The Role of Replication Stress-Related Genes in Cervical Cancer Radiotherapy Resistance: A Bioinformatic and Experimental Validation.

Abstract

Cervical cancer (CC) remains a major global health challenge, with radiotherapy resistance (RR) representing a critical impediment to treatment efficacy. This study investigated the underlying mechanisms of replication stress (RS) in RR and identified potential therapeutic targets for CC. A comprehensive bioinformatics workflow was applied to analyze the expression profiles and prognostic significance of RS-related differentially expressed genes (RSRDs) in patients with RR. The prognostic utility of an RS-based risk score model was subsequently evaluated in the context of the tumor microenvironment, somatic mutation landscape, etc. The clinical relevance of the identified hub RSRDs was validated through immunohistochemistry (IHC), univariate and multivariate Cox regression analyses, and a prognostic nomogram using data from a real-world patient cohort. Functional assays conducted both in vitro and in vivo further confirmed the role of the key RSRD. Thus, enrichment analysis of the 124 common differentially expressed genes showed RS related biological processes were enriched. The RS risk score model, constructed using two hub RSRDs (AXIN1 and CTBP1) identified through LASSO regression, showed strong diagnostic and prognostic performance. Enrichment analysis showed the risk score model influenced CC prognosis by tumor microenvironment and mutation, etc. IHC analysis of tissue microarrays explored a significant downregulation of AXIN1 in RR samples. AXIN1 was also an independent prognosis biomarker for CC patients, particularly among patients receiving radiotherapy. Knock-down of AXIN1 significantly inhibited the radiosensitivity in CC cell lines, and in vivo experiments showed AXIN1 knockdown led to increased tumor volume following radiotherapy. Molecular docking analysis illustrated JQ1 may promote AXIN1 expression. This study is the first to identify AXIN1 as a replication stress associated gene with prognostic value in CC, specifically in the context of radiotherapy. These findings may support personalized treatment strategies and provide a foundation for future investigations into RS-targeted therapies in CC.