Cyclin D1 gene polymorphism, A870G, is associated with an increased risk of salivary gland tumors in the Chinese population

Expression of Cyclin D1 is believed to lead to progression through the G1 to S cell cycle checkpoint, and both experimental and pathological evidence suggests that overexpression of this protein may increase the risk of several cancers. The Cyclin D1 A870G polymorphism may modulate expression of the Cyclin D1 protein and is associated with the development of several types of tumor. We investigated the association between the Cyclin D1 A870G polymorphism and susceptibility to salivary gland tumors (SGTs) by PCR-RFLP in 102 Chinese SGT patients and 101 healthy controls. The frequencies of the AG (p = 0.002; odds ratio (OR), 3.466) and AA (p = 0.003; OR, 3.133) genotypes of Cyclin D1 were significantly higher in patients with SGT than in the healthy controls. The frequencies of these two genotypes were also significantly higher in pleomorphic adenoma (PA) patients (p = 0.002; OR, 2.229), compared with the healthy controls. In addition, the expression of Cyclin D1 was found to be significantly higher in PA patients with the AA genotype, compared with PA patients with the GG genotype. Taken together, our results suggested that the Cyclin D1 A870G polymorphism is associated with an increased risk of SGTs in the Chinese population. The Cyclin D1 AA genotype not only increased the risk of PA, but also increased the expression of Cyclin D1 in this type of tumor.