These included 12 of 20 cases of nodular follicular center cell lymphoma (nine small cleaved cell, one mixed small and large cell, and two large cell types). bcl-2 translocation was detected in only three of 45 cases of diffuse B-cell lymphoma, and cases of AIDS-related malignant lymphoma, monocytoid B-cell lymphoma, and mantle zone lymphoma were all negative.
Histogenesis of diffuse small cleaved cell lymphoma. An immunohistochemical and molecular genetic (bcl-2 gene) study with comparison to follicular small cleaved cell lymphoma and mantle zone lymphoma.
We found oncogene rearrangements in five of the 14 cases: bcl-1 rearrangement on one mantle zone lymphoma, bcl-2 rearrangements in two follicular lymphomas, and c-myc rearrangements in two small noncleaved cell lymphomas.
We and others have previously shown that the BCL1 locus is rearranged in 55% to 60% of MCL patients and that, on chromosome 11, more than 80% of the breakpoints are localized within a 1-kbp DNA segment known as the major translocation cluster (MTC).
These lesions include c-myc translocation and p53 inactivation in small noncleaved-cell lymphoma, and bcl-2 and bcl-1 translocation in follicular (FL) and mantle-zone lymphoma, respectively.
Approximately 70% of centrocytic (mantle-cell) lymphomas have the chromosomal translocation t(11;14) (q13; q32) and associated rearrangements at the bcl-1 breakpoint locus and at the cyclin D1 (PRAD1, CCND1) gene, thus implicating this gene in the pathogenesis of centrocytic lymphoma.
The t(11;14) breakpoint junctions involving the bcl-1 major translocation cluster were amplified by PCR in 4 of 11 (36%) MCL cases and in none of the MCL-PC or SLL cases.
These lesions include c-myc translocation and p53 inactivation in small noncleaved-cell lymphoma, and bcl-2 and bcl-1 translocation in follicular (FL) and mantle-zone lymphoma, respectively.
Among chronic lymphoproliferative disorders other than MCL, only 1 atypical chronic lymphocytic leukemia (CLL) with a t(11;14) translocation and bcl-1 rearrangement and the 2 hairy cell leukemias (HCLs) analyzed showed upregulation of PRAD-1 gene.
Immunolocalization of PRAD1/cyclin D1 expression appears to be a useful diagnostic adjunct to discriminate mantle cell lymphoma from other non-Hodgkin's lymphomas.
To clarify whether mantle cell lymphomas (MCLs) are related to naive pre-germinal center B cells (expressing nonmutated rearranged VH genes) or to germinal center-derived memory B cells (expressing mutated rearranged VH genes), clonal IgH gene rearrangements using DNA from six MCLs were polymerase chain reaction (PCR)-amplified and analyzed for the presence of somatic mutations.
Rearrangement and overexpression of CCND1 (BCL1/PRAD1), a member of the cyclin G1 gene family, are consistent features of t(11q13)-bearing B-lymphoid tumors (particularly mantle-cell lymphoma [MCL]).
Rearrangement and overexpression of CCND1 (BCL1/PRAD1), a member of the cyclin G1 gene family, are consistent features of t(11q13)-bearing B-lymphoid tumors (particularly mantle-cell lymphoma [MCL]).
BCL1/PRAD1 is the gene locus involved in the t(11;14)(q13;q32) translocation, which often occurs in a proposed subtype of non-Hodgkin's lymphoma of B-cell phenotype (B-NHL), named mantle cell lymphoma (MCL).