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

Scanning and transmission electron microscopy (SEM and TEM) were employed t o characterize the cytotoxic effects of vitamin C (VC), Vitamin K-3 (VK3) o r a VC:VK3 combination on a human bladder carcinoma cell line (T24) followi ng 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: VK, treatment exac erbates the damages, especially intranuclear and nucleolar and induces an e xtreme 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 stud ies and previous biochemical reports on the topic, we are able to propose t hat this autoschizic cell death found is induced by oxidative stress.