Deletion analysis of the DR4 and/or Sp1 sequences within the TM promoter. HUVECs were transfected with pGL3-pTM1562 plasmid or some deletion mutants as well as pRL-TK plasmid as described in “Materials and methods.” The culture medium was changed after 4 hours of catinoic liposome transfection, and 24 hours thereafter, the cells were treated with medium alone, or either 50 μg/mL of n-PAPC or ox-PAPC for 12 hours. The activities of firefly and renilla luciferases in the cell extracts were determined and the former activity normalized with respect to the later activity was expressed as a percentage of that with pGL3-pTM1562 plasmid treated without PAPC. □ indicates medium alone; ▦, n-PAPC treated; and ▪, ox-PAPC treated. Results were the average values of 3 independent experiments. pGL3-basic indicates plasmid not containing any TM promoter region; pGL3-pTM1562, pGL3-control plasmid containing –1562 bp from transcription site; pGL3-pTM(–DR4), pGL3-pTM1562 plasmid deleted from –1524 to –1521 in the DR4 site; pGL3-pTM(–Sp1), pGL3-pTM1562 plasmid deleted from –145 to –121 in the Sp1 site; and pGL3-pTM(–DR4/–Sp1), pGL3-pTM1562 plasmid deleted from –1524 to –1521 and from –145 to –121.