Associations of miR‑146aC>G, miR‑149C>T, miR‑196a2C>T and miR‑499A>G polymorphisms with brain tumors.

MicroRNAs (miRNAs/miRs) are short, non‑coding RNAs that are implicated in tumorigenesis, functioning as tumor suppressors and oncogenes. However, the clinical significance of miRNA expression profiles for brain tumors remains unclear. Therefore, the present study was designed to investigate the associations between miRNA genetic variants and brain tumor risk. A total 362 participants were recruited, including 179 who were healthy subjects and 183 who were patients with brain tumors confirmed as gliomas, meningiomas or schwannomas. This study investigated the single nucleotide polymorphisms miR‑146aC>G, miR‑149T>C, miR‑196a2T>C and miR‑499A>G by polymerase chain reaction‑restriction fragment length polymorphism. It was found that the dominant miR‑149 and CC genotypes were significantly more frequent in patients with glioma. The odds ratios for the C‑C‑C‑G, C‑T‑C‑G and G‑C‑T‑G haplotypes (miR‑146aC>G‑miR‑149T>C‑miR‑196a2T>C‑miR‑499A>G) were significantly increased in glioma, as were the odds ratios for the GCT haplotype of miR‑146aC>G, miR‑149T>C and miR‑196a2T>C, and for the C‑C‑G haplotype of miR‑149T>C, miR‑196a2T>C and miR‑499A>G. In meningioma, the odds ratios were increased in the G‑T‑C‑G haplotype of miR‑146aC>G, miR‑149T>C, miR‑196a2T>C and miR‑499A>G. The odds ratios were also increased in the G‑C‑G haplotype of miR‑146aC>G, miR‑196a2T>C and miR‑499A>G, and in the C‑C‑G haplotype of miR‑149T>C, miR‑196a2T>C and miR‑499A>G. The odds ratios for schwannoma were increased in the G‑C‑T‑G haplotype of miR‑146aC>G, miR‑149T>C, miR‑196a2T>C and miR‑499A>G, and in the C‑C‑G haplotype of miR‑149T>C, miR‑196a2T>C and miR‑499A>G. In conclusion, these results suggested that the miR‑149 polymorphism may be involved in the development of gliomas, and the C‑C‑G haplotype of miR‑149T>C, miR‑196a2T>C and miR‑499A>G showed increased odds ratios for all types of brain tumors.