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Updated: Aug 14, 2026
Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay
Published on: June 9, 2017
Radiation and new molecular agents part I: targeting ATM-ATR checkpoints, DNA repair, and the proteasome
Ananya Choudhury1, Andrew Cuddihy, Robert G Bristow
1Department of Radiation Oncology, University of Toronto and Princess Margaret Hospital-University Health Network, Ontario, Canada.
Abstract:
In response to DNA breaks, human cells delay their progression through the G1, S, and G2 phases of the cell cycle. This response requires the coordinated effort of the ATM-CHK2-p53 and ATR-CHK1 DNA damage-sensing pathways and DNA repair (eg, DNA-PK and RAD51 complexes). The turnover of many of these DNA damage-associated proteins is controlled by the 26S proteasome. In this article, we review molecular strategies that target each of these pathways using silencing RNA (siRNA), antisense, or small-molecule inhibition. Although these agents can radiosensitize tumor cells, little data are available regarding potential effects on normal tissues to determine the potential therapeutic ratio of these strategies after fractionated radiotherapy. Clinical trials using such agents will require novel correlative science endpoints to track DNA repair and cell-cycle arrest and will need careful assessment of normal tissue toxicity and stability.
Insights
Targeting DNA damage response pathways with inhibitors can radiosensitize tumor cells. Further research is needed to assess normal tissue toxicity and therapeutic ratios for fractionated radiotherapy.
Area of Science:
- Molecular biology
- Cell biology
- Cancer research
Background:
- DNA breaks trigger cell cycle arrest via ATM-CHK2-p53 and ATR-CHK1 pathways.
- The 26S proteasome regulates DNA damage-associated proteins.
- Targeting these pathways offers potential radiosensitization strategies.
Purpose of the Study:
- To review molecular strategies targeting DNA damage response pathways.
- To discuss the potential of these strategies in cancer therapy.
- To highlight the need for assessing normal tissue effects and toxicity.
Main Methods:
- Review of molecular strategies including siRNA, antisense, and small-molecule inhibitors.
- Analysis of DNA damage-sensing pathways (ATM-CHK2-p53, ATR-CHK1).
- Discussion of DNA repair complexes (DNA-PK, RAD51).
Main Results:
- Targeting DNA damage response pathways can radiosensitize tumor cells.
- Limited data exists on the effects of these agents on normal tissues.
- Potential therapeutic ratios require further investigation.
Conclusions:
- Molecular strategies targeting DNA damage response pathways show promise for radiosensitization.
- Clinical trials need robust correlative science endpoints.
- Careful assessment of normal tissue toxicity is crucial for therapeutic application.
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