Fig. 4

DICER1-AS1 binding protein YY1 is essential for the expression of DICER1. A The diagram for selected candidate transcription factors from the TCGA and GEO (GSE21501) database using the catRAPID and JASPAR website. B The heatmap showing the prediction of the interaction between DICER1-AS1 and YY1 protein. The colors of the heatmap showing the interaction score (ranging from -3 to 3) of the individual amino acid and nucleotide pairs. The interaction propensity between DICER1-AS1 and YY1 protein is 47 and the discriminative power is 93%. C The expression correlation between DICER1-AS1 and DICER1 in PC tissues derived from the GEO database (GSE21501) and the TCGA database. D Kaplan–Meier survival analysis of patients with high or low levels of YY1 in PC patients derived from the GEO database (cutoff value = 5.81). E RIP assay was applied using the anti-YY1 antibody and IgG antibody. The detection of DICER1-AS1 (left panel) was performed using specific primers in BxPC-3 and PANC-1 cells. Then the PCR products were run on a 2% agarose gel (right panel). F Western blot of the proteins from RNA pull-down assays using anti-YY1 and anti-HuR antibodies. RNA from the 3´ untranslated region (UTR) of the androgen receptor (AR) served as the control, containing UC-rich HuR binding regions. G Western blot of YY1 pulled down by full-length (F1: 1–830) or a series of DICER1-AS1 truncates or antisense in BxPC-3 cells. H DICER1 mRNA (upper panel) and protein (lower panel) were detected in BxPC-3 and PANC-1 cells transfected with empty vector, DICER1-AS1, antisense or DICER1-AS1 truncates. I RIP assay (right panel) was performed in BxPC-3 cells to detect the binding efficiencies between different fragments of YY1 protein with DICER1-AS1. Schematic structures of YY1 protein and three truncated mutants of YY1 variants were used in this study (left panel). J Visualization of interaction between the 3D structure of the YY1 zinc-finger domain and DICER1-AS1 (374–830 nt). All data were presented as means ± SD of at least three independent experiments. Values are significant at ^aP < 0.05, ^bP < 0.01 and ^cP < 0.001 as indicated