Translocation t(14;18) and gain of chromosome 18/BCL2: effects on BCL2 expression and apoptosis in B-cell non-Hodgkin's lymphomas

Galteland, E., Sivertsen, E. A., Svendsrud, D. H., Smedshammer, L., Kresse, S. H., Meza-Zepeda, L. A., Myklebost, O., Suo, Z., Mu, D., DeAngelis, P. M., Stokke, T. (December 2005) Translocation t(14;18) and gain of chromosome 18/BCL2: effects on BCL2 expression and apoptosis in B-cell non-Hodgkin's lymphomas. Leukemia, 19 (12). pp. 2313-2323. ISSN 0887-6924

Abstract

Gain of chromosome 18q and translocation t(14;18) are] frequently found in B-cell non-Hodgkin's lymphomas (B-NHL). Increased BCL2 transcription and BCL2 protein expression have been suggested to be the result of the gain. We utilized FISH, PCR and array CGH to study BCL2 and chromosome 18 copy number changes and rearrangements in 93 cases of B-NHL. BCL2 protein was expressed in > 75% of the tumor cells in 92% of the cases by immunohistochemistry. Gain of BCL2 was associated with a 25% increase in BCL2 expression levels (immunoblotting), whereas t(14;18) resulted in a 55% increase in BCL2 levels compared to cases without BCL2 alterations. The tumor cell (spontaneous) apoptotic fractions were similar for the cases with different BCL2 genotypes. However, the normal cell apoptotic fractions were higher for the tumors with t(14; 18) compared to the tumors without BCL2 alterations, while the tumors with gain of BCL2 only showed intermediate levels. Low-level gains of parts of chromosome 18 were found in 14 of the 38 B-NHL cases with t(14; 18), with a consensus region 18pter-q21.33 that did not include the BCL2 gene. The 11 cases with 18q gain only showed a consensus region encompassing 18q21.2-18q21.32 and 18q21.33, which contain PMAIP1/MALT1 and BCL2, respectively.

Item Type: Paper
Uncontrolled Keywords: B-cell non Hodgkin's lymphoma translocation t 14 18 FISH chromosome 18 gain BCL2 apoptosis comparative gene hybridization s-phase fraction DNA copy number follucular lymphoma prognostic value C-MYC aurvival amplication gene proliferation
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > DNA translocation
diseases & disorders > cancer > cancer types > lymphoma
CSHL Authors:
Depositing User: CSHL Librarian
Date: December 2005
Date Deposited: 12 Jan 2012 21:53
Last Modified: 12 Jan 2012 21:53
URI: https://repository.cshl.edu/id/eprint/22574

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