Fig. 4: Oxygen and nutrient deprivation result in accumulation of TRAILR2.

a, b Cell lysates of 2D-cultivated cells or cells grown as spheroids (day 11) were analyzed by western blotting. Blots are representative of three independent experiments. c Paraffin-embedded spheroid slices (day 11) were immunohistochemically stained for Hif-1α and counterstained with hematoxylin. Cells were color coded as positive (yellow) or negative (blue). Pictures are representative of three independent experiments. Scale bars = 200 μm. d Percentages of cells positive or negative for Hif-1α expression are shown as mean values ± SD of 4–16 spheroids from 3 independent experiments. Asterisks indicate statistical significance (***p ≤ 0.001; unpaired t-test). e Lysates from cells cultivated at 1% O₂ were analyzed by western blotting. Blots shown are representative of three independently performed experiments. f TRAILR2 surface expression measured by flow cytometry. Medians of the cell populations were used to calculate surface expression relative to cells cultivated at control conditions. Data are mean values ± SD of at least three independent experiments. g Lysates from cells cultivated at starvation conditions were analyzed by western blotting. Blots shown are representative of three independently performed experiments. h TRAILR2 surface expression measured by flow cytometry. Medians of the cell populations were used to calculate surface expression relative to cells cultivated at control conditions. Data are mean values ± SD of at least three independent experiments.