RAB5A and lung carcinoma: Thus, we first sought to evaluate whether stabilization of HIF-1α under normoxic conditions sufficed to account for Rab5-GTP loading, by transfecting A549 lung carcinoma cells with wild type HIF-1α (HIF-1αWT), or a stable, non-hydroxylatable mutant of HIF-1α (HIF-1αP564A/P402A).