miR-146a and miR-196a-2 genes polymorphisms and its circulating levels in lung cancer patients.

Recently, MicroRNAs polymorphisms and their serum expression have been linked to increase risk of various cancers. The aim of this study was to elucidate the association between single nucleotide polymorphisms of miR-146a and miR-196a-2 and their serum expression and lung cancer risk. One hundred and twenty lung cancer patients and 120 health controls were included in this study. Genotyping and expression for miR-146a and miR-196a-2 were performed using polymerase chain reaction (PCR) restriction fragment length polymorphism and quantitative real time PCR. Individuals carrying miR-146a CG and CC genotypes had significantly increased risk for lung cancer than those carrying miR-146a GG genotype. MiR-146a expression significantly decreased in miR-146a CG and CC genotypes carriers as compared with GG genotype carriers. MiR-196a-2 CT and TT genotypes were significantly associated with increased lung cancer while the highest expression of MiR-196a-2 was detected in miR-196a-2 CC genotype carriers. Serum miR-146a was significantly decreased in lung cancer patients while serum miR-196a-2 expression was significantly increased in lung cancer patients. In conclusion, miR-146a and miR-196a-2 genes polymorphisms and their circulating levels were associated with lung cancer risk in Egyptians and may be helpful in early detection of lung cancer.