Polymorphism (rs16917496) at the miR‑502 Binding Site of the Lysine Methyltransferase 5A (SET8) and Its Correlation with Colorectal Cancer in Iranians

One of the gene expression regulatory mechanisms is mediated by small noncoding RNAs called microRNA (miRNA). They interact with a recognition sequence located mostly in 3’‑untranslated regions (3’‑UTRs) of mRNAs. Polymorphisms in miRNAs recognition sequences could affect gene expression which in turn may alter disease susceptibility. SET8, a member of the SET domain‑containing methyltransferase, acts in a variety of biological processes such as genomic stability. Here, we report correlation of rs16917496 polymorphism, located in the recognition sequence of miR‑502 within 3’‑UTR of SET8, with colorectal cancer (CRC) in Iranians.

One hundred and seventy CRC patients and 170 noncancer counterparts were recruited in this case–control study. Genotyping of rs16917496 was performed using polymerase chain reaction‑restriction fragment length polymorphism method.

There was no significant association of rs16917496 with CRC in population under study (P value for genotype and allele distribution were >0.05). However, stratification analysis based on smoking status revealed that TT+TC genotypes of SET8 rs16917496 are strongly associated with increased risk of CRC (odds ratio: 5.8, 95% confidence interval: 1.37–24.34, P ‑ 0.005) in smoker subgroup.

Correlation of rs16917496 T allele with CRC in smokers is emphasizing the importance of individuals’ genotype in the recruitment of adverse health hazards of smoking more profoundly for certain people compared to others.