Many cases of acute myeloid leukemia (AML) are associated with mutational activation of RTKs such as FLT3. However, RTK inhibitors have limited clinical efficacy as single agents, indicating that AML is driven by concomitant activation of different signaling molecules. We used a functional genomic approach to identify RET, encoding an RTK not previously implicated in AML, as essential gene in different AML subtypes, and observed that RET-dependent AML cells show activation of RET signaling via ARTN/GFRA3 and NRTN/GFRA2 ligand/co-receptor complexes.
RET-mediated autophagy suppression as targetable co-dependence in acute myeloid leukemia.
Specimen part, DiseaseView Samples
Background: Acute myeloid leukemia (AML) is driven by somatic mutations and genomic rearrangements affecting >20 genes. Many of these are recent discoveries and how this molecular heterogeneity dictates AML pathophysiology and clinical outcome remains unclear. Methods: We sequenced 111 leukemia genes for driver mutations in 1540 AML patients with cytogenetic and clinical data. We modeled AMLs genomic structure, defining genetic interactions, patterns of temporal evolution and clinical correlations. Results: We identified 5,236 driver mutations involving 77 loci, including hotspot mutations in MYC. We found 1 driver mutation in 96% patients, and 2 in 85%. Gene mutations implicated in age related clonal hematopoiesis (DNMT3A, ASXL1, TET2) were the earliest in AML evolution, followed by highly specific and ordered patterns of co-mutation in chromatin, transcription and splicing regulators, NPM1 and signaling genes. The patterns of co-mutation compartmentalize AML into 12 discrete molecular classes, each presenting with distinct clinical manifestation. Amongst these, mutations in chromatin and spliceosome genes demarcate a molecularly heterogeneous subgroup enriched for older AML patients currently classified as intermediate risk and results in adverse prognosis. Two- and three-way genetic interactions often implicating rare genes/mutation-hotspots, markedly redefined clinical response and long-term curability, with the NPM1:DNMT3A:FLT3ITD genotype (6% patients) identifying poor prognosis disease, whereas within the same class NPM1:DNMT3A:NRASG12/13 (3%) associated with favorable outlooks. Conclusions: 79% of AML is molecularly classified in 12 genomic subgroups. These represent distinct molecular phylogenies, implicating complex genotypes. Delineation of higher-order genomic relationships, guide the development of personally tailored classification, prognostication and clinical protocols. Similar studies across cancer types are warranted.
Genomic Classification and Prognosis in Acute Myeloid Leukemia.
Specimen part, DiseaseView Samples
Murine healthy tissue samples, DCIS and invasive mammary tumors were analyzed in order to identify marker genes which show enhanced expresssion in DCIS and invasive ductal carcinomas.
Identification of early molecular markers for breast cancer.
Specimen partView Samples
Thalidomide Exerts Distinct Molecular Antileukemic Effects and Combined Thalidomide/Fludarabine Therapy is Clinically Effective in High-Risk Chronic Lymphocytic Leukemia
Thalidomide exerts distinct molecular antileukemic effects and combined thalidomide/fludarabine therapy is clinically effective in high-risk chronic lymphocytic leukemia.
No sample metadata fieldsView Samples
Human mesenchymal stem cells (MSC) display a high potential for the development of novel treatment strategies for cartilage repair. However, the pathways involved in their differentiation to functional and non hypertrophic chondrocytes remain largely unknown, despite the work on embryologic development and the identification of key growth factors including members of the TGF, Hh, Wnt and FGF families. In this study, we asked if we could identify specific biological networks independently from the growth factor used (TGF-3 or BMP-2). To address this question, we used DNA microarrays and performed large-scale expression profiling of MSC at different time points during their chondral differentiation. By comparing these data with those obtained during their differentiation into osteoblasts and adipocytes, we identified 318 genes specific for chondrogenesis. We distributed the selected genes in 5 classes according to their kinetic of expression and used the Ingenuity software in order to identify new biological networks. We could reconstruct 3 phases for chondral differentiation, characterized by functional pathways. The first phase corresponds to cell attachment and apoptosis prevention with the up-regulation of 5 integrins, BCL6, NFIL3, RGS2 and down-regulation of CTGF and CYR61. The second phase is characterized by a proliferation/differentiation step with the continuous expression of MAF, PGF, HGMA1 or NOTCH3, CHI3L1, WNT5A, LEPR. Finally, the last step of differentiation/hypertrophy is characterized by expression of DKK1, APOD/E, SERPINF1 and TIMP4. These data propose new pathways to understand the complexity of MSC differentiation to chondrocytes and new potential targets for cell therapy applied to cartilage repair.
