Gene expression profile changes upon knock-down of Pax8

In order to define the transcriptional network functionally regulated by Pax8 as well as infer its direct targets, we performed RNAi to knock-down Pax8 gene in FRTL-5 thyroid cells. Expression data from three independent silencing experiments were analyzed by microarray technology unraveling 2815 genes differentially expressed between silenced cells and controls. Of these, 1421 genes were down-regulated and 1394 genes were up-regulated 72hrs after Pax8 silencing. The results obtained suggest that Pax8 regulates numerous pathways, some of which involved in the regulation of cell cycle, thyroid cancer and apoptosis, thus confirming that Pax8 is a master regulatory gene. Rat differentiated thyroid cells from FRTL-5 line were transfected with siGENOME Pax8 siRNA (siPax8, experimental) or siGENOME Non-Targeting siRNA (ntPax8, controls). The trascriptome from three siPax8 biological replicates, 72 hours after transfection, was compared to the trascriptome from 3 control ntPax8 biological replicates. Microarray analysis was performed at gene-level using the AffymetrixGeneChip Rat Gene 1.0 ST array