TY - JOUR
T1 - β-catenin stabilization stalls the transition from double-positive to single-positive stage and predisposes thymocytes to malignant transformation
AU - Guo, Zhuyan
AU - Dose, Marei
AU - Kovalovsky, Damian
AU - Chang, Rui
AU - O'Neil, Jennifer
AU - Look, A. Thomas
AU - Von Boehmer, Harald
AU - Khazaie, Khashayarsha
AU - Gounari, Fotini
PY - 2007/6/15
Y1 - 2007/6/15
N2 - Activation of β-catenin has been causatively linked to the etiology of colon cancer. Conditional stabilization of this molecule in pro-T cells promotes thymocyte development without the requirement for pre-TCR signaling. We show here that activated β-catenin stalls the developmental transition from the double-positive (DP) to the single-positive (SP) thymocyte stage and predisposes DP thymocytes to transformation. β-Catenin-induced thymic lymphomas have a leukemic arrest at the early DPstage. Lymphomagenesis requires Rag activity, which peaks at this developmental stage, as well as additional secondary genetic events. A consistent secondary event is the transcriptional up-regulation of c-Myc, whose activity is required for transformation because its conditional ablation abrogates lymphomagenesis. In contrast, the expression of Notch receptors as well as targets is reduced in DP thymocytes with stabilized β-catenin and remains low in the lymphomas, indicating that Notch activation is not required or selected for in β-catenin-induced lymphomas. Thus, β-catenin activation may provide a mechanism for the induction of T-cell-acute lymphoblastic leukemia (T-ALL) that does not depend on Notch activation.
AB - Activation of β-catenin has been causatively linked to the etiology of colon cancer. Conditional stabilization of this molecule in pro-T cells promotes thymocyte development without the requirement for pre-TCR signaling. We show here that activated β-catenin stalls the developmental transition from the double-positive (DP) to the single-positive (SP) thymocyte stage and predisposes DP thymocytes to transformation. β-Catenin-induced thymic lymphomas have a leukemic arrest at the early DPstage. Lymphomagenesis requires Rag activity, which peaks at this developmental stage, as well as additional secondary genetic events. A consistent secondary event is the transcriptional up-regulation of c-Myc, whose activity is required for transformation because its conditional ablation abrogates lymphomagenesis. In contrast, the expression of Notch receptors as well as targets is reduced in DP thymocytes with stabilized β-catenin and remains low in the lymphomas, indicating that Notch activation is not required or selected for in β-catenin-induced lymphomas. Thus, β-catenin activation may provide a mechanism for the induction of T-cell-acute lymphoblastic leukemia (T-ALL) that does not depend on Notch activation.
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U2 - 10.1182/blood-2006-11-059071
DO - 10.1182/blood-2006-11-059071
M3 - Article
C2 - 17317856
AN - SCOPUS:34250004905
SN - 0006-4971
VL - 109
SP - 5463
EP - 5472
JO - Blood
JF - Blood
IS - 12
ER -