(A) Left and right panel, cell viability of FaDu or SCC-25 with log
doses (−9.3 to −4.3) of SU093 in the absence or presence
IR. (B) Left and right panels, cell viability assay of HSNCC FaDu
and SCC-25, respectively, cells were treated with different doses
of radiation (2.5 or 5 Gy) with or without SU093 (1 μM). On
day 7 of post-treatment, viable cells were quantified using the MTT
reagent, and absorbance was read at 570 nm. Cell viability was calculated
by normalizing the response of each condition to the control (absence
of radiation and SU093). (C,D) Colony formation assay of FaDu and
SCC-25 with SU093 with or without 5 Gy of ionizing radiation. Control
group received vehicle only. (E) Colony formation quantification of
FaDu and SCC-25 with SU093 or combined (5 Gy) treatment. Asterisks
indicate t test comparison between each treatment
and control, where ***P < 0.001, **P < 0.01, *P < 0.05.