Fig. 7. TACE siRNA inhibits EGFR signal transmission and cell migration by GPCR agonists. (A and B) TACE siRNA blocks endogenous TACE expression. SCC-9 cells were transfected with TACE or ADAM12 siRNA. Gene expression was analysed by (A) RT–PCR or (B) immunoblot with polyclonal anti-TACE antibody. (C) Knockdown of TACE results in accumulation of proAR at the cell surface. siRNA-transfected SCC-9 cells were analysed for AR cell surface content by FACS. (D) EGFR signal transmission upon GPCR activation requires TACE. SCC-9 cells were transfected with siRNA and stimulated with agonists as indicated. Activation of EGFR, SHC, ERK and Akt was determined as described above. (E) Squamous cancer cell motility in response to LPA depends on TACE. siRNA-transfected SCC-9 cells were treated with LPA or AR and analysed in a transwell migration assay.