OBJECTIVETo explore the inhibitory effect of cinnamaldehyde on invasion capacities of human breast cancer cell line MDA-MB-435S and its relation with regulating the expression of miR-27a.

METHODSThe effect of cinnamaldehyde on invasive capacities of MDA-MB-435S was measured by Transwell matrigel invasion assay. The effect of miR-27a expression on invasive capabilities of MDA-MB-435S, the intervention of cinnamaldehyde in the miR-27a expression, and its relation with its effect on invasive capabilities were defected with liposome 2000 transinfection miRNA27a mimics/inhibitors, real time-polymerase chain reaction (Real-time PCR), and Transwell chamber model.

RESULTSCompared with the control group, the number of cells passing through the transwell chamber was more significantly reduced after treated by cinnamaldehyde for 12 h (P < 0.05). The miR-27a expression was 962.07 times and 40% of that of the control group after transinfected by miR-27a mimics and miR-27a inhibitors. After transinfected by miR-27a inhibitors, the number of cells passing through the transwell chamber was more significantly reduced (P < 0.05). The miR-27a expression of MDA-MB-435S was down-regulated by 12-h treatment of cinnamaldehyde (2(-deltaCt) = 0.56, 0.18, 0.18, respectively). The number of miR-27a mimics transinfection pretreated MDA-MB-435S cells passing through the transwell chamber increased more obviously than the number of un-pretreated MDA-MB-435S cells in the control group (P < 0.05).

CONCLUSIONSCinnamaldehyde could inhibit invasive capabilities of human breast cancer cell line MDA-MB-435S. The over-expression of miR-27a played an important role in the invasive capability of MDA-MB-435S. The inhibition of cinnamaldehyde on invasive capabilities of MDA-MB-435S cells was correlated with down-regulating the expression of miR-27a.