Fig. 6

BMP3 upregulates SMAD4, p21, and caspase-7 expression. a Quantitative RT-PCR was used to validate the expression levels of selected genes from the microarray data in HCT116-BMP3 cells. Data are presented as mean ± SD, n = 3. b WB analysis of SMAD4, p21 and caspase-7 were performed for HCT116-BMP3 and KM12-BMP3-shRNA cells. c The expression levels of SMAD4, p21, and caspase-7 were measured after knockdown of SMAD2, TAK1, or SMAD2/TAK1 via SMAD2 and TAK1 shRNA interference. d The expression of SMAD4, p21, and caspase-7 were examined by immunohistochemistry in xenograft tumors with BMP3 overexpression or knockdown. Scale bar is 200 μm. Bar graphs show the quantified results of cells stained positive for SMAD4, caspase-7, and p21 in xenograft tumors. Data were presented as the mean ± SD. e A correlation between the expression of BMP3 and SMAD4, p21, and caspase-7 was found in paired-normal and carcinoma tissues. Scale bar is 200 μm. f Schematic diagram of SMAD2-dependent and SMAD2-independent signaling pathways regulated by BMP3 in CRC. Red arrow, up-regulation; P, phosphorylation. * p < 0.05, ** p < 0.01