Figure 3. USP7 stabilizes oncogenic EZH2 mutants. (A) Flag-USP7 was expressed in HEK293T cells with HA-tagged gain-of-function EZH2 mutants. Cell lysates were subjected to immunoprecipitation with HA antibody and immunoblotted with anti-Flag or anti-HA antibody. (B) HEK293T cells were transfected with Flag-USP7 and HA-tagged gain-of-function EZH2 mutants. Cell lysates were immunoblotted with anti-Flag or anti-HA antibody. (C) HEK293T cells were transfected with USP7 shRNA and HA-tagged gain-of-function EZH2 mutants. Cell lysates were immunoblotted with anti-HA or anti-USP7 antibody. (D) HA-tagged gain-of-function EZH2 mutants were expressed in HEK293T cells, which were then treated with P5091 (12.5 μM) for 24 h before harvesting. Cell lysates were immunoblotted with anti-HA antibody. (E) Flag-USP7 was expressed in HEK293T cells with HA-tagged therapy-resistant EZH2 mutants. Cell lysates were subjected to immunoprecipitation with HA antibody and immunoblotted with anti-Flag or anti-HA antibody. (F) HEK293T cells were transfected with Flag-USP7 and HA-tagged therapy-resistant EZH2 mutants. Cell lysates were subjected to immunoblotting with anti-HA or anti-Flag antibody. (G) HEK293T cells were transfected with USP7 shRNA and HA-tagged therapy-resistant EZH2 mutants. Cell lysates were immunoblotted with anti-HA or anti-USP7 antibody. (H) HEK293T cells were transfected with HA-tagged therapy-resistant EZH2 mutants and treated with P5091 (12.5 μM) for 24 h before harvesting. Cell lysates were immunoblotted with anti-HA antibody.