Fig. 3. Activation of ß₁-integrins with mAb 12G10 causes an increase in intracellular cAMP levels and PKA activity. (A) HT-1080 cells were incubated with 10 µg/ml anti-ß₁ integrin antibodies or 5 µM forskolin and assayed for cAMP as described in Materials and Methods. Asterisk indicates P<0.01 vs. no treatment. Values shown are mean±s.d. (n=4). (B) HT-1080 cells were incubated with 10 µg/ml anti-ß₁ integrin antibodies or 10 µM Sp-cAMPS and assayed for PKA activity using the biotinylated kemptide peptide substrate as described in Materials and Methods. Asterisk indicates P<0.05 vs. no treatment. Values shown are mean±s.d. (n=2).