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biopax3:comment |
8p11 myeloproliferative syndrome (EMS) is an aggressive disorder that is associated with a translocation event at the FGFR1 gene on chromosome 8p11. Typical symptoms upon diagnosis include eosinophilia and associated T-cell lymphoblastic lymphoma; the disease rapidly advances to acute leukemia, usually of myeloid lineage. At present the only effective treatment is allogenic stem cell transplantation (reviewed in Jackson, 2010). <br><br>At the molecular level, EMS appears to be caused by translocation events on chromosome 8 that create gene fusions between the intracellular domain of FGFR1 and an N-terminal partner gene that encodes a dimerization domain. The resulting fusion protein dimerizes in a ligand-independent fashion based the N-terminal domain provided by the partner protein and stimulates constititutive downstream FGFR1 signaling without altering the intrisic kinase activity of the receptor. To date, 11 partner genes have been identified: ZMYM2, FGFR1OP, FGFR1OP2, HERVK, TRIM24, CUX1, BCR, CEP110, LRRFIP1, MYO18A and CPSF6, although not all have been functionally characterized (reviewed in Jackson, 2010, Turner and Grose, 2010; Wesche, 2011). <br>Where examined, cell lines carrying FGFR1 fusion genes have been shown to be transforming and to support IL3-independent proliferation through anti-apoptotic, prosurvival pathways(Lelièvre, 2008; Ollendorff, 1999; Chase, 2007; Guasch, 2001; Wasag 2011; Roumiantsev, 2004; Demiroglu, 2001; Smedley, 1999). Signaling appears to occur predominantly through PLCgamma, PI3K and STAT signaling, with a more minor contribution from MAPK activation. Because the fusion proteins lack the FRS2-binding site, the mechanism of MAPK activation is unclear. Recruitment of GRB2:SOS1 through recruitment of SHC is one possibility (Guasch, 2001).,
Authored: Rothfels, K, 2012-02-09,
Edited: Rothfels, K, 2012-05-16,
Reviewed: Ezzat, S, 2012-05-15
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