Metastatic breast cancer remains a leading cause of cancer-related mortality worldwide, largely due to its high invasiveness and resistance to conventional therapies. Metastatic breast cancer remains a significant therapeutic challenge, necessitating the development of novel treatment strategies. This study investigated the anti-cancer potential of Citrus bergamia extract (CBE) and its molecular mechanisms in metastatic breast cancer cells. The cytotoxic effects of CBE on 4T1 metastatic breast cancer cells were assessed using the MTT assay. Apoptosis was measured by flow cytometry using Annexin V-Propidium Iodide. Gene expression analyses were conducted using qRT-PCR. Additionally, bioinformatic analysis was used to determine the molecular targets, key proteins, and mechanisms of action of CBE in relation to metastatic breast cancer. The extract exhibited cytotoxicity against 4T1 cells, with an IC50 of ~50 µg/mL at 24h. It induced dose-dependent apoptosis, primarily in the early phase, accompanied by upregulated caspase-3 and p53 expression. Bioinformatics identified 32 overlapping genes between metastasis-associated and bergamottin-regulated genes, highlighting HSP90AA1 and mTOR as key hubs. In vitro validation confirmed CBE significantly downregulated HSP90AA1, mTOR, and metastasis-related genes (HIF-1α, MMP-9, Rac1). While cBioPortal analysis revealed HSP90AA1 alterations in breast cancer patients, survival analysis indicated complex relationships between these alterations and patient outcomes. These findings suggest that CBE is a promising therapeutic agent against metastatic breast cancer, acting through multiple molecular pathways to induce apoptosis and inhibit metastasis. Our study provides novel insights into the molecular mechanisms of CBE's anti-cancer effects and highlights its potential as a therapeutic agent in metastatic breast cancer treatment.
Prajoko et al. (Sun,) studied this question.