Fig. 5

miR-500a-5p is regulated directly by the transcription factor YY1. a The transcriptional factor YY1-binding motif was predicted by informatics analysis. b Schematic illustration of the miR-500a-5p promoter with three potential YY1-binding sites. c Luciferase activity of the miR-500a-5p promoter construct after the transfection of the YY1 plasmid in LoVo cells. Student’s t test; ***P < 0.01 and ****P < 0.001. d A ChIP-qPCR assay demonstrated the direct binding of YY1 to the miR-500a-5p promoter in LoVo cells. Student’s t test; *P > 0.05 and ****P < 0.001. Gene enrichment was quantified relative to input controls by qPCR using primers specific for the promoter regions of miR-500a-5p. Results are shown as a fold change of qPCR value over IgG. e YY1 protein expression in ten freshly collected CRC biopsies using western blot analysis. f YY1 was negatively correlated with miR-500a-5p expression in human CRC tissues measured by qPCR. Linear regression analysis, r = –0.598; ****P < 0.001. g Expression of YY1 and mature miR-500a-5p in YY1-overexpressing CRC cells by real-time PCR. Student’s t test; **P < 0.05 and ***P < 0.01. All experiments were repeated three times with identical findings. h ISH analysis of miR-500a-5p and IHC analysis of HDAC2 and YY1 were performed. These figures are representative of colorectal tissues from 10 cancerous and 10 non-cancerous patients. The scale bars represent 200 μm