Investigating Cisplatin Resistance in Squamous Cervical Cancer: Proteomic Insights into DNA Repair Pathways and Omics-Based Drug Repurposing

Cisplatin-based chemotherapy is a cornerstone in treating cervical cancer, yet the efficacy is frequently limited by the rapid onset of drug resistance, a major challenge in clinical management. To investigate this, we employed HPV16+ human cervix squamous carcinoma cells, SiHa (CIS/S), and their cisplatin-resistant subline (CIS/R) as a model. Using DIA-based proteomics, we identified 5152 protein groups and over 50,000 peptides with a global FDR <1%. Comparative analysis revealed 123 differentially expressed proteins. Gene Set Enrichment Analysis (GSEA) highlighted proteins involved in DNA damage, metabolism, and repair pathways (RFC4, RFC3, RFC2, DUT, DDX54, CDCA8, CDK7, CHAF1B, and GTF2F1), suggesting a role in developing acquired cisplatin resistance. Pathways related to mitotic spindle assembly and P53 signaling were found to be perturbed in resistant cells. Next, we screened a library of approx. 240 FDA-approved drugs against three protein targets and found four small-molecular ligands as potential hits for further <i>in vitro</i> validation. Cabozantinib and sorafenib gave us positive results in terms of increasing the cisplatin sensitivity of CIS/R cells. In conclusion, our findings provide insights into the molecular mechanisms underpinning cisplatin resistance in cervical cancer and propose novel strategies for combating this resistance through targeted therapies and drug repurposing.