TY - JOUR
T1 - Activation of the NF-κB pathway by the leukemogenic TEL-Jak2 and TEL-Abl fusion proteins leads to the accumulation of antiapoptotic IAP proteins and involves IKKα
AU - Malinge, S.
AU - Monni, R.
AU - Bernard, O.
AU - Penard-Lacronique, V.
N1 - Funding Information:
We are grateful to R Weil and V Baud for helpful discussion and to E Delabesse and D Baudry-Bluteau for their help with the real-time PCRs. This work was supported in part by grants from the Ligue Nationale Contre le Cancer (LNCC-équipe labelisée). SM is supported by a Ministère de l’Education Nationale, de la Recherche et des Technologies (MENRT) fellowship.
PY - 2006/6/15
Y1 - 2006/6/15
N2 - Abnormal activation of tyrosine kinases and of signaling pathways they control plays a critical role in the neoplastic process of human hematopoietic malignancy. The nuclear factor-κB (NF-κB) pathway is one of the signalings activated by the TEL-Jak2 and TEL-Abl oncoproteins and required for their antiapoptotic activity. To define the signal relay responsible for this activation, we used mouse embryonic fibroblast (MEF) cells and observed that TEL-Jak2- and TEL-Abl-mediated NF-κB induction was abolished in cells lacking the IκB kinase (IKK)α but not in IKKβ-+- cells. Similar observations were performed with oncogenic forms of the FMS-like tyrosine kinase 3 (Flt-3) involved in the pathogenesis of one-third of acute myeloid leukemias. Rescue of TEL-Jak2-mediated NF-κB activation was obtained with a kinase-proficient form of IKKα in IKKα-+- MEF. Hematopoietic cells transformed by TEL-Jak2 and TEL-Abl showed sustained IKKα activity without promotion of NF-κB2/p100 processing, generally associated to IKKα functions. Furthermore, IAP1, IAP2 and XIAP, which are central regulators of the NF-κB-mediated survival pathway, were highly expressed in cells transformed by these oncoproteins. Our results indicate that these oncogenic tyrosine kinases preferentially use an IKKα-dependent mechanism to induce a persistent NF-κB activity and allow the production of antiapoptotic effectors that participate to their leukemogenic properties.
AB - Abnormal activation of tyrosine kinases and of signaling pathways they control plays a critical role in the neoplastic process of human hematopoietic malignancy. The nuclear factor-κB (NF-κB) pathway is one of the signalings activated by the TEL-Jak2 and TEL-Abl oncoproteins and required for their antiapoptotic activity. To define the signal relay responsible for this activation, we used mouse embryonic fibroblast (MEF) cells and observed that TEL-Jak2- and TEL-Abl-mediated NF-κB induction was abolished in cells lacking the IκB kinase (IKK)α but not in IKKβ-+- cells. Similar observations were performed with oncogenic forms of the FMS-like tyrosine kinase 3 (Flt-3) involved in the pathogenesis of one-third of acute myeloid leukemias. Rescue of TEL-Jak2-mediated NF-κB activation was obtained with a kinase-proficient form of IKKα in IKKα-+- MEF. Hematopoietic cells transformed by TEL-Jak2 and TEL-Abl showed sustained IKKα activity without promotion of NF-κB2/p100 processing, generally associated to IKKα functions. Furthermore, IAP1, IAP2 and XIAP, which are central regulators of the NF-κB-mediated survival pathway, were highly expressed in cells transformed by these oncoproteins. Our results indicate that these oncogenic tyrosine kinases preferentially use an IKKα-dependent mechanism to induce a persistent NF-κB activity and allow the production of antiapoptotic effectors that participate to their leukemogenic properties.
KW - IAP
KW - IKKα
KW - Leukemogenesis
KW - NF-κB
KW - Tyrosine kinase
UR - http://www.scopus.com/inward/record.url?scp=33745175876&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1209390
DO - 10.1038/sj.onc.1209390
M3 - Article
C2 - 16434962
AN - SCOPUS:33745175876
SN - 0950-9232
VL - 25
SP - 3589
EP - 3597
JO - Oncogene
JF - Oncogene
IS - 25
ER -