DNMT3B7 expression related to MENT expression and its promoter methylation in human lymphomas

DNA methyltransferase (DNMT) 3B7 is the most expressed DNMT3B splice variant. It was reported that the loss of DNMT3B function led to overexpression of the MEthylated in Normal Thymocyes (MENT) and accelerated mouse lymphomagenesis. We investigated the DNMT3B7 expression and its relationship to MENT expression and promoter methylation in human lymphomas. DNMT3B7 and MENT expression were significantly (p < 0.0001, p < 0.01) higher in lymphomas than in non-malignant. Expression of DNMT3B7 and MENT were associated with MENT promoter hypomethylation. DNMT3B7 overexpression might interfere with the normal DNA methylation mechanism required for silencing the MENT proto-oncogene, and may accelerate human lymphomagenesis.