FIGURE 1.

PHF20 is highly expressed in GBM, and increases cellular viability, proliferation and invasiveness of GBM cells in vitro and in vivo. (A) Demonstration of ablation of PHF20 in BT115 and U87 GBM PHF20 KO cells by western blotting analysis. PHF20 KO clones were generated with PHF20 sgRNA #1, #2, and #3. Cells transfected with non-specific sgRNA were used as control. (B) A total of 5,000 wild-type (WT) and PHF20 KO BT115 cells and 10,000 WT and PHF20 KO U87 cells were plated in a 96-well plate using 200 μl medium. Cell viability was assayed using an MTT assay (540 nm). Both PHF20 KO BT115 and U87 cells showed significantly reduced cell viability compared to control. (C) PHF20 KO and its control cells were subjected to transwell Matrigel invasion assays. Scale bar, 50 μm. (D) The quantification of migrated cells through Matrigel for each cell line. Scale bar, 100 μm. (E) A tumor sphere formation assay was performed to assess the self-renewal capacity of WT and PHF20 KO cells. Five random wells were photographed. (F) The quantification of the sphere number after 7 days for each cell line. (G) Representative xenografts excised from PHF20 KO and control groups of NSG mice (n = 5). (H) Growth of tumors following the subcutaneous injection of PHF20 KO and control cells. (I) The tumor weight of subcutaneous xenografts formed by U87 WT and PHF20 KO cells. The knockout group is remarkably decreased the tumor volume and weight. (J) IHC staining of PHF20 and Ki-67 of xenografts. Scale bar, 50 μm. Data are plotted as the mean ± SD of three independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001 compared to the controls using Student’s t-test.