Evidence that general genomic hypomethylation and focal hypermethylation are two independent molecular events of non-Hodgkin's lymphoma.

Changes in the DNA methylation profile, including general genomic hypomethylation and regional hypermethylation, have been shown to coexist in many neoplastic tissues. However, the relationship between, and significance of, these different forms of DNA methylation dysregulation in disease onset, progression, or maintenance remains unclear. Previously, our work has shown that the CpG dinucleotide-rich gene Myf-3 is hypermethylated in most cases of malignant lymphoproliferative disease (LPD).

Comparative evaluation of PCR-based methods for the assessment of T cell clonality in the diagnosis of T cell lymphoma.

Aims: The accurate diagnosis of T cell lymphoma often depends on the demonstration of a monoclonal T cell population in a lymphoproliferative disorder (LPD). The aim of this study was to evaluate four polymerase chain reaction (PCR)-based methods used to analyse T cell receptor (TCR) gene rearrangements in the assessment of T cell clonality.

Methods: DNA was tested from 23 T cell neoplasms, seven B cell non-Hodgkin's lymphomas (B-NHL), three Hodgkin's lymphomas (HL), 14 benign LPD and peripheral blood from a healthy donor.