Journal of cell science, 2019-07, Vol.132 (13)
2019
Details
- Autor(en) / Beteiligte
- Titel
- Repair-independent functions of DNA-PKcs protect irradiated cells from mitotic slippage and accelerated senescence
- Ist Teil von
- Journal of cell science, 2019-07, Vol.132 (13)
- Ort / Verlag
- England: The Company of Biologists Ltd
- Erscheinungsjahr
- 2019
- Link zum Volltext
- Quelle
- EZB-FREE-00999 freely available EZB journals
- Beschreibungen/Notizen
- The binding of DNA-dependent protein kinase catalytic subunit (DNA-PKcs, also known as PRKDC) to Ku proteins at DNA double-strand breaks (DSBs) has long been considered essential for non-homologous end joining (NHEJ) repair, providing a rationale for use of DNA-PKcs inhibitors as cancer therapeutics. Given lagging clinical translation, we reexamined mechanisms and observed instead that DSB repair can proceed independently of DNA-PKcs. While repair of radiation-induced DSBs was blocked in cells expressing shRNAs targeting Ku proteins or other NHEJ core factors, DSBs were repaired on schedule despite targeting DNA-PKcs. Although we failed to observe a DSB repair defect, the γH2AX foci that formed at sites of DNA damage persisted indefinitely after irradiation, leading to cytokinesis failure and accumulation of binucleated cells. Following this mitotic slippage, cells with decreased DNA-PKcs underwent accelerated cellular senescence. We identified downregulation of ataxia-telangiectasia mutated kinase (ATM) as the critical role of DNA-PKcs in recovery from DNA damage, insofar as targeting ATM restored γH2AX foci resolution and cytokinesis. Considering the lack of direct impact on DSB repair and emerging links between senescence and resistance to cancer therapy, these results suggest reassessing DNA-PKcs as a target for cancer treatment.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0021-9533eISSN: 1477-9137DOI: 10.1242/jcs.229385Titel-ID: cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_6633392
- Format
- –
- Schlagworte
- Animals, Ataxia Telangiectasia Mutated Proteins - metabolism, Aurora Kinase B - metabolism, Cell Cycle Checkpoints - drug effects, Cell Cycle Checkpoints - radiation effects, Cell Cycle Proteins - antagonists & inhibitors, Cell Cycle Proteins - metabolism, Cell Death - drug effects, Cell Death - radiation effects, Cellular Senescence - drug effects, Cellular Senescence - radiation effects, Cyclin-Dependent Kinase Inhibitor p21 - metabolism, Cytokinesis - drug effects, Cytokinesis - radiation effects, Cytoprotection - drug effects, Cytoprotection - radiation effects, DNA Breaks, Double-Stranded - drug effects, DNA Breaks, Double-Stranded - radiation effects, DNA Repair - radiation effects, DNA-Activated Protein Kinase - antagonists & inhibitors, DNA-Activated Protein Kinase - metabolism, Down-Regulation - drug effects, Down-Regulation - radiation effects, Histones - metabolism, Humans, MCF-7 Cells, Mice, Mitosis - drug effects, Mitosis - radiation effects, Morpholines - pharmacology, Polo-Like Kinase 1, Protein Kinase Inhibitors - pharmacology, Protein Serine-Threonine Kinases - antagonists & inhibitors, Protein Serine-Threonine Kinases - metabolism, Proto-Oncogene Proteins - antagonists & inhibitors, Proto-Oncogene Proteins - metabolism, Pyrones - pharmacology, Radiation Tolerance - drug effects, Radiation Tolerance - radiation effects, Radiation, Ionizing