The extracellular domain of epithelial cell adhesion molecule (EpCAM) enhances multipotency of mesenchymal stem cells through EGFR-LIN28-LET7 signaling - PubMed

EpEX up-regulates cell cycle regulators and stemness markers via EGFR–STAT3 signaling. A, MSCs were treated with EpEX (3 μg/ml) for the indicated times. After treatment, the protein levels of total STAT3 and phospho-STAT3 (Tyr-705) were examined by Western blotting. B, MSCs were treated with EGFR shRNA or shLuc, and total STAT3 and phospho-STAT3 (Tyr-705) was examined by Western blotting with or without EpEX treatment. The results in Figs. 2, I and J, and 3B were from one and the same experiment and are shown separately because of the size of the image; therefore, Figs. 2, I and J, and 3B were with the same EGFR. C and D, cells were pretreated with a STAT3 inhibitor (WP1066, 5 μ

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), followed by stimulation with EpEX for 18 h. Cell cycle progression was investigated by flow cytometry with PI staining. Fraction of cells in each phase (G₁, S, and G₂/M) of the cell cycle was evaluated. E and F, cells expressing STAT3 shRNA were treated with EpEX for 18 h, after which cell cycle progression was investigated by flow cytometry with PI staining. Fraction of cells in each phase (G₁, S, and G₂/M) of the cell cycle was evaluated. G and H, MSCs were pretreated with or without WP1066 and then stimulated by EpEX. The protein levels of cell cycle regulators (cyclin D1, cyclin D2, cyclin E1, CDK4, and CDK9) and pluripotency factors (Oct4, Sox2, c-Myc, and Lin28) were examined by Western blotting. The results of G and H were from one and the same experiment and are shown separately because of the size of the image; therefore, G and H were with the same GAPDH. I and J, MSCs expressing STAT3 shRNA or shLuc were stimulated with EpEX. After treatment, the protein levels of cell cycle regulators (cyclin D1, cyclin D2, cyclin E1, CDK4, and CDK9) and pluripotency factors (Oct4, Sox2, c-Myc, and Lin 28) were examined by Western blotting. K, MSCs expressing STAT3 shRNA or shLuc were stimulated with EpEX. After treatment, the gene expression of pluripotency factors (Oct4, Sox2, c-Myc, Lin28, and EpCAM) was examined by qPCR. Data represent the mean ± S.D. *, p < 0.05.