MiR-34a and miR-34c overexpression or PDGFR-α/β silencing increases the response of NSCLC cells to TRAIL-induced apoptosis.

<p>(<b>a</b>) Western blot in Calu-6 cells after miR-34a, -34b and -34c forced expression. MiR-34a or miR-34c and not miR-34b forced expression decreases PDGFRβ expression levels and reduces the activation of the ERK1/2. (<b>b</b>) Western blot showing the inactivation of the Akt and ERKs pathways after PDGFR-α silencing. (<b>c</b>) Caspase 3/7 assay. MiR-34a and -34c enforced expression in Calu-6 and H1703 semi-resistant cells, increases the response to TRAIL-induced apoptosis. (<b>d</b>) Caspase 3/7 assay showing that PDGFR-α or PDGFR-β silencing increases the response to TRAIL-induced apoptosis. (<b>e</b>) PDGFR-α or PDGFR-β overexpression in H460 TRAIL-sensitive cells decreases the response to the drug. (<b>f</b>) Combined treatment of PDGFR inhibitor (20 μM) and different TRAIL concentrations (0-100-150 ng/ml) for 24h sensitizes NSCLC cells to TRAIL-induced apoptosis. *P<0.001, ** P<0.05.