Detecting methylation patterns of p16, MGMT, DAPK and E-cadherin genes in multiple myeloma patients.

Multiple myeloma (MM) is a B-cell neoplasia characterized by the clonal proliferation of plasma cells. Besides known genetic abnormalities, epigenetic changes are also known to effect MM pathogenesis. DNA methylation is an epigenetic mechanism that silences genes by adding methyl groups to cytosine-guanine dinucleotides at the promoter regions. In this study, the methylation status of four genes; p16, O6-methyl guanine DNA methyl transferase (MGMT), death-associated protein kinase (DAPK) and E-cadherin (ECAD); at the time of diagnosis was investigated using methylation-specific polymerase chain reaction (MS-PCR). In the 20 cases studied; methylation of the promoter regions of p16, MGMT, DAPK and ECAD genes was detected in 10%, 40%, 10% and 45% of the cases, respectively. In 65% (13/20) of cases, at least one of the genes studied had promoter methylation; while 35% of cases (7/20) had methylated promoters of more than one gene. There was a significant correlation between promoter hypermethylation of MGMT and the presence of extramedullary involvement; but for the other genes no correlation was found regarding disease properties like age, disease stage, clinical course and the presence of lytic bone lesions. Determining the methylation profiles of genes in MM, could lead to a new understanding of the disease pathogenesis and guide the assessment of treatment options.