Figure 2

Global gene expression profiling identifies downstream targets of Par-4-overexpression in HT29 cells. (A) Differential expression of genes in HT29 cells transfected with the Par-4 gene versus empty vector. A total of 692 genes were significantly differentially expressed (Par-4-target genes). EASE analysis of Par-4-target genes revealed significant over-representation in GO categories such as apoptosis, cell cycle/proliferation, mitochondrial, chromatin remodeling, and microRNA regulation. Each row in the cluster image represents an individual gene and each column represents an independent hybridization experiment. The relative transcript abundance of each gene is color coded. A red indicates high expression, black indicates intermediate expression and green indicates low expression. (B) Validation of selected genes by qRT-PCR. Genes downregulated by Par-4 were validated by qRT-PCR. Results are the mean ± S.D. of 3-4 independent experiments. *,** Significant difference between Par-4-overexpressing cells and empty vector-transfected cells (P < 0.05). (C) Validation of genes by immunoblot analysis. Caspase 10, BCL2, and BTG1 were assayed by immunoblot analysis. Actin served as loading control. Similar immunoblot results were obtained in 4-5 independent experiments.