Cancer Epidemiology Biomarkers & Prevention Vol. 14, 2457-2458, October 2005
© 2005 American Association for Cancer Research
Lack of Association between –251 T>A Polymorphism of IL8 and Lung Cancer Risk
Daniele Campa1,2,
Rayjean J. Hung1,
Dana Mates3,
David Zaridze4,
Neonila Szeszenia-Dabrowska5,
Peter Rudnai6,
Jolanta Lissowska7,
Eleonóra Fabiánová8,
Vladimir Bencko9,
Lenka Foretova10,
Vladimir Janout11,
Paolo Boffetta1,
Paul Brennan1 and
Federico Canzian1
1 IARC, Lyon, France; 2 Dipartimento di Scienze dell'Uomo e dell'Ambiente, Universita' di Pisa, Pisa, Italy; 3 Institute of Hygiene, Public Health, Health Services and Management, Bucharest, Romania; 4 Institute of Carcinogenesis, Cancer Research Center, Moscow, Russia; 5 Department of Occupational and Environmental Epidemiology, Institute of Occupational Medicine, Lodz, Poland; 6 National Institute of Environmental Health, Budapest, Hungary; 7 Cancer Center and Maria Sklodowska Institute of Oncology, Warsaw, Poland; 8 Department of Occupational Health, Specialized State Health Institute, Banska Bystrica, Slovakia; 9 Institute of Hygiene and Epidemiology, First Faculty of Medicine, Charles University, Prague, Czech Republic; 10 Department of Cancer Epidemiology and Genetics, Masaryk Memorial Cancer Institute, Brno, Czech Republic; and 11 Department of Preventive Medicine, Faculty of Medicine, Palacky University, Olomouc, Czech Republic
Requests for reprints: Federico Canzian, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany. Phone: 49-6221-421791; Fax: 49-6221-421810. E-mail: canzian{at}iarc.fr
 |
Introduction
|
|---|
Inflammation is a contributing factor in pathogenesis of many cancers (1). Cigarette smoke increases expression of inflammatory mediators in airway epithelial cells as well as immune cells (2). Chronic inflammation, arising as a result of continuous exposure to tobacco components, may result in oxidative stress and contribute to tumor promotion and progression in the lung (3).
Interleukin-8 is a member of the family of chemokines. It is mainly involved in the initiation and amplification of acute inflammatory reactions and in chronic inflammatory processes. Therefore, it plays an important role in diseases in which inflammation is a substantial pathophysiologic feature, namely in diseases with a chronic inflammatory component such as bronchial asthma and cancer.
Studies have shown that protein levels of interleukin-8 were significantly higher in small-airway epithelial cells from smokers. In current smokers, this was positively correlated with smoking history (2). Interleukin-8, originally discovered as a chemotactic factor for leukocytes, has recently been shown to contribute to human cancer progression through its potential functions as a mitogenic, angiogenic, and motogenic factor. Whereas it is constitutively detected in human cancer tissues and established cell lines, interleukin-8 expression is regulated by various tumor microenvironment factors, such as hypoxia, acidosis, nitric oxide, and cell density (4).
In this context, it is interesting to study whether polymorphic variation of the IL8 gene may have an impact of lung cancer susceptibility. A common single nucleotide polymorphism is known in the promoter of IL8, at position –251 from transcription start. The A-allele of this single nucleotide polymorphism was found to be related to higher in vitro levels of interleukin-8 after stimulation with lipopolysaccharide and associated with respiratory syncytial virus bronchiolitis in children (5).
We previously investigated the association between this polymorphism and lung cancer in a case-control study based on a Norwegian population, and we found a protective effect, although only in women (6).
Hypothesis
In the present study, we have investigated the role of a functional polymorphism in IL8, a key inflammation-related gene, as risk factor for lung cancer. The single nucleotide polymorphism was selected on the bases of reported functional and biological relevance, and of our previous results in a smaller case-control study.
|
Materials and Methods
|
|---|
Study Subjects
The study includes 2,144 cases and 2,116 controls recruited in 15 centers of six countries in Central and Eastern Europe including Czech Republic (Prague, Olomouc, Brno), Hungary (Borsod, Heves, Szabolcs, Szolnok, Budapest), Poland (Warsaw, Lodz), Romania (Bucharest), Russia (Moscow), and Slovakia (Banska Bystrica, Bratislava, Nitra). Details on the study setup and on subject recruitment have been previously reported (7). Cases and controls were recruited between 1998 and 2002. The study population consisted of 324 individuals from Romania (143 cases and 181 controls), 627 from Hungary (340 cases and 287 controls), 1,425 from Poland (699 cases and 726 controls), 723 from Russia (402 cases and 321 controls), 518 from Slovakia (301 cases and 217 controls), and 643 from Czech Republic (259 cases and 384 controls). Most centers recruited hospital controls, while in Poland population controls were selected. Cases and controls underwent an identical interview, with a standard questionnaire on consumption of alcohol and tobacco and occupational history. Both cases and controls gave written consent to participate in the study and to allow their biological samples to be genetically analyzed. Approval for the study was given by the relevant Ethical Committees.
