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Cellular Stress Responses Following Photodynamic Therapy
Published in Barbara W. Henderson, Thomas J. Dougherty, Photodynamic Therapy, 2020
Stefan W. Ryter, Charles J. Gomer, Angela Ferrario, Anita M. R. Fisher, Marian Luna, Natalie Rucker, Sam Wong
A wide variety of chemical and physical agents stimulate the expression of the 32- to 34-kd heme oxygenase stress protein, including its substrate heme, endotoxin, sulfhydryl reagents (sodium arsenite, iodoacetamide), heavy metals (methyl mercury, cadmium), UVA radiation, oxidative stress (hydrogen peroxide, menadione), and agents that react with or deplete cellular glutathione (menadione, buthionine sulfoximine, diethyl maléate, diamide) [20–24]. Modulations in glutathione levels may be a signal for the increased expression of heme oxygenase [24]. Photofrin II incubation (16 hr) and PII-mediated photosensitization of V-79 Chinese hamster fibroblasts induce a transient increase in the steady-state levels of heme oxygenase mRNA (Northern analysis) and heme oxygenase protein (Western immunoblot analysis) [3]. It is not yet clear whether porphyrin-mediated photooxidative stress stimulates heme oxygenase by the same mechanism as heme incubation. Interestingly, photosensitization of V-79 cells by the xanthine dye rose bengal, but not the drug alone, also induces heme oxygenase transcription and translation [3].
Xenobiotic Metabolism
Published in Lorris G. Cockerham, Barbara S. Shane, Basic Environmental Toxicology, 2019
Larry G. Hansen, Barbara S. Shane
Compounds that alter protein synthesis will obviously inhibit the synthesis of biotransformation enzymes. Some inhibitors are more specific than others in that they inhibit the synthesis of cytochrome P450 but not the synthesis of proteins in general. Two chemicals that are known to inhibit the synthesis of heme, a coenzyme of cytochrome P450, and its precursor porphyrin are, respectively, cobalt and 3-amino-1,2,3-triazole. Some compounds are known to affect the tissue levels of certain cofactors. Both L-methionine-S-sulfoximine and buthionine sulfoximine inhibit the synthesis of glutathione, while diethyl maleate rapidly reduces the tissue stores of glutathione. The synthesis of UDP-glucuronic acid is inhibited by galactosamine. As a result of this depletion or reduction in concentration of these cofactors, the formation of glutathione and glucuronide conjugates may be inhibited.
Poly(Alkyl Cyanoacrylate) Nanoparticles for Delivery of Anti-Cancer Drugs
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
R. S. R. Murthy, L. Harivardhan Reddy
In support of the above results, Kisara et al.174 observed that the two compounds buthionine sulfoximine (BSO) and cepharanthine (CE), which decrease the glutathione content in the MDR cells, showed greater reversal of multi-drug resistance to Dox in MDR cells. Treatment of the MDR cells with BSO resulted in an enhancement of the cytotoxic effect of Dox by 1.8-fold, whereas CE caused a greater reversal of drug resistance. BSO treatment also resulted in the decrease in GSH content of MDR cells compared to that of the sensitive ones. The combination of BSO with CE caused further potentiation of the antiproliferative effect of Dox in MDR cells.
Buthionine sulfoximine and chemoresistance in cancer treatments: a systematic review with meta-analysis of preclinical studies
Published in Journal of Toxicology and Environmental Health, Part B, 2023
Camila dos Reis Oliveira, Joedna Cavalcante Pereira, Andressa Barros Ibiapina, Italo Rossi Roseno Martins, João Marcelo de Castro e Sousa, Paulo Michel Pinheiro Ferreira, Felipe Cavalcanti Carneiro da Silva
The PICO strategy was used to construct the following research question: Does buthionine sulfoximine show antitumor effects when used alone or in association with other chemotherapy drugs in preclinical cancer models?