New perspective therapy of breast cancer based on selective dopamine receptor D2 agonist and antagonist effects on MCF-7 cell line.

Different studies have shown the role of neurotransmitters (e.g., dopamine) in the progression of cancers via their various types of receptors. The aim of this study was to determine the pattern of dopamine receptors gene expression on MCF-7 cells and to evaluate the selective dopamine receptors agonist and antagonist effects on them. In addition, some other discoveries which are patented for the treatment of breast cancer are reviewed in this article. To determine the pattern of dopamine receptors gene expression in human breast cancer cells (MCF-7), RT-PCR was performed. Then, MCF-7 cells were treated by different doses of bromocriptine and remoxipride for 48 hours. Cell viability was evaluated by MTT assay. Thus, nuclear morphology of cells was analyzed by mixed dye florescent staining. Real time PCR technique was performed to determine the decreasing rate of proliferating cell nuclear antigen (PCNA) gene expression in treated MCF-7 cells. Finally, quantification of apoptosis and its difference with necrosis at the single cell level were assessed by Flowcytometery technique. This study revealed that, unlike remoxipride, bromocriptine suppressed proliferation of the MCF-7 cells (54.3% at 12.5µM bromocriptine concentration), but remoxipride could suppress the effect of bromocriptine. Bromocriptine has inhibitory effects on MCF- 7 cells by induction of apoptosis via D2-like receptors. Therefore, in future studies, bromocriptine can be used as a new choice for the treatment of tumoral breast cancer cells.