Abstract
MicroRNAs (miRNAs) have been reported to play a key role in oncogenesis and, recently, studies have examined the role miRNAs might play in the risk of premalignant lesions. To our knowledge, no study has investigated the association between miRNA polymorphisms and risk of oral premalignant lesions (OPLs). We genotyped 31 single nucleotide polymorphisms (SNPs) among 21 miRNAβrelated genes in a caseβcontrol study including 136 OPL patients and 136 matched controls. Patients with at least one variant allele of __mir26aβ1:__rs7372209 had a significantly increased risk of OPL (OR, 2.09; 95% CI, 1.23β3.56). Likewise, patients with at least one variant allele of DICER:rs3742330 had a significantly increased risk of OPL (OR, 2.09; 95% CI, 1.03β4.24). To assess the cumulative effects, we performed a combined unfavorable genotype analysis that included all SNPs showing at least a borderline statistical significance. A significant trend of increased risk of OPL with increasing number of unfavorable genotypes was observed (P for trend <0.0001). This study presents the first epidemiologic evidence supporting that individual as well as combined genotypes of miRNAβrelated variants may be used to predict the risk of OPL, and may be useful for identifying patients with OPL at high risk for progression to oral cancer. Β© 2009 WileyβLiss, Inc.