The effect of unsaturated fatty acids on membrane composition and signal transduction in HT-29 human colon cancer cells.

Full Abstract

The objective of the present study was to investigate the effect of membrane fatty acid (FA) composition on the activity of phospholipase C (PLC) in HT-29 human colon cancer cells. The membrane FA composition was altered by supplementing cultured cells with FAs of different composition. The FAs were stearic acid (18:0; SA), gamma linolenic acid (18:3 omega 6; gamma LnA); alpha linolenic acid (18:3 omega 3; alpha LnA;); eicosapentaenoic acid (20:5 omega 3; EPA) and docosahexaenoic acid (22:6 omega 3; DHA). The fatty acids were supplemented as a FA/BSA complex. Cells supplemented with SA served as the control. Tumor growth was followed by counting the number of cells in culture. The results indicate that polyunsaturated fatty acid (PUFA) supplementation had no consistent effect on tumor growth from 1 day to another throughout the 15 days of growth. The fatty acid composition of membranes indicates that cells incorporated and modified the supplemented fatty acids by desaturation, elongation and retroconversion. The unsaturation index (UI) of membranes of cells supplemented with EPA and DHA was higher than other groups. PLC activity; measured in the absence of GTP gamma(S) in the assay mixture; was not influenced by membrane FA modification. However, in the presence of GTP gamma(S) PLC of cells supplemented with 18:3(omega 6) was the lowest among the groups. It has been shown that 18:3(omega 6) accumulated the most in the phosphatidylethanolamine (PE) fraction. There was a negative correlation between the activity of PLC in the presence of G protein activation and PE 18:3 (omega 6) content without affecting UI. It was concluded that G protein may be sensitive to the level of 18:3(omega 6) content and not to the general fluidity of the membranes.

Author information

Author/s: Awad, A B (AB); Young, A L (AL); Fink, C S (CS);

Affiliation: Nutrition Program, State University of New York at Buffalo 14214, USA.

Journal and publication information

Publication Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't

Journal: Cancer letters (Cancer Lett), published in IRELAND. (Language: eng)

Reference: 1996-Nov; vol 108 (issue 1) : pp 25-33

Dates: Created 1996/12/30; Completed 1996/12/30; Revised 2006/11/15;

PMID: 8950205, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Animals
Cattle
Cell Membrane - chemistry; drug effects
Colonic Neoplasms - chemically induced; chemistry; pathology
Dietary Fats - adverse effects; classification
Docosahexaenoic Acids - pharmacology
Eicosapentaenoic Acid - pharmacology
Fatty Acids - pharmacology
Fatty Acids, Unsaturated - analysis; physiology
GTP-Binding Proteins - metabolism
Humans

Associated Chemicals: Dietary Fats (0) ; Fatty Acids (0) ; Fatty Acids, Unsaturated (0) ; Membrane Lipids (0) ; Neoplasm Proteins (0) ; Serum Albumin, Bovine (0) ; Stearic Acids (0) ; Eicosapentaenoic Acid (1553-41-9) ; Docosahexaenoic Acids (25167-62-8) ; alpha-Linolenic Acid (463-40-1) ; gamma-Linolenic Acid (506-26-3) ; stearic acid (57-11-4) ; Phosphoric Diester Hydrolases (EC 3.1.4.-) ; GTP-Binding Proteins (EC 3.6.1.-) ; Phosphatidylinositol Diacylglycerol-Lyase (EC 4.6.1.13)

These are the highest related articles currently in the database: