Interaction effects of knockdown of PML and TNFalpha treatment in HUVEC cells

To study the interaction effects between promyelocytic leukemia (PML) gene knockdown and tumor necrosis factor-alpha (TNFalpha) signaling in human umbilical vein endothelial cells (HUVECs), we transfected control or two independent PML siRNAs into HUVEC cells without or with 20 ng/mL TNFalpha treatment for 20 h. The total RNA was extracted for gene expression microarray analyses. The experiment is a 3x2 two-factor design. One factor is siRNA and it has three levels (siCtrl, siPML1, siPML2). siCtrl is RISC-inducing non-targeting control siRNA. siPML1 and siPML2 designate two independent siRNAs against the PML gene. Two independent siRNAs were used to eliminate the off-target effects of siRNA. The other factor is TNFalpha treatment (20 ng/mL for 20 h) and it has two levels: Untreated (U) or Treated (T). Each sample has technical duplicates.