Showing papers by "Norimitsu Kadowaki published in 1996"
TL;DR: BCL6 gene rearrangement is primarily involved in large cell lymphoma irrespective of growth pattern of neoplastic cells, and that BCL6(+)BCL2(−) NHL could be curable with modern intensive chemotherapy.
Abstract: We report a series of B-cell neoplasms with regard to rearrangement of the BCL6 gene on chromosome band 3q27. Southern blot analysis using probes from the major translocation cluster (MTC) region of the BCL6 revealed rearrangement in 21/197 patients (l0.7%) with B-cell neoplasms studied at presentation, and 11/25 patients (44%) first studied at relapse. In non-Hodgkin's lymphoma (NHL) studied at diagnosis, rearrangements of the BCL6 gene were not closely associated with a specific histopathologic subtype but distributed in subcategories in the Working Formulation. The incidence in follicular lymphoma was 12.1%, with significantly higher frequency in mixed and large cell subtypes, and that in diffuse aggressive lymphoma was 14.1%. Comigration analysis using probes from the immunoglobulin genes revealed association of the BCL6 gene with one of the three immunoglobulin loci in 9/25 cases analysed. A comparative study between NHL associated either with BCL2 or BCL6 rearrangement showed that advanced disease and bone marrow involvement were more frequent in BCL2(+) NHL. In contrast, extranodal involvement was more frequently observed in the BCL6(+) NHL. The survival curve of BCL6(+) NHL was characterized by a rapid decline followed by a plateau. Of the total of 32 BCL6(+) patients, six carried both BCL2 and BCL6 rearrangements ; five of these six showed clinicopathological properties characteristic of follicular lymphoma, suggesting that the presence of the two genetic abnormalities does not necessarily have synergistic effects on malignant phenotypes. The high level of BCL6 expression in follicular lymphoma cell lines carrying a BCL2 rearrangement suggests that the deregulated BCL2 gene may have an effect on the development of genetic abnormalities of the BCL6 gene. The present study suggests that BCL6 gene rearrangement is primarily involved in large cell lymphoma irrespective of growth pattern of neoplastic cells, and that BCL6(+)BCL2(-) NHL could be curable with modern intensive chemotherapy.
57 citations
Journal Article•
TL;DR: Heterogeneity is demonstrated not only in clinicopathological presentation of B cell disease with rearrangements of 5'-BCL2, but also in molecular lesions resulting from the rearrangement.
Abstract: Rearrangement of the BCL2 gene with the immunoglobulin (IG) genes is the most frequent genetic abnormality in B cell lymphoid neoplasms. In the majority of cases, breakages occur at two breakpoint cluster regions; major breakpoint cluster (MBR) and minor cluster region (mcr). In a minority of cases with non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL), rearrangements involving the 5' flanking region of the BCL2 (5'-BCL2) have been reported. Here, we investigated 196 patients with NHL and 31 with CLL, with regard to rearrangement of the BCL2 gene. Hybridization analyses using probes representing the three cluster regions revealed that a total of 57 patients had a rearrangement of the BCL2; 42 (73.7%) were within the MBR, seven (12.2%) were within the mcr, and nine (15.8%) had a rearrangement at the 5'-BCL2. The nine patients with 5'BCL2 rearrangement included two with follicular lymphoma, four with diffuse large cell lymphoma and immunoblastic variant, two with leukemic phase of follicular lymphoma, and one with CLL. Comigration analysis with probes for the IG heavy chain gene (IGH), kappa-chain gene (IG kappa) and lambda-chain gene (IG lambda), demonstrated a 5'-BCL2/IGH junction at the JH region in four patients with NHL derived from follicular center B cell. Thus, the 5'flanking region is a third cluster for recombination between the BCL2 and IGH, which is closely associated with the development of follicular center cell lymphoma. Molecular cloning of a 5'-BCL2/IGH junction demonstrated recombination of the two affected genes in divergent orientation. A 5'-BCL2/IG kappa junction was observed in two patients with immunoblastic lymphoma, and one with CLL had a 5'-BCL2/IG lambda recombination. Two patients, including one with a BCL2-MBR/JH junction, lacked obvious recombination of the 5'-BCL2 with IG genes, suggesting the presence of a deletion at the 5'-BCL2. Our findings demonstrated heterogeneity not only in clinicopathological presentation of B cell disease with rearrangement of 5'-BCL2, but also in molecular lesions resulting from the rearrangement.
26 citations
TL;DR: It is suggested that p53 alteration exhibits diverse functions in the development and progression of B‐cell tumors related to the presence or absence of oncogene rearrangement, and that chemotherapy‐related influences may be involved in the occurrence of progression‐associated p53 mutations.
Abstract: We investigated mutations of the p53 tumor suppressor gene in B-cell lymphoid neoplasms with reference to oncogene rearrangements associated with specific chromosomal translocations. These included 15 patients with a BCL1/PRAD1 gene rearrangement and/or PRAD1 overexpression, 45 with a BCL2 rearrangement, 2 with a BCL3 rearrangement, 24 with a BCL6 rearrangement, and 6 with both BCL2 and BCL6 rearrangements. Thirty-six patients lacked detectable oncogene rearrangements. Genomic DNA was isolated from involved tissues or leukemic cells obtained at diagnosis and/or at relapse, and established cell lines. Polymerase chain reaction-mediated single-strand conformation polymorphism analysis and direct sequencing were performed to analyze abnormalities of the p53 gene. We detected p53 gene alterations in 18 of 128 patients, representing 21 of the total 151 materials analyzed. In the total of 66 patients with an oncogene rearrangement studied at diagnosis, only one had a mutation; however, 6 of 37 patients studied at relapse showed p53 mutations. Sequential analysis revealed that the p53 mutation was closely associated with transformation from follicular lymphoma to large cell lymphoma, exclusively in BCL2-positive lymphoma cases. Two of 13 mutations observed in oncogene rearrangement-positive cases and cell lines were transitions at CpG dinucleotides. In contrast, the relationship between p53 mutations and clinical behavior in oncogene rearrangement-negative cases was variable; 5 patients including one with indolent follicular lymphoma were positive for p53 mutation at initial presentation, and 2 of the 5 showed prolonged disease-free survival. Our findings suggest that p53 alteration exhibits diverse functions in the development and progression of B-cell tumors related to the presence or absence of oncogene rearrangement, and that chemotherapy-related influences may be involved in the occurrence of progression-associated p53 mutations.
9 citations