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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., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Telomerase activity has been found in most common cancers, thus indicating that telomerase detection may be a useful marker in cancer diagnosis. The telomeric amplification protocol (TRAP) assay and RT-PCR are customarily used to detect telomerase activity and the expression of the associated genes in cells. However, these methods do not provide any information about telomerase activation at an individual cell level. To analyze cells separately, those cells have to be isolated by sometimes complicated method. The immunohistochemical detection of human telomerase reverse transcriptase (hTERT) is useful to detect telomerase positive cells in a background of non-cancerous cells. A method has been developed for the detection of intranuclear hTERT protein, in a subpopulation of hematopoietic cells, using concurrent staining of a cell surface antigen and multicolor flow cytometry. Only mouse monoclonal anti-hTERT antibody demonstrated the specific positivity in immunocytochemistry and immunofluorescent flow cytometry. Human leukemia and myeloma cell lines showed 100% positivity, whereas normal neutrophils showed 0% positivity. hTERT expression was analyzed in hematopoietic precursor cells of bone marrow samples using concurrent staining of surface CD34 antigen and intracellular hTERT protein and multi-parameter flow cytometry. CD34 positive cells demonstrated higher expression of hTERT than CD34 negative cells. A quick, easy and sensitive assay for determining the hTERT protein expression has been developed. Using this method and the multi-parameter nature of flow cytometry and its ability to identify cellular subpopulations will provide a better understanding of the mechanisms regarding the activation of telomerase., (Copyright 2009 Elsevier Ltd. All rights reserved.)

The incidence of chronic lymphocytic leukemia (CLL) is low in Asian countries including Japan, while CLL is the most common type of leukemia in the west. To elucidate which factors contribute to the low frequency of CLL in Japan, we investigated immunoglobulin (Ig) heavy chain gene usage and somatic hypermutation status in 44 Japanese patients with CLL. Only one of these patients used V(H)1-69. The finding is in striking contrast to data from western countries, where the frequency of CLL expressing V(H)1-69 ranges from 12 to 21%.

To determine the clinical significance of the T helper 1(Th1)/T helper 2 (Th2) ratio in multiple myeloma, the intracellular IFN-gamma and IL-4 were analyzed by flow cytometry in 56 patients with multiple myeloma. The mean Th1/Th2 ratio of cases in the initial diagnosis phase and the refractory phase were higher than that of the control group. The mean serum beta-2-microglobulin in the high Th1/Th2 subgroup was significantly higher than that in the normal Th1/Th2 subgroup (P < 0.05). In conclusion, the Th1/Th2 ratio was closely related to the disease status of multiple myeloma.

We studied Cyclin D1 (CyD1) and CD23 mRNA expression with real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) method. CyD1 expression in peripheral blood of seven mantle cell lymphoma (MCL) patients was found to be 1305.4 times higher than in 24 B-chronic lymphocytic leukemia (CLL) patients. CD23 expression in CLL was found to be 54.8 times higher than in MCL. These differences were statistically significant, and no overlap was found in CyD1 expression intensities between MCL and CLL. RQ-PCR allows rapid, simple and accurate quantification of CyD1 and CD23 expression, even from small samples, and is thus useful for the diagnosis of MCL and CLL.