The Latency of Peroxisomal Catalase in Terms of Effectiveness Factor for Pancreatic and Glioblastoma Cancer Cell Lines in the Presence of High Concentrations of H2O2: Implications for the use of Pharmacological Ascorbate in Cancer Therapy.

The Latency of Peroxisomal Catalase in Terms of Effectiveness Factor for Pancreatic and Glioblastoma Cancer Cell Lines in the Presence of High Concentrations of H2O2: Implications for the use of Pharmacological Ascorbate in Cancer Therapy. Free Radic Biol Med. 2020 Jun 06;: Authors: Erudaitius DT, Buettner GR, Rodgers VGJ Abstract Previous research has identified variation in cancer cell line response to high levels of extracellular H2O2 (eH2O2) exposure. This directly contributes to our understanding cellular efficacy of pharmacological ascorbate (P-AscH-) therapy. Here we investigate the factors contributing to latency of peroxisomal catalase of a cell and the importance of latency in evaluating cell exposure to eH2O2. First, we develop a mathematical framework for the latency of catalase in terms of an effectiveness factor, ηeff, to describe the catalase activity in the presence of high levels of eH2O2. A simplified relationship emerges, [Formula: see text] when mprp/Dij≪1, where mp,rp,and [Formula: see text] are the experimentally determined peroxisome permeability, average peroxisome radius, and the pseudo first-order reaction rate constant, respectively. [Formula: see text] is the catalase concentration in the peroxisome and k2=1.7x107M-1s-1. Next, previously published parameters are used to determine the latency effect of the cell lines: normal pancreatic cells (H6c7), pancreatic cancer cells (MIA PaCa-2), and glioblastoma ...
Source: Free Radical Biology and Medicine - Category: Biology Authors: Tags: Free Radic Biol Med Source Type: research