Abstract | BACKGROUND: ATM plays an important role in response to DNA damage, while the roles of ATM in radiation-induced autophagy are still unclear in cervical cancer cells. METHODS: Human cervical cancer cells, Hela, were used, and cell models with ATM(-/-) and MAPK14(-/-) were established by gene engineering. Western blot was implemented to detect protein expression. MDC staining and GFP-LC3 relocalization were used to detect autophagy. CCK-8 was used to detect cell viability. Radiosensitivity was analyzed by colony formation assays. Co-immunoprecipitation was used to detect the interaction between different proteins, and apoptosis was detected by flow cytometry. RESULTS: After radiation autophagy was induced, illustrated by the increase of MAPLC3-II/MAPLC3-I ratio and decrease of p62, and phosphorylation of ATM simultaneously increased. ATM(-/-) cells displayed hypersensitivity but had no influence on IR-induced apoptosis. Then inhibitor of ATM, KU55933, ATM and MAPK14 silencing were used, and autophagy was induced by IR more than 200% in control, and only by 35.72%, 53.18% and 24.76% in KU55933-treated cells, ATM(-/-) and MAPK14(-/-) cells, respectively. KU55933 inhibited IR-induced autophagy by activating mTOR pathways. ATM silencing decreased the expression of MAPK14 and mTOR signals significantly. Beclin's bond to PI3KIII and their interaction increased after IR, while in ATM(-/-) and MAPK14(-/-) cells this interaction decreased after IR. Both ATM and MAPK14 interacted with Beclin, while ATM(-/-) and MAPK14(-/-) cells showed no interaction. CONCLUSIONS: ATM could promote IR-induced autophagy via the MAPK14 pathway, the mTOR pathway, and Beclin/PI3KIII complexes, which contributed to the effect of ATM on radiosensitivity.
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Authors | Nan Liang, Lili Jia, Yang Liu, Bing Liang, Dejuan Kong, Mengmeng Yan, Shumei Ma, Xiaodong Liu |
Journal | Cellular signalling
(Cell Signal)
Vol. 25
Issue 12
Pg. 2530-9
(Dec 2013)
ISSN: 1873-3913 [Electronic] England |
PMID | 23993957
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © 2013. |
Chemical References |
- RNA, Small Interfering
- Class III Phosphatidylinositol 3-Kinases
- Ataxia Telangiectasia Mutated Proteins
- TOR Serine-Threonine Kinases
- Mitogen-Activated Protein Kinase 14
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Topics |
- Ataxia Telangiectasia Mutated Proteins
(genetics, metabolism)
- Autophagy
(radiation effects)
- Class III Phosphatidylinositol 3-Kinases
(metabolism)
- Female
- HeLa Cells
- Humans
- Mitogen-Activated Protein Kinase 14
(genetics, metabolism)
- RNA Interference
- RNA, Small Interfering
(genetics)
- Radiation, Ionizing
- Signal Transduction
- TOR Serine-Threonine Kinases
(metabolism)
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