Analysis of aberrant methylation on promoter sequences of tumor suppressor genes and total DNA in sputum samples: a promising tool for early detection of COPD and lung cancer in smokers

Guzmán Leda, Depix María, Salinas Ana, Roldán Rosa, Aguayo Francisco, Silva Alejandra, Vinet, Vinet Raul

Description

Chronic obstructive pulmonary disease (COPD) is a disorder associated to cigarette smoke and lung cancer (LC). Since epigenetic changes in oncogenes and tumor suppressor genes (TSGs) are clearly important in the development of LC. In this study, we hypothesize that tobacco smokers are susceptible for methylation in the promoter region of TSGs in airway epithelial cells when compared with non-smoker subjects. The purpose of this study was to investigate the usefulness of detection of genes promoter methylation in sputum specimens, as a complementary tool to identify LC biomarkers among smokers with early COPD. Methods We determined the amount of DNA in induced sputum from patients with COPD (n = 23), LC (n = 26), as well as in healthy subjects (CTR) (n = 33), using a commercial kit for DNA purification, followed by absorbance measurement at 260 nm. The frequency of CDKN2A, CDH1 and MGMT promoter methylation in the same groups was determined by methylation-specific polymerase chain reaction (MSP). The Fisher’s exact test was employed to compare frequency of results between different groups. Results DNA concentration was 7.4 and 5.8 times higher in LC and COPD compared to the (CTR) (p < 0.0001), respectively. Methylation status of CDKN2A and MGMT was significantly higher in COPD and LC patients compared with CTR group (p < 0.0001). Frequency of CDH1 methylation only showed a statistically significant difference between LC patients and CTR group (p < 0.05). Conclusions We provide evidence that aberrant methylation of TSGs in samples of induced sputum is a useful tool for early diagnostic of lung diseases (LC and COPD) in smoker subjects. Virtual slides The abstract MUST finish with the following text: Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1127865005664160

Sujets

• DNA methylation
• Sputum
• Lung cancer
• Chronic obstructive pulmonary disease

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 9
• Langue: English

Extrait

Guzmánet al. Diagnostic Pathology2012,7:87 http://www.diagnosticpathology.org/content/7/1/87

R E S E A R C H

Open Access

Analysis of aberrant methylation on promoter sequences of tumor suppressor genes and total DNA in sputum samples: a promising tool for early detection of COPD and lung cancer in smokers 1* 2 2 3 4 2 Leda Guzmán , María Soledad Depix , Ana María Salinas , Rosa Roldán , Francisco Aguayo , Alejandra Silva 5,6 and Raul Vinet

Abstract Background:Chronic obstructive pulmonary disease (COPD) is a disorder associated to cigarette smoke and lung cancer (LC). Since epigenetic changes in oncogenes and tumor suppressor genes (TSGs) are clearly important in the development of LC. In this study, we hypothesize that tobacco smokers are susceptible for methylation in the promoter region of TSGs in airway epithelial cells when compared with nonsmoker subjects. The purpose of this study was to investigate the usefulness of detection of genes promoter methylation in sputum specimens, as a complementary tool to identify LC biomarkers among smokers with early COPD. Methods:= 23), We determined the amount of DNA in induced sputum from patients with COPD (n = 26),LC (n as well as in healthy subjects (CTR) (n = 33), using a commercial kit for DNA purification, followed by absorbance measurement at 260 nm. The frequency of CDKN2A, CDH1 and MGMT promoter methylation in the same groups was determined by methylationspecific polymerase chain reaction (MSP). The Fisher’s exact test was employed to compare frequency of results between different groups. Results:DNA concentration was 7.4 and 5.8 times higher in LC and COPD compared to the (CTR) (p<0.0001), respectively. Methylation status of CDKN2A and MGMT was significantly higher in COPD and LC patients compared with CTR group (p<0.0001). Frequency of CDH1 methylation only showed a statistically significant difference between LC patients and CTR group (p<0.05). Conclusions:We provide evidence that aberrant methylation of TSGs in samples of induced sputum is a useful tool for early diagnostic of lung diseases (LC and COPD) in smoker subjects. Virtual slides:The abstract MUST finish with the following text:Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1127865005664160 Keywords:DNA methylation, Sputum, Lung cancer, COPD

* Correspondence: [e-mail] 1 Departamento de Bioquímica, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile Full list of author information is available at the end of the article

© 2012 Guzman et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.