Project description:Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of leukemia in children. Multiple lncRNAs participate in normal and may be implicated in malignant hematopoiesis associated with blood cell cancers, such as leukemia. Currently, the expression profile of lncRNAs in pediatric AML is unclear. In this study, we evaluated the lncRNA expression profile in the tissue of three pediatric AML patients with lncRNA microarray techniques. In order to gain insight into the function of targets of lncRNAs, GO term and KEGG pathway annotation were applied to the target gene pool. qPCR was performed to evaluate the expression patterns of dys-regulated lncRNAs. Bone marrow specimens were obtained at the time of diagnosis during routine clinical assessment of 3 pediatric patients with AML, who presented at the Department of Hematology and Oncology, Children's Hospital of Soochow University between 2000 and 2011. Additionally, bone marrow samples from 3 healthy donors were analyzed as controls. Human LncRNA Array analysis was performed by KangChen Bio-tech, Shanghai P.R. China. Total RNA from each sample was quantified by the NanoDrop ND-1000 and RNA integrity was assessed by standard denaturing agarose gel electrophoresis. For microarray analysis, Agilent Array platform was employed. The sample preparation and microarray hybridization were performed based on the manufacturerâs standard protocols with minor modifications. Briefly, mRNA was purified from total RNA after removal of rRNA (mRNA-ONLYâ¢ Eukaryotic mRNA Isolation Kit, Epicentre). Then, each sample was amplified and transcribed into fluorescent cRNA along the entire length of the transcripts without 3â bias utilizing a random priming method. The labeled cRNAs were hybridized onto the Human LncRNA Array v2.0 (8 x 60K, Arraystar). After having washed the slides, the arrays were scanned by the Agilent Scanner G2505C. Agilent Feature Extraction software (version 11.0.1.1) was used to analyze acquired array images. Quantile normalization and subsequent data processing were performed using the GeneSpring GX v12.0 software package (Agilent Technologies). After quantile normalization of the raw data, LncRNAs and mRNAs that at least 4 out of 6 samples have flags in Present or Marginal (âAll Targets Valueâ) were chosen for further data analysis. Differentially expressed LncRNAs and mRNAs with statistical significance between the two groups were identified through Volcano Plot filtering. Pathway analysis and GO analysis were applied to determine the roles of these differentially expressed mRNAs played in these biological pathways or GO terms. Finally, Hierarchical Clustering was performed to show the distinguishable LncRNAs and mRNAs expression pattern among samples.

Project description:microRNAs, important regulators of cell proliferation and apoptosis, have been shown to be involved in the pathogenesis of acute myeloid leukemia in adulthood AML. However, comprehensive studies in AML of children and adolescents are missing so far. We investigated the miRNA expression profiles of different AML subtypes from 102 pediatric patients in comparison to CD34+ cells from healthy donors and adult AML patients, in order to identify differentially expressed miRNAs. Pediatric samples with core factor binding acute myeloid leukemia and promyelocytic leukemia could be distinguished from each other and MLL rearranged AML subtypes by 9 and 18 miRNAs, respectively. miR-126, -146a, -181a/b, -100, and miR-125b were identified as highest differentially expressed with marked difference of expression between pediatric and adulthood samples of the same cytogenetic subgroup. We next isolated the miRNA targeting complex from t(8;21) and t(15;17) cell line models and comprehensively identified bound miRNAs and targeted mRNAs by a newly devised immunoprecipitation assay followed by rapid microarray detection. Our findings indicate separate binding preferences for the four human Argonaute proteins. Subsequent bioinformatic analysis revealed a concerted action of different Ago proteins in the regulation of AML-relevant pathways, providing an experimental based database of miRNA-mRNA target interaction in Argonaute proteins. Ago-associated microRNAs: Co-immunoprecipitation in the acute myeloid leukemia cell line models, KASUMI-1 and NB4, of the four human Argonaute complexes using monoclonal antibodies and stringent washing conditions. We performed photo-activated UV cross-linking using 4M-bM-^@M-^Y-thioruidine before cell lysis. Unspecific binding to the bead matrix and to the Fc part of the monoclonal rat antibody were recorded and corrected by empty bead controls and an antibody isotype control. Argonaute-associated miRNAs/mRNAs and unspecific bound miRNAs/mRNAs of the isotype control were identified by microarray hybridization. These experiments were performed in triplicates. Ago-associated mRNAs: Co-immunoprecipitation in the acute myeloid leukemia cell line models, KASUMI-1 and NB4, of the four human Argonaute complexes using monoclonal antibodies and stringent washing conditions. We performed photo-activated UV cross-linking using 4M-bM-^@M-^Y-thioruidine before cell lysis. Unspecific binding to the bead matrix and to the Fc part of the monoclonal rat antibody were recorded and corrected by empty bead controls and an antibody isotype control. Argonaute-associated miRNAs/mRNAs and unspecific bound miRNAs/mRNAs of the isotype control were identified by microarray hybridization. These experiments were performed in triplicates. AML-patient microRNAs: RNA extraction using the TRIzol protocol (Invitrogen), labeling of RNA with Cy3- (universal reference) and Cy5-Dyes (samples) using a truncated and mutated RNA ligase, hybridization of miRNAs over night at 42M-BM-0C using miRXplore microarrays and the a-Hyb Hybridization Station (MACS molecular Miltenyi Biotec)

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