Fig. 5
Oridonin blocks the inhibition of ER stress by TCF4 in colorectal cancer. A-C EdU, Tranwell, and Wound healing assays showing proliferation, invasion, and migration of RKO cells stably transfected with Mock or TCF4 and treated with or without oridonin (n = 3). Scale bars of B: 50 μm. D Flowchart of xenografts by subcutaneous injection of RKO cells stably transfected with Mock or TCF4 and treatment with or without oridonin. E Representative fluorescence and tumor images of the xenografts by subcutaneous injection of RKO cells stably transfected with Mock or TCF4 and treatment with or without oridonin (n = 5). F Western blot assay indicating the levels of TCF4, IRE1α, p-IRE1α, PERK, p-PERK, and CHOP in RKO cells stably transfected with Mock or TCF4 and treated with or without oridonin (n = 3). Normalized to β-actin. G Representative fluorescence images and the quantized histogram of ER tracker-red in RKO cells stably transfected with Mock or TCF4 and treated with or without oridonin (n = 3). Scale bars: 10 μm. H Flow cytometry analysis of intracellular ROS levels in RKO cells stably transfected with Mock or TCF4 and treated with or without oridonin (n = 3). G The calcium indicator Fluo-3 AM detects intracellular Ca2+ levels in RKO cells stably transfected with Mock or TCF4 and treated with or without oridonin (n = 6). The statistical results were presented as mean ± SD. Student’s t-test compared the difference in A-B and G-I, and two-way ANOVA compared the difference in C. * P < 0.05, ** P < 0.01 compared with Mock + ORI, and # P < 0.05, ## P < 0.01 compared with TCF4 + DMSO