FIGURE 2.

A, effect of echinomycin on RON protein expression: equal amounts of total cell lysates from control or echinomycin-treated cells were resolved by 7.5% SDS-PAGE, and Western analysis using rabbit anti-human RON and actin polyclonal antibodies was performed. B, effect of echinomycin on RON message: total RNA from control or echinomycin-treated cells was reverse-transcribed into cDNA and PCR analysis was performed using primers for RON and actin as described under “Experimental Procedures.” C, echinomycin blocks MSP-mediated invasion: control or echinomycin-treated breast cancer cells were plated in Matrigel invasion chamber (upper). The cells were treated with 2.5 ng MSP for 24 h. The migrant cells on the undersurface of the membrane were fixed in 70% methanol and stained with crystal violet. Images of migrant cells were captured by a photomicroscope (Nikon Eclipse-TE 2000-U, 10×). Quantification data represents the mean ± S.D. of three separate invasion assays.