Screening of Differentially Expressed Genes among Various TNM Stages of Lung Adenocarcinoma by Genomewide Gene Expression Profile Analysis

Background: To further investigate the molecular basis of lung cancer development, we utilize a microarray to identify differentially expressed genes associated with various TNM stages of adenocarcinoma, a subtype with increasing incidence in recent years in China. Methods: A 35K oligo gene array, covering about 25,100 genes, was used to screen differentially expressed genes among 90 tumor samples of lung adenocarcinoma in various TNM stages. To verify the gene array data, three genes (Zimp7, GINS2 and NAG-1) were confirmed by real-time RT-PCR in a different set of samples from the gene array. Results: First, we obtained 640 differentially expressed genes in lung adenocarcinomas compared to the surrounding normal lung tissues. Then, from the 640 candidates we identified 10 differentially expressed genes among different TNM stages (Stage I, II and IIIA), of which Zimp7, GINS2 and NAG-1 genes were first reported to be present at a high level in lung adenocarcinoma. The results of qRT-PCR for the three genes were consistent with those from the gene array. Conclusions: We identified 10 candidate genes associated with different TNM stages in lung adenocarcinoma in the Chinese population, which should provide new insights into the molecular basis underlying the development of lung adenocarcinoma and may offer new targets for the diagnosis, therapy and prognosis prediction.