Lack of association between the unique LMP2 gene polymorphism and the outcome of lung cancer in a population of Chinese Han nationality

Abstract

Lung cancer is characterized by a widely ranging incidence variation; it is the most common cancer in China. In this study we will assess the association of low-molecular-mass protease 2 (LMP2) gene codon 60 polymorphism with the risk of lung cancer. Genomic DNA of peripheral blood mononuclear cells was isolated from 207 patients with lung cancer and 264 healthy controls. DNA direct sequencing and polymerase chain reaction-restriction fragment length polymorphism were performed to scrutinize LMP2 gene codon 60 polymorphism. The risk of LMP2 gene polymorphism in lung cancer was assessed using an unconditional logistic regression model adjusted by the confounding factors. As a result of DNA direct sequencing, the LMP2 codon 60 polymorphic substitution of the nucleotide was CGC → TGC in Chinese individuals, not CGC → CAC as reported in other ethnic populations. In histology-specific analysis and TNM stages, there was no apparent association between this LMP2 gene polymorphism and any of the histologic types or TNM stages of lung cancer using the Arg/Arg genotypes as the reference group (all p values > 0.05). These results suggest that the polymorphic site is unique in the Chinese population of Han nationality at the LMP2 codon 60 loci (Arg60Cys), but a lack of association with lung cancer exists.