SOX11 binds to regulatory regions of PDGFA and positively regulates its transcription. (A) GSEA analysis on expression data set from SOX11-positive and SOX11-silenced MCL cell lines showing enriched gene sets related to angiogenesis pathways. NES, P-val, and FDR are represented. Statistical significance is considered when FDR < 0.2. (B) Top panel, Image showing human-specific angiogenesis antibody array membranes incubated with protein lysates from Z138 SOX11-positive (n = 2) and SOX11-silenced (n = 2) MCL cell lines. Bottom panel, Quantification of mean pixel density of the proangiogenic factors Activin A, ANGPT2, PDGFA, and VEGF comparing SOX11-positive and SOX11-silenced MCL cell lines. (C) Graph displaying the relative levels of PDGFA secreted by SOX11-positive and SOX11-silenced CM derived from Z138 and GRANTA519 MCL cell lines. Concentration was analyzed by a quantibody human angiogenesis array. Results are shown as relative percentage of PDGFA secretion compared with SOX11-positive CM. (D) Graph displaying the GO term results obtained from DAVID functional annotation tool of the high confidence SOX11-bound genes identified by ChIP-chip experiments (GSE3502).¹⁵  The 6 most significant biological process GO terms and their gene count, enrichment score, and P-val are shown. Underlined is the blood vessel development GO biological term. (E) ChIP-qPCR analysis of specific binding of SOX11 to the regulatory regions of PDGFA in JEKO1 and Z138 MCL cell lines. Binding to PAX5 was used as a positive internal control.¹⁵  Relative DNA enrichment was measured by qPCR using specific primers for the respective regulatory regions (see “Methods”), and is displayed as fold enrichment relative to their respective input chromatin. Purple bars represent ChIP-qPCR enrichment of the SOX11 pull-down (SOX11-ChIPed DNA) while gray bars represent the negative control (IgG-ChIPed DNA). (F) Luciferase assays in transient cotransfections of PAX5-GL4.23 Luc and PDGFA-GL4.23 Luc with SOX11 full-length (pcDNA3-SOX11) and the truncated SOX11 proteins (pcDNA3-SOX11ΔHMG) expression vectors in HEK293 cells. Results are shown as the percentage of fold induction relative to luciferase activity in cotransfection with the empty vector (pcDNA3-Ǿ). Bar plot represents the mean percentage ± SD of 3 independent experiments. P-val are shown. The significance of difference was determined by independent samples Student t test.