In silico insights into pyrazolochalcones: molecular modeling and design of novel antagonists of estrogen receptor for breast cancer intervention using QSAR modeling, molecular docking, molecular dynamics, DFT, and ADMET studies
摘要
Estrogen receptor alpha (ERα) is the key mediator of estrogen receptor-positive (ER+) breast carcinoma; the most common form of breast malignancy and the principal target of existing medications against the disease. Due to the declining efficacy of the existing drugs against ER+ breast cancer, it has become expedient to search for newer and better options. Herein, we applied integrated in silico drug discovery techniques, including 2D-QSAR modeling, molecular docking, MM/GBSA calculations, ADMET profiling, molecular dynamics, and DFT calculations to prioritize pyrazolochalcone-based ERα antagonists. The optimal QSAR model achieved R2train = 0.946, R2adj = 0.934, Q2 = 0.917, and cRp2 = 0.888. In addition, the model displays sound external predictive ability (R2Test = 0.725, k = 1.024, k’ = 0.974, and CCC = 0.73). Among the designed ligands, PC-2 demonstrated the most promising characteristics to be prioritized as a lead molecule in the search for potent and less toxic antagonists of ERα for breast cancer intervention. The ligand showed the strongest binding interactions with the receptor (∆G = − 8.8 kcal/mol and ∆GT = − 55.04 kcal/mol), good gastrointestinal absorption (GIA) potential (≈ 70%), negative AMES status, and a non-inhibitor of hERG1. Also, 100 ns MD simulations confirmed a stable binding pose. While the findings of this in silico study highlights PC-2 as a priority candidate for synthesis and experimental evaluation, confirmation of its potential advantages over tamoxifen will require further in vitro and in vivo validation.