HIF1A Knockout Cell Lysate

Background Previous genome-wide transcriptome profiling found circ_ZNF124 was highly expressed in lung adenocarcinoma, however, the role of circ_ZNF124 in non-small cell lung cancer (NSCLC) is still unknown. The purpose of this study was to investigate the role and molecular mechanism of circ_ZNF124 in NSCLC development. Methods The expression of circ_ZNF124, miR-337-3p and JAK2 (Janus Kinase 2) in lung cancer cell lines and normal epithelial cells were detected by qRT-PCR (quantitative real-time PCR). siRNA was used to knockdown circ_ZNF124 expression in cells. The effects of circ_ZNF124 in NSCLC cells were determined by cell growth, cell migration, cell cycle analysis and colony formation. Bioinformatics analysis, RNA immunoprecipitation, luciferase assay and western blots were used to study the molecular mechanism of circ_ZNF124 in NSCLC. Results The results showed that circ_ZNF124 expression was highly upregulated in NSCLC cells than in normal epithelial cells. Knockdown of circ_ZNF124 by using siRNA significantly decreased cell growth, promoted cell cycle arrested in sub-G1 phase, impaired cell migration and colony formation. Bioinformatic analysis discovered that miR-337-3p was a direct target of circ_ZNF124. In contrast to circ_ZNF124, miR-337-3p expression was significantly downregulated in NSCLC cells. Biotin labeled circ_ZNF124 immunoprecipitation and luciferase assay showed that miR-337-3p could directly bind to and affect circ_ZNF124 activity. The regulation of circ_ZNF124 on miR-337-3p was also investigated. Further analysis showed that despite STAT3 (signal transducer and activator of transcription 3), JAK2 was also a target of miR-337-3p, overexpression of miR-337-3p greatly downregulated JAK2, STAT3 and JAK2/STAT3 downstream regulated oncogenes HIF1a (Hypoxia-inducible factor 1-alpha), BCL2 (B cell lymphoma 2) and c-FOS expression, however, the roles of miR-337-3p in JAK2/STAT3 signaling pathway were greatly inhibited in the presence of circ_ZNF124. Conclusion In NSCLC, highly expressed circ_ZNF124 promoted the activation of JAK2/STAT3 signaling pathway by acting as a sponge of miR-337-3p, thus promoting the occurrence and development of NSCLC. Circ_ZNF124 could be a potential biomarker or target for the treatment of NSCLC patients in the future.

Aim Hypoxia-inducible factor (HIF)1 alpha is induced by endothelial cells under hypoxic conditions, suggesting that HIF1 alpha may be involved in vascular impairment in patients with systemic sclerosis (SSc). The purpose of this study was to evaluate whether single nucleotide polymorphisms (SNPs) of the HIF1A gene are associated with susceptibility to SSc and its complications, including pulmonary arterial hypertension (PAH). Method This study involved 182 Japanese SSc patients (discovery cohort) and 178 healthy controls. Four SNPs (rs11549465, rs11549467, rs1957757, and rs12434438) of the HIF1A gene were genotyped using specific TaqMan probes. We also employed another SSc cohort (N = 135) to validate the significant results of SNPs found in the discovery SSc cohort. Results The frequencies of the four SNPs did not show any significant differences between the SSc and healthy control groups. The AA genotype at rs12434438 was significantly higher in SSc patients with PAH than in those without PAH (P = .012). These results were validated using another SSc cohort (N = 135, P = .006). Moreover, the AA genotype was significantly associated with the severity of PAH. Conclusion Although HIF1A gene polymorphisms were not associated with susceptibility to SSc, the AA genotype at rs12434438 was associated with a subset of SSc patients with severe PAH, suggesting that the rs12434438 SNP may contribute to the development of PAH with SSc.