Cytosolic phospholipase A2, cyclo-oxygenases and arachidonate in human stomach tumours
| Autor: | S. Kargman, J.D. Gaffen, I A Tavares, Alan Bennett, A.S. Soydan, G. O'Neill, P.K. Weech, N.M. Tremblay |
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| Rok vydání: | 1997 |
| Předmět: |
Cancer Research
medicine.medical_specialty Oxygenase Immunoblotting Prostaglandin Biology Phospholipases A chemistry.chemical_compound Cytosol Phospholipase A2 Stomach Neoplasms Internal medicine medicine Humans Aged Aged 80 and over chemistry.chemical_classification Arachidonic Acid Stomach Fatty acid Phospholipases A2 medicine.anatomical_structure Enzyme Endocrinology Oncology chemistry Gastric Mucosa Prostaglandin-Endoperoxide Synthases biology.protein Electrophoresis Polyacrylamide Gel Arachidonic acid Cyclo-oxygenase |
| Zdroj: | European Journal of Cancer. 33:1508-1512 |
| ISSN: | 0959-8049 |
| DOI: | 10.1016/s0959-8049(97)00168-8 |
| Popis: | Human stomach tumours usually form more prostaglandins (PGs) than their associated normal mucosa/submucosa, but the mechanisms are not fully understood. The key enzymes are cytosolic phospholipase A2 (cPLA2, Mr 85,000) and the cyclo-oxygenases (COXs) which exist in constitutive (COX-1) and inducible forms (COX-2). In human stomach tumours and associated macroscopically normal tissues, we determined the fatty acid composition by gas chromatography, amounts of cPLA2, COX-1 and COX-2 by immunoblotting with specific antibodies and cPLA2 enzyme activity using a tritiated substrate. Although compared to normal mucosa there was less arachidonate in tumours (P < 0.05), the arachidonate/total fatty acid ratio was higher. Mean amounts of cPLA2 and COX-1 and cPLA2 activity were similar in tumours and normal mucosa. However, substantial amounts of COX-2 were found in the tumours but not in the mucosa, which may explain why many gastric tumours form increased amounts of PGs. |
| Databáze: | OpenAIRE |
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