Luteolin Increases the Expression of GRP94 in HeLa Cells

We found increased expression of GRP94, the 94-kDa glucose-regulated protein, in HeLa cells 24h after treatment with luteolin. Luteolin increased the levels of GRP94 mRNA and protein, but it did not increase the expression of unfolded protein response (UPR)-regulated genes. In addition, luteolin also enhanced GRP94 promoter activity, suggesting that it enhances the expression of GRP94 at the transcriptional level, not via the UPR signaling pathway.