Gene expression profile of multipotent mesenchymal stromal cells: Identification of pathways common to TGFbeta3/BMP2-induced chondrogenesis.
No sample metadata fieldsView Samples
Discrimination of rheumatoid arthritis (RA) patients from patients with other inflammatory/degenerative joint diseases or healthy individuals purely on the basis of genes differentially expressed in high-throughput data has proven very difficult. Thus, the present study sought to achieve such discrimination by employing a novel unbiased approach using rule-based classifiers. Three multi-center genome-wide transcriptomic data sets (Affymetrix HG- U133 A/B) from a total of 79 individuals, including 20 healthy controls (control group - CG), as well as 26 osteoarthritis (OA) and 33 RA patients, were used to infer rule- based classifiers to discriminate the disease groups. The rules were ranked with respect to Kiendls statistical relevance index, and the resulting rule set was optimized by pruning. The rule sets were inferred separately from data of one of three centers and applied to the two remaining centers for validation. All rules from the optimized rule sets of all centers were used to analyze their biological relevance applying the software Pathway Studio.
Identification of rheumatoid arthritis and osteoarthritis patients by transcriptome-based rule set generation.
Specimen part, Disease, Disease stageView Samples
We previously identified multipotent stem cells within the lamina propria of the human olfactory mucosa, located in the nasal cavity. We also demonstrated that this cell type differentiates into neural cells and improves locomotor behavior after transplantation in a rat model of Parkinsons disease. Yet, next to nothing is known about their specific stemness characteristics. We therefore devised a study aiming to compare olfactory lamina propria stem cells from 4 individuals to bone marrow mesenchymal stem cells from 4 age- and gendermatched individuals. Using pangenomic microarrays and immunostaining with 34 cell surface marker antibodies, we show here that olfactory stem cells are closely related to bone marrow stem cells. However, olfactory stem cells exhibit also singular traits. By means of techniques such as proliferation assay, cDNA microarrays, RT-PCR, in vitro and in vivo differentiation, we report that, when compared to bone marrow stem cells, olfactory stem cells display i) a high proliferation rate; ii) a propensity to differentiate into osseous cells and iii) a disinclination to give rise to chondrocytes and adipocytes. Since peripheral olfactory stem cells originate from a neural crest-derived tissue and, as shown here, exhibit an increased expression of neural cellrelated genes, we propose to name them olfactory ecto-mesenchymal stem cells (OE-MSC). Further studies are now required to corroborate the therapeutic potential of OE-MSCs in animal models of bone and brain diseases.
The human nose harbors a niche of olfactory ectomesenchymal stem cells displaying neurogenic and osteogenic properties.
Sex, Age, Specimen part, TreatmentView Samples
Apoptosis is deregulated in most, if not all, cancers, including hematological malignancies. In this study, we wanted to test whether primary acute myeloid leukemia (AML) samples are sensitive for inhibitor of apoptosis (IAP) protein antagonist treatment in vitro, and which AML subgroup might profit most from such a novel therapeutic strategy. We treated diagnostic samples of 67 adult AML patients with either cytarabine (ara-C) or IAP antagonist BV6 and correlated sensitivity with clinical, cytogenetic and molecular markers, and expression levels of selected genes involved in apoptosis. Primary AML samples showed differential sensitivity to treatment with either ara-C (40% sensitive, 17% intermediate, 43% resistant) or BV6 (51% sensitive, 21% intermediate, 28% resistant). Notably, 69% of ara-C resistant samples showed a good to fair response to IAP inhibition. Furthermore, combination treatment of ara-C with BV6 showed additive effects in most samples. Differences in sensitivity to IAP antagonist treatment correlated with significantly elevated expression levels of TNF and lower levels of XIAP in BV6 sensitive samples, as well as with NPM1 mutations. Gene expression profiling pointed to apoptosis-related pathways, which were specifically induced by IAP inhibition in sensitive samples. Thus, our results suggest IAP inhibition as a potential novel therapeutic option in AML.
Targeting inhibitor of apoptosis proteins by Smac mimetic elicits cell death in poor prognostic subgroups of chronic lymphocytic leukemia.
Sex, Age, TreatmentView Samples