Effect of BRCA1 on the Concurrent Chemoradiotherapy Resistance of Cervical Squamous Cell Carcinoma Based on Transcriptome Sequencing Analysis

Background. Cervical squamous cell carcinoma (CSCC) is the main pathological type of cervical cancer, accounting for 80%-85% of cervical cancer. Owing to concurrent chemoradiotherapy (CCRT) resistance in a subset of CSCC patients, the treatment response is often unsatisfactory. Identifying predictors and therapeutic targets related to cisplatin-based CCRT resistance in CSCC is critical.Methods. We reanalyzed GSE56363, an mRNA dataset from the GEO database with 21 patients with locally advanced CSCC, to identify differentially expressed genes (DEGs) related to CCRT resistance. The hub genes were screened from the protein-protein interaction network of DEGs using cytoHubba plug-in of Cytoscape software. Transcriptome sequencing technology was used to compare differential expression between SiHa cells overexpressing BRCA1 compared with control SiHa cells. Functional annotation for DEGs and gene set enrichment analysis (GSEA) was performed to identify DEG-enriched relative signaling pathways to examine the molecular mechanisms of BRCA1 in CCRT resistance of CSCC. qPCR was used to verify the expression of key genes in SiHa/DDP cells.Results. A total of 609 DEGs including 223 upregulated DEGs and 386 downregulated DEGs were identified between the complete response to CCRT (CR) and noncomplete response to CCRT (NCR) CSCC patients based on the GSE56363 dataset. Ten hub genes with the highest degrees were identified via the plug-in CytoHubba in Cytoscape: BRCA1, CDCA8, ASPM, CDC45, RAD51, HMMR, CENPF, EXO1, DTL, and ZWINT genes, and BRCA1 ranked first. Through transcriptome sequencing analysis based on GSE141558, 1344 DEGs were identified in BRCA1-overexpressing SiHa cells, including 824 upregulated DEGs and 520 downregulated DEGs. GSEA results showed that CCRT-resistance related signaling pathways, such as the JAK/STAT signaling pathway and the WNT signaling pathway, were differentially enriched in BRCA1-expressing SiHa cells. STAT1, STAT2, and CCND1 were screened as the differentially expressed target genes of BRCA1 and may correlate with resistance of CSCC. qPCR results showed that only STAT1 was significantly increased in SiHa cells with GV230-BRCA1 plasmid transfection.Conclusion. BRCA1 overexpression in SiHa cells may upregulate STAT1 to activate the JAK/STAT signaling pathway, suggesting a mechanism for enhanced CCRT resistance.