Figure 2

CD155 mediates tumor cell invasion and migration. (a) FALI of CD155 resulted in a significant inhibition of HT1080 transwell invasion through matrigel towards a serum chemoattractant (Δ invasion ± FALI: no Ab 19 ± 6%; β1-int 32 ± 4%; CD155 32 ± 11%). (b) FALI of CD155 using multiple mAbs resulted in a significant inhibition of HT1080 transwell migration towards a serum chemoattractant (Δ migration ± FALI: no Ab l ± 4%; β1-int 30 ± 6%; 1A2 (control, surface binding scFv) 1 ± 3%; CD155: D171 23 ± 4%; pv404 20 ± 3%; 5D11 22 ± 4%; 1D8(20) 21± 2%; 1D8(40) 23 ± 4%; CD155pool 22 ± 1%). FALI with CD155 mAb pools did not yield greater inhibition, suggesting maximal inactivation or that the binders share a common epitope. (c) CD155-specific siRNA duplexes were used to knockdown protein expression by about 90% by 72 h. Knockdown of CD155 in HT1080 cells resulted in a significant decrease in transwell migration compared to control cells transfected with a scrambled duplex (23 ± 4%). * indicates p < 0.01, t-test.