Association between MLL3 genetic polymorphisms and development of laryngeal cancer in a Chinese population

We firstly conducted a case-control study to investigate the role of two SNPs in MLL3 gene (rs6943984 and rs4725443) in the development of laryngeal cancer in a Chinese population. Between May 2012 and October 2014, a total of 171 patients with laryngeal cancer and 251 control subjects were collected from the Zhumadian Central Hospital. Genotyping of MLL3 rs6943984 and rs4725443 were analyzed using polymerase chain reaction coupled with restriction fragment length polymorphism. The chi-square test revealed that individuals with the laryngeal cancer were more likely to be males, have a habit of tobacco smoking and alcohol drinking, and have a habit of family history of cancer. By unconditional logistic regression analyses, we found that subjects carrying GG genotype of rs6943984 was associated with increased risk of laryngeal cancer compared to the AA genotype (Adjusted OR=3.58, 95% CI=1.54-8.81). In the dominant model, the AA+GG genotype of rs6943984 was marginal significant correlated with an increased risk of laryngeal cancer compared to the wide-type genotype (Adjusted OR=1.60, 95% CI=1.03-2.49). Moreover, the GG genotype of rs6943984 was associated with a heavy increased risk of laryngeal cancer compared to the AA+AG genotype (Adjusted OR=3.37, 95% CI=1.47-8.23). However, we did not find any significant association between the rs4725443 gene polymorphism and laryngeal cancer risk. In conclusion, our study suggests that the rs6943984 polymorphism was associated with increased risk of laryngeal cancer in co-dominant, dominant and recessive models.