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MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in regulation of eukaryotic gene expression. Aberrant expression and structural alternation of miRNAs are considered to participate in tumorigenesis and cancer development. Recently, different genotypes of miR-196a polymorphisms (SNP, rs11614913) were found to be associated with the survival of patients with lung cancer and increased risk of breast cancer. To further investigate whether this polymorphism may influence glioma risk or not, we examined the SNP allele frequency in Chinese population. Our data shows the genotype CC of miR-196a (rs11614913) polymorphism is associated with decreased risk of glioma in the Chinese population (OR = 0.74, 95% CI:0.56-0.98). Furthermore, a significant association was observed between this genotype and glioma risk in the subgroups of adult glioma (OR = 0.73, 95% CI:0.55-0.98), male glioma (OR = 0.69, 95% CI:0.48-0.99) and patients with glioblastoma (OR = 0.58, 95% CI:0.37-0.91). This was the first study investigating the association between the miR-196a rs11614913 and glioma risk. Compared with the results from previous studies in lung cancer and breast cancer, our data suggest a different genotype association in glioma. This may be related to the diversity on the tissue origin, tumor type, tumorigenesis, and developing process.

SPP1 was found to be significantly upregulated in many kinds of malignant tumors, including gliomas. Considering that gene polymorphisms have been implicated in the development of gliomas, we performed an association study between SPP1 functional promoter region polymorphisms and glioma risk in a Chinese population. We found significant evidence of an association between SPP1 promoter polymorphisms and glioma risk. For the -155_156insG variant, the -155_156GG allele was found to be significantly associated with an increased risk of glioma (P=0.020, odds ratio (OR)=1.202, 95% confidence interval (CI): 1.028-1.408). Individuals with the genotype containing the GG allele had a 1.372-fold increased risk (P=0.006, OR=1.372, 95% CI: 1.095-1.719). Further stratified analyses suggested that a significant association existed in adult glioma patients, male subjects and in cases without a family history of cancer. Alternatively, the study of single-nucleotide polymorphism -443C/T in a recessive model revealed that the genotype CC+CT significantly decreased the risk of glioma when compared with TT (P=0.023, OR=0.774, 95% CI: 0.621-0.966). After the analysis of haplotypes, the haplotype -155_156GG/-443T was represented at a significantly higher frequency in cases (P=0.029, OR=1.192, 95% CI: 1.018-1.395). Cellular assay indicated that the transcriptional activity of the SPP1 promoter containing the -155_156GG allele significantly increased in glioma cells. Thus, variants of the SPP1 promoter might influence the risk of glioma by regulating promoter activity. Further analyses are necessary to validate our observation in larger samples or in other ethnic groups.

MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in regulation of eukaryotic gene expression. Aberrant expression and structural alternation of miRNAs are considered to participate in tumorigenesis and cancer development. Recently, different genotypes of miR- 196a polymorphisms (SNP, rs11614913) were found to be associated with the survival of patients with lung cancer and increased risk of breast cancer. To further investigate whether this polymorphism may influence glioma risk or not, we examined the SNP allele frequency in Chinese population. Our data shows the genotype CC of miR- 196a (rs11614913) polymorphism is associated with decreased risk of glioma in the Chinese population (OR = 0.74, 95% CI:0.56-0.98). Furthermore, a significant association was observed between this genotype and glioma risk in the subgroups of adult glioma (OR = 0.73, 95% CI:0.55-0.98), male glioma (OR = 0.69, 95% CI:0.48-0.99) and patients with glioblastoma (OR = 0.58, 95% CI:0.37-0.91). This was the first study investigating the association between the miR-196a rs11614913 and glioma risk. Compared with the results from previous studies in lung cancer and breast cancer, our data suggest a different genotype association in glioma. This may be related to the diversity on the tissue origin, tumor type, tumorigenesis, and developing process. [ABSTRACT FROM AUTHOR]