Fig. 3.

Snail is involved in hypoxia-induced TEL2 down-regulation in NPC. a Migration and invasion activity was measured after 24 h in transwell assays under normoxia (Nor, 21% O₂) or hypoxia (Hyp, 1% O₂). Data are mean ± SEM. The number of cells passing through the membrane in each transwell was analyzed in triplicate and repeated three times with similar results. **P < 0.01. b Representative image of the assay in a. Red scale bar, 100 μm. c Levels of Snail, HIF1α and TEL2 proteins were analyzed by Western blot in S26 cells exposed for 24 h to normoxia (21% O₂) or hypoxia (1% O₂). d Levels of Snail, E-cadherin and TEL2 mRNA were measured by qRT-PCR in S26 cells treated as in (c). e Level of Snail protein in S26 cells was analyzed by Western blot after Snail knockdown. Tubulin was used as a loading control. f Levels of TEL2 and HIF1α proteins were measured in the indicated cells after treatment as in c. Tubulin was used as a loading control