Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2007 Jun;7(4):335-42.
doi: 10.2174/156800907780809769.

ATM-NF-kappaB connection as a target for tumor radiosensitization

Affiliations
Review

ATM-NF-kappaB connection as a target for tumor radiosensitization

Kazi Mokim Ahmed et al. Curr Cancer Drug Targets. 2007 Jun.

Abstract

Ionizing radiation (IR) plays a key role in both areas of carcinogenesis and anticancer radiotherapy. The ATM (ataxia-telangiectasia mutated) protein, a sensor to IR and other DNA-damaging agents, activates a wide variety of effectors involved in multiple signaling pathways, cell cycle checkpoints, DNA repair and apoptosis. Accumulated evidence also indicates that the transcription factor NF-kappaB (nuclear factor-kappaB) plays a critical role in cellular protection against a variety of genotoxic agents including IR, and inhibition of NF-kappaB leads to radiosensitization in radioresistant cancer cells. NF-kappaB was found to be defective in cells from patients with A-T (ataxia-telangiectasia) who are highly sensitive to DNA damage induced by IR and UV lights. Cells derived from A-T individuals are hypersensitive to killing by IR. Both ATM and NF-kappaB deficiencies result in increased sensitivity to DNA double strand breaks. Therefore, identification of the molecular linkage between the kinase ATM and NF-kappaB signaling in tumor response to therapeutic IR will lead to a better understanding of cellular response to IR, and will promise novel molecular targets for therapy-associated tumor resistance. This review article focuses on recent findings related to the relationship between ATM and NF-kappaB in response to IR. Also, the association of ATM with the NF-kappaB subunit p65 in adaptive radiation response, recently observed in our lab, is also discussed.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Cell extracts of MCF-7, MCF+FIR C6, and ATM-deficient GM05849 fibroblasts (as a negative control) were immunoprecipitated with an anti-ATM antibody and then blotted with p65, p50 or ATM antibody. For another negative control (Neg. control), immunoprecipitation (IP) and immunoblotting (IB) were performed without cell extracts [113].
Scheme 1
Scheme 1
Schematic presentation of the ATM-NF-κB connection in adaptive radioresistance. In chronic response (cells with pre-irradiation), ATM interacts directly with NF-κB subunits p65 and p50, resulting in the induction of both activity and expression of NF-κB. This event causes the interaction of p65 with MEK/ERK, resulting MEK/ERK inhibition. Therefore, ATM-mediated negative regulation of NF-κB on MEK/ERK pathway may cause increased cell survival under the genotoxic conditions of a long-term therapeutic irradiation.
Scheme 2
Scheme 2
ATM-NF-κB-regulated signaling network causing the adaptive resistance to IR in normal human skin epithelial HK18 cells. Low level radiation induces ATM-NF-κB p65 interaction through NF-κB activation by an ATM-dependent fashion (ATM/unknown kinase/MEK/ERK pathway). These events result in up-regulation of 14-3-3s and cyclins, and a reduction of 14-3-3ζ-cyclin D1 complex. Overall, these results demonstrate a novel molecular events of adaptive radioresistance involving ATM-NF-κB connection in human keratinocytes.

Similar articles

Cited by

References

    1. Shao R, Karunagaran D, Zhou BP, Li K, Lo SS, Deng J, Chiao P, Hung MC. Inhibition of nuclear factor-kappaB activity is involved in ElA-mediated sensitization of radiation-induced apoptosis. J. Biol. Chem. 1997;272(52):32739–32742. - PubMed
    1. Kato T, Duffey DC, Ondrey FG, Dong G, Chen Z, Cook JA, Mitchell JB, Van Waes C. Cisplatin and radiation sensitivity in human head and neck squamous carcinomas are independently modulated by glutathione and transcription factor NF-kappaB. Head Neck. 2000;22(8):748–759. - PubMed
    1. Yang JP, Hori M, Takahashi N, Kawabe T, Kato H, Okamoto T. NF-kappaB subunit p65 binds to 53BP2 and inhibits cell death induced by 53BP2. Oncogene. 1999;18(37):5177–5186. - PubMed
    1. Herscher LL, Cook JA, Pacelli R, Pass HI, Russo A, Mitchell JB. Principles of chemoradiation: theoretical and practical considerations. Oncology. 1999;13(10 Suppl 5):11–22. - PubMed
    1. Tang G, Mmemoto Y, Dibling B, Purcell HN, Li Z, Karin M, Lin A. Inhibition of JNK activation through NF-kappaB target genes. Nature. 2001;414(6861):313–317. - PubMed

Publication types

MeSH terms