Decreased NK Cells in Patients with Head and Neck Cancer Determined in Archival DNA
ABSTRACT PURPOSE: Natural killer (NK) cells are a key element of the innate immune system implicated in human cancer. To examine NK cell levels in archived bloods from a study of human head and neck squamous cell carcinoma (HNSCC), a new DNA-based quantification method was developed.EXPERIMENTAL DESIGN: NK cell-specific DNA methylation was identified by analyzing DNA methylation and mRNA array data from purified blood leukocyte subtypes (NK, T, B, monocytes, granulocytes), and confirmed via pyrosequencing and quantitative methylation specific PCR (qMSP). NK cell levels in archived whole blood DNA from 122 HNSCC patients and 122 controls were assessed by qMSP.RESULTS: Pyrosequencing and qMSP confirmed that a demethylated DNA region in NKp46 distinguishes NK cells from other leukocytes, and serves as a quantitative NK cell marker. Demethylation of NKp46 was significantly lower in HNSCC patient bloods compared with controls (P < 0.001). Individuals in the lowest NK tertile had over 5-fold risk of being a HNSCC case, controlling for age, gender, HPV16 status, cigarette smoking, alcohol consumption, and BMI (OR = 5.6, 95% CI, 2.0 to 17.4). Cases did not show differences in NKp46 demethylation based on tumor site or stage.CONCLUSIONS: The results of this study indicate a significant depression in NK cells in HNSCC patients that is unrelated to exposures associated with the disease. DNA methylation biomarkers of NK cells represent an alternative to conventional flow cytometry that can be applied in a wide variety of clinical and epidemiologic settings including archival blood specimens. Clin Cancer Res; 1-8. ©2012 AACR.
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ABSTRACT: Background. Human papillomaviruses (HPVs) have been proved as one of the etiological factors of oropharyngeal squamous cell carcinoma (OPSCC). Patients with tumors of viral etiology have a lower recurrence rate and better prognosis. OPSCC is linked to an alteration in the immune system. Only a limited number of studies have correlated both the immunological parameters and HPV status with patient prognosis. The aim of this study was to determine whether HPV infection and the immunological status influence patient prognosis individually or in concurrence. Material and Methods. Sixty patients with oral and oropharyngeal carcinomas were enrolled. They were divided into HPV-positive and HPV-negative groups based on the expression of HPV 16 E6 mRNA. Basic lymphocyte subpopulations were determined in the peripheral blood by means of flow cytometry. Results. Significantly better disease-specific survival (DSS) was observed in patients with HPV-positive tumors. Nodal status, tumor grade, recurrence, and CD8+/Tregs ratio were identified as factors influencing DSS. A higher level of Tregs and a lower ratio of CD8/Tregs influenced overall survival (OS) independently of HPV status and age. Patients with HPV-positive tumors and high levels of Tregs survived significantly better than patients from the other groups. Conclusion. Better survival is associated with HPV positivity and elevated Tregs levels. Our data suggest that HPV infection and Tregs do not influence patient prognosis in concurrence.BioMed Research International 04/2014; 2014:303929. DOI:10.1155/2014/303929 · 2.71 Impact Factor
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ABSTRACT: Abstract Pteridium aquilinum (bracken fern), one of the most important toxic plants in the world, contains the toxic norsequiterpene ptaquiloside that induces cancers in humans and farm animals. Previous studies in the laboratory demonstrated immunotoxic effects produced by ptaquiloside, which are characterized by suppression of natural killer (NK) cell activity (i.e. cytotoxicity and interferon [IFN]-γ production). However, it is unknown whether these immunosuppressive effects could contribute to carcinogenesis in situ in general because of the important function of NK cells in innate killing of tumor cells. This study assessed the impact of P. aquilinum-induced immunosuppression on urethane-induced lung cancer in C57BL/6 mice. Adult mice were treated with an extract of P. aquilinum (30 g/kg/day) by gavage once daily for 14 days, followed by gavage (5 days/week) during an 11-week period that was accompanied by treatment with urethane (1 g/kg) via once-weekly intraperitoneal injection; 20 weeks after the end of the treatment period, all lungs were evaluated. The results indicated there was a significant increase in lung nodule number as well as in multiplicity of lesions in mice treated with both P. aquilinum and urethane (PU group) compared to values in mice treated only with the urethane (U group). In addition, histologic evaluation revealed a 76% increase in the rate of lung adenomas and a 41% increase in rate of bronchiolization of alveoli in the mice from the PU group compared to levels seen in mice within the U group. Taken together, the results here show for the first time that immunosuppressive effects of P. aquilinum could increase the risk of cancer formation in exposed hosts.Journal of Immunotoxicology 02/2014; 12(1). DOI:10.3109/1547691X.2014.885619 · 1.91 Impact Factor
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ABSTRACT: Background The impact of cell-composition effects in analysis of DNA methylation data is now widely appreciated. With the availability of a reference data set consisting of DNA methylation measurements on isolated cell types, it is possible to impute cell proportions and adjust for them, but there is increasing interest in methods that adjust for cell composition effects when reference sets are incomplete or unavailable. Results In this article we present a theoretical basis for one such method, showing that the total effect of a phenotype on DNA methylation can be decomposed into orthogonal components, one representing the effect of phenotype on proportions of major cell types, the other representing either subtle effects in composition or global effects at focused loci, and that it is possible to separate these two types of effects in a finite data set. We demonstrate this principle empirically on nine DNA methylation data sets, showing that the first few principal components generally contain a majority of the information on cell-type present in the data, but that later principal components nevertheless contain information about a small number of loci that may represent more focused associations. We also present a new method for determining the number of linear terms to interpret as cell-mixture effects and demonstrate robustness to the choice of this parameter. Conclusions Taken together, our work demonstrates that reference-free algorithms for cell-mixture adjustment can produce biologically valid results, separating cell-mediated epigenetic effects (i.e. apparent effects arising from differences in cell composition) from those that are not cell mediated, and that in general the interpretation of associations evident from DNA methylation should be carefully considered. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0527-y) contains supplementary material, which is available to authorized users.BMC Bioinformatics 03/2015; 16(1). DOI:10.1186/s12859-015-0527-y · 2.67 Impact Factor