Triple negative breast cancer (TNBC) is an aggressive form of breast cancer that is negative for estrogen, progesterone, and human epidermal growth factor (HER2) receptors. Hormone treatment of breast cancer involves one of the three receptors TNBC is negative for, thus leaving TNBC without an established treatment. Cisplatin is a commonly used chemotherapy in breast cancer patients, but many TNBC patients acquire cisplatin resistance. The objective here is to synthesize and characterize new chemotherapeutic agents that can be used to combat cisplatin resistance. Copper-containing complexes are known for inhibiting topoisomerase, breaking DNA strands, and intercalating DNA in cells. The hypothesis is treating MDA-MB-231-VIM-RFP cells with a copper(II) complex with the ligand, (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide will induce cell death with a low inhibitory concentration at 50% of cell viability (IC₅₀ value).

To test this hypothesis, we plated 15,000 cells in 96 well plates, treated MDA-MB-231-VIM-RFP cells using increasing concentrations of the copper(II) complex and incubated cells for 72 h; then utilized cell counting kit (CCK-8) cell viability assay to determine the IC₅₀ value. The copper(II) complex had an IC₅₀ value of 5.33 ± 0.9 μM.

Flow cytometry determined time points at which cells reached apoptosis, and whether the cells activated caspase 3/7 or reactive oxygen species (ROS) after treatment. Flow cytometry showed that caspase 3/7 and ROS were activated between 22 and 33 h after treatment. It was determined that 20% of cells died before 22 h, suggesting more than one cell death mechanism. Future studies will include DNA binding studies and to determine gene expression in treated cells.

Alexis Fletcher

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