Ultrastructural aspects of autoschizis: A new cancer cell death induced bythe synergistic action of ascorbate/menadione on human bladder carcinoma cells

Scanning and transmission electron microscopy were employed to further char acterize the cytotoxic effects of a ascorbic acid/menadione (or vitamin C/v itamin K-3) combination on a human bladder carcinoma T24 cell line. Followi ng l-h treatment T24 cells display membrane and mitochondrial defects as we ll as excision of cytoplasmic fragments that contain no organelles. These c ontinuous self-excisions reduce the cell size. Concomitant, nuclear changes , chromatin disassembly, nucleolar condensation and fragmentation, and decr eased nuclear volume lead to cell death via a process similar to karyorrhex is and karyolysis. Because this cell death is achieved through a progressiv e loss of cytoplasm due to self-morsellation, the authors named this mode o f cell death autoschizis (from the Creek autos, self, and schizein, to spli t, as defined in Scanning. 1998; 20: 564-575). This morphological character ization of autoschizic cell death confirms and extends the authors previous reports and demonstrates that this cell death is distinct from apoptosis.