Fig. 6

SUV39H1 regulates the expression of Smad9/BMP4 in A549 cells. a Data obtained from the TCGA database analyzed for the expression levels of Smad9 in lung tumor and normal samples. The x-axis represents the sample type and the y-axis represents the gene expression value. b Expression levels of SUV39H1, Smad9, and BMP4 determined by RT-qPCR in A549 cells treated with EVs from BEAS-2B and H1299 cells. c Western blot analysis showing the expression of SUV39H1, Smad9, BMP4 and the extent of Smad9 phosphorylation in A549 cells treated with EVs from BEAS-2B and H1299 cells (* p < 0.05, vs. A549 cells treated with EVs from BEAS-2B cells). d Expression of SUV39H1, Smad9, and BMP4 determined by RT-qPCR in si-SUV39H1-treated A549 cells. e Western blot analysis evaluating the expression of SUV39H1, Smad9, and BMP4 and the extent of Smad9 phosphorylation in si-SUV39H1-treated A549 cells (* p < 0.05, vs. A549 cells treated with si-NC). f Knockdown efficiency of siRNA targeting Smad9 determined by RT-qPCR in A549 cells. g Western blot analysis validating the knockdown efficiency of siRNA targeting Smad9 in A549 cells (* p < 0.05, vs. A549 cells treated with si-NC). h Expression of SUV39H1, Smad9, and BMP4 in A549 cells transfected with si-Smad9, si-SUV39H1 or both. i Western blot analysis detecting the expression of SUV39H1, Smad9, and BMP4 and the extent of Smad9 phosphorylation in A549 cells transfected with si-Smad9, si-SUV39H1 or both (* p < 0.05, vs. A549 cells treated with si-NC; # p < 0.05, vs. A549 cells treated with si-Smad9). Data are summarized as mean ± standard deviation of three technical replicates. Data from two groups were compared using unpaired t-test and data from multiple groups were analyzed by one-way ANOVA with Tukey's post hoc tests