Fig. 5.
EVI1 enhances the ATRA response of the endogenous RARβ gene in U937T_EVI1-HA cells. (A) Immunoblot analysis demonstrating induction of EVI1-HA in U937T_EVI1-HA E10 cells (E10) 48 h after removal of tetracycline (tet) from the culture media. U937T cells transfected with empty plasmid (U937T_EP P3 cells; P3) were used as a negative control. EVI1-HA was detected with an HA antibody; hybridization with an antibody against β-tubulin was used as a loading control. (B) U937T_EVI1-HA E10 cells (E10) and U937T_EP P3 cells (P3) were maintained in the presence or absence of tetracycline and of ATRA for 24 and 48 h. RARβ mRNA levels were determined by RTQ-RT-PCR and related to those of the housekeeping gene cyclophilinD using the ΔΔCT method [45]. Because RARβ expression was undetectable in the absence of ATRA, the corresponding data are not shown. White and black columns, cells cultured in the presence or absence of tetracycline, respectively.