CD13/APN promoter constructs are induced in response to serum concentration and angiogenic factors.

(A) KS1767 cells in 1% serum were transiently transfected with 3 μg reporter plasmids containing the proximal promoter or promoterless vector and 1 μg MAP1-SEAP control, followed by stimulation with the indicated angiogenic factors alone or in combination (bFGF, VEGF, TNFα, or IGF-1). Cells were harvested and assayed for luciferase activity at 24 hours. Results are shown as fold activation over the activity of pGL2 basic control plasmid. (B) Anti-bFGF and anti-VEGF neutralizing antibodies inhibit CD13/APN promoter activity in KS1767 cells. Twenty-four hours after transfection, KS1767 cells in 10% serum were incubated with 20 μg/mL of goat IgG, antihuman bFGF, antihuman VEGF, or both anti-bFGF and anti-VEGF for 24 hours and assayed for luciferase activity. Results are shown as fold activation over identical treatment of cells transfected with the promoterless plasmid pGL2basic.