Apoptotic Pathway Induced by Dominant Negative ATM Gene in CT-26 Colon Cancer Cells.
- Author:
Jung Chang LEE
1
;
Ho Keun YI
;
Sun Young KIM
;
Dae Yeol LEE
;
Pyoung Han HWANG
;
Jin Woo PARK
Author Information
1. Department of Pediatrics, Schoool of Medicine, Chonbuk National University, Jeonju, Korea. hwaph@moak.chonbuk.ac.kr
- Publication Type:Original Article
- Keywords:
Dominant negative ATM;
Ionizing radiation;
Apoptotic pathway
- MeSH:
Adenoviridae;
Apoptosis;
Ataxia Telangiectasia;
Blotting, Western;
Caspase 3;
Caspase 9;
Cell Cycle Checkpoints;
Colon*;
Colonic Neoplasms*;
DNA Damage;
DNA Fragmentation;
Phenotype;
Radiation, Ionizing
- From:Journal of the Korean Pediatric Society
2003;46(7):679-686
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Ataxia telangiectasia mutated(ATM) is involved in DNA damage responses at different cell cycle checkpoints, and signalling pathways associated with regulation of apoptosis in response to ionizing radiation(IR). However, the signaling pathway that underlies IR-induced apoptosis in ATM cells has remained unknown. The purpose of this study was, therefore, to investigate the apoptotic pathway that underlies IR-induced apoptosis in a CT-26 cells expressing dominant negative ATM (DN-ATM). METHODS: We generated a replication-deficient recombinant adenovirus encoding the DN-ATM(Ad/DN-ATM) or control adenovirus encoding no transgene(Ad/GFP) and infected adenovirus to CT-26 cells. After infection, we examined apoptosis and apoptotic pathway by [3H]-thymidine assay, DNA fragmentation, and Western immunoblot analysis. RESULTS: DN-ATM gene served as the creation of AT phenotype in a CT-26 cells as revealed by decreased cell proliferations following IR. In addition, IR-induced apoptosis was regulated through the reduced levels of the anti-apoptotic protein Bcl-2, the increased levels of the apoptotic protein Bax, and the activation of caspase-9, caspase-3, and PARP. CONCLUSION: These results indicate that the pathway of IR-induced apoptosis in CT-26 cells expressing DN-ATM is mediated by mitochondrial signaling pathway involving the activation of caspase 9, caspase 3, and PARP.
