Influence of oxygen partial pressure on the characteristics of human hepatocarcinoma cells

• Published in: Redox biology Vol. 12; pp. 103 - 113
• Main Authors: Trepiana, Jenifer, Meijide, Susana, Navarro, Rosaura, Hernández, M Luisa, Ruiz-Sanz, José Ignacio, Ruiz-Larrea, M Begoña
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier 01.08.2017
• Subjects: Carcinoma, Hepatocellular - genetics; Carcinoma, Hepatocellular - metabolism; Cell Culture Techniques; Cell Line, Tumor; Cell Movement - drug effects; Cell Proliferation - drug effects; Glutathione - metabolism; Hep G2 Cells; Humans; Liver Neoplasms - genetics; Liver Neoplasms - metabolism; Oxidative Stress; Oxygen - pharmacology; Partial Pressure; Reactive Oxygen Species - metabolism; Research Paper; Tumor Suppressor Protein p53 - genetics; Superoxide dismutase; Oxygen tension; Cell migration; Hepatoma cells
• ISSN: 2213-2317; 2213-2317
• DOI: 10.1016/j.redox.2017.02.004

Most of the in vitro studies using liver cell lines have been performed under atmospheric oxygen partial pressure (21% O ). However, the oxygen concentrations in the liver and cancer cells are far from this value. In the present study, we have evaluated the influence of oxygen on 1) the tumor cell lines features (growth, steady-state ROS levels, GSH content, activities of antioxidant enzymes, p66 Shc and SOD expressions, metalloproteinases secretion, migration, invasion, and adhesion) of human hepatocellular carcinoma cell lines, and b) the response of the cells to an oxidant stimulus (aqueous leaf extract of the V. baccifera plant species). For this purpose, three hepatocarcinoma cell lines with different p53 status, HepG2 (wild-type), Huh7 (mutated), and Hep3B (deleted), were cultured (6-30 days) under atmospheric (21%) and more physiological (8%) pO . Results showed that after long-term culturing at 8% versus 21% O , the cellular proliferation rate and the steady-state levels of mitochondrial O were unaffected. However, the intracellular basal ROS levels were higher independently of the characteristics of the cell line. Moreover, the lower pO was associated with lower glutathione content, the induction of p66 Shc and Mn-SOD proteins, and increased SOD activity only in HepG2. This cell line also showed a higher migration rate, secretion of active metalloproteinases, and a faster invasion. HepG2 cells were more resistant to the oxidative stress induced by V. baccifera. Results suggest that the long-term culturing of human hepatoma cells at a low, more physiological pO induces antioxidant adaptations that could be mediated by p53, and may alter the cellular response to a subsequent oxidant challenge. Data support the necessity of validating outcomes from studies performed with hepatoma cell cultures under ambient O .