Expression Of Coxsackie And Adenovirus Receptor In Non-small Cell Lung Carcinoma And Its Significance

Objective:To study the expression of coxsackie and adenovirus receptor(CAR) mRNA and protein in lung normal tissue,paraneoplastic tissue and carcinoma tissue, analyzing their correlation with carcinogenesis and development,as well as their different expression in different clinicopathologic parameter,Confirming the role of CAR in lung cancer formation especially adenocarcinoma,and demonstrating the clinical significance of CAR as a new therapeutics target.Method:Collecting fresh lung cancer 32 samples,as well as its corresponding paraneoplastic tissue and normal tissue,put into liquid nitrogen as soon as removed from the patient's body,-80℃followed.Simultaneously the clinical data of the patients was collected for the results analysis.The expression of CAR protein was determined by IHC and Western blot and CAR mRNA was detected by RT-PCR in lung norm tissue,and paraneoplastic tissue carcinoma tissue respectively.Results:1.CAR protein expression in lung normal tissue,para-carcinoma tissue and carcinoma tissue.Using immuhistochemical method,19 lung cacinoma tissue were positive in the 32 lung cancer cases:14 adenocarcima(6-bronchiolo-aleolar carcinoma BAC ) and 5 squamous cell carcinoma..By Western blot assay,a band of about 46 kd was detected in in lung normal tissue, paraneoplastic tissue and carcinoma tissue,with the expression value 0.902±0.038, 0.944±0.042,1.08±0.052.Carcinoma tissue were statistically higher than lung normal tissue and paraneoplastic tissue(P=0.09,P=0.027).2.CAR mRNA expression in lung normal tissue,para-carcinoma tissue and carcinoma tissue.The expression value of CAR mRNA in lung normal tissue,paraneoplastic tissue and carcinoma tissue were 1.000±0.012,1.048±0.035,1.282±0.072.And Carcinoma tissue were significantly higher than lung normal tissue and paraneoplastic tissue,the difference having significance(P=0.022,P=0.007).3.There was a statistically positive correlation between expression of CAR mRNA and protein(r=0.448,P=0.026).By McNemar method,We calculated the value ofк=0.652,P=0.011,P＜0.05.The two has high anastomosis. 4.The correlation of CAR expression with different clinicopathologic parameters. There was no statistical significance in other clinicopathologic parameters(P＞0.05), including gender,age,smoke or not,tumor size,with or without lymph node metastasis and TNM stage.The expression level of CAR has significant difference between squamous cell carcinoma and adenocarcinoma(P=0.012),with 7 BAC all expressing higher level CAR than non-BAC(P=0.029).But significance disappear when we excluded the BCA from adenocarcinoma(P=0.125).Conclusion:1.Carcinoma tissue were statistically higher than lung normal tissue and paraneoplastic tissue;CAR expression in lung adenocarcinama was higher than squamous cell.These data predicted that CAR expression might be necessary for the formation of human lung cancer,particularly for the development of adenocarcinoma.2.The expression level of CAR has significant difference among different pathological types but no statistical significance in other clinicopathologic parameters. 7-BAC all expressed high level CAR than non-BAC.This might thoroughly demonstrate the role of CAR in the formation of BAC.But need more research.3.CAR mRNA and protein has significantly positive correlation.When the expression of CARmRNA rises,the CAR protein increases.4.If CAR is a promoting factor for human lung cancer,we might develop the antibody-directed therapy as EGFR TKI did in human lung cancer.If CAR is not a promoting factor of human lung cancer,the elevated expression of CAR in lung cancer will be more favorable to the gene therapy of human lung cancer.