Analysis of MIR155HG gene polymorphisms and ulcerative colitis susceptibility in the Chinese Han Population

Aberrant expression of miR-155 has been implicated in the pathogenesis of inflammatory bowel disease (IBD), where its dysregulation may contribute to impaired intestinal barrier integrity and sustained inflammation. However, the precise role of miR-155 in the development of ulcerative colitis (UC) remains incompletely understood. This case-control study aimed to evaluate the association between polymorphisms of MIR155HG gene and susceptibility to UC in a Chinese Han population. The study included 84 UC patients and 216 matched healthy controls. Four single nucleotide polymorphisms (SNPs) of MIR155HG (rs1893650, rs2282471, rs2829803, and rs2829806) were genotyped using the Sequenom MassARRAY platform. Function prediction of SNPs were conducted using RNAfold databases. We observed MIR155HG rs2282471 polymorphism was significantly associated with a reduced risk of UC. Specifically, the minor T allele, homozygous TT genotype, and the recessive genetic model (TT vs CT + CC) of rs2282471 conferred protective effect to the disease. The stratified analysis indicated this protective effect was more pronounced in male patients. Furthermore, haplotype analysis showed a strong linkage disequilibrium among the four SNPs and identified a specific haplotype (TGTT) that was also associated with decreased UC risk. No significant correlations were observed between four SNPs and clinical features such as disease severity or lesion location. Structure prediction suggested that rs2282471 may influence the secondary structure of miR-155. These findings provided the first evidence that the MIR155HG rs2282471 polymorphism were associated with decreased UC susceptibility in the Chinese Han population, suggesting MIR155HG might be a predictive biomarker for risk of UC.