Lymphoma and the control of B cell growth and differentiation.
It is now widely accepted that lymphomagenesis is a multistep transformation process. A number of genetic changes and environmental and infectious factors contributing to the development and malignant progression of B-cell lymphoproliferative disorders are well documented. Reciprocal chromosomal translocations involving the immunoglobulin loci are a hallmark of most mature B cell lymphomas and lead to dysregulated expression of proto-oncogenes (c-myc) important for cell proliferation or genes involved in cell cycle progression (cyclin D1), differentiation block (bcl-6, PAX5) and cell survival (bcl-2, NF-kappaB). In addition, genetic alterations that inactivate tumor suppressor genes (p53, p16) have been frequently detected in some lymphoma tissues. Many of these genes are normally regulated by signals from the B cell antigen receptor. The high prevalence of bacterial and viral infection in lymphoma patients supports the hypothesis that infectious agents may play a contributory role in the development and evolution of B cell lymphoproliferative disorders by either directly inducing polyclonal B cell hyperactivation (EBV, HCV), or providing a chronic antigenic stimulus (EBV, HCV, HBV, H. pylori), or mimicking B cell antigen receptor signaling (EBV, HCV, HHV8), although whether these are causative factors or they are secondary to genetic changes in lymphomagenesis remains to be defined. Stimulatory signals from reactive T cells, local cytokines and growth factors can also contribute, to some extent, to the progression of transformation. Modulation of B cell antigen receptor signaling therefore emerges as a potentially powerful strategy for controlling the growth of certain B cell lymphomas.
Rui
Lixin
L
Australian Cancer Research Foundation Genetics Laboratory and Medical Genome Centre, John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia.
Goodnow
Christopher C
CC
D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016393:Lymphoma, B-Cell / Q000378:metabolism* / Q000473:pathology; D008954:Models, Biological; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D011947:Receptors, Antigen, B-Cell; D025521:Tumor Suppressor Proteins