Research Article Purine-Metabolizing Ectoenzymes Control IL-8 Production in Human Colon HT-29 Cells Fariborz Bahrami, 1,2 Filip Kukulski, 1,2 Joanna Lecka, 1,2 Alain Tremblay, 2 Julie Pelletier, 2 Liliana Rockenbach, 1,2 and Jean Sévigny 1,2 1 D´ epartement de Microbiologie-Infectiologie et d’Immunologie, Facult´ e de M´ edecine, Universit´ e Laval, Qu´ ebec, QC, Canada G1V 0A6 2 Centre de Recherche du CHU de Qu´ ebec, 2705 Boulevard Laurier, Local T1-49, Qu´ ebec, QC, Canada G1V 4G2 Correspondence should be addressed to Jean S´ evigny; jean.sevigny@crchul.ulaval.ca Received 29 May 2014; Accepted 3 July 2014; Published 23 July 2014 Academic Editor: Mireia Mart´ ın-Satu´ e Copyright © 2014 Fariborz Bahrami et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Interleukin-8 (IL-8) plays key roles in both chronic inlammatory diseases and tumor modulation. We previously observed that IL-8 secretion and function can be modulated by nucleotide (P2) receptors. Here we investigated whether IL-8 release by intestinal epithelial HT-29 cells, a cancer cell line, is modulated by extracellular nucleotide metabolism. We irst identiied that HT-29 cells regulated adenosine and adenine nucleotide concentration at their surface by the expression of the ectoenzymes NTPDase2, ecto- 5  -nucleotidase, and adenylate kinase. he expression of the ectoenzymes was evaluated by RT-PCR, qPCR, and immunoblotting, and their activity was analyzed by RP-HPLC of the products and by detection of P i produced from the hydrolysis of ATP, ADP, and AMP. In response to poly (I:C), with or without ATP and/or ADP, HT-29 cells released IL-8 and this secretion was modulated by the presence of NTPDase2 and adenylate kinase. Taken together, these results demonstrate the presence of 3 ectoenzymes at the surface of HT-29 cells that control nucleotide levels and adenosine production (NTPDase2, ecto-5  -nucleotidase and adenylate kinase) and that P2 receptor-mediated signaling controls IL-8 release in HT-29 cells which is modulated by the presence of NTPDase2 and adenylate kinase. 1. Introduction Inlammation is a major contributor to the development and progression of many human cancers [1] and is obviously a key constituent of inlammatory diseases such as inlammatory bowel diseases (IBD) [2–4]. Indeed, a number of chronic inlammatory conditions increase the risk of developing cancers [5]. For instance, IBD is associated with an increased risk of colon cancer development [6, 7]. In addition, the long-term use of anti-inlammatory drugs such as aspirin decreases the risk of several cancer types [8]. Interleukin-8 (IL-8) or CXCL8 is a proinlammatory chemokine originally identiied as a neutrophil chemoattrac- tant [9], which is an important contributor to the induction of innate immunity [10]. Accordingly, IL-8 has been implicated in a number of inlammatory diseases such as IBD [11, 12]. Elevated IL-8 signaling has also been observed within the tumor microenvironment of numerous cancers where it enhances tumor progression via the activation of pathways that promote proliferation, angiogenesis, migration, invasion, and cell survival [13, 14]. Altogether, this suggests that inhibition of IL-8 production could be a potential treatment for both chronic inlammatory diseases and cancer [13, 15]. herefore, a better understanding of the mechanisms that drive or mediate IL-8 release is imperative. We have previously observed that IL-8 secretion, and even function, can be controlled by nucleotide receptors [16–18]. Extracellular nucleotides (e.g., ATP, ADP, UTP, and UDP) are secreted by host cells in response to injury, such as in condi- tions of inlammation, and act as danger signals (alarmins) and damage-associated molecular patterns (DAMPs). hese substances initiate the host immune responses [19–21] by activating speciic P2 receptors [22]. he concentration of P2 receptor agonists is regulated by ectoenzymes that metab- olize nucleotides [23–26]. While ectonucleotidases such as nucleoside triphosphate diphosphohydrolases (NTPDases) Hindawi Publishing Corporation Mediators of Inflammation Volume 2014, Article ID 879895, 10 pages http://dx.doi.org/10.1155/2014/879895