Fig 1: Proscillaridin A upregulates the expression of TRAIL receptors in a cell type-specific manner. (A) HT29, SW480, and SW620 cells were treated with 11.1 nM proscillaridin A (ProsA) for 24 h. Cell surface expression levels of DR4 and DR5 were determined via flow cytometry. Dotted lines indicate the cells stained without primary antibodies. Representative histograms from three independent experiments are shown. Bar-dot graphs indicate the mean fluorescence intensity (MFI). Results are represented as the mean ± SD of triplicate. (B) Relative gene expression levels of TNF receptor superfamily member 10a (TNFRSF10A; DR4) and TNFRSF10B (DR5) was determined via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The expression levels of the target gene were normalized to that of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Results pooled from two independent experiments are shown (n = 4). Results are represented as the mean ± SD. * p < 0.05; ** p < 0.01, *** p < 0.001; **** p < 0.0001 (unpaired t-test with Welch’s correction). ns, not significant.