Figure 5. Sig1R enhanced the crosstalk between bladder cells and HUVECs and promoted migration and tube formation in HUVECs. (A, B) Sig1R promoted tumor-induced HUVEC migration according to wound healing and transwell migration assays, scale bar = 100 μm. (C) Sig1R promoted tumor-induced HUVEC angiogenesis according to tube formation assays in BEM in vitro, scale bar = 100 μm. (D) Quantification of VEGFA concentration in CM are shown. (E) Sig1R promoted tumor-induced HUVEC angiogenesis according to tube formation assays in BEM in vivo. *p < 0.05, **p < 0.01, and ***p < 0.001.