High molecular weight phospholipase A2 and fatty acids in human colon tumours and associated normal tissue

• Published in: European journal of cancer (1990) Vol. 32; no. 10; pp. 1781 - 1787
• Main Authors: SOYDAN, A. S, TAVARES, I. A, WEECH, P. K, TREMBLAY, N. M, BENNETT, A
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.09.1996
• Subjects: Adult; Aged; Aged, 80 and over; Arachidonic Acid - analysis; Biological and medical sciences; Colon - chemistry; Colon - enzymology; Colonic Neoplasms - chemistry; Colonic Neoplasms - enzymology; Fatty Acids - analysis; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunoblotting; Male; Medical sciences; Middle Aged; Molecular Weight; Phospholipases A - analysis; Phospholipases A - chemistry; Phospholipases A - metabolism; Phospholipases A2; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tumors; Human; Enzyme; Exploration; Lipids; Esterases; Malignant tumor; Arachidonic acid; Fatty acids; Phospholipase A; Carboxylic ester hydrolases; Colonic disease; Assay; Enzymatic activity; Digestive diseases; Hydrolases; Intestinal disease; Colon
• ISSN: 0959-8049; 1879-0852
• DOI: 10.1016/0959-8049(96)00166-9

Human colon tumours usually form more prostaglandins (PGs) than associated normal tissues, but the mechanism(s) are not fully understood. We analysed fatty acid compositions, in particular arachidonate, and measured the amount and the activity of high molecular weight cytoplasmic phospholipase A2 (cPLA2) of these tissues. Total lipids extracted from homogenised surgical specimens were transesterified and fatty acids were analysed by gas chromatography. cPLA2 was separated by SDS-PAGE, Western-blotted, immunoblotted using a specific antibody to cPLA2 and semiquantified following enhanced chemiluminescence using a scanning densitometer. cPLA2 biological activity was also assayed using 1-stearoyl, 2-[1-14C]-arachidonyl, L-3-phosphatidylcholine. Compared with normal mucosa/submucosa, there was more total arachidonate in tumours (P < 0.01), and increased levels of cPLA2 occurred in 6 of 17 tumours. In conclusion, the higher amounts of tumour total arachidonate and the sometimes higher levels of cPLA2, might help to explain why some human colon tumours form increased amounts of PGs.