 90-100; p = 0.100). An association was observed between MRP1 and tumor grade (p < 0.001). Pgp and MRP1 expression was higher in ovarian tumor cells than in cells lining the ovarian cyst. The lowest level of expression was found in normal ovarian tissue. ATP-binding cassette proteins play an important role in ovarian cancer pathogenesis.Key words: ATP-binding cassette proteins - ovarian cancer - P-glycoprotein (Pgp) - multidrug related protein 1 (MRP1) - multidrug related protein 3 (MRP3) - drug resistanceThis work was supported by the Czech Ministry of Health NT 14107-3/2013.The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 9. 11. 2015Accepted: 30. 8. 2016.