The effects of ANRIL polymorphisms on colorectal cancer, tumor stage, and tumor grade among Iranian population.

BACKGROUND: Colorectal cancer (CRC) is a type of neoplasm, developing in the colon or rectum. The exact etiology of CRC is not well known, but the role of genetic, epigenetic, and environmental factors are established in its pathogenesis. Therefore, the aim of this research was to explore the effects of ANRIL polymorphisms on the CRC and its clinical findings.

METHODS AND RESULTS: The peripheral blood specimens were collected from 142 CRC patients and 225 controls referred to Milad Hospital, Tehran, Iran. PCR- RFLP method was used to analyze ANRIL rs1333040, rs10757274 rs4977574, and rs1333048 polymorphisms. The ANRIL rs1333040 polymorphism was related to a higher risk of CRC in the co-dominant, dominant, and log-additive models. ANRIL rs10757274, rs4977574, and rs1333048 polymorphisms showed no effect on CRC susceptibility. The CGAA and TGGA haplotypes of ANRIL rs1333040/ rs10757274/ rs4977574/rs1333048 polymorphisms were associated with the higher and the lower risk of CRC respectively. The rs1333040 polymorphism was associated with higher TNM stages (III and IV). The frequency of ANRIL rs10757274 polymorphism was lower in CRC patients over 50 years of age only in the dominant model. In addition, the rs10757274 was associated with well differentiation in CRC patients.

CONCLUSION: The ANRIL rs1333040 polymorphism was associated with a higher risk of CRC and higher TNM stages. ANRIL rs10757274 polymorphism was associated with the well-differentiated tumor in CRC.