In vitro evaluation of a novel antimitotic estradiol analog and dichloroacetic acid on breast adenocarcinoma and breast non-tumorigenic cells

In vitro evaluation of a novel antimitotic estradiol analog and dichloroacetae, which restore mitochondrion function in breast adenocarcinoma and breast non-tumorigenic cells, will contribute to the field of combination therapy in cancer.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.am201

Synergistic Anticancer Potential of Dichloroacetate and Estradiol Analogue Exerting their Effect via ROS-JNK-Bcl-2-Mediated Signalling Pathways

Background: C9, a newly in silico-designed inhibitor of microtubule dynamics induces G2/M arrest culminating in apoptosis. Dichloroacetate (DCA) inhibits pyruvate dehydrogenase kinase, an enzyme that promotes pyruvate entry into mitochondria. The use of antitumor drugs targeting different cancer features can be a more effective way to overcome drug resistance. Methods: The influence of C9 (130 nM) + DCA (7.5 mM) on MCF-7 and MCF-12 cells was assessed via microscopy spectrophotometry global gene expression and flow cytometry assays. Results: An LDH assay showed that C9+DCA treatment decreased cell viability to 83.5% in MCF-7 cells when compared to the non-tumorigenic MCF-12A cells 92.4% (P P 70 and caspase 7 activation. Kinase inhibition revealed sustained activation of the JNK pathway caused increased Bcl-2 protein Ser70 hypo-and hyper-phosphorylation. Elevated levels of DCF fluorescence was observed in DCA-, C9- and C9+DCA-exposed MCF-7 cells, but not in MCF-12A cells, indicating cytosolic H2O2/Fe2+ formation in treated tumorigenic cells. LC3-II expression was elevated in C9+DCA-treated cells in both cell lines, indicating that autophagy was also induced. Conclusions: Synergistic effects of C9+DCA were demonstrated on breast carcinoma and non-tumorigenic cells with selectivity towards the MCF-7 cells. Antimitotic compound C9 in combination with a glycolytic inhibitor dichloroacetate eradicates breast cancer cells through ROS-JNK-Bcl-2-mediated signalling pathways in vitro and it is argued that autophagy acts as protective mechanism in the treated cells before apoptosis occurs