Figure 3.

c-Myc positively regulates miR-30a-5p transcriptional activity. (A) Schematic diagram shows the locations of the predicted c-Myc binding sites (black hollow circle) surrounded by 5 CpG sites (red vertical bars) in the miR-30a-5p gene core promoter sites (−216/-761). (B) Sequential deletion and substitution mutation analyses identified c-Myc-responsive regions at the miR-30a-5p gene promoter region, miR-30a-5p transcriptional activities in 293T cells were detected using a luciferase reporter assay after solely or serially truncated c-Myc binding sites at the miR-30a-5p promoter region. (C and D) Reverse transcription-quantitative PCR and western blotting were performed to determine c-Myc expression in the senescent cardiomyocytes. Data are presented as the mean ± SD from three independent experiments. *P<0.05, **P<0.01. HPostC, hypoxia postconditioning; miR, microRNA; H/R, hypoxia/reoxygenation.