ABSTRACT
@# To indentify the candidate genes and signaling pathways in lung adenocarcinoma by analyzing gene profiles with bioinformatics. Methods: The expression profiles of GSE40791, GSE68571, GSE43458, and GSE18842 were down-loaded from the Gene Expression Omnibus (GEO) database. The four microarray datasets were integrated to obtain the differentially expressed genes related to lung adenocarcinoma. STRING database was used to construct the protein-protein interaction (PPI) network of differentially expressed genes, and to further explore the gene modules and the key genes. DAVID was used to perform the gene enrichment analysis of each gene module, and to explore the regulatory function of each gene module in adenocarcinoma cells, as well as the relationship between the key genes in the module and the prognosis of the patients. Results: Thirty-seven up-regulated genes and 120 down-regulated genes were obtained from the primary screen, and the protein-protein interaction(PPI) network was successfully constructed. According to MCODE algorithm, we constructed gene modules and calculated the core genes (KIF14, SEPP1, SPP1, RBP4) in the PPI network. Finally, four modules were proved to be involved in regulation of cell cycle, blood coagulation, cell adhesion and cell metabolism, and four key genes were proved to be differentially expressed between lung adenocarcinoma tissues and normal tissues (all P<0.05). Survival analysis showed that expressions of KIF14, SEPP1 and SPP1 had significant effect on the prognosis of lung adenocarcinoma (P<0.01 or P<0.05), while RBP4 exerted insignificant difference in the survival rate of lung adenocarcinoma patients (P>0.05). Conclusion: With bioinformatics, three differentially expressed genes between lung adenocarcinoma tissues and normal adjacent tissues were finally screened out and proved to be closely related to the prognosis of patients, which provided new thoughts in the diagnosis and prognosis prediction of lung adenocarcinoma and improved the study efficiency on the mechanism of lung adenocarcinoma.
ABSTRACT
Objective To construct a specific small interfering double-stranded RNA(siRNA) expression vector of Caspase-12 and to evaluate inhibitory effect of this siRNA on caspase-12 mRNA activity.Methods Three groups of siRNA targeting different gene sites of caspase-12 were designed and synthesized chemically.Mouse hepatoma cell line,Hepa1-6,was transfected with the siRNA by 24 h.Reverse transcription-polymerase chain reaction(RT-PCR)was performed to analyze the inhibi- tion of caspase-12.Then the most effective siRNA was selected and the two template sequences for the siRNA were inserted into pRNAT-H1.1Neo expression vector.The recombinant plasmid, referred to as pRNAT-casp12,was verified by PCR analysis and sequencing.The expression of caspase-12 at mRNA and protein level,after transfection with pRNAT-casp12 by 48 h and 72 h respectively,were analyzed by using real-time PCR and Western blotting.Results The chemically synthesized siRNA*1 and siRNA*3 could inhibit mouse hepatoma cell caspase-12 mRNA by 59.9% and 39.6%(P