Screening feature genes of lung carcinoma with DNA microarray analysis

Lung carcinoma is the most common and aggressive malignant tumor with poor clinical outcome. Identification of new marker of lung cancer is essential for the diagnosis and prognosis of the disease. To identify differentially expressed genes (DEGs) and find associated pathways that may function as targets of lung cancer. Gene expression profiling of GSE40791 were downloaded from GEO (Gene Expression Omnibus), including 100 normal specimens and 94 lung cancer samples. The DEGs were screened out by LIMMA package in R language. Besides, novel genes associated with lung cancer were identified by co-expression analysis. Then, GO enrichment and transcription binding site analysis were performed on these DEGs, and novel genes were predicted using DAVID. Finally, PPI network was constructed by String software in order to get the hub codes involved in cancer carcinoma. A total of 541 DEGs were filtered out between normal samples and patients with lung carcinoma, including 155 up-regulated genes and 386 down-regulated genes. Additionally, nine novel genes, CA4, CDC20, CHRDL1, DLGAP5, EMCN, GPM6A, NUSAP1, S1PR1 and TCF21, were figured out. The transcription biding site analysis showed that these genes were regulated by LHX3, HNF3B, CDP, HFH1, FOXO4, STAT, SOX5, MEF2, FOXO3 and SRY. Hub codes as BUB1B, MAD2L and TOP2A may play as target genes in lung carcinoma in the result of PPI network analysis. Newly predicted genes and hub codes can perform as target genes for diagnose and clinical therapy of lung cancer.