Immunomodulatory effects and anti-tumor activities of conjugated linolenic acids on the murine macrophage-like leukemia cells

Abstract

Event Abstract Back to Event Immunomodulatory effects and anti-tumor activities of conjugated linolenic acids on the murine macrophage-like leukemia cells KN Leung1* and Wai Nam Liu1 1 The Chinese University of Hong Kong, Hong Kong, SAR China Naturally-occurring conjugated linolenic acids (CLN) derived from various plant seed oils have shown to possess various biological and pharmacological activities, including antioxidative, hypolipidemic, chemopreventive and anti-tumor properties. Although CLN are known to inhibit the growth of several cancer cell lines in vitro, however, their modulatory effects on macrophages and their action mechanisms on macrophage-like leukemia have not been investigated. In the present study, various CLN isomers were found to exhibit potent anti-proliferative effect on the murine macrophage-like leukemia PU5-1.8 cells in a time- and dose-dependent manner. The most potent CLN isomer, jacaric acid, also exerted significant growth-inhibitory effects on other murine macrophage-like leukemia cell lines in vitro. Mechanistic studies indicated that jacaric acid could lead to cell cycle arrest of PU5-1.8 cells at the G0/G1 phase, and this was associated with a decrease in cyclin E and CDK2 proteins, and an increase in p21, p27 and p53 proteins. Moreover, jacaric acid could induce apoptosis in PU5-1.8 cells as revealed by DNA fragmentation, phosphatidylserine externalization, and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins expression. Furthermore, pre-treatment of PU5-1.8 cells with jacaric acid significantly reduced the in vivo tumorigenicity of the leukemia cells in syngeneic BALB/c mice. Interestingly, jacaric acid exhibited no significant cytotoxicity on the thioglycollate-induced peritoneal macrophages but stimulated their cytostatic activity towards tumor cells and production of nitric oxide in vitro. Collectively, our results indicate that CLN can stimulate macrophages and exert their anti-tumor effects on the macrophage-like leukemia cells through cell cycle arrest and apoptosis induction. Keywords: conjugated linolenic acids, macrophage-like leukemia, jacaric acid, Immunomodulatory effects, anti-tumor activities Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Translational immunology and immune intervention Citation: Leung K and Liu W (2013). Immunomodulatory effects and anti-tumor activities of conjugated linolenic acids on the murine macrophage-like leukemia cells. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00163 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Prof. KN Leung, The Chinese University of Hong Kong, HKSAR, Hong Kong, SAR China, knleung@cuhk.edu.hk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers KN Leung Wai Nam Liu Google KN Leung Wai Nam Liu Google Scholar KN Leung Wai Nam Liu PubMed KN Leung Wai Nam Liu Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.