Effect of 5-Aza-CdR on ERα expression, proliferation and invasion of breast cancer cell line MDA-MB-231

Objective: To explore the effect of 5-Aza-2′ -deoxycytidine (5-Aza-CdR) on ERα expression, proliferation and invasion of human breast cancer cell line MDA-MB-231. Methods: The breast cancer cell line MDA-MB-231 was treated with 5-Aza-CdR. The effect of 5-Aza-CdR on proliferation was evaluated by MTT assay and cell growth curve was drawn. The cell cycle was analyzed by flow cytometry. Immunohistochemistry and RT-PCR were used to determine the changes of ERα expression and matrix metalloproteinase-2 (MMP-2) expression in the MDA-MB-231 cell after 5-Aza-CdR treatment. The invasion ability of MDA-MB-231 cells was tested by Boyden chamber assay. Results: Compared with the control, the cell growth speed was significantly slowed down and the cell cycle was arrested at G0/G1 phase after 5-Aza-CdR treatment. The expression of ERα gene was partly restored in ERα-negative human breast cancer MDA-MB-231 cell after 5-Aza-CdR treatment. The expression of MMP-2 in MDA-MB-231 cells was down-regulated and the invasion ability of MDA-MB-231 cell was decreased after 5-Aza-CdR treatment. Conclusion: 5-Aza-CdR treatment effectively inhibited cell proliferation, induced cell cycle arrest, and decreased cell invasion ability of breast cancer MDA-MB-231 cells. The findings suggested that the partial restoration of ERα expression and the decrease in MMP-2 expression may be one of the mechanisms for the biological behaviour changes of MDA-MB-231 cells induced by 5-Aza-CdR.