3.3 GR mediates the downregulation of DOT1L and its target gene by Dex in B lymphoma cells
Dex suppressed the viability of Raji cells with apparent concentration-dependent effect (Figure 3A). However, Dex did not inhibit the growth of THP-1 cells even at a high concentration (8 μM). Moreover, Dex dramatically reduced the mRNA level of DOT1L and its target gene MEIS1 in Raji cells (Figure 3B). In addition, Dex remarkably downregulated the level of H3K79 in Dex-sensitive Raji cells but not in the Dex-insensitive THP-1 cells (Figure ). Pretreatment with GR antagonist RU486 significantly mitigated the Dex-induced suppression of cell growth, the mRNA levels of DOT1L , and MEIS1 , and protein levels of H3K79 in Raji cells (Figure 3D-F). Together, Dex could downregulate DOT1L and its target gene in a GR-dependent manner for B lymphoma cells.