Project description:Acute myeloid leukemia (AML) is the most common and severe acute leukemia in adults. It is a heterogeneous disease where the subset of molecularly different types, presenting various morphological features and differentiation stage, can be distinguished. Genomic research of leukemias is conducted since 1999 and large cohort studies shown that particular genetic alterations correspond with specific gene expression signatures. However, not always they provide clinically relevant information. The most unknown group is cytogenetically normal acute myeloid leukemia (CN-AML, 40-49% of all AML cases). The aim of our experiment was to determine selected gene expression profiles in CN-AML, using small, boutique microarray. The array contained 933 oligonucleotide probes, mainly complementary to acute myeloid leukemia markers, genes involved in leukemic transformation and myeloid cell proliferation, differentiation and maturation. Our test dataset included 40 hybridizations: 24 corresponding with blood and bone marrow samples collected from 12 patients with AML M1 or M2 FAB subtype and 16 corresponding with healthy control samples. Total RNA was extracted from the mononuclear cell fractions, reversibly transcribed to cDNA and labeled with Alexa 647 dye. The common reference was RNA isolated from HL-60 cell culture, labeled with Alexa 555 dye.
Project description:We performed a genome-wide analysis of gene expression in primary human CD151 myeloid progenitor cells. By using the serial analysis of gene expression (SAGE) technique, we obtained quantitative information for the expression of 37,519 unique SAGE-tag sequences. Of these unique tags, (i) 25% were detected at high and intermediate levels, whereas 75% were present as single copies, (ii) 53% of the tags matched known expressed sequences, 34% of which were matched to more than one known expressed sequence, and (iii) 47% of the tags had no matches and represent potentially novel genes. The correct genes were confirmed by application of the generation of longer cDNA fragments from SAGE tags for gene identification (GLGI) technique for high-copy tags with multiple matches. A set of genes known to be important in myeloid differentiation were expressed at various levels and used different spliced forms. This study provides a normal baseline for comparison of gene expression in myeloid diseases. The strategy of using SAGE and GLGI techniques in this study has broad applications to the genome-wide identification of expressed genes. (Lee S et al. The pattern of gene expression in human CD15+ myeloid progenitor cells. Proc Natl Acad Sci U S A. 98(6):3340-5, 2001; Lee S et al. Gene expression profiles in acute myeloid leukemia with common translocations using SAGE. Proc Natl Acad Sci U S A. 103(4):1030-5, 2006)
Project description:We assessed lineage involvement by NUP98 translocations in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and T-cell acute lymphoblastic leukemia (T-ALL). Single cell analysis by FICTION (Fluorescence Immunophenotype and Interphase Cytogenetics as a Tool for Investigation of Neoplasms) showed that NUP98-translocations with various partners, i.e. NSD1, DDX10, RAP1GDS1, and LNP1, always affected a CD34+/CD133+ hematopoietic precursor. Interestingly, in MDS/AML myelomonocytes, erythroid cells, B- and T- lymphocytes belonged to the abnormal clone, while in T-ALL only CD7+/CD3+ cells were involved. The partner did not appear to play a major role in determining the leukemia phenotype as shown in AML and T-ALL with the same NUP98-RAP1GDS1 fusion. Additional hits, namely mutations of FLT3 and CEBPA in MDS/AML and mutation of NOTCH1 plus MYB duplication in T-ALL, were identified in leukemias with, respectively, myeloid or T-lymphoid phenotype. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples. Copy number and Copy neutral LOH analysis of with Affymetrix Cytogenetic 2.7 and Cytoscan HD SNP arrays was performed on 6 NUP98 rearranged leukemias.
