Abstract: Objective：To Investgiate the expression of C/EBPβ in APL cells during differentiation induced by TanⅡA. Methods TanⅡA treated NB4 and MR2 cells 120h, the characterizations of differentiation were examined by morphology and membrane differentiation antigens；The mRNA and protein expressions of C/EBPβ in different concentration TanⅡA-intervened APL cells were examined by RT-PCR and Western-blot；APL cells were treated with different concentration TanⅡA, the characterizations of differentiation were examined by membrane differentiation antigens. Results TanIIA induced the differentiation of ATRA-sensitive and ATRA-resistant APL cells（p<0.05）; TanIIA dose-dependend upregulated the expression of C/EBPβin mRNA and protein（p<0.05）; TanIIA promoted the differentiation of the NB4 and MR2 cells in a dose-independent manner and exerted its strongest effect at a concentration of 1 mg/L. Conclusion TanIIA promoted the differentiation of ATRA-sensitive and ATRA-resistant APL cells and exerted its strongest effect at a concentration of 1mg/L; C/EBPβ played a key role in TanIIA-induced differentiation.

Key words: TanⅡA, C/EBPβ, differentiation