Analysis of plasma microRNA expression profiles in male textile workers with noise-induced hearing loss.

BACKGROUND: Circulating microRNAs (miRNAs) have attracted interests as non-invasive biomarkers of physiological and pathological conditions, which may be applied in noise-induced hearing loss (NIHL). However, no epidemiology studies have yet examined the potential effects of NIHL or noise exposure on miRNA expression profiles. OBJECTIVES: We sought to identify permanent NIHL-related miRNAs and to predict the biological functions of the putative genes encoding the indicated miRNAs. METHODS: In the discovery stage, we used a microarray assay to detect the miRNA expression profiles between pooled plasma samples from 10 noise-exposed individuals with normal hearing and 10 NIHL patients. In addition, we conducted a preliminary validation of six candidate miRNAs in the same 20 workers. Subsequently, three miRNAs were selected for expanded validation in 23 non-exposed individuals with normal hearing and 46 noise-exposed textile workers which including 23 noise-exposed workers with normal hearing and 23 NIHL patients. Moreover, we predicted the biological functions of the putative target genes using a Gene Ontology (GO) function enrichment analysis. RESULTS: In the discovery stage, compared with the noise exposures with normal hearing, 73 miRNAs demonstrated at least a 1.5-fold differential expression in the NIHL patients. In the preliminary validation, compared with the noise exposures, the plasma levels of miR-16-5p, miR-24-3p, miR-185-5p and miR-451a were all upregulated (P < 0.001) in the NIHL patients. In the expanded validation stage, compared with the non-exposures, the plasma levels of miR-24, miR-185-5p and miR-451a were all significantly downregulated (P < 0.001) in the exposures. And compared with the noise exposures, the plasma levels of miR-185-5p and miR-451a were slightly elevated (P < 0.001) in the NIHL patients, which were consistent with the results of preliminary validation and microarray analysis. CONCLUSION: The two indicated plasma miRNAs may be biomarkers of indicating responses to noise exposure. However, further studies are necessary to prove the causal association between miRNAs changes and noise exposure, and to determine whether these two miRNAs are clear biomarkers to noise exposure.

Fas -670A/G (rs1800682) polymorphism and digestive cancer risk in Asians: a meta-analysis.

OBJECTIVES: Tumorigenesis is a multistep process that begins with the abrogation of normal controls of apoptosis and cell proliferation, and the Fas receptor-ligand system is a key regulator of apoptosis. The Fas -670 A/G single-nucleotide polymorphism (SNP) has been demonstrated to affect the expression of the Fas gene by altering the transcriptional activity in this gene's promoter. However, the association between the Fas -670 A/G polymorphism and digestive cancer risk is still controversial and ambiguous in the Asian population, so we conducted a meta-analysis to confirm and clarify the association between the Fas -670 A/G polymorphism and digestive cancer. MATERIALS AND METHODS: A search of PubMed, China National Knowledge Infrastructure (CNKI), and WanFang databases was conducted and encompassed all available articles that had been published up to July 20, 2013. Overall, 15 case-control studies containing 3692 cases and 4895 controls were retrieved based on search criteria for digestive cancer susceptibility related to -670A/G SNP. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of this association. RESULTS: In the overall analysis, the country type and source of control subgroups, no association between the Fas -670 A/G polymorphism and digestive cancer risk was found. However, in the digestive cancer-type subgroups, a significant protective effect was detected between Fas -670 A/G polymorphism and hepatocellular carcinoma in Asians (AG vs. GG: OR=0.89, 95% CI=0.80-0.99; AA+AG vs. GG: OR=0.93, 95% CI=0.87-1.00). CONCLUSIONS: Our investigations demonstrated that the Fas -670 A/G polymorphism might decrease the hepatocellular carcinoma risk in Asian populations. Further studies based on larger sample sizes, other ethnicities, and gene-environment interactions should be conducted to further understand the role of Fas -670 A/G polymorphism in digestive cancer risk.