Autoschizis: another cell death for cancer cells induced by oxidative stress.

Scanning and transmission electron microscopy (SEM and TEM) were employed to characterize the cytotoxic effects of vitamin C (VC), Vitamin K3 (VK3) or a VC:VK3 combination on a human bladder carcinoma cell line (T24) following vitamin treatment. T24 cells exposed to VC alone showed membrane defects. VK3-treated cells show greater damage than VC treated cells because they exhibit membrane defects, cytoskeletal damage, excision of cytoplasm, and a substantial decrease in the number of viable cells. VC: VK3 treatment exacerbates the damages, especially intranuclear and nucleolar and induces an extreme reduction of cell size by cytoplasmic self-excision. Conversely, the nuclear envelope remains intact and the rough endoplasmic reticulum (RER) maintains its integrity until karyorrhexis occurs through a new phenomenon of cell death that we have named "autoschizis". From our morphological studies and previous biochemical reports on the topic, we are able to propose that this autoschizic cell death found is induced by oxidative stress.