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Updated: Jun 18, 2026

Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay
Published on: June 9, 2017
ATM regulates a RASSF1A-dependent DNA damage response
Garth Hamilton1, Karen S Yee, Simon Scrace
1Gray Institute for Radiation Oncology and Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK.
Abstract:
Hypermethylation of CpG islands in the RASSF1 promoter is one of the most frequent events identified in human cancer. The epigenetic-driven loss of RASSF1A protein expression is observed more often in tumors of higher grade and correlates with a decreased responsiveness to DNA-damaging therapy. Ras association domain-containing family 1A (RASSF1A) promotes apoptosis by signaling through the MST2 and LATS1 kinases, leading to stabilization of the YAP1/p73 transcriptional complex. Here we provide evidence for a new pathway linking DNA damage signaling to RASSF1A via the main sensor of double-strand breaks in cells, ataxia telangiectasia mutated (ATM). We show that, upon DNA damage, RASSF1A is phosphorylated by ATM on Ser131 and is involved in the activation of both MST2 and LATS1, leading to the stabilization of p73. Furthermore, lung and ovarian tumor cell lines that retain RASSF1A expression commonly harbor polymorphisms in the region of Ser131, and our analysis shows that the S131F polymorphism conveys resistance to DNA-damaging agents. Thus, we present a novel DNA damage pathway emanating from ATM that is frequently disabled in tumors via epigenetic silencing of RASSF1 or mutation of an ATM phosphorylation site.
Insights
Epigenetic silencing of RASSF1A or mutations disabling its ATM phosphorylation site are frequent in cancer. This disrupts a novel DNA damage pathway, reducing apoptosis and therapy response.
Area of Science:
- Molecular Biology
- Cancer Research
- Epigenetics
Background:
- Hypermethylation of the RASSF1 promoter is common in cancer, leading to RASSF1A loss and reduced DNA-damaging therapy response.
- RASSF1A normally promotes apoptosis via MST2/LATS1 kinases, stabilizing the YAP1/p73 complex.
Purpose of the Study:
- To identify a novel DNA damage signaling pathway involving RASSF1A.
- To investigate the role of ATM in RASSF1A activation and its implications in cancer.
Main Methods:
- Investigated the link between DNA damage signaling and RASSF1A using cell lines.
- Analyzed RASSF1A phosphorylation by ATM and its effect on downstream signaling.
- Examined RASSF1A polymorphisms in tumor cell lines and their association with therapy resistance.
Main Results:
- DNA damage induces RASSF1A phosphorylation by ATM at Ser131, activating MST2/LATS1 and stabilizing p73.
- Lung and ovarian tumors with retained RASSF1A expression often have Ser131 polymorphisms.
- The S131F polymorphism confers resistance to DNA-damaging agents.
Conclusions:
- A novel ATM-RASSF1A DNA damage pathway exists and is frequently disrupted in cancer.
- Disruption occurs via RASSF1 epigenetic silencing or ATM phosphorylation site mutations.
- This pathway disruption contributes to tumor progression and therapy resistance.
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