Figure 9

SMAD4 has a crucial role in TAZ-induced phenotypes. (a) TAZ represses SMAD4 protein level. Cells were infected with empty vector or flag-TAZ, and shRNA control or shTAZ. Cell lysates were subjected to immunoblotting. (b) Knockdown or overexpression of TAZ does not influence SMAD4 mRNA level. Total RNA was extracted from U2OS and MG-63 cells transfected with the indicated plasmids, and SMAD4 mRNA levels were determined by qRT-PCR (n=4, mean±S.D.). (c) Knockdown of Lats1/2 represses SMAD4 protein level. Cells were transfected with siRNAs as indicated and analyzed by immunoblotting. (d) Cell proliferation assay for SMAD4 and TAZ overexpression in U2OS and MG-63 OS cells. The cell growth rates were measured by the MTT assay (n=4, mean±S.D.). (e) SMAD4 reduced the migration ability induced by TAZ overexpression. Cell migration assay of TAZ-overexpressing cells transfected with SMAD4 or empty vector (n=4, mean±S.D., *P<0.01). (f) Cell proliferation assay for SMAD4 and TAZ knockdown in U2OS and MG-63 OS cells. The cell growth rates were measured by the MTT assay (n=4, mean±S.D.). (g) TAZ knockdown had no effect on the migration inhibition ability induced by SMAD4 knockdown. Cell migration assay of SMAD4 knockdown cells transfected with shTAZ or shControl vector (n=4, mean±S.D., *P<0.01). (h) Nude mice were injected with 1 × 10⁷ MG-63 stable cells. Tumors were dissected and photographed after 5 weeks