Fig. 3. Cdc42 silencing upregulates MMP-1 protein level. (A) Representative western-blot analysis of serum-free medium conditioned by HSFs for 16 hours between days 2 and 3 after transfection with calcium phosphate alone (CaP), with 20 nM siRNA targeting RhoA (siRhoA), Rac1 (siRac1) or Cdc42 (siCdc42), or with 20 nM irrelevant siRNA (siScr). (B) Densitometric analysis of A. Results are the means±s.d. of three independent experiments. (C) Representative western-blot analysis of cell lysates of HSFs 72 hours after transfection (cell lysates) or serum-free medium conditioned by HSFs for 16 hours between days 2 and 3 after transfection (C.M.). Cells were transfected with the indicated concentrations of either an irrelevant siRNA (siScr) or the siRNA targeting Cdc42 (siCdc42).