Telmisartan Repurposing Targets Novel Biomarkers for Precision Colorectal Cancer Therapy

Background/Objectives: Colorectal cancer (CRC) remains a leading cause of cancer-associated mortality worldwide. The current therapeutic interventions are heavily constrained by the development of resistance and severe systemic toxicity. To address these challenges, this study integrated a multi-disciplinary framework involving high-throughput in silico screening followed by in vitro experimental validation to identify novel genetic targets of CRC and evaluate the efficacy of FDA-approved drugs. The primary objective was to identify safe and selective therapeutic agents capable of modulating their effect. Methods: The methodology employed a systematic screening of recent large-scale Genome-Wide Association Studies (GWASs) to pinpoint novel targets, followed by in silico pathogenicity prediction, homology modelling and high-throughput virtual screening of over 1615 FDA-approved drugs. The prioritized candidates were validated in vitro using MTT cytotoxicity assays and differential gene expression analysis across CRC cell lines (HCT116 and HT29) and a non-tumorigenic control, Human embryonic kidney cell line HEK293. Results: In silico analysis identified CLUH, CLSTN3 and SLC11A2 as novel potential targets. Based on in silico predicted deleterious mutations and subsequent molecular docking-based virtual screening, Telmisartan, Dutasteride and Venetoclax were prioritized. This prioritization was supported by their high binding affinity and dose-dependent cytotoxicity in MTT assays; thus, suggesting their repurposing potential for CRC treatment. Telmisartan exhibited a superior therapeutic profile not only in terms of the statistically significant cytotoxicity (p < 0.01), but also its selective effect on HCT116 and HT29 when compared to high safety profile in HEK293. This was further validated when Telmisartan selectively downregulated CLUH and SLC11A2 in CRC cell lines, HCT116 and HT29 while maintaining expression levels in the non-cancerous HEK293 cell line remained significantly unaffected. Furthermore, a 100 ns molecular dynamics simulation confirmed the stable binding conformation and structural reliability of the SLC11A2 (Trp179Ser)-Telmisartan complex. Conclucions: Our findings conclude that Telmisartan is a promising candidate for drug repurposing for CRC treatment and capable of modulating selected novel biomarkers CLUH and SLC11A2. However, further multi-omics-based confirmatory studies and pre-clinical validation studies are needed in the future to confirm the long-term efficacy of this repositioning strategy.