Figure 2. Hypoxia down-regulates Wnt/β-catenin signaling in human OS cells.

A, MG-63 human OS cells were cultured under hypoxia over 72 hour, and increased HIF protein expression was observed by western blot. Protein levels of active β-catenin were decreased under hypoxic conditions relative to normoxic conditions (0 hour). Actin was the loading control. B, Axin2 mRNA levels were determined as a measure of Wnt/β-catenin signaling under hypoxic conditions (72 hour, 0.5% O₂) via quantitative reverse-transcription PCR (qrt-PCR) normalized to normoxia. Asterisks indicate statistical significance (*p<0.05).