Fig. 7. Decreased activation of ß₁ integrin in MCF10A cells after inhibition of myosin II, actin polymerization and MLCK. Untransformed MCF-10A (A) or Ras-transformed MCF-10A cells (B) were treated with MLCK, myosin II and actin polymerization inhibitors, as indicated. Cells were grown on coverslips and treated for 2 hours, then fixed in 3% paraformaldehyde and stained with an anti-ß₁-integrin antibody (clone HUTS-21), which recognizes integrins in their active state, Topro-3 and anti-actin (Rhodamine-phalloidin). (C) Western blot showing level of ß₁ integrin after 2 hours of treatment with inhibitors.