Figure 4. MSC-derived TGF-β promotes chemoresistance and autophagy in OS cells. (A) Western blot was performed to test TGF-β expression in leptin-treated MSCs after shRNA-mediated TGF-β knockdown. (B) CCK8 assay results from MG-63 and U-2 OS cells exposed to cisplatin (40 μM) in the presence of CM from leptin-treated MSCs transfected with TGF-β shRNA or a scrambled control shRNA. *p<0.05. (C) Apoptosis detection by PI/Annexin V-FITC flow cytometry in OS cells treated with CM from leptin- and TGF-β shRNA-treated MSCs. *p<0.05. (D) Western blot was employed to examine the expression of LC3 and P62 in OS cells treated with CM from leptin- and TGF-β shRNA-treated MSCs.