Morphology and DNA degeneration during autoschizic cell death in bladder carcinoma T24 cells induced by ascorbate and menadione treatment

Abstract

Feulgen and actin-phalloidin staining as well as gel electrophoresis have been employed in conjunction with cell ultrastructure to describe the effects of 1-, 2-, and 4-hr ascorbate (VC), menadione (VK 3 ), and ascorbate:menadione (VC:VK 3 ) treatments on the T24 human bladder carcinoma cell line. T24 cells exposed to VC alone display blebs and other superficial membrane defects related to membrane alterations and to superficial cytoskeleton changes. VK 3 treatment damages the cell nucleus and organelles, leads to the redistribution of the organelles in the perikaryon as a consequence of cytoskeletal damage, and results in cytoplasmic self-excisions. After VC:VK 3 treatment, the cells show exaggerated alterations characteristic of each vitamin treatment alone, including damaged mitochondria, self-excision of organelle-free pieces of cytoplasm, and extrusion of the perikaryon containing a nucleus surrounded by the damaged organelles. The nuclear envelope appears intact and contains chromatin that decondenses and dissipates. During the cellular demise that concludes with apparent karyolysis, the cells significantly decrease their size and alter their shape. However, the cisterns of rough endoplasmic reticulum are undamaged, but may become dilated. Since the cellular phenomena leading to cell death differ morphologically from apoptosis and necrosis, but entail selfcutting without nuclear bodies, this new form of cell death was called autoschizis. In addition, gel electrophoresis and Feulgen staining demonstrate that autoschizis is accompanied by random DNA degeneration.

The effect of intracellular ascorbate on the susceptibility of HL60 and Jurkat cells to chemotherapy agents

“…Ascorbate can act as a pro-or anti-oxidant and considerable recent attention has been given to its pro-oxidant activity [19,20,22,26,29,56,57]. However, this evidence for its pro-oxidant activity comes from in vitro studies that either use high extracellular concentrations of ascorbate or combinations with redox-cycling compounds [19,20,56].…”

“…For example high concentrations of Vitamin C have been shown to prevent camptothecin-induced apoptosis but not necrosis in Jurkat cells [22], and high concentrations of ascorbate combined with menadione induce cell death in a range of tumour cells by autoschizis, a novel mechanism described as distinct from apoptosis or necrosis [23][24][25][26][27]. However, most of these studies have examined the effect of extracellular ascorbate in cultured cells that do not contain intracellular ascorbate [19,20,24,[27][28][29].…”

The Bladder Tumor Suppressor Protein TERE1 (UBIAD1)Modulates Cell Cholesterol: Implications for Tumor Progression

“…As a ligand for SXR, vitamin K-2 can activate LXR targets such as APOE and the ABC transporters that efflux vitamin K and cholesterol (Shukla et al, 2007;Chisaki et al, 2009). Pharmacological application of vitamins K-2 and K-3 are also linked to oxidative stress (Gilloteaux et al, 2006;Shibayama-Imazu et al, 2006;Shearer and Newman, 2008;Amalia et al, 2010). APOE is believed to play a role in oxysterol-induced efflux as part of a lipoprotein-mediated defense against oxidative stress (Laffitte et al, 2001;Landes et al, 2003;Carter, 2007;Rezen et al, 2010).…”

Role of glycolysis inhibition and poly(ADP‐ribose) polymerase activation in necrotic‐like cell death caused by ascorbate/menadione‐induced oxidative stress in K562 human chronic myelogenous leukemic cells

“…7 Finally, the cancer cell death is caspase independent, and on the basis of morphological observations, this type of cell death has been called ''autoschizis''. [7][8][9][10][11][12][13] Since cancer cells are strongly dependent on glycolysis, we postulate that cell death by ascorbate/menadione occurs by ATP depletion due to glycolysis arrest. Therefore, the aim of this study was to analyse the mechanisms by which ascorbate/menadione may affect glycolysis thus conditioning cell death or cell survival.…”