To study the regulatory effect of miR-9 on the proliferation of breast cancer cells by targeting hexokinase 2 (HK2) .

Breast cancer tissues and paracancer tissues were collected and the expression levels of miR-9 and HK2 were detected. MCF-7 cells were cultured and divided into blank control group, NC group, miR-9 group, NC-siRNA group and HK2-siRNA group. The cell viability, expression levels of HK2 and cleaved caspase-3 were detected, the targeted binding of miR-9 to HK2 was verifed.

the expression level of miR-9 in breast cancer was lower than that in paracancer tissue (0.52±0.08 vs 1.05±0.25, t=16.685, P<0.000) , and the expression level of HK2 was higher than that in paracancer tissue (0.73±0.14 vs 0.34±0.08, t=17.587, P<0.000) , and the expression level of miR-9 was negatively correlated with HK2; the OD490 level, the expression level of HK2 and the fluorescence activity of double luciferase reporter gene containing HK2 mRNA 3 'UTR in miR-9 group were lower than those in NC group (0.58±0.09 vs 1.04±0.21, 0.51±0.08 vs 1.18±0.24, 41.11±9.28 vs 148.28±29.59, t/P=4.027/0.007, 5.297/0.002, 6.912/0.001) , and the expression level of cleaved caspase-3 was higher than that in NC group (1.08±0.26 vs 0.42±0.09, t/P=4.797/0.003) . The OD490 level and the expression level of HK in HK-siRNA group were higher than that in NC-siRNA group, and the expression level of cleaved caspase-3 was higher than that of NC-siRNA group.

miR-9 can inhibit the proliferation of breast cancer cells, and its mechanism may be related to the targeted inhibition of HK2 expression and the increase of downstream cleaved caspase-3 expression.

Breast cancer; miR-9; Hexokinase 2; Target gene; Proliferation