Fig. 2

Oridonin induces Endoplasmic Reticulum stress in colorectal cancer. A CCK-8 assay showing the cell inhibition ratio of LoVo and RKO cells. LoVo and RKO cells were treated with oridonin (ORI, 22 μM) and with or without Z-VAD (10 μM) or CQ (20 μM) or 4-PBA (3 mM) for 24 h (n = 6). B CCK-8 assay showing the cell viability of LoVo and RKO cells treated with oridonin (22 μM) and 4-PBA (0, 1, 2, 3, 4, 5 mM) for 24 h (n = 6). C Western blot assay showing the expression of the ATF4 and CHOP in LoVo and RKO cells treated with oridonin (0, 20, 25, 30 μM) for 24 h (n = 3). D-F The quantitative histogram (D) and representative fluorescence images (E–F) for ATF4 and CHOP in LoVo and RKO cells treated with or without oridonin for 24 h. Scale bars of E: 50 μm. Scale bars of F: 75 μm (n = 3). G The representative fluorescence images (left panel) and fluorescence intensity quantitative histogram (right panel) of ER tracker-red in LoVo and RKO cells (n = 3). Scale bars: 10 μm. The statistical results were presented as mean ± SD. Student’s t-test compared the difference in A, D, and G; one-way ANOVA compared the difference in B. * P < 0.05, ** P < 0.01 compared with the Control in LoVo cells; # P < 0.05, ## P < 0.01 compared with the Control in RKO cells. ER: Endoplasmic reticulum; Z-VAD: Z-VAD-FMK; CQ: chloroquine; 4-PBA: 4-Phenylbutyric acid; ATF4: Activating transcription factor 4; CHOP: DNA damage-inducible transcript 3