A variant in microRNA-196a2 is not associated with susceptibility to and progression of colorectal cancer in Chinese

Abstract

Background: MicroRNAs (miRNAs) are small non-coding RNAs with regulatory functions as tumour suppressors and oncogenes. Although single nucleotide polymorphism (SNP) in miRNA regions have been reported to be rare and unlikely to be functionally important, recent evidence suggested that rs11614913 SNP in miR-196a2 was associated with the susceptibility of lung cancer, breast cancer, congenital heart disease and shortened survival time of non-small-cell lung cancer. Aims: The aim of this study was to investigate the association between this genetic variant and the risk and/or progression of colorectal cancer (CRC). Methods: A total of 126 CRC patients and 407 healthy controls was periodically enrolled. DNA was extracted from blood specimens, and miR-196a2 polymorphism was genotyped by polymerase chain reaction-ligation detection reaction (PCR-LDR). Results: Although the frequency of CC homozygotes or miR-196a2C allele-containing genotypes (CT and CC) was lower in CRC patients than in the healthy controls, no significant association between miR-196a2 polymorphism and the risk of CRC was found. The frequency of the 'C' allele in CRC patients was also not significantly lower than in healthy controls. In a subsequent analysis of the association between this polymorphism and the progression of CRC, there was still no significant difference in both genotype and allelic frequency. Conclusions: Our results suggest that miR-196a2 polymorphism is not associated with both an increased risk and progression of CRC in Chinese. © 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians.