Combination of tetrandrine and cisplatin synergises cytotoxicity and apoptosis in triple negative breast cancer

Background

Breast cancer is one of the leading causes of cancer deaths among women worldwide. Cisplatin is a broad-spectrum anticancer drug used in the treatment of breast cancer. Recent research showed the potent anticancer effect of tetrandrine against different cancers.

Objective

Present study is aimed at determining the synergistic cytotoxic effect of tetrandrine and cisplatin against breast cancer under in vitro.

Methods

Cytotoxic effect of tetrandrine and cisplatin on MDA-MB-231 cells was performed using MTT - (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide). Synergistic, antagonistic and additive effects of tetrandrine and cisplatin were calculated using Compusyn software. Clonogenic assay was performed in 12 wells plate. The generation of Reactive Oxygen Species (ROS) was measured using H₂DCF-DA. Cell cycle assay was carried out using flow cytometry. The caspase-3, -8 and -9 activities in the cells were measured based on the hydrolysis of peptide substrates by their respective enzymes to release p-nitroaniline (pNA).

Results

The study demonstrated synergistic cytotoxic effect on MDA-MB-231 cells in a dose dependent manner. The cells undergoing apoptosis and necrosis were evidenced by microscopic observation and colony formation and cell cycle assays. The study also revealed elevated levels of ROS and, increased activities of caspase-3 and -8 which also indicate the apoptosis of cells.

Conclusion

The study showed a promising synergistic cytotoxic effect of tetrandrine and cisplatin against MDA-MB-231 cells with cell cycle arrest and intracellular ROS mediated apoptosis. Hence, the study suggests the possible synergistic use of tetrandrine and cisplatin to treat triple negative breast cancer.