BACKGROUND Head and neck squamous cell carcinoma (HNSCC) is an aggressive and recurrent malignancy owing to intrinsic radioresistance and lack of induction of apoptosis. The major focus of this work was to design a transient glutathione depleting strategy during the course of irradiation of HNSCC in order to overcome their radioresistance associated with redox adaptation. METHODOLOGY/PRINCIPA...

Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial...

OBJECTIVES Methylnaphthalenes have been used extensively as chemical intermediates in organic synthesis, as solvents for pesticides, sulphur and various aromatic compounds. A wide use of methylnaphthalenes has contributed to their emission into the environment. The aim of the study was to explain the role of glutathione in metabolism of selected dimethylnaphthalenes in rat. MATERIALS AND METH...

This paper reports that a novel protein extract isolated from Calvatia lilacina (CL) can induce cell death against four types of human colorectal cancer cells. Importantly, CL was shown to be free of apoptotic effects against normal rat liver cells. We have also identified that CL-induced glutathione (GSH) depletion is the major contributor responsible for the apoptotic cell death induction of ...

Aging alters cellular responses to both heat and oxidative stress. Thiol-mediated metabolism of reactive oxygen species (ROS) is believed to be important in aging. To begin to determine the role of thiols in aging and heat stress, we depleted liver glutathione (GSH) by administering l-buthionine sulfoximine (BSO) in young (6 mo) and old (24 mo) Fisher 344 rats before heat stress. Animals were g...

Glutathione (GSH), glutathione S-transferase (GST), and glutathione conjugate export pump (GS-X pump) have been shown to participate collectively in the detoxification of many anticancer drugs, including cisplatin. Identification and regulation of the rate-limiting step in the overall system for cisplatin detoxification is of crucial importance for sensitization of human tumor cells to cisplati...

Abstract Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) is a potential redox agent in cells. The present study investigated changes cellular reactive oxygen species (ROS) and glutathione (GSH) levels antioxidant enzymes, Tempol-treated Calu-6 A549 lung cancer cells, normal WI-38 VA-13 primary pulmonary fibroblasts. Results demonstrated that (0.5–4 mM) either increased or decreased gene...

We have investigated the role played by GSH efflux in apoptosis of human HaCaT keratinocytes induced by UVA irradiation. UVA irradiation of HaCaT cells caused a rapid rise in GSH efflux across the intact cell membrane, followed by an increase in apoptosis. GSH efflux was stimulated by glucose and was reduced by the addition of exogenous GSH and intracellular GSH depletion by buthionine sulfoxim...

Clara-cell populations show a high degree of variation in susceptibility to injury by bioactivated cytotoxicants. Because glutathione (GSH) is critical for detoxification of electrophilic metabolites, heterogeneity in Clara cell GSH levels may lead to a wide range of cytotoxic responses. This study was designed to define the distinct GSH pools within Clara cells, characterize heterogeneity with...