Association between risk of oral precancer and genetic variations in microRNA and related processing genes

MicroRNAs have been implicated in cancer but studies on their role in precancer, such as leukoplakia, are limited. Sequence variations at eight miRNA and four miRNA processing genes were studied in 452 healthy controls and 299 leukoplakia patients to estimate risk of disease. Genotyping by TaqMan assay followed by statistical analyses showed that variant genotypes at Gemin3 and mir-34b reduced risk of disease [OR = 0.5(0.3-0.9) and OR = 0.7(0.5-0.9) respectively] in overall patients as well as in smokers [OR = 0.58(0.3-1) and OR = 0.68(0.5-0.9) respectively]. Among chewers, only mir29a significantly increased risk of disease [OR = 1.8(1-3)]. Gene-environment interactions using MDR-pt program revealed that mir29a, mir34b, mir423 and Xpo5 modulated risk of disease (p