[Methylation status of LINE-1 sequences in patients with MDS or secondary AML].
OBJECTIVE
This study analyzes changes in the degree of global methylationlevel in myelodysplastic syndrome during progression of the disease.


METHODS
Methylation status was analyzed in 127 patients with histologically confirmed MDS and 26 reactive controls. We employed Pyrosequencing, Luminometric Methylation Assay (LUMA) and a realtime PCR-based quantitative assay.


RESULTS
We detected an increase of methylation level of LINE-1 sequences using pyrosequencing and an increase of methylation in the HpaII recognition site employing LUMA during the progression of MDS. Methylation sensitive quantitative PCR showed no statistically significant differences, only a trend.


CONCLUSIONS
LINE-1 and methylation sensitive cleavage of DNA can act as a surrogatmarker for global DNA methylation. The genome wide hypermethylation of MDS is a distinct feature of this disease. It discriminates MDS from other neoplasia and may explains the success of hypomethylation inducing reagents like azadeoxycytidine in MDS therapy.
Römermann
D
D
Institut für Pathologie, Medizinische Hochschule Hannover.
Hasemeier
B
B
Metzig
K
K
Schlegelberger
B
B
Länger
F
F
Kreipe
H
H
Lehmann
U
U
D019175:DNA Methylation; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D009190:Myelodysplastic Syndromes / Q000235:genetics*