Fig. 1

Cycloheximide induces apoptosis in CGL3 cells. a Phase-contrast micrograph of the normoxic CGL3 cells treated with 100 μg/ml CHX for 3 h. Dying cells show typical dark granular appearance. b Fluorescence image of the CHX-treated CGL3 cells subjected to terminal deoxytransferase-based labeling. The apoptotic cells show nuclear fragments of intense fluorescence. c Electrophoretic analysis of the chromosomal DNA fragmentation in CGL3 cells treated with 20 μg/ml CHX for 2 h, 4 h, and absence of apoptotic fragments in the control non-treated cells. d FACS analysis of the subG1 cells in subpopulations expressing versus non-expressing CA IX following the treatment with 20 μg/ml CHX for 2 and 4 h and staining with M75 and propidium iodide. e Staining of the CHX-treated CGL3 cells for CA IX with the M75 MAb and FITC-conjugated secondary antibody (green) and for cell nuclei with propidium iodide (red). Fragmented apoptotic nuclei are visible in the CA IX-negative cells (see arrows)