OBJECTIVETo study the data of gene expression microarray by protein interaction network analysis, establish an interaction network of differentially expressed genes in invasive bladder cancer and verify the central nodes of the network.

METHODSA total of 152 differentially expressed genes in invasive bladder cancer detected by gene expression microarray were inputted into STRING database online for analysis and establishment of the interaction network. The interaction data were imported into Cytoscape 2.6.2 software for screening the central nodes of the network. KEGG database was exploited for pathway analysis and functional study of the central node genes. Real-time RT-PCR was used for verification, and the genes with maximal differential expressions were screened for exploring the molecular mechanism of carcinogenesis of invasive bladder cancer.

RESULTSThe protein products of 103 differentially expressed genes in bladder cancer had interactions, forming a complicated interaction network. Twenty-six nodes involved in several signal pathways were confirmed by Cytoscape as the central nodes of the network, among which UBE2C, VEGF, TGFBR2, and CAV1 nodes were verified by real-time RT-PCR as the genes with maximal differential expressions between the bladder cancer and normal tissues, and the 2(-delta delta Ct) of these genes were 9.45, 4.17, 0.13 and 0.18 (GAPHD as the internal control), respectively.

CONCLUSIONThe interaction network of the differentially expressed genes, especially the central nodes of this network, can provide clues to the carcinogenesis, early diagnosis and molecular targeted therapy of invasive bladder cancer.