Antitumoral and Antimetastatic Activity by Mixed Chelate Copper(II) Compounds (Casiopeínas®) on Triple-Negative Breast Cancer, In Vitro and In Vivo Models.

Triple-negative breast cancer (TNBC), accounting for 15-20% of all breast cancers, has one of the poorest prognoses and survival rates. Metastasis, a critical process in cancer progression, causes most cancer-related deaths, underscoring the need for alternative therapeutic approaches. This study explores the anti-migratory, anti-invasive, anti-tumoral, and antimetastatic effects of copper coordination compounds Casiopeína IIIia (CasIIIia) and Casiopeína IIgly (CasIIgly) on MDA-MB-231 and 4T1 breast carcinoma cell lines in vitro and in vivo. These emerging anticancer agents, mixed chelate copper(II) compounds, induce apoptosis by generating reactive oxygen species (ROS) and causing DNA damage. Whole-transcriptome analysis via gene expression arrays indicated that subtoxic concentrations of CasIIIia upregulate genes involved in metal response mechanisms. Casiopeínas® reduced TNBC cell viability dose-dependently and more efficiently than Cisplatin. At subtoxic concentrations (IC20), they inhibited random and chemotactic migration of MDA-MB-231 and 4T1 cells by 50-60%, similar to Cisplatin, as confirmed by transcriptome analysis. In vivo, CasIIIia and Cisplatin significantly reduced tumor growth, volume, and weight in a syngeneic breast cancer model with 4T1 cells. Furthermore, both compounds significantly decreased metastatic foci in treated mice compared to controls. Thus, CasIIIia and CasIIgly are promising chemotherapeutic candidates against TNBC.