Figure 5.

Knockdown of Sam68 suppresses cell proliferation by inhibiting Wnt/β-catenin signaling pathway. A. A549 cells were co-transfected with 0.1 μg of the TOP flash or FOP flash reporter plasmid, 50 pmol siRNA oligos and 0.05 μg of β-galactosidase expressing plasmid. 72 h later, cells were lysed, luciferase and β-galactosidase activities were examined. Fold induction (Luc/β-gal) were calculated and expressed as means ± SD. B. Knockdown of Sam68 reduced the mRNA levels of downstream cyclin D1 and c-Myc genes as determined by qRT-PCR in A549 cells. C. Knockdown of Sam68 decreased the protein levels of downstream cyclin D1 and c-Myc as determined by western blotting in A549 and H1299 cells. D. H1299 cells were co-transfected with 0.1 μg of the TOP flash, 50 pmol siRNA oligos, 0.05 μg of β-galactosidase expressing plasmid and 0.25 μg flag-β-catenin expression plasmid. 72 h later, cells were lysed, luciferase and β-galactosidase activities were examined. Fold induction (Luc/β-gal) were calculated and expressed as means ± SD. E. H1299 cells were co-transfected with Sam68 siRNA oligos and flag-β-catenin expression plasmid. In 24 h, the cells were trypsinzed and seeded into 12-well plate. Colony formation assay was performed as described in Materials and Methods. **: P<0.01, ***: P<0.001, NS: no significance versus control group.