The Association Of Expression Levels Of Nucleotide Excision Repair Genes With Lung Cancer Susceptibility

Objective To study the association between the expression levels of nucleotide excision repair genes and susceptibility to lung cancer,and explore factors related to risk of lung cancer developing in molecular level.Methods The relative expression levels of nucleotide excision repair genes(XPA,XPB,XPC,XPG and ERCC1)mRNA were measured by real time fluorescent quantitative PCR assay in a case-control study including 50 patients with lung cancer,30 patients with benign pulmonary disease and 32 healthy controls.The association between expression levels of five genes and susceptibility to lung cancer was analyzed.Results Relative expression levels of XPA,XPB,XPC,XPG and ERCC1 mRNA were 0.0684±0.0156,0.0109±0.0026,0.0602±0.0234, 0.0322±0.0072 and 0.2418±0.0443 in patients with lung cancer, respectively;and were 0.1218±0.0408,0.0112±0.0048,0.0516±0.0183,0.0577±0.0172 and 0.0800±0.0154 in patients with benign pulmonary disease,respectively;and were 0.3362±0.0376,0.0371±0.0060,0.1610±0.0437,0.0545±0.0215 and 0.3500±0.0700 in healthy controls,respectively.The expression level of XPB mRNA were significantly decreased in patients with lung cancer(P=0.000)and benign pulmonary disease(P=0.001),as compared to healthy controls;but there were no significant differences of expression levels of XPA,XPC,XPG and ERCC1 mRNA among lung cancer,benign disease patients and healthy controls(P＞0.05).Individuals having low expression level of XPB gene were in significant higher risk of lung cancer occurrence,and exhibited a 2.57 fold greater risk of lung cancer(95%CI=1.03～6.43),while other genes(XPA,XPC,XPG and ERCC1)were 1.77,1.17,1.08 and 1.5 fold respectively than that having higher expression level of those genes. There was no relationship between all five genes expression and sex,age, smoking degree,pathology,TNM stage of lung cancer patients, respectively.Among lung cancer patients the expression level of ERCC1 gene was correlated positively with XPA,XPB,XPC and XPG genes(r_S =0.682,0.53,0.743,0.434,all P＜0.01),and also XPC gene with XPA, XPB and XPG genes(r_S=0.523,0.441,0.56,all P＜0.01).Conclusions Individuals who have low expression level of XPB gene might be in higher risk of lung cancer,and detection of expression of nucleotide excision repair genes may be used as a predictive marker of susceptibility to lung cancer.