These authors contributed equally.
Leupeptin-sensitive proteases involved in cell survival after X-ray irradiation in human RSa cells
Article first published online: 2 JAN 2013
© The Author(s) Journal compilation © 2005 International Federation for Cell Biology
Cell Biology International
Volume 29, Issue 8, pages 662–668, August 2005
How to Cite
Zhang, H.-C., Karata, K., Matsushita, K., Takahashi, S., Tong, X.-B., Lu, J., Zhu, C.-L., Sugaya, S., Suzuki, T. and Suzuki, N. (2005), Leupeptin-sensitive proteases involved in cell survival after X-ray irradiation in human RSa cells. Cell Biology International, 29: 662–668. doi: 10.1016/j.cellbi.2005.03.023
- Issue published online: 2 JAN 2013
- Article first published online: 2 JAN 2013
- Received 16 March 2004; revised 28 February 2005; accepted 25 March 2005
- Human RSa cells;
Proteases have received attention as important cellular components responsible for stress response in human cells. However, little is known about the role of proteases in the early steps of cell response after X-ray irradiation. In the present study, we first searched for proteases whose activity levels are changed soon after X-ray irradiation in human RSa cells with a high sensitivity to X-ray cell-killing. RSa cells showed an increased level of fibrinolytic protease activity within 10 min after irradiation with X-ray (up to 3 Gy). The induced protease activity was proved to be inhibited by leupeptin. We next examined whether this protease inducibility is related to the X-ray susceptibility of cells. Treatment of RSa cells with leupeptin prior to X-ray irradiation resulted in lowered colony survival and an increased ratio of G2/M-arrested cells and apoptotic cells. These results suggest that leupeptin-sensitive proteases are involved in the resistance of human RSa cells to X-ray cell-killing.