title: T cell acute lymphoblastic leukemia/lymphoma: a human cancer commonly associated with aberrant NOTCH1 signaling.
abstract: OBJECTIVE
  Although constitutively activated forms of the NOTCH1 receptor are potent inducers of T cell acute lymphoblastic leukemia/lymphoma when expressed in the bone marrow stem cells of mice, the known involvement of NOTCH1 in human T cell acute lymphoblastic leukemia/lymphoma has been restricted to very rare tumors associated with a (7;9) chromosomal translocation involving the NOTCH1 gene. This picture has changed dramatically in the past year with the discovery of frequent mutations involving NOTCH1 in human T cell acute lymphoblastic leukemia/lymphoma.
  
  
  RESULTS
  NOTCH1 point mutations, insertions, and deletions producing aberrant increases in NOTCH1 signaling are frequently present in both childhood and adult T cell acute lymphoblastic leukemia/lymphoma and are detected in tumors from all major molecular subtypes. These observations are particularly important in the light of experiments using human and murine T cell acute lymphoblastic leukemia/lymphoma cell lines indicating that NOTCH1 signals are required for sustained growth and, in a subset of lines, survival. This inference is based in part on experiments conducted with small molecule inhibitors of gamma-secretase, a protease required for normal NOTCH signal transduction and the activity of the mutated forms of NOTCH1 found commonly in human T cell acute lymphoblastic leukemia/lymphoma.
  
  
  CONCLUSIONS
  These findings support a central role for aberrant NOTCH signaling in the pathogenesis of human T cell acute lymphoblastic leukemia/lymphoma, and they provide a rationale for trials of NOTCH inhibitors, such as gamma-secretase antagonists, in this aggressive human malignancy.
authors.affiliation: Abramson Center Cancer Research Institute, Institute for Medicine & Engineering and Department of Pathology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Warren S
authors.initials: WS
authors.lastname: Pear
authors.forename: Jon C
authors.initials: JC
authors.lastname: Aster
mesh_terms: D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D010450:Endopeptidases / Q000378:metabolism; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics*; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C497761:NOTCH1 protein, human; D009363:Neoplasm Proteins; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface; D014157:Transcription Factors; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human