Impact of adenomatous polyposis coli (APC) tumor supressor gene in human colon cancer cell lines on cell cycle arrest by apigenin
Article first published online: 9 JUL 2007
Copyright © 2007 Wiley-Liss, Inc.
Volume 46, Issue 9, pages 773–782, September 2007
How to Cite
Chung, C.S., Jiang, Y., Cheng, D. and Birt, D.F. (2007), Impact of adenomatous polyposis coli (APC) tumor supressor gene in human colon cancer cell lines on cell cycle arrest by apigenin. Mol. Carcinog., 46: 773–782. doi: 10.1002/mc.20306
- Issue published online: 21 AUG 2007
- Article first published online: 9 JUL 2007
- Manuscript Accepted: 13 DEC 2006
- Manuscript Revised: 6 DEC 2006
- Manuscript Received: 12 OCT 2006
- adenomatosis polyposis coli;
- Ht-29 colon cancer cells
This research assessed the importance of the adenomatous polyposis coli (APC) tumor suppressor mutation in the ability of apigenin to induce cell cycle arrest using HT29–APC cells, which contain inducible wild-type APC under the metallothionein promoter. HT29–GAL cells, containing β-galactosidase (GAL), were included as control. Treatment with apigenin (0, 20, 40, 60, and 80 µM) for 48 h resulted in reduction in the cell number (P < 0.05) concurrent with flow cytometry results showing a dose-dependent accumulation of cells in the G2/M phase in both HT29–APC and HT29–GAL cells without ZnCl2 treatment. Flow cytometric analysis showed an increase (P < 0.05) in the percentage of cells in G2/M when HT29–APC cells were treated with 80 µM apigenin for 120 h. This increase was not present in HT29–APC cells when treated with both 80 µM apigenin and 100 µM ZnCl2 for 120 h. Western blot analysis verified the induction of APC protein expression in ZnCl2-treated HT29–APC cells but not in ZnCl2-treated HT29–GAL cells. Apigenin plus ZnCl2 treatment increased the expression of APC protein in HT29–APC cells by 50 fold above expression observed with ZnCl2 alone. Upon induction of the APC gene with ZnCl2 in HT29–APC cells, the percentage of apoptotic cells increased significantly (P < 0.05) after 120-h treatment. Additionally, apigenin treatment (80 µM) further increased the percentage of apopototic HT29–APC following ZnCl2 treatment to induce wild-type APC expression. These results suggest that APC dysfunction may be critical for apigenin to induce cell cycle arrest in human colon cancer cell lines and furthermore, apigenin enhances APC expression and apoptosis in cells with wild-type APC. © 2007 Wiley-Liss, Inc.