title: Sensitivity to anticancer agents and resistance mechanisms in clear cell carcinoma of the ovary.
abstract: We conducted the present study to determine the chemoresistance mechanisms in clear cell carcinoma of the ovary (CCC). Five human CCC cell lines (HAC-2, RMG-I, RMG-II, KK, and KOC-7c) were used in this study. The sensitivity of the cells to the anticancer agents was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and we assessed drug sensitivity by calculating assay area under the curve (AUC) for each agent. The expression of multi-drug resistance genes (MDR-1, MRP-1, MRP-2) was detected by reverse transcription-polymerase chain reaction (RT-PCR). Glutathione (GSH) concentration was measured by an enzymatic assay. Topoisomerase (topo) I activity was assayed in terms of relaxation of supercoiled plasmid substrate DNA. The IC(50) to anticancer agents ranged widely. The assay AUC indicated that 3 of 5 cell lines (RMG-I, RMG-II, and KK) were sensitive to paclitaxel (PTX), 3 (HAC-2, RMG-I, and RMG-II) were sensitive to 7-ethyl-10-hydroxycamptothecin (SN-38), which is an active metabolite of camptothecin (CPT-11), and only one (HAC-2) was sensitive to cisplatin (CDDP). All cell lines were resistant to mitomycin-C (MMC) and etoposide (VP-16). The MRP-1 gene was detected in all cell lines. Only one cell line showed both MRP-2 and MDR-1 gene expression. Except for HAC-2 cells, expression of MRP genes was related to CDDP resistance, and MDR-1 gene expression was associated with PTX resistance. GSH concentrations increased after exposure to CDDP or MMC in all cell lines. There was a significant correlation between topo-I enzymatic activity and the response to SN-38. The present study revealed several resistance mechanisms in CCC and the results suggested that PTX and CPT-11 might be effective agents to treat CCC.
authors.affiliation: Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago 683-8504. itamochi@hotmail.com
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Itamochi
authors.forename: Junzo
authors.initials: J
authors.lastname: Kigawa
authors.forename: Habiba
authors.initials: H
authors.lastname: Sultana
authors.forename: Takahiro
authors.initials: T
authors.lastname: Iba
authors.forename: Ryoji
authors.initials: R
authors.lastname: Akeshima
authors.forename: Shunji
authors.initials: S
authors.lastname: Kamazawa
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Kanamori
authors.forename: Naoki
authors.initials: N
authors.lastname: Terakawa
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis; D018262:Adenocarcinoma, Clear Cell / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D019540:Area Under Curve; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002945:Cisplatin / Q000494:pharmacology; D004396:Coloring Agents / Q000494:pharmacology; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D005047:Etoposide / Q000494:pharmacology; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D000077146:Irinotecan; D024101:Mitochondrial Proteins; D016685:Mitomycin / Q000494:pharmacology; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D017239:Paclitaxel / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000096:biosynthesis; D029701:Saccharomyces cerevisiae Proteins; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D002166:Camptothecin; D002945:Cisplatin; D004396:Coloring Agents; D004264:DNA Topoisomerases, Type I; D005047:Etoposide; D005978:Glutathione; D000077146:Irinotecan; D024101:Mitochondrial Proteins; D016685:Mitomycin; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D017239:Paclitaxel; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; C000715087:ABCC2 protein, human; C093947:MRP2 protein, S cerevisiae; C022616:thiazolyl blue; C421109:multidrug resistance-associated protein 1