[Sequence analyses of HIRA gene 3'UTR region and related microRNA]

To explore the HIRA gene sequences of 3'UTR region and elucidate the role of 3'UTR region of HIRA gene in the pathogenesis of tetralogy of Fallot (TOF).

Patients of TOF were confirmed by cardiac catheterization or surgery between April 2007 and December 2012 at our hospital. Mutations and single nucleotide polymorphisms (SNPs) were screened in 278 unrelated probands with isolated TOF and 515 controls. Target Scan was used to predict micro RNAs with possible combinations with 3'UTR region of HIRA gene. Dual-luciferase assay and real-time PCR were performed to detect the inhibition activity of micro RNAs on target genes. And χ(2) and t tests were used to analyze the results.

Statistically significant change occurred in the alleleic frequencies of existing SNPs (rs:117447448) between TOF patients and control group (11.5% (32/278) vs 4.9% (25/515), P = 0.001) . The combining site of miR328 was predicted to be 10 bp upstream of SNP site. MiR328 was expressed in heart and it was related with myocardial infarction and atrial fibrillation. Dual-luciferase assay showed a decreased level of luciferase after co-transfection with miR328 (0.012 5 ± 0.000 6 vs 0.019 6 ± 0.003 8, P = 0.034). So was the expression of HIRA (1.039 6 ± 0.077 2 vs 1.608 7 ± 0.274 9, P = 0.037). However, the luciferase level was not affected by SNP (rs:117447448) (P = 0.380).

The SNP (rs:117447448) of 3'UTR region of HIRA gene is related with TOF. HIRA is the target gene of miR328. Although SNP (rs:117447448) is not a major site of target gene HIRA for micro RNA328, it provides an important clue to in-depth studies of 3'UTR region of HIRA gene in the pathogenesis of TOF.