Pneumologie 2015; 69 - A66
DOI: 10.1055/s-0035-1556658

Aberrant DNA methylation of ribosomal RNA genes in lung cancer

S Teschler 1, A Richter 1, A Jimenez 1, B Linder 1, R Dammann 1
  • 1Justus-Liebig-University, Gießen

Aberrant epigenetic modification of rDNA has been reported in cancers. Here we analyzed DNA methylation of rRNA genes in lung cancer and correlated methylation levels with different chromatin states. In general, methylation of rDNA ranged from 10% to 30% at individual CpG sites in the promoter region. In primary lung cancers a significant increased rDNA methylation was observed at 19 analyzed CpGs (1.2-fold increase, p < 0.001). Moreover, we report an increased methylation of rDNA towards the 28S region of rRNA genes. Polymerase I- and CTCF-associated rDNA exhibited reduced methylation compared to global rDNA. In DNMT1 knock out cells a strong reduction of methylation of 18S and 28S regions was found compared to wild type cells (2.7- and 1.4-fold reduction, respectively). In double DNMT1 and DNMT3B knock out cells no substantial rDNA methylation was detected. Independently of this hypomethylation, 28S level and number of rDNA repeats were constant in wild type, single knock out and double knockout cells. Our data suggest that aberrant methylation of rDNA occurs in lung cancer.

*Presenting author