Absence of p21CIP1, p27KIP1 and p57KIP2 methylation in MDS and AML

Transcriptional silencing of tumour suppressor genes (TSG) due to hypermethylation is a common event in human tumours. The three members of the KIP/CIP family of cyclin dependent kinase inhibitors (CDKIs), p21CIP1, p27KIP1, and p57KIP2, play key roles in cell cycle regulation, but little is known about their methylation in myeloid neoplasia. Therefore, we analysed 9 haematopoietic cell lines, 67 myelodysplastic syndrome (MDS) and 26 acute myeloid leukaemia (AML) cases as well as 11 controls. p57KIP2 hypermethylation was found in 4/9 cell lines, but methylation of p21CIP1 and p27KIP1 was infrequent. All patient samples analysed were methylation-negative for these three genes.