Molecular Analysis of rs2910164 Polymorphism and its Association with TNF-α Gene Expression in Colorectal Cancer: Before and After the Age of 50

Colorectal cancer (CRC) is one of the most common malignant tumors in the world, which has been diagnosed as the third most common cancer and the third leading cause of death. This cancer before the age of 50 is uncommon, and its prognosis is controversial, with many studies reporting a worse prognosis than in older patients and others showing no difference. In addition to factors, including diet, environmental factors, somatic and hereditary mutations, genetic factors, including altered expression of some microRNAs and mutations in tumor necrosis factor-α (TNF-α) gene, may be involved in this cancer.

This study aimed to investigate the rs2910164 polymorphism from the miRNA146a gene and its association with the expression of TNF-α gene in CRC before and after the age of 50 for early diagnosis and treatment.

In this study, 65 samples of cancerous lesions (37 cases over 50 years were considered the case group and 28 cases under 50 years were considered the control group) was collected from in an Iranian population. DNA was extracted from the samples, and rs2910164 polymorphism of the miRNA146a gene was investigated by PCR. Moreover, RNA was extracted from the samples, and the expression of the miRNA146a and TNF-α genes were evaluated. Finally, for data analysis, Epi Info software version 7.1.3.10 and MedCalc Version 19.2.0 were used.

The frequency of GG, GC, and CC genotypes from rs2910164 polymorphism of miRNA146a gene in the control group was 0.29, 0.46, and 0.25, respectively, but in the case group it was 0.54, 0.38, and 0.08, respectively. The results also showed that the expression of miRNA146a (P = 0.00006) and TNF-α (P = 0.009) genes was higher in the case group than the control group.

Based on the results of this study, a significant correlation was found between GG genotype and rs2910164 polymorphism of miRNA146a gene and TNF-α gene expression in the CRC samples. Therefore, investigation of these factors may be helpful in patients over 50 years with CRC.