![Figure 7. p85β suppresses the oncogenic potential of activating KITD814V mutation. (A) p85β inhibits the constitutive growth of oncogenic KITD814V-expressing cells. Cells (32D) were coinfected with WT KIT or KITD814V and p85α or p85β subunits, and cells were sorted to homogeneity. Cells were starved in serum- and cytokine-free medium for 6 hours and cultured in the absence of growth factors. After 48 hours, proliferation was evaluated by [3H]thymidine incorporation assay. Bars represent the mean [3H]thymidine incorporation (CPM + SD) from one representative experiment performed in quadruplicate. Similar results were observed in 3 independent experiments. *P < .01, KITD814V and p85α versus KITD814V and p85β. (B) p85β prolongs the survival of mice transplanted with oncogenic KITD814V-expressing cells. Kaplan-Meier survival curves of mice transplanted with 32D cells coinfected with WT KIT or KITD814V and p85α or p85β subunits. Cells (32D; 1 × 106) were injected into syngenic C3H/HeJ mice and mice were monitored for MPD (n = 7). Solid lines represent the survival of p85β-expressing oncogenic KITD814V-transplanted mice; and dotted lines, survival of p85α-expressing KITD814V-transplanted mice. *P < .01, p85β versus p85α. (C) HMC1.2 cells transduced with indicated p85 constructs were sorted to homogeneity based on EGFP expression. To detect the expression of p85 subunits, cells were harvested and subjected to Western blot analysis using anti-HA and β-actin antibodies as indicated. Similar expression of p85α and p85β was observed in transduced cells. (D) HMC1.2 cells transduced with indicated p85 constructs were starved in serum- and cytokine-free medium for 6 hours and cultured in the absence of growth factors. After 48 hours, proliferation was evaluated by [3H]thymidine incorporation assay. Bars represent the mean [3H]thymidine incorporation (CPM + SD) from one representative experiment performed in quadruplicate. Similar results were observed in 3 independent experiments. *P < .05, HMC1.2 versus HMC1.2/p85β. *P < .05, HMC1.2/p85α versus HMC1.2/p85β.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/119/17/10.1182_blood-2011-05-355602/4/zh89991289410007.jpeg?Expires=1723745926&Signature=sPAYvo1NKpp6evHF5bNd2uJpeBwgqonQd4VeDHf4-grnsw9OXAfqSmbbpuyflnM0GD7DETJaWH5Qg~eUjN-9ZI2n4ZPTvXquKWbfAF106vhKATkCTYVfl5WdrmVoV0l6cahNepHiXLxx-tEXZxoroEbJxdnZFjjvMsJAWGB1Bv4WYhNUlPmato6EICBAxr9xpL9e7RuzyjaSytNhyF4HnPbfi43C8Qu4TGtdlVHLfYuDRlIMwiAwogSf9k8LyMasuitjXF5~L0sSXObdShpp1RT6gqKULaSizJ7xxBYK0ujOuoOYaBa5EnXuBantS2RjEvLYxWU5Zbv0gpQIlmjISQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
p85β suppresses the oncogenic potential of activating KITD814V mutation. (A) p85β inhibits the constitutive growth of oncogenic KITD814V-expressing cells. Cells (32D) were coinfected with WT KIT or KITD814V and p85α or p85β subunits, and cells were sorted to homogeneity. Cells were starved in serum- and cytokine-free medium for 6 hours and cultured in the absence of growth factors. After 48 hours, proliferation was evaluated by [3H]thymidine incorporation assay. Bars represent the mean [3H]thymidine incorporation (CPM + SD) from one representative experiment performed in quadruplicate. Similar results were observed in 3 independent experiments. *P < .01, KITD814V and p85α versus KITD814V and p85β. (B) p85β prolongs the survival of mice transplanted with oncogenic KITD814V-expressing cells. Kaplan-Meier survival curves of mice transplanted with 32D cells coinfected with WT KIT or KITD814V and p85α or p85β subunits. Cells (32D; 1 × 106) were injected into syngenic C3H/HeJ mice and mice were monitored for MPD (n = 7). Solid lines represent the survival of p85β-expressing oncogenic KITD814V-transplanted mice; and dotted lines, survival of p85α-expressing KITD814V-transplanted mice. *P < .01, p85β versus p85α. (C) HMC1.2 cells transduced with indicated p85 constructs were sorted to homogeneity based on EGFP expression. To detect the expression of p85 subunits, cells were harvested and subjected to Western blot analysis using anti-HA and β-actin antibodies as indicated. Similar expression of p85α and p85β was observed in transduced cells. (D) HMC1.2 cells transduced with indicated p85 constructs were starved in serum- and cytokine-free medium for 6 hours and cultured in the absence of growth factors. After 48 hours, proliferation was evaluated by [3H]thymidine incorporation assay. Bars represent the mean [3H]thymidine incorporation (CPM + SD) from one representative experiment performed in quadruplicate. Similar results were observed in 3 independent experiments. *P < .05, HMC1.2 versus HMC1.2/p85β. *P < .05, HMC1.2/p85α versus HMC1.2/p85β.
