Comparative Investigation of Cytotoxic Effects of Structurally Diverse Small Molecules and In Silico Analysis of 1-Acetyl-4-(4-Hydroxyphenyl)piperazine.

This study assessed the anticancer activity of boron-containing and structurally diverse small molecules in 4T1 breast cancer and Caco-2 colon adenocarcinoma cells. Initial screening showed that five boronic acids lacked significant cytotoxicity, underscoring the structural specificity required for boron-mediated bioactivity. Similarly, reference compounds, including fumaric acid, caffeic acid, ferulic acid, dimethyl malonate and N-(tert-butoxycarbonyl)-L-alanine, showed no cytotoxic effect under identical conditions. Among the tested agents, 1-acetyl-4-(4-hydroxyphenyl)piperazine (1A4HP) displayed the most potent cytotoxicity, with IC50 values of 149.7 μM in 4T1 and 825 μM in Caco-2 cells. For comparison, the clinically investigated antimetastatic agent tasquinimod showed moderate activity in 4T1 cells (IC50 = 180.7 μM), serving as a pharmacological benchmark. Mechanistic assays revealed that 1A4HP induced apoptosis and significantly impaired 4T1 cell migration, suggesting combined antiproliferative and antimetastatic effects. Computational analyses further supported 1A4HP's drug-like potential by predicting favourable physicochemical properties, including balanced lipophilicity and high solubility. Molecular docking studies indicated a strong binding affinity to oestrogen receptor alpha (ERα), surpassing that of tamoxifen. Notably, despite 4T1's ER-negative status, 1A4HP suppressed cell growth, suggesting possible ER-independent or off-target mechanisms, similar to tamoxifen's secondary effects. Collectively, these results identify 1A4HP as a promising lead compound for further exploration in breast cancers.