title: Immunohistochemical analysis of P-glycoprotein expression in diverse histological types of epithelial ovarian tumors.
abstract: P-glycoprotein is a transmembrane protein which acts as an energy-dependent drug efflux pump for a variety of anti-cancer drugs. The mdr-1 gene which encodes P-glycoprotein was successfully cloned in 1986. To investigate P-glycoprotein expression in diverse ovarian tumors, including benign, low malignant potential and malignant, immunohistochemical study was done using a monoclonal antibody (C 219). Overall, 8 out of the 59 epithelial ovarian tumors (13.6%) expressed P-glycoprotein. It was noted that 5 of the 12 mucinous tumors were found to express P-glycoprotein, while none of the 31 serous tumors were immunohistochemically positive. In 10 malignant ovarian tumors, P-glycoprotein immunostaining was examined both prior to and after chemotherapy. Nine of them did not express any P-glycoprotein before or after chemotherapy. However, one tumor expressed P-glycoprotein after six courses of multidrug resistance-related drug administration. These findings indicate that P-glycoprotein expression is not so common in ovarian tumors, regardless of their malignant potential. Nevertheless, the results suggest a strong association between P-glycoprotein expression and certain histological cell types in epithelial ovarian tumors. It is also possible that P-glycoprotein appears as a result of chemotherapy, but such a phenomenon can not occur unless chemotherapy is administered at high doses for a long period of time.
authors.affiliation: Department of Obstetrics and Gynecology, Okayama University Medical School, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kodama
authors.forename: R
authors.initials: R
authors.lastname: Hayase
authors.forename: M
authors.initials: M
authors.lastname: Yoshinouchi
authors.forename: H
authors.initials: H
authors.lastname: Okuda
authors.forename: T
authors.initials: T
authors.lastname: Kudo
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis*; D018432:Drug Resistance, Multiple; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000737:chemistry*; D010051:Ovarian Neoplasms / Q000737:chemistry* / Q000188:drug therapy
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1