Leukemia (2010) 24, 2048-2055;doi:10.1038/leu.2010.211; published online 23 September 2010″
“Fragile X syndrome is caused by the loss of expression of the fragile X mental retardation protein (FMRP). As a RNA binding protein, FMRP functions in translational regulation, localization, and stability of its neuronal target transcripts. The Drosophila homologue, dFMR1, is well conserved in sequence and function with respect to human FMRP. Although dFMR1 is known to express two main isoforms, the mechanism behind production of the second, more slowly migrating isoform has remained elusive. Furthermore, it remains unknown whether the two isoforms may
also contribute differentially to dFMR1 function. We have found that this Nutlin-3 in vitro second dFMR1 isoform is generated through an alternative
translational start site in the dfmr1 5′UTR. This 5′UTR coding sequence is well conserved in the melanogaster group. Translation this website of the predominant, smaller form of dFMR1 (dFMR1-S(N)) begins at a canonical start codon (ATG), whereas translation of the minor, larger form (dFMR1-L(N)) begins upstream at a non-canonical start codon (CTG). To assess the contribution of the N-terminal extension toward dFMR1 activity, we generated transgenic flies that exclusively express either dFMR1-S(N) or dFMR1-L(N). Expression analyses throughout development revealed that dFMR1-S(N) is required for normal dFMR1-L(N) expression levels in adult brains. In situ expression analyses showed that either dFMR1-S(N) or dFMR1-L(N) is individually sufficient for proper dFMR1 localization in the nervous system. Functional studies demonstrated that both dFMR1-S(N)
and dFMR1-LN can function independently to rescue dfmr1 null defects in synaptogenesis and axon guidance. Thus, dfmr1 encodes two functional isoforms with respect to expression and activity throughout neuronal development. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Fludarabine combination chemotherapy achieves high response rates in chronic lymphocytic leukemia (CLL) and indolent lymphoma. The aim of this study was to investigate the incidence and characteristics of treatment-related myelodysplasia and acute myeloid leukemia (t-MDS/AML) after treatment with fludarabine in combination A-769662 datasheet for lymphoproliferative disorders and identify risk factors for its development. In all, 176 patients treated with fludarabine combination were followed for a median of 41 months (range 6-125 months). In all, 19 cases of t-MDS/AML have been identified for an overall rate of 10.8%. Median overall survival post-t-MDS/AML diagnosis was 11 months. Patients developing t-MDS/AML included 11/54 with follicular lymphoma (FL) (crude rate 20.4%), 5/82 with CLL (6.1%) and 3/24 with Waldenstrom macroglobulinemia or marginal zone lymphoma (12.5%).