Fig. 3
Anti-cancer effect of DHEA and NALA was reversed by inhibition of 5-LO, but not by inhibition of COX-2. (a) SNU-1041 and (b) SNU-1076 were treated with DHEA or NALA (20 μM) plus AA861 (5 μM) or zileuton (5 μM) or Ebselen (5 μM). At 72 h, cells were subjected to cell proliferation assay (Left). The siRNA of 5-LO was transfected at 200 nM doses (the si-NC was used for negative control of siRNA). Forty-eight hours later cells were treated with DHEA or NALA (20 μM). At additional 48 h, cells were subjected to cell proliferation assay (Right). Results are expressed as a percentage relative to control (% of control). P values were based on comparison with DHEA-treated group and NALA-treated group (*P < 0.005, #P < 0.01). c 5-LO siRNA was transfected into SNU-1076 cells. At 48 h, total cell lysates were prepared and the expression of 5-LO was determined by western blotting (upper). Data are presented as a representative of 3 separate experiments. At 48 h, cells were treated with 20 μM of arachidonic acid. After an additional 2 h, cultured media were collected and applied to LTB4 EIA (lower). The inhibitory effect of 5-LO siRNA was compared with that of 5-LO inhibitors – AA861 and zileuton. Results are expressed as a percentage relative to the control (% of control)