Assessing 12( S)-lipoxygenase inhibitory activity using colorectal cancer cells overexpressing the enzyme

• Published in: Food and chemical toxicology 2007-03, Vol.45 (3), p.508-514
• Main Authors: Bednar, Wolfgang, Holzmann, Klaus, Marian, Brigitte
• Format: Article
• Language: English
• Subjects: 12( S)-HETE; 12( S)-Lipoxygenase; anticarcinogenic activity; Apoptosis - drug effects; Arachidonate 12-Lipoxygenase - biosynthesis; Arachidonate 12-Lipoxygenase - genetics; arachidonic acid; Biological and medical sciences; Cell Line, Tumor; chemoprevention; colorectal neoplasms; Colorectal Neoplasms - pathology; Colorectal Neoplasms - prevention & control; DNA Primers; ELISA; enzyme inhibition; enzyme inhibitors; enzyme-linked immunosorbent assay; Gastroenterology. Liver. Pancreas. Abdomen; Humans; kaempferol; lipoxygenase; Lipoxygenase Inhibitors - administration & dosage; Lipoxygenase Inhibitors - pharmacology; Lipoxygenase Inhibitors - therapeutic use; Medical sciences; nordihydroguaiaretic acid; nutrition-genotype interaction; phenols; phytochemicals; Phytotherapy; plant extracts; Plants, Medicinal; Polymerase Chain Reaction; Protective Agents - administration & dosage; Protective Agents - pharmacology; Protective Agents - therapeutic use; quercetin; resveratrol; RNA - analysis; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Toxicology; Tumors
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2006.08.013

12( S)-Lipoxygenase (LOX) is regarded as a pro-tumorigenic enzyme and as a potential target for therapy and prevention of cancer so that the search for specific 12( S)-LOX inhibitors is part of drug development strategies. To facilitate the identification of specific 12( S)-LOX inhibitors we have created an assay cell line by introducing a12( S)-LOX expression vector into SW480 colorectal cancer cells. When arachidonic acid was supplied in the medium both transiently and stably overexpressing cells produced 12( S)-hydroxytetraenic acid (HETE) originating from the transfected gene at 4–5-fold the amount obtained from control transfectants. 12( S)-HETE production was 1913.7 ± 17.2 pg/ml and reached a steady state level 24 h after addition of arachidonic acid. To demonstrate the models suitability of 12( S)-LOX overexpressing SW480 cells they were used to measure the inhibitory activity of the plant phenols baicalein, kaempferol, quercetin, nordihydroguaretic acid and resveratrol which are known for their chemopreventive as well as LOX-inhibitory activity in different tumour models. All 5 compounds inhibited 12( S)-HETE production at concentrations below those necessary for growth inhibition.