Abstract:Objective: To investigate molecular mechanism of tanshinone ⅡA inducing differentiation and apoptosis in acute promyelocytic leukemia NB4 cells. Method: NB4 cells were cultured in vitro and treated with tanshinone ⅡA and observed cellular morphology, cell category and the cellular proliferation. DNA microarray technique was used to analyze the gene expression profiles of NB4 cells induced by tanshinone ⅡA. Result: 92.8% of NB4 cells treated with 0.5 mg·L-1 tanshinone ⅡA were induced into mature neutrophils, in which myetocytes and melamyetocytes were 27.0%, banded and segmented neutrophits 68.2%. Cell growth were inhibited. cDNA microarray showed the enormously expressed 183 genes including 23 differentiation associated genes, and other interrelated genes. Conclusion: Tanshinone ⅡA inducing differentiation in NB4 cells may be via regulation of many kinds of genes, especially differentiation associated genes expression. This partially explained the molecular mechanism of tanshinone ⅡA inducing differentiation.