Deregulated epigenetic mechanisms are likely involved in the pathogenesis of 
myelodysplastic syndromes (MDSs). Which genes are silenced by aberrant promotor 
methylation during MDS hematopoiesis has not been equivalently investigated. 
Using an in vitro differentiation model of human hematopoiesis, we generated 
defined differentiation stages (day 0, day 4, day 7, day 11) of erythro-, 
thrombo- and granulopoiesis from 13 MDS patients and seven healthy donors. 
Promotor methylation analysis of key regulatory genes involved in cell cycle 
control (p14, p15, p16, CHK2), DNA repair (hMLH1), apoptosis (p73, survivin, 
DAPK), and differentiation (RARb, WT1) was performed by methylation-specific 
polymerase chain reaction. Corresponding gene expression was analyzed by 
microarray (Affymetrix, HG-U133A). We provide evidence that p16, survivin, CHK2, 
and WT1 are affected by promotor hypermethylation in MDSs displaying a selective 
International Prognostic Scoring System risk association. A 
methylation-associated mRNA downregulation for specific hematopoietic lineages 
and differentiation stages is demonstrated for survivin, CHK2, and WT1. We 
identified a suppressed survivin mRNA expression in methylated samples during 
erythropoiesis, whereas WT1 and CHK2 methylation-related reduction of mRNA 
expression was found during granulopoiesis in all MDS risk types. Our data 
suggest that lineage-specific methylation-associated gene silencing of survivin, 
CHK2, and WT1 in MDS hematopoietic precursor cells may contribute to the 
MDS-specific phenotype