(A) Knock-down of Ang-1 or Ang-2 efficiently represses the expression of Ang-1 or Ang-2 mRNA in HuH-7 cells. HuH-7 cells were transfected to Ang-1 or Ang-2 siRNA. Forty eight hours after the transfection, we evaluated the expression of Ang-1 or Ang-2 mRNA by real time RT-PCR. Values shown are relative induction of the indicated genes. (B) The supernatant of HuH-7 cells after knockdown of Ang-1 completely abrogated the anti-proliferative effects of the conditioned medium from IFN/5-FU treated HuH-7 cells. HuH-7 cells treated with siRNA for Ang-1, Ang-2 or non-specific for 24 hours, and then we collected the supernatant after treatment with or without IFN/5-FU for 48 hours. We evaluated viability of HUVEC cells by MTT assay. The percentage of viable cells was significantly reduced by the conditioned media after the treatment of IFN/5-FU. There is no significant difference between the conditioned media after treatment with or without IFN/5-FU after knockdown of Ang-1 or Ang-2.