Figure 6.

Suppression of Gnpat expression by NF-κB-induced c-Myc. A, Transfection of p65- and p50-expressing plasmids (1 μg each) in N2A cells (1 × 10⁵ cells/well of 6-well plate) for 48 h increased c-Myc mRNA (left) and protein (right) expression. B, In the same experimental condition, p65 and p50 overexpression reduced Gnpat expression. C, MG6 cells (1 × 10⁵ cells/well of 6 well platees) infected with c-Myc- and Mycn-expressing lentiviruses for 48 h showing the reduction of Gnpat expression compared with control lentivirus infection. D, Luciferase assays in N2A cells showing that the reduction of Gnpat promoter activity by NF-κB (p65 plus p50) (middle panel, third row) and c-Myc (right panel) was canceled by the deletion of Myc-binding sequences from the Gnpat promoter (first and second rows). The data represent six independent experiments. **p < 0.01; ***p < 0.001. E, Western blot data showing the reduction of c-Myc protein expression in MG6 cells infected with the c-Myc sh-RNA-delivering lentivirus for 48 h. F, Gnpat mRNA expression was increased in the c-Myc knockdown cells. G, Reduction of Gnpat expression induced by 6 h treatments with LPS (10 μg/ml), Poly I:C (10 μg/ml), and IL-1β (20 ng/ml) was blocked by c-Myc knockdown in MG6 cells. *p < 0.05; **p < 0.01 (n = 4).