Figure 1. HIF-1α pathway is induced by hypoxia and mTOR activity in uveal melanoma.

A, HIF-1α protein levels were determined by Western blot in OCM1, Mel285, Mel290, OMM1 and 92.1 lines grown in normoxia (N) or in hypoxia (H) for 24 hours; β-Actin was used as loading control. B, C, VEGF (B) and LOX (C) mRNA levels were analyzed by qPCR in five uveal melanoma lines after exposure for 24 hours to normoxia (N) or hypoxia (H), (*p = 0.02; **p = 0.005; ***p<0.0001). D, Expression of HIF-1α and CD34 was examined in snap frozen primary uveal melanoma specimens by immunohistochemistry. Scleral tissue is present on the left (asterisks) and tumor showing irregular cracking artefact due to freezing on the right. CD34 stains (arrows) highlight a dense capillary network, with diffuse HIF-1α staining in tumor tissue. E, HIF-1α, phospho-Ser^235/236 S6 and total S6 ribosomal protein levels were determined by Western blot in OMM1 and 92.1 lines after 24 hours of treatment with rapamycin at 25, 50, 100 nM or DMSO; total ribosomal S6 protein was used for loading control.