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Updated: Sep 12, 2025
Techniques to Induce and Quantify Cellular Senescence
Published on: May 1, 2017
Dexmedetomidine Stimulates Cellular Senescence of Lung Cancer Cells Via NOX5
Dongcheng Zhang1, Wei Liang1, Zigang Li2
1Department of Radiation Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei City, China.
Abstract:
Dexmedetomidine is a highly selective α- 2 adrenergic receptor agonist which has been considered as a promising anticancer agent. However, the underlying molecular mechanisms whereby Dexmedetomidine exerts its anticancer and chemopreventive actions need to be elucidated. In this study, we found that Dexmedetomidine reduced cell viability of the lung cancer cell line A549 cells in a dose-dependent manner. Importantly, Dexmedetomidine reduced the telomerase activity in A549 cells by reducing the gene levels of hTERT but increasing the gene levels of TERF2. The senescence- associated-β- galactosidase (SA-β-Gal) staining assay demonstrates that Dexmedetomidine stimulated cellular senescence by activating the p53/p16 signaling. Additionally, treatment with Dexmedetomidine led to increased ROS production and the expression of γH2AX, implicating typical DNA damage in lung cancer cells. Interestingly, Dexmedetomidine increased the expression of NOX5 but not NOX1 or NOX2. Knockdown of NOX5 abolished the effects of Dexmedetomidine in telomerase activity, gene expression of hTERT and TERF2, the p53/p16 signaling, as well as cellular senescence, suggesting that the effects of Dexmedetomidine are mediated by NOX5. In summary, these findings show that Dexmedetomidine blunts the growth of lung cancer cells by inducing premature senescence via ROS-mediated DNA damage.
Insights
Dexmedetomidine reduces lung cancer cell growth by inducing premature senescence. This occurs through reactive oxygen species (ROS)-mediated DNA damage, involving NOX5 and activating the p53/p16 signaling pathway.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Dexmedetomidine, an α-2 adrenergic receptor agonist, shows potential as an anticancer agent.
- The precise molecular mechanisms of its anticancer effects require further investigation.
Purpose of the Study:
- To elucidate the molecular mechanisms underlying the anticancer and chemopreventive actions of Dexmedetomidine in lung cancer.
- To investigate Dexmedetomidine's impact on cell viability, telomerase activity, cellular senescence, DNA damage, and the role of NOX5.
Main Methods:
- Assessed Dexmedetomidine's effect on A549 lung cancer cell viability.
- Measured telomerase activity, hTERT and TERF2 gene expression.
- Utilized senescence-associated-β-galactosidase (SA-β-Gal) staining.
- Quantified reactive oxygen species (ROS) production and γH2AX expression.
- Investigated the role of NOX5 through gene knockdown experiments.
Main Results:
- Dexmedetomidine reduced A549 cell viability and telomerase activity by downregulating hTERT and upregulating TERF2.
- It induced cellular senescence via p53/p16 signaling activation.
- Increased ROS production and γH2AX expression indicated DNA damage.
- NOX5 was identified as a key mediator, as its knockdown abolished Dexmedetomidine's effects.
Conclusions:
- Dexmedetomidine inhibits lung cancer cell growth by inducing premature senescence.
- This process is mediated by NOX5, leading to ROS-dependent DNA damage and activation of the p53/p16 pathway.