Project description:We assessed lineage involvement by NUP98 translocations in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and T-cell acute lymphoblastic leukemia (T-ALL). Single cell analysis by FICTION (Fluorescence Immunophenotype and Interphase Cytogenetics as a Tool for Investigation of Neoplasms) showed that NUP98-translocations with various partners, i.e. NSD1, DDX10, RAP1GDS1, and LNP1, always affected a CD34+/CD133+ hematopoietic precursor. Interestingly, in MDS/AML myelomonocytes, erythroid cells, B- and T- lymphocytes belonged to the abnormal clone, while in T-ALL only CD7+/CD3+ cells were involved. The partner did not appear to play a major role in determining the leukemia phenotype as shown in AML and T-ALL with the same NUP98-RAP1GDS1 fusion. Additional hits, namely mutations of FLT3 and CEBPA in MDS/AML and mutation of NOTCH1 plus MYB duplication in T-ALL, were identified in leukemias with, respectively, myeloid or T-lymphoid phenotype.
Project description:We performed a genome-wide analysis of gene expression in primary human CD151 myeloid progenitor cells. By using the serial analysis of gene expression (SAGE) technique, we obtained quantitative information for the expression of 37,519 unique SAGE-tag sequences. Of these unique tags, (i) 25% were detected at high and intermediate levels, whereas 75% were present as single copies, (ii) 53% of the tags matched known expressed sequences, 34% of which were matched to more than one known expressed sequence, and (iii) 47% of the tags had no matches and represent potentially novel genes. The correct genes were confirmed by application of the generation of longer cDNA fragments from SAGE tags for gene identification (GLGI) technique for high-copy tags with multiple matches. A set of genes known to be important in myeloid differentiation were expressed at various levels and used different spliced forms. This study provides a normal baseline for comparison of gene expression in myeloid diseases. The strategy of using SAGE and GLGI techniques in this study has broad applications to the genome-wide identification of expressed genes. (Lee S et al. The pattern of gene expression in human CD15+ myeloid progenitor cells. Proc Natl Acad Sci U S A. 98(6):3340-5, 2001; Lee S et al. Gene expression profiles in acute myeloid leukemia with common translocations using SAGE. Proc Natl Acad Sci U S A. 103(4):1030-5, 2006) Human bone-marrow mononuclear cells were isolated from bone marrow with FicollyPaque solution and stored in liquid nitrogen. Cells from three donors were thawed at 37°C, pooled, and used immediately for the isolation of myeloid progenitor cells with CD15 magnetic beads (Dynal, Oslo, Norway). The cells isolated by CD15 magnetic beads were lysed directly with TRIzol reagent for isolation of total RNA. mRNA was purified from 5 mg of total RNA with oligo(dT)25 beads. cDNA was synthesized with a cDNA synthesis kit, and SAGE was performed according to the SAGE protocol with the exceptions described in the original paper. SAGE-tag sequences were collected with the Big-Dye sequencing kit and ABI377 sequencer, and tag sequences were extracted with SAGE 300 software.
Project description:Large-scale chromosomal translocations are frequent oncogenic drivers in acute myeloid leukemia (AML). These translocations often occur in critical transcriptional/epigenetic regulators and contribute to malignant cell growth through alteration of normal gene expression. Despite this knowledge, the specific gene expression alterations that contribute to the development of leukemia remain incompletely understood. Here, through characterization of transcriptional regulation by the RUNX1-ETO fusion protein, we have identified Ras-association domain family member 2 (RASSF2) as a critical gene that is aberrantly transcriptionally repressed in t(8;21)-associated AML. Based on this, we performed molecular and functional characterization of RASSF2 in AML cells.
Project description:Resistance to chemotherapy is the most common cause of treatment failure in acute myeloid leukemia and the drug efflux pump ABCB1 is a critical mediator. Here we demonstrate that in vitro daunorubicin exposure can induce activating ABCB1 promoter translocations in human myeloid cells, similar to those recently described in recurrent high-grade serous ovarian and breast cancer. We then develop a targeted nanopore sequencing approach that enables efficient identification of ABCB1 structural variants in high-grade serous ovarian cancer. Finally, we confirm that ABCB1high cases of relapsed AML are not characterized by ABCB1 promoter translocations but instead show high-level activity of native promoters, consistent with endogenous regulation.