Abstract
BackgroundThe role of microRNAs (miRNAs), important post-transcriptional regulators, in the pathogenesis of acute myeloid leukemia (AML) is just emerging and has been mainly studied in adults. First studies in children investigate single selected miRNAs, however, a comprehensive overview of miRNA expression and function in children and young adults is missing so far.Methodology/Principal FindingsWe here globally identified differentially expressed miRNAs between AML subtypes in a survey of 102 children and adolescent. Pediatric samples with core-binding factor AML and promyelocytic leukemia could be distinguished from each other and from MLL-rearranged AML subtypes by differentially expressed miRNAs including miR-126, -146a, -181a/b, -100, and miR-125b. Subsequently, we established a newly devised immunoprecipitation assay followed by rapid microarray detection for the isolation of Argonaute proteins, the hallmark of miRNA targeting complexes, from cell line models resembling core-binding factor and promyelocytic leukemia. Applying this method, we were able to identify Ago-associated miRNAs and their targeted mRNAs.Conclusions/SignificancemiRNAs as well as their mRNA-targets showed binding preferences for the different Argonaute proteins in a cell context-dependent manner. Bioinformatically-derived pathway analysis suggested a concerted action of all four Argonaute complexes in the regulation of AML-relevant pathways. For the first time, to our knowledge, a complete AML data set resulting from carefully devised biochemical isolation experiments and analysis of Ago-associated miRNAs and their target-mRNAs is now available.
Highlights
acute myeloid leukemia (AML) in children is a clinically and genetically heterogeneous disease characterized by differentiation arrest and malignant proliferation of clonal myeloid precursors
The nearest shrunken centroid method using the predictive analysis of microarray (PAM) algorithm on the whole dataset identified class predictors for t(8;21), t(15;17) and MLL rearranged AML patient sample, but not for the other cytogenetic subtypes
Since translocation t(8;21) and t(15;17) were most distinct from each other in unsupervised hierarchical clustering, we identified differentially expressed miRNAs between these two groups and in comparison to all others (Table 2). miR-27a, -126, -150 and miR-223 were significantly higher expressed in t(8;21)-positive pediatric AML samples in comparison to t(15;17)-positive samples (Table 2)
Summary
AML in children is a clinically and genetically heterogeneous disease characterized by differentiation arrest and malignant proliferation of clonal myeloid precursors It is the second most frequent hematologic malignancy, accounting for 15 to 20% of all childhood leukemia. In adult AML patients, miRNAs can be used as biomarkers [2], and recently, first studies investigating the expression of selected miRNAs in 50 and 80 pediatric AML samples suggest the same for children [3,4]. MiRNAs are small (,21 to 24 nt), non-coding, regulatory and highly conserved molecules found in humans, animals, plants and some viruses [5] They regulate a variety of developmental and physiological processes like cell differentiation, apoptosis and immune responses [6] and their role in hematopoiesis is beginning to be appreciated [7]. First studies in children investigate single selected miRNAs, a comprehensive overview of miRNA expression and function in children and young adults is missing so far
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
