RESUMO
<p><b>OBJECTIVE</b>To investigate the mRNA and proten expression of coxsackievirus and adenovirus receptor (CAR) in the corresponding normal lung tissue, para-neoplastic tissue and lung cancer tissue, and the correlation of CAR expression with the carcinogenesis as well as the expression difference in various clinicopathologic parameters.</p><p><b>METHODS</b>The expression of CAR mRNA and protein in the samples from 32 lung cancer patients was determined by RT-PCR and Western blot, respectively.</p><p><b>RESULTS</b>The expression level of CAR mRNA and protein in normal lung tissue, paraneoplastic tissue and cancer tissue were 1.000 +/- 0.012, 1.048 +/- 0.035, 1.282 +/- 0.072, and 0.902 +/- 0.038, 0.944 +/- 0.042, 1.08 +/- 0.052, respectively, with a statistical significance among the groups (P = 0.022, P = 0.007, P = 0.009, P = 0.027). There was a statistically significant positive correlation between expression of CAR mRNA and that of CAR protein (r = 0.448, P = 0.026). The expression levels of CAR were significantly different among different pathological types (P = 0.012), with a high level of CAR in all 7 bronchiolo-alveolar carcinoma (BAC, P = 0.029). However, there was no statistical significance in other clinicopathologic parameters (P > 0.05), including gender, age, smoking or not, tumor size, with or without lymph node metastasis and TNM stage.</p><p><b>CONCLUSION</b>The expression of CAR mRNA and protein in cancer tissue samples are significantly higher than that in the normal and paraneoplastic samples, indicating that CAR might play a crucial role in the carcinogenesis. It may become a new potential prognostic marker for lung cancer patients.</p>