Brief Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Mar 7, 2009; 15(9): 1079-1084
Published online Mar 7, 2009. doi: 10.3748/wjg.15.1079
Docosahexaenoic acid suppresses arachidonic acid-induced proliferation of LS-174T human colon carcinoma cells
Piet Habbel, Karsten H Weylandt, Katja Lichopoj, Johannes Nowak, Martin Purschke, Jing-Dong Wang, Cheng-Wei He, Daniel C Baumgart, Jing X Kang
Piet Habbel, Karsten H Weylandt, Katja Lichopoj, Johannes Nowak, Martin Purschke, Jing-Dong Wang, Cheng-Wei He, Jing X Kang, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States
Piet Habbel, Karsten H Weylandt, Katja Lichopoj, Johannes Nowak, Daniel C Baumgart, Department of Medicine, Division of Gastroenterology and Hepatology, Charité Medical Center-Virchow-Hospital, Medical School of the Humboldt-University of Berlin, 13344 Berlin, Germany
Author contributions: Habbel P and Weylandt KH contributed equally to this work; Habbel P, Weylandt KH, Kang JX designed research; Habbel P, Lichopoj K, Nowak J, Purschke M, Wang JD, He CW performed experiments; Habbel P and Weylandt KH analyzed data; Habbel P, Weylandt KH, Baumgart DC, Kang JX prepared the manuscript.
Correspondence to: Karsten H Weylandt, MD, PhD, Dr. Kang’s Lab, Massachusetts General Hospital, 149-13th Street, Room 4433, Charlestown, MA 02129, United States. karsten.weylandt@gmx.de
Telephone: +1-617-7268509
Fax: +1-617-7266144
Received: October 25, 2008
Revised: January 14, 2009
Accepted: January 21, 2009
Published online: March 7, 2009
Abstract

AIM: To investigate the impact of arachidonic acid (AA) and docosahexaenoic acid (DHA) and their combination on colon cancer cell growth.

METHODS: The LS-174T colon cancer cell line was used to study the role of the prostaglandin precursor AA and the omega-3 polyunsaturated fatty acid DHA on cell growth. Cell viability was assessed in XTT assays. For analysis of cell cycle and cell death, flow cytometry and DAPI staining were applied. Expression of cyclooxygenase-2 (COX-2), p21 and bcl-2 in cells incubated with AA or DHA was examined by real-time RT-PCR. Prostaglandin E2 (PGE2) generation in the presence of AA and DHA was measured using a PGE2-ELISA.

RESULTS: AA increased cell growth, whereas DHA reduced viability of LS 174T cells in a time- and dose-dependent manner. Furthermore, DHA down- regulated mRNA of bcl-2 and up-regulated p21. Interestingly, DHA was able to suppress AA-induced cell proliferation and significantly lowered AA-derived PGE2 formation. DHA also down-regulated COX-2 expression. In addition to the effect on PGE2 formation, DHA directly reduced PGE2-induced cell proliferation in a dose-dependent manner.

CONCLUSION: These results suggest that DHA can inhibit the pro-proliferative effect of abundant AA or PGE2.

Keywords: Colorectal carcinoma; Colon cancer; Omega-3; Omega-6; Polyunsaturated fatty acids; Arachidonic acid; Docosahexaenoic acid; Prostaglandin E2; Cyclooxygenase-2; Apoptosis