ER stress is triggered in goniothalamin-treated HeLa cells. (A) mRNA expression levels of ER stress-associatead genes, including CHOP, ERdj4, GADD34 and GRP78 in HeLa cells treated with 15 µM of goniothalamin for 3, 6, 9 and 12 h using RT-qPCR analysis. (B) Immunoblotting analysis of ER stress mediators, CHOP and GRP78. Images shown are representative from three independent experiments. (C) Analysis of the splicing of XBP1 mRNA using RT-PCR analysis. Values of fluorescence intensity are presented as the mean ± standard deviation from at least three independent experiments. ***P<0.001, vs. ctrl (control). ER, endoplasmic reticulum; CHOP, C/EBP homologous protein; ERdj4, ER-localized Dna J homologue 4; GADD34, growth arrest and DNA damage protein 34; GRP78; glucose-regulated protein 78; RT-qPCR, reverse transcription-quantitative polymerase chain reaction; ctrl, control.