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Updated: Jul 26, 2025
Techniques to Induce and Quantify Cellular Senescence
Published on: May 1, 2017
MAPK11 (p38β) is a major determinant of cellular radiosensitivity by controlling ionizing radiation-associated
D M Fernández-Aroca1, N García-Flores1, S Frost2
1Laboratorio de Oncología Molecular, Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha. Unidad Asociada de Biomedicina UCLM, Unidad asociada al CSIC, Albacete, España.
Background And Purpose:
MAPKs are among the most relevant signalling pathways involved in coordinating cell responses to different stimuli. This group includes p38MAPKs, constituted by 4 different proteins with a high sequence homology: MAPK14 (p38α), MAPK11 (p38β), MAPK12 (p38γ) and MAPK13 (p38δ). Despite their high similarity, each member shows unique expression patterns and even exclusive functions. Thus, analysing protein-specific functions of MAPK members is necessary to unequivocally uncover the roles of this signalling pathway. Here, we investigate the possible role of MAPK11 in the cell response to ionizing radiation (IR).
Materials And Methods:
We developed MAPK11/14 knockdown through shRNA and CRISPR interference gene perturbation approaches and analysed the downstream effects on cell responses to ionizing radiation in A549, HCT-116 and MCF-7 cancer cell lines. Specifically, we assessed IR toxicity by clonogenic assays; DNA damage response activity by immunocytochemistry; apoptosis and cell cycle by flow cytometry (Annexin V and propidium iodide, respectively); DNA repair by comet assay; and senescence induction by both X-Gal staining and gene expression of senescence-associated genes by RT-qPCR.
Results:
Our findings demonstrate a critical role of MAPK11 in the cellular response to IR by controlling the associated senescent phenotype, and without observable effects on DNA damage response, apoptosis, cell cycle or DNA damage repair.
Conclusion:
Our results highlight MAPK11 as a novel mediator of the cellular response to ionizing radiation through the control exerted onto IR-associated senescence.
Insights
Mitogen-activated protein kinase 11 (MAPK11) is crucial for cellular response to ionizing radiation (IR), specifically by controlling IR-induced senescence. MAPK11 does not impact DNA damage, apoptosis, cell cycle, or repair.
Area of Science:
- Cellular signaling pathways
- Molecular biology
- Cancer research
Background:
- Mitogen-activated protein kinases (MAPKs) are key regulators of cellular responses.
- The p38 MAPK family, including MAPK11, has distinct functions despite sequence homology.
- Understanding individual MAPK roles is vital for deciphering signaling pathway functions.
Purpose of the Study:
- Investigate the specific role of MAPK11 in cellular response to ionizing radiation (IR).
- Elucidate MAPK11's contribution to cancer cell responses post-IR exposure.
Main Methods:
- Utilized shRNA and CRISPR interference for MAPK11/14 knockdown in A549, HCT-116, and MCF-7 cancer cell lines.
- Assessed IR toxicity, DNA damage response, apoptosis, cell cycle, DNA repair, and senescence induction.
- Employed clonogenic assays, immunocytochemistry, flow cytometry, comet assays, X-Gal staining, and RT-qPCR.
Main Results:
- MAPK11 plays a critical role in the cellular response to ionizing radiation.
- MAPK11 specifically controls the senescent phenotype induced by IR.
- No significant effects of MAPK11 modulation were observed on DNA damage response, apoptosis, cell cycle, or DNA repair.
Conclusions:
- MAPK11 is identified as a novel mediator of cellular response to ionizing radiation.
- MAPK11's primary mechanism involves the regulation of IR-associated senescence.
- Targeting MAPK11 may offer new strategies for modulating radiation response in cancer therapy.
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