Real-time PCR was carried out using an Express SYBR® GreenER qPCRs supermix Universal kit (Invitrogen) on a Rotor-gene 6000 system (Qiagen, Valencia, CA, USA). USA). The relative amount of miR-124was normalized against U6 RNA. In current study, we calculated a ΔCt (target-reference) that is equal to the difference between threshold cycles for miR-124 (target) and those for U6 RNA.
The fold-change between cancer tissues and normal breast tissue control for miR-124 was calculated by the 2ΔΔCt method, in which ΔΔCt = ΔCt (target-reference in tumor samples) - ΔCt (target-reference in normal samples). The relative expression levels of miRNAs in cancer compared to their non-tumorous controls were calculated using the method of 2-ΔΔCt. The primers for miR-124 were used as follows: forward: 5′-GATACTCATAAGGCACGCGG-3′ and reverse: 5′-GTGCAGGGTCCGAGGT-3′.