Genotyping
The population used for the present study is smaller than the total of subjects recruited, because it includes only the subjects for whom good quality DNA was available. DNAs were extracted from whole blood samples or normal tissue by use of QIAamp Blood Kit (Qiagen, Hilden, Germany).
DNA from cases and controls were randomized and mixed on PCR plates to assure that an equal number of cases and controls could be analyzed simultaneously. Genotyping was done using the Taqman assay (Applied Biosystems, Foster City, CA). Primers and probes used for genotyping and all experimental conditions were identical to those previously reported (1).
Statistical Analysis
The frequency distribution of demographic variables and putative risk factors of lung cancer, including country of residence, age, sex, education, and smoking was examined for cases and controls. Former smokers were defined as smokers who quit smoking at least 2 years before interview or diagnosis. Tobacco pack-years were calculated as the product of smoking duration (years) and smoking intensity (packs per day). Hardy-Weinberg equilibrium was tested in cases and in controls separately. We used logistic regression for multivariate analyses to assess the main effects of the genetic polymorphism on lung cancer risk. The primary end point of the analysis was odds ratios and associated confidence intervals. All the analyses were done with STATA software (StataCorp, College Station, TX).
|
Results
|
|---|
The genotype frequencies among the control group were in Hardy-Weinberg equilibrium (P = 0.20). The frequencies and distribution of the genotypes and the odds ratios for the associations of the polymorphism are shown in Table 1. We did not find an association between IL8 –251T>A polymorphism and lung cancer risk, either overall or when subjects were stratified on the basis of smoking status, gender, histology, and age (Table 1).
Statistical Power
Our study has 80% power to detect a minimum odds ratio of 1.20 for this single nucleotide polymorphism, assuming 
= 0.05, two-sided test, and a codominant model.
Study Limitations
The present work failed to reproduce the association observed in our previous study (6). The previous association was found only in a subset of subjects of a study based on 250 cases and 214 controls. It is, therefore, probable that the previously reported association may be a false-positive finding.
|
Conclusion
|
|---|
Our study does not support a major role of polymorphism –251T>A of interleukin-8 in lung carcinogenesis within this population.
|
Footnotes
|
|---|
Grant support: National Cancer Institute R01 grant (contract no. CA 092039-01A2) and a grant from the Polish State Committee for Scientific Research grant no. SPUB-M-COPERNICUS/P-05/DZ-30/99/2000 (in Warsaw).
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Note: D. Campa and R.J. Hung were recipients of Special Training Awards from the IARC.
Received 6/16/05;
accepted 8/11/05.
|
References
|
|---|
- Coussens L-M, Werb Z. Inflammation and cancer. Nature 2002;420:860–7.[CrossRef][Medline]
- Takizawa H, Tanaka M, Takami K, et al. Increased expression of inflammatory mediators in small-airway epithelium from tobacco smokers. Am J Physiol Lung Cell Mol Physiol 2000;278:L906–13.[Abstract/Free Full Text]
- Godschalk R, Nair J, van Schooten F-J, et al. Comparison of multiple DNA adduct types in tumor adjacent human lung tissue: effect of cigarette smoking. Carcinogenesis 2002;23:2081–6.[Abstract/Free Full Text]
- Xie K. Interleukin-8 and human cancer biology. Cytokine Growth Factor Rev 2001;12:375–91.[CrossRef][Medline]
- Hull J, Thomson A, Kwiatkowski D. Association of respiratory syncytial virus bronchiolitis with the interleukin 8 gene region in UK families. Thorax 2000;55:1023–7.[Abstract/Free Full Text]
- Campa D, Zienolddiny S, Maggini V, Skaug V, Haugen A, Canzian F. Association of a common polymorphism in the cyclooxygenase 2 gene with risk of non-small cell lung cancer. Carcinogenesis 2004;25:229–35.[Abstract/Free Full Text]
- Hung RJ, Brennan P, Canzian F, et al. Large-scale investigation of base excision repair genetic polymorphisms and lung cancer risk in a multicenter study. J Natl Cancer Inst 2005;97:567–76.[Abstract/Free Full Text]
Top
Introduction
Materials and Methods
