Effect of sequential combination of DAC and IDA in inhibiting Wnt/β-catenin pathway in AML cells in vitro and tumor cells from a subcutaneous AML mouse model. A, The mRNA expression of inhibitors and downstream genes of Wnt/β-catenin signaling pathway was measured by RT-PCR in control cultures, DAC treated cultures, IDA treated cultures and DAC followed by IDA treated cultures in the U937, HEL and SKM-1 cell lines. Expression was normalized in comparison with control cultures. The mean ± SD of four different experiments is shown. Statistical differences were calculated by one-way ANOVA. *p < 0.05, **p < 0.01, ***p < 0.001. B, Western blot analyze the protein expression of inhibitors and downstream genes of Wnt/β-catenin signaling pathway in four cultures of AML cell lines and tumor cells from AML mouse model. C, Immunohistochemistry for β-catenin in tumor tissues of subcutaneous AML mouse model. β-catenin expression was more frequently observed in group treated with DAC combining with IDA than treated with DAC or IDA alone.