Figure 7.

Pharmacological modulation of PP2A activity regulates DP thymocyte hyperproliferation‐associated tumorigenesis. A) Intraperitoneal injection of ENU at around postnatal day 13 ∼15 (three‐time) was performed to Ripk3^+/+ mice. After 30 days of injection, mice were injected with LB‐100 or PBS intraperitoneally at 2 mg kg⁻¹ on alternate days for 30 days. (n = 4 for each group). B) Phosphorylation of ERK increased in response to anti‐CD3 (1 µg mL⁻¹) and anti‐CD28 (2 µg mL⁻¹) stimulation, which was further increased by LB‐100 treatment. C) Activation of ERK increased in LB‐100 injected Ripk3^+/+ thymus. D) Relative fluorescence of Ki‐67 in thymic T cells analyzed by Flow Cytometry. Ki‐67 expression is enhanced in LB‐100 injected Ripk3 ^+/+ thymocytes. E) Schematic diagram of an ENU injection experiment. After 30 days of ENU injection, Ripk3^−/− mice were injected with SMAP or PBS intraperitoneally at 2 mg kg⁻¹ on alternate days for 30 days. (n = 4 – 6 for each group). F) Activation of ERK reduced in SMAP injected Ripk3^−/− thymus. G) Ki‐67 expression is decreased in SMAP injected Ripk3^−/− thymocytes. Relative fluorescence of Ki‐67 expression analyzed by Flow Cytometry. Statistical analyses were performed using the two‐tailed unpaired Student t‐test. P values below 0.05 were considered significant in the following manner: *p < 0.05, **p < 0.01, ***p < 0.001.