Combined use of arginase and dichloroacetate exhibits anti-proliferative effects in triple negative breast cancer cells

Objectives Drug combination in cancer therapy aims to achieve synergistic therapeutic effect, reduced drug dosage, reduced drug toxicity and minimizes or delays the induction of drug resistance. In the present study, we investigated the anticancer effects of the combination of two metabolic modulators, dichloroacetate (DCA) and bacillus caldovelox arginase (BCA) (or pegyated human arginase (HA)). Methods The combination treatments were evaluated in MCF-7 and MDA-MB 231 cells as well as in MDA-MB 231 breast cancer xenograft model. Key findings Dichloroacetate and BCA combination exhibited anti-proliferative effects on MCF-7 cells, which were found to be synergistic. Analysis of the gene expression upon drug treatments revealed that the synergistic anti-proliferative effect on MCF-7 cells was possibly in part due to the activation of the p53 pathway. A similar synergistic anti-proliferative effect was observed in the combined use of DCA and HA on MCF-7 and MDA-MB231 cells, which was due to induction of cell cycle arrest at G2/M phase. Moreover, the combination enhanced anti-tumour activity in a MDA-MB 231 xenograft mouse model. Conclusions Our results suggested that dichloroacetate and arginase combination exhibited enhanced anti-cancer effects in preclinical breast cancer models which may offer an additional treatment option for breast cancer.