Fig. 2. MAPK and NF-κB regulation of circ-4099 expression.

a qRT-PCR analysis shows that the TNF-α-dependent induction of circ-4099 in NP cells is blocked by MAPK and NF-kB pathway inhibitors. b Immunofluorescence detection of GFP in human NP cells transduced with lentivirus (LV) co-expressing GFP and either sh-p65 or sh-Ikkβ showed high transduction efficiency. c Western blot, d corresponding densitometry, and e RT-PCR analyses of cells transduced with LV-shLaz, LV-shp65, and LV-shIkkβ. Expression of p65 and Ikkβ is significantly blocked by the respective shRNAs compared with the control. f qRT-PCR analysis of circ-4099 expression in cells infected with LV-shC, LV-shp65, and LV-shIkkβ following TNF-α treatment. Note that the TNF-α-dependent induction of circ-4099 is significantly blocked by suppression of NF-κB pathway components