Sex-specific effects of a microsatellite polymorphism on human growth hormone receptor gene expression

The Association of HIF-1α/rs2057482 Polymorphism with Idiopathic Scleritis in a Chinese Han Population

BACKGROUND

To investigate the association of hypoxia-inducible factor-1α (HIF-1α), Janus tyrosine kinase-signal transducer and activator of transcription (JAK-STAT) gene polymorphisms with idiopathic scleritis in a Chinese Han population.

METHODS

Ten single nucleotide polymorphisms (SNP) of HIF-1α, tyrosine kinase 2 (TYK2), signal transducer and activator of transcription 3 (STAT3), signal transducer and activator of transcription 4 (STAT4), and retinoid-related orphan nuclear receptors-γ (ROR-γ) were selected for this study. A total of 496 idiopathic scleritis patients and 1009 controls were genotyped by the MassARRAY platform and iPLEX Gold Genotyping Assay. The allele and genotype frequencies were analyzed by Chi-square test and Fisher's exact test. Stratified analyses were performed based on gender and anatomic locations of idiopathic scleritis.

RESULTS

The frequencies of CC genotype (p = 6.18 × 10-4, Pc = 0.04, OR = 0.67,95%CI = 0.53-0.84) and C allele (p = 7.08 × 10-4, Pc = 0.04, OR = 0.71,95%CI = 0.58-0.87) for HIF-1α/rs2057482 were found significantly lower in idiopathic scleritis patients when compared to healthy controls. Stratified analysis depending on gender showed significant decreased frequencies of CC genotype (CC: p = 4.04 × 10-4, Pc = 0.02, OR = 0.54, 95%CI = 0.39-0.76) and C allele (C: p = 1.62 × 10-4, Pc = 0.01, OR = 0.58, 95%CI = 0.44-0.77) in male patients. Stratification analysis of rs2057482 according to location of scleritis did not show any significant difference between three subgroups and healthy controls.

CONCLUSION

This study showed association between polymorphism of HIF-1α/rs2057482 and susceptibility to idiopathic scleritis in Han Chinese male patients.

Solution Structure of Poly(UG) RNA

Poly(UG) or "pUG" RNAs are UG or GU dinucleotide repeat sequences which are highly abundant in eukaryotes. Post-transcriptional addition of pUGs to RNA 3' ends marks mRNAs as vectors for gene silencing in C. elegans. We previously determined the crystal structure of pUG RNA bound to the ligand N-methyl mesoporphyrin IX (NMM), but the structure of free pUG RNA is unknown. Here we report the solution structure of the free pUG RNA (GU)12, as determined by nuclear magnetic resonance spectroscopy and small and wide-angle x-ray scattering (NMR-SAXS-WAXS). The low complexity sequence and 4-fold symmetry of the structure result in overlapped NMR signals that complicate chemical shift assignment. We therefore utilized single site-specific deoxyribose modifications which did not perturb the structure and introduced well-resolved methylene signals that are easily identified in NMR spectra. The solution structure ensemble has a root mean squared deviation (RMSD) of 0.62 Å and is a compact, left-handed quadruplex with a Z-form backbone, or "pUG fold." Overall, the structure agrees with the crystal structure of (GU)12 bound to NMM, indicating the pUG fold is unaltered by docking of the NMM ligand. The solution structure reveals conformational details that could not be resolved by x-ray crystallography, which explain how the pUG fold can form within longer RNAs.

An atypical RNA quadruplex marks RNAs as vectors for gene silencing

The addition of poly(UG) ('pUG') repeats to 3' termini of mRNAs drives gene silencing and transgenerational epigenetic inheritance in the metazoan Caenorhabditis elegans. pUG tails promote silencing by recruiting an RNA-dependent RNA polymerase (RdRP) that synthesizes small interfering RNAs. Here we show that active pUG tails require a minimum of 11.5 repeats and adopt a quadruplex (G4) structure we term the pUG fold. The pUG fold differs from known G4s in that it has a left-handed backbone similar to Z-RNA, no consecutive guanosines in its sequence, and three G quartets and one U quartet stacked non-sequentially. The compact pUG fold binds six potassium ions and brings the RNA ends into close proximity. The biological importance of the pUG fold is emphasized by our observations that porphyrin molecules bind to the pUG fold and inhibit both gene silencing and binding of RdRP. Moreover, specific 7-deaza substitutions that disrupt the pUG fold neither bind RdRP nor induce RNA silencing. These data define the pUG fold as a previously unrecognized RNA structural motif that drives gene silencing. The pUG fold can also form internally within larger RNA molecules. Approximately 20,000 pUG-fold sequences are found in noncoding regions of human RNAs, suggesting that the fold probably has biological roles beyond gene silencing.

Associations of BCL2 CA-Repeat Polymorphism and Breast Cancer Susceptibility in Isfahan Province of Iran

BCL2 apoptosis regulator (BCL2) is a cause of tumorigenesis whose CA-repeat promoter polymorphisms has inconsistent association with various types of cancers. The association of BCL2 polymorphism with breast cancer was investigated in the Isfahan province of Iran. PCRamplification of the CA-repeat was followed by polyacrylamide gel electrophoresis and direct sequencing for 120 breast cancer women and an equal number of corresponding healthy control individuals. Seven different alleles, ranging from 11 to 17 CA-repeats were observed. Short alleles with 11 to 14 repeats were protective (OR 0.363, P = 0.001), but large alleles with 15 to 17 repeats were threatening against breast cancer development (OR 2.780, P = 0.001). Accordingly, genotypes with large alleles showed a higher risk of breast cancer development (OR 3.400, P = 0.004). ERS1\ERBB2 positive breast cancer patients, but not PGRpositive ones, showed protection against breast cancer (OR 0.405, OR 0.346 respectively). In conclusion, women with at least one large allele of BCL2 were 3.4 times at higher risk of breast cancer development in the Isfahan province of Iran.