Global DNA methylation status in laryngeal cancer

Background. The purpose of our study was to evaluate if DNA methylation level in leukocytes may be used as a surrogate marker of genome methylation status in laryngeal cancer tissues. Methods. We evaluated global DNA methylation using an ultra performance liquid chromatography (UPLC)-based method to assess the total content of 5-methylcytosine (5 mC). Results. The study was performed on DNA isolated from cancer tissues, adjacent normal tissues, and peripheral blood leukocytes in a group of 72 patients with laryngeal cancer. DNA hypomethylation was found in tumor tissue (56%) and normal tissue (49%). There was a significant correlation between the levels of 5 mC in these 2 types of tissue. There was no significant DNA hypomethylation in blood. A negative correlation between tumor grade and blood levels of 5 mC was found. Conclusion. The level of leukocyte DNA methylation measured using total 5 mC content cannot be used as a surrogate marker for genome methylation status in laryngeal cancer tissues. © 2013 Wiley Periodicals, Inc.