The combined effect of tRA and As2O3 on differentiation induction, gene modulation, and PML-RARα degradation in tRA-resistant APL cells.
(A) Growth inhibition. R4, MR-2, and HL-60/Res were treated with 0.5 μM As2O3 with or without 10−7 tRA for 4 days. (B) Differentiation. NBT reduction was used to measure differentiation ability. R4, MR-2, and HL-60/Res were treated with 0.5 μM As2O3 with or without 10−7 tRA for 4 days. (C) PML-RARα and RARα protein levels. NB4, R4, and MR-2 cells were treated with 0.5 μM As2O3 with or without 10−7 tRA for 4 days. Anti-RARα antibody was used to detect PML- RARα and RARα. (D) Gene expression. NB4, R4, and MR-2 cells were treated with 0.5 μM As2O3 with or without 10−7 tRA for 4 days. Northern blot analysis was used to measure gene expression.
