RESUMO
OBJECTIVE: The main aim of the present study was to determine the clinical significance of the DNA methyltransferase 3B (DNMT3B) gene -579 G>T polymorphism in colorectal cancer (CRC) patients. METHODS: A total of 140 patients with CRC and 164 healthy individuals were included in the study. According to the manufacturer's instructions, DNA was isolated from blood, and genotypes were determined on agarose gel by the PCR-RFLP method. Genotype confirmation was performed using Sanger sequencing in randomly selected samples. RESULTS: When comparing the case and control groups, heterozygous GT (OR=0.53; 95% CI=0.32-0.88), under the dominant model (OR=0.53; 95% CI=0.33-0.87), and the mutant T allele (OR=0.71; 95% CI=0.51-0.98) were statistically associated with a reduced risk of CRC. However, when the age, pathological tumor grade and stage, smoking habit, and alcohol consumption were compared, no significant relationship was determined (P>0.05). Furthermore, among males, heterozygous GT was associated with a reduced risk of CRC (OR=0.40; 95% CI=0.19-0.84). CONCLUSION: Our study highlighted that the -579 G>T polymorphism of the DNMT3B gene plays a protective role against CRC development.