The cell of origin of B-cell chronic lymphocytic leukemia (B-CLL) is still uncertain. Recent studies have indicated that a fraction of B-CLL displays somatically mutated immunoglobulin variable heavy chain (IgV(H)) genes, which suggests an origin from a post-germinal center (GC) B cell. It has been shown that the 5' noncoding region of the BCL-6 proto-oncogene is affected by mutations in normal...

The Wilms' tumor suppressor gene, WT1, encodes a zinc finger transcription factor that has been demonstrated to negatively regulate several growth factor and cognate receptor genes. However, inconsistent with its tumor suppressor function, WT1 has also been demonstrated to be required to inhibit programmed cell death in vitro and in vivo. Moreover, anaplastic Wilms' tumors, which typically expr...

The Bcl-2 (Bcl is B-cell lymphocytic-leukaemia proto-oncogene) family comprises two groups of proteins with distinct functional biology in cell-fate signalling. Bcl-2 protein was the first member to be discovered and associated with drug resistance in human lymphomas. Since then a host of other proteins such as Bcl-xL, Bcl-2A1 and Mcl-1 with similar anti-apoptotic functions have been identified...

bcl-2 proto-oncogene encodes an inner mitochondrial membrane protein that blocks programmed cell death (apoptosis). There is now increasing evidence that regulation of bcl-2 expression is a determinant of life or death in normal lymphocytes. We have recently described that activated (CD45RO+) CD4+ and CD8+ T cells in acute infectious mononucleosis (IM) undergo apoptotic cell death on culturing,...

The regulatory Tat protein of human immunodeficiency virus type-l (HIV-1) exerts a pleyotropic activity on the survival and proliferation of different cell types in culture. In this report, we investigated the effect of either endogenous or exogenous Tat on Bcl-2 proto-oncogene expression and cell survival in Jurkat T-cell lines and primary peripheral blood mononuclear cells. Stable and transie...

Recent studies have shown that the Bcl-2 protein suppresses programmed cell death or apoptosis induced by a variety of stimuli including chemotherapeutic drugs. Because estrogen promotes the survival of estrogen-dependent breast cancer cells in vivo, we investigated whether estrogen might regulate levels of Bcl-2 gene expression in an estrogen-responsive human breast cancer cell line. Estrogen ...