Figure 5: SAHA inhibition of UPS allograft growthis dependent on HIF-2α re-expression.

(a) Proliferation of KP230 and KP250 cells treated with DMSO or SAHA (2 μM) under 21% O₂ or 1% O₂. Drug treatment began on day 1. Each line represents three independent experiments performed in duplicate. ***P<0.001. (b) Tumour size of subcutaneous (s.c.) KP250 allografts in DMSO (n=10) or SAHA (50 mg kg⁻¹ per day)-treated mice (n=10). Mice were treated once tumours reached ∼100 mm³. *P<0.05, ***P<0.001. (c) Tumour weights from DMSO- and SAHA-treated mice. Images are representative of tumours from the DMSO and SAHA cohorts. ***P<0.001. (d) Weights of mice pre-treatment and at time of killing. Black squares, DMSO-treated mice; red circles, SAHA-treated mice. (e) Left: Epas1 mRNA expression of KP250 cells harbouring scrambled (SCR) shRNA, and two independent HIF-2α (H2α) shRNAs, treated with DMSO or SAHA (2 μM) in vitro. Bars represent two independent experiments performed in triplicate. Right: Relative size increases of s.c. KP250 allografts with SCR shRNA, H2α 1 shRNA and H2α 2 shRNA-treated with DMSO or SAHA (50 mg kg⁻¹ per day). Mice were treated 10 days post-injection of tumour cells. For each shRNA, 7 mice were treated DMSO and 7 mice were treated with SAHA. *P<0.05, **P<0.01. (f) Relative tumour size of s.c. KP250+SCR shRNA allografts treated with DMSO, doxorubicin or doxorubicin and SAHA. Treatment began 10 days post-injection of tumour cells. Doxorubicin was administered at 5 mg kg⁻¹ per week, and SAHA was administered at 50 mg kg⁻¹ per day. *P<0.05, **P<0.01. (g) Comparative tumour size of KP250+HIF-2α shRNA 2 (H2α) allografts treated with DMSO, doxorubicin or doxorubicin and SAHA. *P<0.05. (h) Relative tumour weights of KP250 allografts with SCR or H2α shRNA. Sizes of doxorubicin and doxorubicin with SAHA treatment are normalized to their respective DMSO control. **P<0.01. All data shown are the mean±s.e.m. All P-values were calculated using a two-tailed Student’s t-test.