Figure 2. Upregulation of HIF-1α increases cellular invasion in uveal melanoma lines.

A, Transwell invasion assay was performed in five uveal melanoma lines exposed to normoxia (N) or hypoxia (H) for 24 hours. In the microphotographs of the right panels the invading Mel285 or Mel290 cells are visualized on the lower surface of the Matrigel-coated filter after 24 hours of incubation in normal (21%) or low (1%) oxygen tension (*p = 0.02; **p = 0.002; ***p<0.0001). B, HIF-1α protein levels were determined by Western blot in Mel285 cells expressing an oxygen stable mutant of HIF-1α (HIF-1α^{Pro402Ala/Pro564Ala}) or pBABE control vector. GAPDH was used as loading control. C, VEGF and LOX mRNA levels were analyzed by qPCR in Mel285 cells expressing HIF-1α oxygen stable mutant or pBABE vector (*p = 0.01; ***p<0.0001). D, MTS assay shows induction of cell growth in Mel285 cells infected with HIF-1α oxygen stable mutant compared to pBABE vector (*p = 0.04). E, Transwell invasion assay reveals increase of the invading capacity of Mel285 cells expressing HIF-1α oxygen stable mutant compared to control vector (***p<0.0001).