NEDD9 and BCAR1 Negatively Regulate E-Cadherin Membrane Localization, and Promote E-Cadherin Degradation
Figure 5
Cas proteins activate SRC to downregulate E-cadherin expression.
A, B. Western analysis (A) of whole cell lysates prepared from MCF-7 cells overexpressing pcDNA vector alone (-), or HA-tagged BCAR1 (B), NEDD9 (N), or both (NB), and treated with dasatinib versus vehicle. Quantification of results comparing levels of E-cadherin, normalized to β-actin, within treated and, separately, untreated groups from 4 independent experiments, is also shown (B). Src Y416 phosphorylation reflects activity state of kinase. P values reflect the difference between the vehicle and drug treatment condition, for each transfected protein indicated; *, P<0.01, **, P<0.001, ns, non-significant. C. Experiment as in A performed with PP2. Note, SRC inhibition was not as complete as in A in these experiments, because at higher PP2 concentrations extensive cell death was observed, probably due to the broader spectrum of PP2 versus dasatinib targets. D, E. Experiment as in A, B, but in cells treated with Y27632 versus vehicle. Phosphorylation of the downstream p160ROCK target MYPT1 was assessed in parallel to confirm complete inhibition of p160ROCK (not shown). *, P<0.001, **, P<0.01 ***, P<0.0001, ns, non-significant. Error bars represent SE.