Cas proteins activate SRC to downregulate E-cadherin expression.

<p><b>A</b>, <b>B</b>. Western analysis (<b>A</b>) 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>B</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. <b>C</b>. Experiment as in <b>A</b> performed with PP2. Note, SRC inhibition was not as complete as in <b>A</b> in these experiments, because at higher PP2 concentrations extensive cell death was observed, probably due to the broader spectrum of PP2 versus dasatinib targets. <b>D</b>, <b>E</b>. Experiment as in <b>A</b>, <b>B</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.