Heterogeneous Protein Thiol Oxidation after DiMethoxyNaphthoQuinone (DMNQ) Metabolism in A549 Lung Cancer Cells
Poster Number
9B
Introduction/Abstract
Cancer metastasis is present in, or responsible for, an estimated 90% of cancer deaths from solid tumors. Epithelial Mesenchymal Transition (EMT) is a cellular program that interconverts epithelial cells (lining or covering organs) to mesenchymal cells (migratory and less differentiated cells) and is regulated by multiple signaling pathways. A process called reduction-oxidation (redox) signaling, a series of chemical reactions within the cells, is also thought to trigger EMT. However, the protein target of redox signaling in EMT is unknown.
Purpose
To identify the predominant protein target of peroxide-dependent oxidation in redox signaling leading to epithelial mesenchymal transition in lung cancer.
Method
Cultured human A549 lung cancer cells were treated with 5 or 10 µM 2,3-DiMethoxyNaphthoQuinone (DMNQ) for 1 hour. Cells were lysed in the presence of fluorescein-5-maleimide for labeling of native free thiols. Samples were then further derivatized by chemical reduction of thiol oxidation products, derivatized with a second fluorescent maleimide to label reducible oxidation products, and analyzed using the RedoxiFluor method of Tuncay et al. 2022.
Results
Treatment of cells with DMNQ resulted in a significant global redox decrease in the cellular content of reduced protein thiols (as a percentage of total reducible thiols). However, investigation of specific proteins within EMT regulatory networks has not yielded substantial changes in the ratio of reduced to total thiol content. Specific proteins investigated were SMAD2/3, beta-catenin, Akt, and SNAI1/2.
Significance
A large global redox change in cells was successfully measured after the metabolism of a drug (DMNQ) that generates superoxide anion radical and hydrogen peroxide. While similar oxidation events triggered EMT, specific oxidation-influenced protein targets have not yet been identified. This result implies a heterogeneous reactivity among cellular protein thiols which may provide regulatory control over cellular processes.
Location
Library and Learning Center, 3601 Pacific Ave., Stockton, CA 95211
Format
Poster Presentation
Heterogeneous Protein Thiol Oxidation after DiMethoxyNaphthoQuinone (DMNQ) Metabolism in A549 Lung Cancer Cells
Library and Learning Center, 3601 Pacific Ave., Stockton, CA 95211
Cancer metastasis is present in, or responsible for, an estimated 90% of cancer deaths from solid tumors. Epithelial Mesenchymal Transition (EMT) is a cellular program that interconverts epithelial cells (lining or covering organs) to mesenchymal cells (migratory and less differentiated cells) and is regulated by multiple signaling pathways. A process called reduction-oxidation (redox) signaling, a series of chemical reactions within the cells, is also thought to trigger EMT. However, the protein target of redox signaling in EMT is unknown.
