Objective: To investigate the repression of c-myc induced by Blimp-1 in 2-methoxyestradiol(2ME2)-mediated differentiation of multiple myeloma cells.
Methods: CZ-1 and LP-1 myeloma cells lines were exposed to 0.5 micromol/L of 2ME2 and 0.5 micromol/L of 2ME2 + antisense oligonucleotides (ASODN) for 72 h. The effects on transcription of c-myc mRNA were studied by RT-PCR. The c-myc protein was assayed with Western blot. The changes of the cell lines in morphology, expression of surface CD49e and quantity of immunoglobin light chain secretion in the supernatant were studied.
Results: Incubation of the cells with 0.5 micromol/L of 2ME2 could up-regulated Blimp-1 expression and increase the expression of c-myc gene. In contrast, c-myc expression was decreased with Blimp-1 expression down-regulated by ASODN and the cell lines differentiation was arrested.
Conclusion: Blimp-1 could directly repress the expression of c-myc in 2ME2-mediated differentiation induction of multiple myeloma cells.