Environmental Hazards and Chemoresistance in OTSCC: Molecular Docking and Prediction of Paclitaxel and Imatinib as BCL2 and EGFR Inhibitors.

Oral tongue squamous cell carcinoma (OTSCC) is a common type of oral cancer influenced by genetic, epigenetic, and environmental factors like exposure to environmental toxins. These environmental toxins can decrease the effectiveness of established chemotherapy drugs, such as Irinotecan, used in OTSCC treatment. Bioinformatics, drug discovery, and machine learning techniques were employed to investigate the impact of Irinotecan on OTSCC patients by identifying targets and signaling pathways, including those that positively influence protein phosphorylation, protein tyrosine kinase activity, the PI3K-Akt (Phosphatidylinositol 3-kinase- Protein Kinase B) signaling system, cancer pathways, focal adhesion, and the HIF-1 (Hypoxia-Inducible Factor 1) signaling pathway. Later, the protein-protein interactions (PPIs) network, along with twelve cytoHubba approaches to finding the most interacting molecule, was employed to find the important proteins BCL2 and EGFR. Drugs related to BCL2 and EGFR were extracted from the DGIdb database for further molecular docking. Molecular docking revealed that Docetaxel, Paclitaxel, Imatinib, Ponatinib, Ibrutinib, Sorafenib, and Etoposide showed more binding affinity than Irinotecan (i.e., -9.8, -9.6). Of these, Paclitaxel (-10.3, -11.4) and Imatinib (-9.9, -10.4) are common in targeting BCL2 and EGFR. Using these identified candidate genes and pathways, we may be able to uncover new therapeutic targets for the treatment of OTSCC. Furthermore, molecular dynamics (MD) simulations were performed for selected ligand-receptor complexes, revealing stable binding interactions and favorable energetic profiles that supported the docking results and strengthened the reliability of the proposed drug repurposing strategy.