title: HER2 is frequently over-expressed in ovarian clear cell adenocarcinoma: possible novel treatment modality using recombinant monoclonal antibody against HER2, trastuzumab.
abstract: Ovarian clear cell adenocarcinoma (CCA) is generally chemo-resistant. Recently the poor prognosis and resistance to chemotherapeutic agents of HER2/neu over-expressing tumors have become clear. Thus, we investigated the expression level of HER2 in surgically resected CCA and ovarian serous adenocarcinoma, endometrioid adenocarcinoma, and mucinous adenocarcinoma specimens, as well as CCA cell lines, by an immunohistochemical method. HER2 was over-expressed in 42.9% of CCA (P=0.026, vs. ovarian serous adenocarcinoma), 20.8% of ovarian serous adenocarcinoma, 23.1% of ovarian endometrioid adenocarcinoma, and 30.0% of mucinous adenocarcinoma specimens. Three CCA cell lines, RMG-1, HAC-II and KK were also positively stained for HER2. A flow-cytometric study of HER2 revealed 7.2-, 6.4- and 4.5-fold greater expression of HER2 than that of normal mammary gland, respectively. Trastuzumab, a humanized recombinant monoclonal antibody against HER2 significantly and dose-dependently reduced the growth of CCA cell lines in vitro. The extent of the inhibitory effect of trastuzumab was dependent on the expression level of HER2. Trastuzumab also dose-dependently inhibited the growth of xenografted RMG-1 tumor. The survival period of trastuzumab-treated mice was longer than that of the control group. From these findings, trastuzumab appears to be a candidate as a treatment modality for HER2 over-expressing ovarian CCA.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama-city. masakif@ms.toyama-mpu.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujimura
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Katsumata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuda
authors.forename: Naoko
authors.initials: N
authors.lastname: Uchi
authors.forename: Satomi
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Takao
authors.initials: T
authors.lastname: Hidaka
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Sakai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000737:chemistry / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D016513:Mice, SCID; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000737:chemistry / Q000188:drug therapy*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000037:antagonists & inhibitors*; D000068878:Trastuzumab; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab