Measurement of Menadione-Mediated DNA Damage in Human Lymphocytes Using the Comet Assay

Abstract

The model quinone compound menadione has been used to study the effects of oxidative stress in mammalian cells, and to investigate the mechanism of action of the quinone nucleus which is present in many anti-cancer drugs. We have used the alkaline single cell gel electrophoresis assay (comet assay) to investigate the effects of low doses of this compound on isolated human lymphocytes. We found that concentrations of menadione as low as 1 microM were sufficient to induce strand breaks in these cells. Pre-incubation with the NAD(P)H quinone oxidoreductase inhibitor dicoumarol, enhanced the production of menadione-induced strand breaks. In contrast, the metal ion chelator 1,10-phenanthroline inhibited formation of strand breaks, although prolonged incubation with 1,10-phenanthroline in combination with menadione resulted in an increase in a population of very severely damaged nuclei. A marked variation in the response of lymphocytes from different donors to menadione, and in different samples from the same donor was also observed.

Cytoprotective Effect of Afobazole and Its Main Metabolite M-11

“…1). In similar experiments, addition of dicumarol without menadione to the incubation medium did not change the level of nuclear DNA damage [14]. Afobazole signifi cantly reduced TDNA% at 10 and 15 μM in the presence and absence of dicumarol.…”

“…Quinone reductase 1 was inhibited with 10 μM dicumarol [14]. Afobazole concentrations in the incubation medium were 5, 10, and 15 μM.…”

Identification of Yin-Yang Regulators and a Phosphorylation Consensus for Male Germ Cell-Associated Kinase (MAK)-Related Kinase

“…Thapsigargin treatment negates the ability of caffeine (an ATM inhibitor) to release the G 2 delay caused by ␥ radiation in tumor cells (27). Menadione is a model quinone compound used to study the effects of oxidative stress because it generates superoxide in mammalian cells that causes strand breaks in DNA (60). In addition to the link of PP5 to DNA damage control, the link of Scythe to apoptosis induced by DNA damage further motivated us to speculate that MRK and/or MAK may play a key role in cell cycle checkpoint control and apoptosis in response to stress conditions, such as DNA damage.…”

Antiproliferative action of menadione and 1,25(OH)2D3 on breast cancer cells

“…It has been shown to produce DNA single-strand breaks and to modify the DNA bases in S30 breast cancer cells [12]. MEN genotoxicity has been attributed to its ability to damage DNA via ROS generation [13]. MCF-7 cell growth is estrogen-dependent [14].…”