Project supported by grants from the Cooperation Foundation of Sun Yat-Sen University (No 162004), the National Natural Science Foundation of China (No 30200285) and Natual Science Foundation of Guangdong Province (No 4009423).
Bufalin induces apoptosis in human osteosarcoma U-2OS and U-2OS methotrexate300-resistant cell lines1
Article first published online: 1 MAY 2007
Acta Pharmacologica Sinica
Volume 28, Issue 5, pages 712–720, May 2007
How to Cite
YIN, J.-q., SHEN, J.-n., SU, W.-w., WANG, J., HUANG, G., JIN, S., GUO, Q.-c., ZOU, C.-y., LI, H.-m. and LI, F.-b. (2007), Bufalin induces apoptosis in human osteosarcoma U-2OS and U-2OS methotrexate300-resistant cell lines. Acta Pharmacologica Sinica, 28: 712–720. doi: 10.1111/j.1745-7254.2007.00559.x
- Issue published online: 1 MAY 2007
- Article first published online: 1 MAY 2007
- Received 2006-09-14Accepted 2006-11-10
- dihydrofolate reductase
Aim: To investigate the antiproliferative activity and apoptosis-inducing effects of bufalin on human osteosarcoma cell lines. Methods: U-2OS and U-2OS methotrexate (MTX) 300-resistant cell lines were treated with bufalin. Cell viability was assessed using the MTT assay. Cell-cycle status, apoptosis-inducing effects, and the expression of apoptosis-related proteins were evaluated by flow cytometry, fluorescent staining, DNA fragmentation assays, and Western blotting. The effect of bufalin on dihydrofolate reductase (DHFR) expression was studied by RT-PCR and Western blotting. Results: Bufalin inhibited cell growth in both U-2OS and U-2OS MTX300 cells. The induction of G2/M cell-cycle arrest was also seen in the cells treated with bufalin. The induction of apoptosis by bufalin was confirmed by increased expression of the tumor suppressor protein p53 and the increased ratio of the Bax/Bcl-2 proteins. Bufalin induced apoptosis to the same extent in both cell lines without regard to DHFR levels in the cells. Conclusion: Bufalin inhibited the growth of and induced apoptosis in both MTX-sensitive and MTX-resistant human osteosarcoma U-2OS cells. The apoptosis-inducing effect of bufalin was not influenced by the presence of high levels of the DHFR protein.