MOLECULAR ANALYSIS OF CELLULAR SENESCENCE ASSOCIATED WITH DNA DAMAGE RESPONSE MECHANISMS

Abstract

Cellular senescence is a stable form of cell phase arrest which is very important in ageing and inhibition of malignant changeover. It is mainly stimulated by numerous stressors; DNA damage is one of the principal triggers of this heuristic due to the increase in the DNA damage response (DDR) pathway. The DDR is a more complicated system of subsidiary signals that engages the activation of ATM/ATR kinases and their downstream effectors, such as p53 and p21, which along with it control cell fate choices. The objective of the current study is to investigate molecular processes in cellular senescosis that have pathways in DNA damage response. In particular, the paper is aimed at examining the expression profile of important regulatory genes and proteins whose work in DDR-induced senescence was crucial. In vitro cell culture models were experimented with models in which DNA damaging agents were used. The level of gene expression was determined by means of the quantitative real time PCR (RT-PCR), protein expressions and pathway activation by the western blot technology. Moreover, senescence-related β-galactosidase (SA- 8 -gal) staining was used to verify the senescence induction. Pathway analysis and data interpretation was supported using the bioinformatics tools. The findings showed a high level of upregulation of the p53 and p21 expression after DNA damage and higher levels of senescence-associated biomarkers. There was also the activation of major signalling pathways of DDR including the ATM-mediated responses. To sum up, the paper gives information on the molecular aspects of the interaction between mechanisms of DNA damage response and cellular senescence and their possible contribution to ageing and pathogenesis of disease. The results could be used to compile specific therapeutic measures in issues associated with age and cancer.