Peroxisomal Oxidation in Normal and Tumoral Human Breast.
Abstract
The peroxisomal enzyme catalase protects aerobic organisms from free radical damage by converting hydrogen peroxide (H2O2) to molecular oxygen and water before it can decompose to form the highly reactive hydroxyl radical. In this manner catalase plays a central role in protecting against cellular oxidative damage. In humans, changes in catalase activity have been implicated in aging and in a number of disease states including cancer. We hypothesized that reduced catalase could potentially lead to an excess of H2O2 produced by peroxisomal oxidative reactions, which may then leak into the cell and cause DNA damage. To test this hypothesis we have examined the mRNA levels of catalase and peroxisomal fatty acyl-CoA oxidase in a variety of human breast samples and in breast cancer cell lines and in normal tissue and non-immortalized cells in culture. In addition, we previously found that the human Peroxisome Proliferator-Activated Receptor (hPPAR), a transcription factor involved in the regulation of peroxisomal beta-oxidation enzymes, is highly expressed in human mammary tissue. Therefore we also compared the levels of hPPAR with those of catalase and acyl-CoA oxidase. Using the polymerase chain reaction to quantitate the expression of the genes encoding each of these proteins, we found that the levels were similar in the human breast tumor samples and in normal controls, with the exception that we were unable to detect hPPAR in an estrogen receptor positive carcinoma cell line.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1998
- Accession Number
- ADA364684
Entities
People
- Gillian Small
Organizations
- Icahn School of Medicine at Mount Sinai