Fig. 4: Cell death in B3-KO cells following RT is primarily necrotic.

a–m Transmission electron micrographs of HT3 (a–f) and SW756 (g–l) B3-WT and B3-KO cells 96 h after treatment with Sham or indicated doses of RT. Black scale bars shown for each image. Inset (c, f, i, l) shows magnified images of irradiated cells and are bound by a dashed black box. Yellow arrows indicate breaks in the plasma membrane, yellow c is cytoplasmic clearing, yellow asterisks indicate mitochondria, and yellow n indicates devolving nucleus. m Quantitation of percent of total cells showing necrotic morphology on 20 random TEM images by two blinded reviewers. Histogram height indicates mean of reviewers, * = student’s t-test p-value < 0.05, ** = student’s t-test p-value < 0.01. n–q Representative transmission electron micrographs of HT3-B3-KO (n, o) and SW756-B3-KO (p, q) cells 96 h after treatment with RT, with insets (o, q) showing high magnification regions delineated by a black box. Cytoplasmic lysosome-like structures with ruptured membranes are indicated by yellow arrows. Mitochondria marked with yellow arrows.