Inhibition of matrix metalloproteinase-2 enhances radiosensitivity by abrogating radiation-induced FoxM1-mediated G2/M arrest in A549 lung cancer cells
Article first published online: 8 DEC 2008
Copyright © 2009 Wiley-Liss, Inc.
International Journal of Cancer
Volume 124, Issue 10, pages 2468–2477, 15 May 2009
How to Cite
Chetty, C., Bhoopathi, P., Rao, J. S. and Lakka, S. S. (2009), Inhibition of matrix metalloproteinase-2 enhances radiosensitivity by abrogating radiation-induced FoxM1-mediated G2/M arrest in A549 lung cancer cells. Int. J. Cancer, 124: 2468–2477. doi: 10.1002/ijc.24209
- Issue published online: 16 MAR 2009
- Article first published online: 8 DEC 2008
- Accepted manuscript online: 8 DEC 2008 12:00AM EST
- Manuscript Accepted: 27 NOV 2008
- Manuscript Received: 30 SEP 2008
- National Cancer Institute Grant. Grant Numbers: CA 75557, CA 92393, CA 95058, CA 116708
- N.I.N.D.S.. Grant Numbers: NS47699, NS57529, NS61835
- American Cancer Society Grant. Grant Number: 06-03
- Caterpillar, Inc.
- OSF Saint Francis, Inc. (Peoria, IL)
- G2/M arrest;
Matrix metalloproteinase-2 (MMP-2), is known to degrade the collagen IV, plays a role in radiation-induced lung injury. We therefore investigated the antitumor effects of combining MMP-2 inhibition using an adenovirus expressing siRNA against MMP-2 (Ad-MMP-2-Si) with radiation therapy (IR) on A549 lung cancer cells in vitro and in vivo. IR increased MMP-2 mRNA, protein and activity in lung cancer cells. MMP-2 inhibition along with IR enhanced radiosensitivity as determined by clonogenic assay, flow cytometry and TUNEL assay. We show that MMP-2 inhibition prior to irradiation reduced p53 phosphorylation, with a corresponding reduction in the expression of the p53 downstream target gene p21Cip1/Waf1. Irradiated tumor cells induced the FoxM1-mediated DNA repair gene, XRCC1 and Checkpoint kinases 2/1, which were abrogated with combined treatment of Ad-MMP-2-Si and IR. Further, the combination of Ad-MMP-2-Si with radiotherapy significantly increased antitumor efficacy in vivo compared to either agent alone. Indeed, histological analysis of tumor sections collected from the combination group revealed more apoptotic cells. These studies suggest that MMP-2 inhibition in combination with radiotherapy abrogates G2 cell cycle arrest leading to apoptosis and provide evidence of the antitumor efficacy of combining MMP-2 inhibition with irradiation as a new therapeutic strategy for the effective treatment of NSCLC patients. © 2008 Wiley-Liss, Inc.