RT Journal Article SR Electronic T1 RARĪ²2 methylation level in blood for lung cancer assessment JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP p1951 VO 38 IS Suppl 55 A1 Anastasia Ponomaryova A1 Elena Rykova A1 Nadezda Cherdyntseva A1 Tatiana Skvortsova A1 Alexey Dobrodeev A1 Alexander Zav'yalov A1 Sergey Tuzikov A1 Valentin Vlassov A1 Pavel Laktionov YR 2011 UL http://erj.ersjournals.com/content/38/Suppl_55/p1951.abstract AB Background: Cell-free DNA bearing the same epigenetic changes as the tumor tissues were shown to be detectable in plasma circulating DNA (cirDNA) of cancer patients indicating their usefulness as complementary diagnostic and prognostic markers for lung cancer.Methods: Blood samples of 30 healthy men and 55 patients with confirmed non-small-cell lung cancer (NSCLC) before and after surgery were enrolled in this study. Methylation level of RARb2 gene in the cirDNA from blood plasma and cirDNA eluated from blood cell surface with PBS/EDTA and trypsin solutions was assessed by quantitative methylation-specific PCR.Results: It was found that RARb2 gene methylation level was significantly increased in plasma cirDNA and cell-surface-bound cirDNA from NSCLC patients compared with healthy subjects (7620 copies/ml and 1083 copies/ml in the cell-surface-bound fractions, 3589 copies/ml and 1068 copies/ml in the blood plasma, Mann-Whitney U test, P<0.05). The increase of RARb2 methylation level was associated with stage and unfavorable outcome of the disease. 93% of NSCLC patients demonstrated the significant decrease of RARb2 methylation level in cirDNA at the time point of 10-15 days after surgery.Conclusions: Epigenetic alterations of RARb2 gene in the total cirDNA were found to be associated with lung cancer progression. Correlation of RARb2 methylation level with tumor stage, outcome of disease and surgical treatment efficacy demonstrate applicability of cirDNA methylation marker analysis as a valuable tool for lung cancer prognosis and treatment monitoring improvement.