Although most of the VH genes expressed by DLC tumor cells contained mutations with respect to their germline counterparts, almost all of these mutations occurred before the clonal expansion of the tumor.
AIDS-DLCL is characterized by EBV infection in the large majority of cases and by the mutually exclusive presence of bcl-6 rearrangements and c-myc translocations in 40% of the cases.
In the case for which FL and DLL cells showed different bcl-2/IgH junctional sequences, DLL cells incorporated larger bcl-2 and Ig-joining (JH) gene fragments than the corresponding FL cells, suggesting that DLL clones developed by a distinct t(14; 18) translocation rather than by alteration of the hybrid bcl-2/IgH gene detected in the FL cells.
When compared with six other DLCL cell lines lacking t(9;14)(p13;q32), the KIS-1 cell line showed an 11-fold overexpression of PAX-5 mRNA and a significantly reduced expression of the p53 gene, which is normally regulated by PAX-5.
When compared with six other DLCL cell lines lacking t(9;14)(p13;q32), the KIS-1 cell line showed an 11-fold overexpression of PAX-5 mRNA and a significantly reduced expression of the p53 gene, which is normally regulated by PAX-5.
Deregulation of PAX-5 by translocation of the Emu enhancer of the IgH locus adjacent to two alternative PAX-5 promoters in a diffuse large-cell lymphoma.
When compared with six other DLCL cell lines lacking t(9;14)(p13;q32), the KIS-1 cell line showed an 11-fold overexpression of PAX-5 mRNA and a significantly reduced expression of the p53 gene, which is normally regulated by PAX-5.
To analyze whether additional structural alterations of the translocated bcl-2 gene are associated with morphologic transformation of FL, we PCR-amplified, cloned, and sequenced the major breakpoint region (MBR) and the open reading frames (ORF) of the translocated bcl-2 oncogene in six paired samples of FL and subsequent diffuse large-cell lymphoma (DLL).
Sequential samples of the indolent and transformed phase of three cases showed the presence of p16(INK4a) deletions in the Richter's syndrome but not in the CLL component of two cases, whereas in a follicular lymphoma the deletion was present in both the follicular tumor and in the diffuse large-cell lymphoma.
Codeletion of CDKN2 and MTAP genes in a subset of non-Hodgkin's lymphoma may be associated with histologic transformation from low-grade to diffuse large-cell lymphoma.
Codeletion of CDKN2 and MTAP genes in a subset of non-Hodgkin's lymphoma may be associated with histologic transformation from low-grade to diffuse large-cell lymphoma.
Immunoglobulin heavy chain locus variable gene segment V4-34 (V(H)4.21) use in productive heavy chain (IgH) gene rearrangements has been described in a number of human reactive and autoimmune B cell responses, and has been shown to be frequently used in some series of cases of diffuse large cell lymphoma (DLCL).
Codeletion of CDKN2 and MTAP genes in a subset of non-Hodgkin's lymphoma may be associated with histologic transformation from low-grade to diffuse large-cell lymphoma.
Thus, an understanding of the PAX-5 gene's physiological role in B-cell development and the pathological role in tumorigenesis may lead to the optimal clinical treatment strategy for LPL and LPL-derived diffuse large cell lymphoma (DLCL).
Semi-quantitative fluorescence in situ hybridization analysis indicates that the myc protein is consistently stabilized both before and after transformation of low-grade follicular center to high-grade diffuse large cell lymphoma.