Fig. 4.

Xanthatin upregulates the expression of ER stress-related genes and induces the nuclear translocation of CHOP in glioma cells. a U251 cells were treated with xanthatin (15 and 20 µM) for 12 h, and the mRNA levels of GRP78, XBP1s, ATF4, CHOP, PERK, and eIF2α were assessed by qRT-PCR. GAPDH was used as a control. Values are expressed as the mean ± SEM of three independent experiments. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 vs. the vehicle control group. n.s. no significance. b Representative images showing the nuclear translocation of CHOP in C6 cells treated with xanthatin (10 and 15 µM) or the ER stress inducer tunicamycin (TM). Scale bar = 50 µm