Investigation of cyclin D1 (CCND1) A870G polymorphism in patients with papillary thyroid cancer

Cyclin D1 (CCND1) plays a critical role in the transition from G1 to the S phase in the cell cycle. In the polymorphisms of the genes which encode these cyclin proteins, the cell cycle is affected and a normal cell may become a cancer cell which proliferates in an uncontrolled way. Many studies have showed that A870G polymorphism of the CCND1 gene, which is coding D1 cyclin protein, is associated with many different cancer types. In this study we investigated the A870G polymorphism of the CCND1 gene on the patients with papillary thyroid cancer, in Turkish population. Peripheral blood samples of 102 papillary thyroid cancer patients and 174 healthy controls were analysed as part of the study. The A870G polymorphism of the CCND1 was analysed by using PCR-RFLP techniques and alleles and genotype frequencies were calculated. In this study, there was a statistically significant difference between patient and control groups for alleles frequencies (p=0,042) but no statistically significant difference for genotype's distribution (p=0,085). In the model that was set up according to logistics regression analysis and was adjusted to age, sex, alcohol and cigarette use; in comparison with GG genotype, papillary thyroid cancer's risk was 2,036 fold higher for AA genotype (%95 GA, 0.854-4.852) and 1,662 fold higher for AG genotype (%95 GA, 0.738-3.747) but this data wasn't statistically significant (p>0,05). In the patients with A allele and older than 45 years (OR=1.91, %95 GA, 1.09-3.349, p=0.024) and female patients with A allele (OR=1.731, %95, GA, 1.056-2.838, p=0,029) there was statistically significant high risk for papillary thyroid cancer, using the G allele as the reference allele. In patients with AA genotype and older than 45 years (OR=2.281, %95 GA, 1.015-5.126, p=0.046) was associated with a significantly higher risk of papillary thyroid cancer compared with GG+AG combined genotype. In this study, we founded that the A870G polymorphism of the CCND1 gene can be associated with the risk of papillary thyroid cancer development, in Turkish population.