ENGINEERING DNA DAMAGE RESPONSE PATHWAYS FOR ENHANCED CELLULAR RESISTANCE TO GENOTOXIC STRESS

Abstract

Background: DNA damage caused by radiation, oxidative stress, environmental toxins and chemotherapeutic agents, is a threat to genome stability and cell survival. Cellular DNA damage response (DDR) pathways play a critical role in the detection, signaling and repair of genomic lesions to maintain cellular integrity. However, under conditions of severe genotoxic stress, endogenous repair mechanisms are often not sufficient.
Objective: The goal of this study is to utilize synthetic biology and genome engineering approaches to design DNA damage response pathways, to improve cell resistance, genome stability and survival under genotoxic stress.
Methodology:  CRISPR-Cas9-mediated genome editing, synthetic promoter systems and pathway optimization strategies were used to enhance homologous recombination and ATM/ATR-mediated stress signaling pathways in engineered cellular models. The efficacy of DNA repair, apoptosis reduction and cell survival were evaluated in conditions of radiation and oxidative stress by comet assays, γ-H2AX analysis and flow cytometry.
Findings:  Engineered cellular systems showed significantly enhanced double strand break repair efficiency (88%), decreased DNA fragmentation (65%), increased oxidative stress tolerance (79%) and enhanced post-stress cell viability (82%) as compared to non-engineered cells. Upregulation of BRCA1 and RAD51 pathways further improved genome stability and decreased apoptosis.

Conclusion: Engineering of DDR pathways is an effective strategy for enhancing cellular resistance to genotoxic stress with promising applications in regenerative medicine, radiation biology, cancer therapeutics and advanced cellular biotechnology.