Abstract
BackgroundRecent studies on the association between miR-146a rs2910164 polymorphism and risk of gastrointestinal (GI) cancers showed inconclusive results. Accordingly, we conducted a comprehensive literature search and a meta-analysis to clarify the association.Methodology/Principal FindingsData were collected from the following electronic databases: Pubmed, Excerpta Medica Database (Embase), and Chinese Biomedical Literature Database (CBM), with the last report up to February 24, 2012. The odds ratio (OR) and its 95% confidence interval (95%CI) were used to assess the strength of association. Ultimately, a total of 12 studies (4,817 cases and 5,389 controls) were found to be eligible for meta-analysis. We summarized the data on the association between miR-146a rs2910164 polymorphism and risk of GI cancers in the overall population, and performed subgroup analyses by ethnicity, cancer types, and quality of studies. In the overall analysis, there was no evidence of association between miR-146a rs2910164 polymorphism and the risk of GI cancers (G versus C: OR = 1.07, 95%CI 0.98−1.16, P = 0.14; GG+GC versus CC: OR = 1.14, 95%CI 1.00−1.31, P = 0.05; GG versus GC+CC: OR = 1.06, 95%CI 0.91−1.23, P = 0.47; GG versus CC: OR = 1.17, 95%CI 0.95−1.44, P = 0.13; GC versus CC: OR = 1.14, 95%CI 1.00−1.31, P = 0.05). Similar results were found in the subgroup analyses by ethnicity, cancer types, and quality of studies.Conclusions/SignificanceThis meta-analysis demonstrates that miR-146a rs2910164 polymorphism is not associated with GI cancers susceptibility. More well-designed studies based on larger sample sizes and homogeneous cancer patients are needed.
Highlights
MicroRNAs are small, non-coding, endogenous RNAs that represent a significant mechanism of post transcriptional gene regulation [1]
Among the 12 publications, five studies focused on liver cancer [22,24,25,26,32], three studies on gastric cancer [27,28,30], two studies on esophageal cancer [29,33], one study on colorectal cancer [23] and one study on gallbladder cancer [31], respectively
Overall, when all types of GI cancers were considered together in the meta-analysis, there was no evidence of association between miR-146a rs2910164 polymorphism and the risk of GI cancers in any genetic model (G versus C: odds ratio (OR) = 1.07, 95% confidence interval (95%CI) 0.9821.16, P = 0.14; GG+GC versus CC: OR = 1.14, 95%CI 1.0021.31, P = 0.05; GG versus GC+CC: OR = 1.06, 95%CI 0.9121.23, P = 0.47; GG versus CC: OR = 1.17, 95%CI 0.9521.44, P = 0.13; GC versus CC: OR = 1.14, 95%CI 1.0021.31, P = 0.05)
Summary
MicroRNAs (miRNAs) are small, non-coding, endogenous RNAs that represent a significant mechanism of post transcriptional gene regulation [1]. Several miRNA expression analyses in human epithelial malignancies have shown that distinct tumor specific miRNA signatures can distinguish different cancer types and classify their sub-types [3]. Primary miRNA transcripts are cleaved by Ribonuclease (RNase) III Drosha in the cell nucleus into 70-nucleotide to 80nucleotide precursor miRNA (pre-miRNA) hairpins and transported to the cytoplasm. Pre-miRNAs are processed by RNase III Dicer into miRNA: miRNA duplexes. One strand of these duplexes is generally degraded, whereas the other is used as mature miRNA. It was hypothesized that single nucleotide polymorphisms (SNPs) within the miRNA sequence or miRNA target could either weaken or reinforce the binding between miRNA and target [10]. Recent studies on the association between miR-146a rs2910164 polymorphism and risk of gastrointestinal (GI) cancers showed inconclusive results. We conducted a comprehensive literature search and a meta-analysis to clarify the association
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