Biology of Hodgkin's lymphoma.
Significant progress has been made in recent years in our understanding of the cellular origin of Hodgkin and Reed-Sternberg (HRS) cells in Hodgkin's lymphoma (HL). It is now clear that in most instances HRS cells represent clonal populations of transformed germinal centre (GC) B cells. While the tumour cells in the lymphocyte predominant type of the disease resemble mutating and antigen-selected GC B cells, there is evidence that HRS cells in classical HL originate from pre-apoptotic GC B cells. HRS cells of the recently defined novel subtype lymphocyte-rich classical HL moleculary resemble HRS cells of the other types of classical HL, but there appear to be phenotypic differences. In rare cases, HRS cells derive from T cells. In contrast to previous speculations, cell fusion apparently does not play a role in the generation of the tumour clone. By gene expression profiling of HL cell lines, it became evident that HRS cells have lost most of the B cell-typical gene expression program, which may explain why these cells can persist without B cell receptor expression and which suggests that at least one of the transforming events involved in HL pathogenesis affects a master regulator of cell lineage identity.
Küppers
R
R
Institute for Genetics, Department of Internal Medicine I, University of Cologne, Germany. ralf.kuppers@.uni-koeln.de
Schwering
I
I
Bräuninger
A
A
Rajewsky
K
K
Hansmann
M L
ML
D000818:Animals; D001402:B-Lymphocytes / Q000473:pathology; D002999:Clone Cells; D015870:Gene Expression; D015321:Gene Rearrangement; D006689:Hodgkin Disease / Q000235:genetics / Q000473:pathology*; D006801:Humans; D016539:Reed-Sternberg Cells / Q000473:pathology; D013601:T-Lymphocytes / Q000473:pathology