PDGFA inhibition on endothelial cells impairs SOX11-enforced angiogenesis in MCL. (A) Graph showing the relative fold change expression levels of the basal and phosphorylated forms of PDGFRα and PDGFRβ by HUVEC cells upon 3-hour incubation with RPMI + 10% FBS (HUVEC) or Z138 SOX11-positive CM (HUVEC+SOX11-positive CM). Results are shown as fold increase relative to the corresponding expression levels by the HUVECs incubated with RPMI + 10% FBS. (B) Graphs showing number of branching points representing tube formation by HUVECs. HUVECs were pretreated with control PBS (gray), imatinib (blue), or a neutralizing antibody anti-PDGFRα (yellow) for 1 hour, and then incubated for 6 hours with RPMI + 10% FBS, SOX11-positive or SOX11-negative CM from Z138, GRANTA519, and JEKO1 MCL cell lines. (C) Graph displaying the relative perctage reduction in migration of HUVECs. HUVECs were pretreated with control PBS, imatinib, or a neutralizing antibody anti-PDGFRα for 1 hour, and then allowed to migrate toward RPMI + 10% FBS (gray), SOX11-positive CM (blue) or SOX11-negative CM (yellow) from Z138 MCL cell line. Upon overnight incubation, migratory cells were quantified and represented as the percentage of migration HUVECs compared with no drug (control PBS) treatment. 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.