Researchers published a study in Cell Biology and Toxicology investigating the antitumour activity of BnpM-NH₂, a hydroxyethylamino synthetic precursor of darunavir analogues, in breast cancer. The work represents a drug repurposing strategy aimed at overcoming therapeutic resistance, a significant challenge in the treatment of breast cancer. While BnpM-NH₂ has previously shown anticancer activity in haematological malignancies, its specific effects on breast cancer cells had not been previously characterized in the literature.
The study utilized a panel of human breast cancer cell lines to represent distinct molecular subtypes. These included MCF7 cells for hormone receptor-positive cancer, SK-BR-3 cells for HER2-positive cancer, and MDA-MB-231 and HCC1937 cells for triple-negative cancer. To assess selectivity and potential toxicity, the researchers also included non-tumorigenic MCF-10A cells. The experimental design involved treating these cell lines with BnpM-NH₂ alone, tamoxifen alone, or in combination.
Several cellular and molecular endpoints were evaluated to understand the mechanism of action. The researchers used MTS assays and xCELLigence to measure cell viability and proliferation. Western blotting was employed to analyze key signaling pathways, including endoplasmic reticulum stress, autophagy, mitochondrial oxidative phosphorylation, and the Akt–mTOR signalling cascade. Apoptosis, or programmed cell death, was also assessed. Additionally, computational methods such as molecular docking and SwissADME analyses were used to predict how the compound interacts with its targets and to evaluate its pharmacokinetic properties, such as drug-likeness and gastrointestinal absorption.
The results indicated that BnpM-NH₂ significantly reduced the viability of breast cancer cells across the tested subtypes. Importantly, this reduction in viability occurred with limited toxicity toward the non-tumorigenic MCF-10A cells, suggesting a degree of selectivity for cancerous tissue. When combined with tamoxifen, the antiproliferative effects were enhanced beyond what was observed with either agent alone.
Mechanistically, the study found that BnpM-NH₂ modulated endoplasmic reticulum stress, as evidenced by changes in the expression of ATF4 and eIF2α. It also altered autophagy markers, specifically LC3 and p62. A key finding was the disruption of mitochondrial homeostasis, involving oxidative phosphorylation complexes and the TOM20 protein. The compound further modulated the Akt–mTOR and S6 signalling pathways. Finally, the treatment activated caspase-dependent apoptosis and mechanisms mediated by apoptosis-inducing factor (AIF), leading to cell death. These multi-pathway effects contribute to the broad antitumour activity observed in the study.
Computational docking simulations suggested that BnpM-NH₂ and tamoxifen have favourable interactions with mTOR and Akt proteins. The models indicated that the two ligands can be accommodated simultaneously within adjacent regions of the respective binding pockets, providing a structural basis for their combined effect. SwissADME analysis predicted that BnpM-NH₂ has favourable drug-likeness properties and high gastrointestinal absorption.
The study concludes that BnpM-NH₂ exhibits broad antitumour activity across multiple breast cancer subtypes and enhances the anticancer effects of tamoxifen. The combination of experimental data, computational modelling, and pharmacokinetic predictions supports the need for further preclinical evaluation. The researchers suggest that BnpM-NH₂ is a promising candidate for combination therapy in breast cancer.
This work highlights the potential of repurposing existing drug scaffolds, such as darunavir analogues, for new therapeutic applications. By targeting multiple stress response pathways and mitochondrial function, BnpM-NH₂ offers a novel approach to treating breast cancer.
Subject of Research: Antitumour activity of a darunavir-analogue precursor in breast cancer
Article Title: A hydroxyethylamino derived of darunavir-analogue induces mitochondrial dysfunction, activates stress response pathways, and enhances tamoxifen response in breast cancer
Article References: Mecca, M., Giglio, E., Giuseffi, M., Calice, G., Lupattelli, P., Santarsiere, A., Chiummiento, L., Calabrese, C., & Sichetti, M. (2026). A hydroxyethylamino derived of darunavir-analogue induces mitochondrial dysfunction, activates stress response pathways, and enhances tamoxifen response in breast cancer. Cell Biology and Toxicology. https://doi.org/10.1007/s10565-026-10298-6
Image Credits: AI Generated
DOI: 10.1007/s10565-026-10298-6
Keywords: breast cancer, drug repurposing, tamoxifen, mitochondrial dysfunction, BnpM-NH₂, cell biology, apoptosis, mTOR signalling, preclinical research, Cell Biology and Toxicology, hydroxyethylamino, derived
