Checkpoint kinase inhibitor azd7762overcomescisplatin resistance in clear cell carcinoma of the ovary

Hiroaki Itamochi, Mayumi Nishimura, Nao Oumi, Misaki Kato, Tetsuro Oishi, Muneaki Shimada, Shinya Sato, Jun Naniwa, Seiya Sato, Akiko Kudoh, Junzo Kigawa, Tasuku Harada

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37 Citations (Scopus)


Objective: Checkpoint kinase (Chk) inhibitors are thought to increase the cytotoxic effects of DNA-damaging agents and are undergoing clinical trials. The present study was aimed to assess the potential to use the Chk1 and Chk2 inhibitor, AZD7762, with other anticancer agents in chemotherapy to treat ovarian clear cell carcinoma. Methods: Four ovarian clear cell carcinoma cell lines were used in this study. We treated the cells with AZD7762 and anticancer agents, then assessed cell viability, cell cycle distribution, apoptosis, and the expression of protein in apoptotic pathways and molecules downstream of the Chk signaling pathways. We also investigated the effects of these drug combinations on tumor growth in a nude mouse xenograft model. Results: Synergistic effects from the combination of AZD7762 and cisplatin were observed in all 4 cell lines. However, we observed additive effects when AZD7762 was combined with paclitaxel on all cell lines tested. AZD7762 effectively suppressed the Chk signaling pathways activated by cisplatin, dramatically enhanced expression of phosphorylated H2A.X, cleaved caspase 9 and PARP, decreased the proportion of cells in the gap 0/ gap 1 phase and the synthesis-phase fraction, and increased apoptotic cells. Combinations of small interfering RNA against Chk 1 and small interfering RNA against Chk2 enhanced the cytotoxic effect of cisplatin in both RMG-I and KK cells. Finally, treating mice-bearing RMG-I with AZD7762 and cisplatin significantly suppressed growth of tumors in a xenograft model. Conclusions: The present study indicates that chemotherapy with AZD7762 and cisplatin should be explored as a treatment modality for women with ovarian clear cell carcinoma.

Original languageEnglish
Pages (from-to)61-69
Number of pages9
JournalInternational Journal of Gynecological Cancer
Issue number1
Publication statusPublished - 2014 Jan


  • Checkpoint kinase
  • Cisplatin
  • Clear cell
  • Ovarian carcinoma
  • Resistance


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