Fig. 4

CAF-secreted STC1 directly bound to Notch1 receptor and activated the Notch signaling pathway. A Correlations between STC1 and Notch1 expression in HCC TCGA database were determined by as Pearson correlation analysis; B MHCC-97H cells were cultured with CAF-CM or DMEM. Immunofluorescence images of cells showing the localization of STC1 (red) and Notch1 (green) after 48 h of pretreatment. Scale bar, 50 μm; C, D Reciprocal co-IP experiments were performed with an anti-STC1 or anti-Notch1 antibody in MHCC-97H (C) and SNU-398 (D) cells. The interaction of endogenous STC1 and endogenous Notch1 was verified by immunoblotting. E The expression of STC1 and Notch1 in tumor tissues and adjacent nontumor tissues on tissue microarrays was analyzed by IHC staining. F Correlation between STC1 and Notch expression in HCC tissues. Scale bars: 200 μm and 50 μm. **** P < 0.0001, Pearson correlation analysis