OBJECTIVETo study the relationship between E-cadherin gene expression and the methylation status of E-cadherin 5' CpG islands in acute myeloid leukemia (AML).

METHODSReverse transcription-PCR (RT-PCR), flow cytometry and methylation specific PCR were used to analyze the E-cadherin gene and protein expression and its 5' CpG island methylation status respectively in bone marrow cells from 55 AML patients and 7 normal controls.

RESULTSAML cells displayed a significant reduction or lack of E-cadherin gene and protein expression, the positive rates were 23.6% and 18.2% (P < 0.01), respectively. All normal bone marrow cells were E-cadherin positive. Thirty-eight of the 55 patients (69.1%) were E-cadherin 5' CpG island methylated whereas the normal controls were completely unmethylated. Twenty-nine of thirty-one (93.5%) E-cadherin-negative samples showed abnormal hypermethylation of the E-cadherin CpG islands.

CONCLUSIONExpression downregulation and methylation of E-cadherin gene in AML suggest that it might be an important event in AML. E-cadherin methylation was associated with the inhibition of E-cadherin gene and protein expression in AML.