Figure 2.

Kinetics studies of HIF-1α expression. FaDu^CD44low, SQ20B^CD44low, FaDu-CSCs and SQ20B-CSCs cell lines were exposed to 10 Gy of photon or carbon ion irradiation under normoxia (respectively lines B and D) or acute hypoxia (line C and line E, line A for hypoxia alone). Kinetic studies from 30 min to 24 h were realised (n=3). The reference time was defined when cells were irradiated and/or placed under hypoxia. Forty micrograms of proteins were loaded on western blots and GAPDH was used as a reference protein. Positive and negative controls were realised with cells incubated 16 h in normoxia respectively after treatment with or without 200 μM cobalt salts.