Pirarubicin inhibits multidrug-resistant osteosarcoma cell proliferation through induction of G2/M phase cell cycle arrest

• Published in: Acta pharmacologica Sinica 2012-06, Vol.33 (6), p.832-838
• Main Authors: Zheng, Shui-er, Xiong, Sang, Lin, Feng, Qiao, Guang-lei, Feng, Tao, Shen, Zan, Min, Da-liu, Zhang, Chun-ling, Yao, Yang
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents - pharmacology; Biomedical and Life Sciences; Biomedicine; CDC2 Protein Kinase - genetics; cdc25 Phosphatases - genetics; Cell Cycle Checkpoints - drug effects; Cell Line, Tumor; Cell Proliferation - drug effects; Cyclin B1 - genetics; Doxorubicin - analogs & derivatives; Doxorubicin - pharmacology; G2 Phase - drug effects; Gene Expression Regulation, Neoplastic - drug effects; Humans; Immunology; Internal Medicine; Medical Microbiology; Original; original-article; Osteosarcoma - drug therapy; Osteosarcoma - genetics; Pharmacology/Toxicology; Vaccine
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1038/aps.2012.20

Aim: Pirarubicin (THP) is recently found to be effective in treating patients with advanced, relapsed or recurrent high-grade osteosarcoma. In this study, the effects of THP on the multidrug-resistant (MDR) osteosarcoma cells were assessed, and the underlying mechanisms for the disruption of cell cycle kinetics by THP were explored. Methods: Human osteosarcoma cell line MG63 and human MDR osteosarcoma cell line MG63/DOX were tested. The cytotoxicity of drugs was examined using a cell proliferation assay with the Cell Counting Kit-8 (CCK-8). The distribution of cells across the cell cycle was determined with flow cytometry. The expression of cell cycle-regulated genes cyclin B1 and Cdc2 (CDK1), and the phosphorylated Cdc2 and Cdc25C was examined using Western blot analyses. Results: MG63/DOX cells were highly resistant to doxorubicin (ADM) and gemcitabine (GEM), but were sensitive or lowly resistant to THP, methotrexate (MTX) and cisplatin (DDP). Treatment of MG63/DOX cells with THP (200–1000 ng/mL) inhibited the cell proliferation in time- and concentration-dependent manners. THP (50–500 ng/mL) induced MG63/DOX cell cycle arrest at the G 2 /M phase in time- and concentration-dependent manners. Furthermore, the treatment of MG63/DOX cells with THP (200–1000 ng/mL) downregulated cyclin B1 expression, and decreased the phosphorylated Cdc2 at Thr 161 . Conversely, the treatment increased the phosphorylated Cdc2 at Thr 14 /Tyr 15 and Cdc25C at Ser 216 , which led to a decrease in Cdc2-cyclin B1 activity. Conclusion: The cytotoxicity of THP to MG63/DOX cells may be in part due to its ability to arrest cell cycle progression at the G 2 /M phase, which supports the use of THP for managing patients with MDR osteosarcoma.