Double-hit lymphomas (DHLs) are collectively defined as B-cell non-Hodgkin lymphomas harboring rearrangements of MYC as well as B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6).
'Double-Hit' (DH) B cell non-Hodgkin lymphomas are characterized by the presence of a MYC rearrangement and additional rearrangement(s) most commonly involving BCL2 and/or BCL6.
BCL6 alternative breakpoint region break and homozygous deletion of 17q24 in the nodular lymphocyte predominance type of Hodgkin's lymphoma-derived cell line DEV.
Detection of chimaeric transcripts of the immunoglobulin heavy chain and BCL6 genes by reverse-transcriptase polymerase chain reaction in B-cell non-Hodgkin's lymphomas.
These data expand the spectrum of B-cell non-Hodgkin's lymphomas associated with BCL-6 5' mutations and have implications for the pathogenesis, histogenesis and clinical monitoring of Burkitt's lymphoma.
The above immunohistological findings suggest that (a) bcl-6 may play a role in regulating B-cell differentiation step(s) occurring within germinal centers; (b) deregulated bcl-6 expression caused by rearrangements may contribute to B-lymphomagenesis; (c) bcl-6 is possibly involved in the pathogenesis of NLPHD.
The LAZ3/BCL6 gene on chromosone 3q27 is recurrently disrupted in B cell non-Hodgkin's lymphomas by translocations involving immunoglobulin genes or other chromosone regions.
These results further support the concept that NLPHD is an histogenetically distinct, B-cell-derived subtype of HD and suggest a role for BCL-6 in its development.
Rearrangements and mutations of the LAZ3/BCL6 gene are the most frequent events associated with diffuse large-cell lymphoma, a particular class of non-Hodgkin's lymphomas.
These findings confirm that BCL-6 is rearranged in a significant percentage of diffuse B-large cell lymphomas, suggesting that this proto-oncogene might have a pathogenetic role in this subset of NHLs, but our preliminary analysis suggests that BCL-6 lesions are not involved in the pathogenesis of HD.
To assess the frequency and role of this gene's involvement in lymphomagenesis and tumor progression, we examined a series of 170 cases of non-Hodgkin's lymphomas of B-cell lineage for LAZ3 gene rearrangement, expression, and mutation.