Project description:We report the DNA methylation and transcriptional molecular features of paired diagnosis and relapsed Acute Myeloid Leukemia samples
Project description:We report the DNA methylation and transcriptional molecular features of paired diagnosis and relapsed Acute Myeloid Leukemia samples
Project description:<p>Acute Myeloid Leukemia (AML) remains a clinical challenge since most patients diagnosed with AML will die from the disease. Some patients harbor treatment-refractory disease and others relapse with disease that in many cases is resistant to treatments. Our study was designed to understand the molecular basis of disease progression in AML through interrogation of patient samples collected through an international collaboration which assembled 138 paired (diagnosis and relapse) patient specimens.</p> <p>It is hoped that this resource will help researchers understand mechanisms of disease relapse in AML and contribute to the general pool of data available for analyses for this disease and general research use.</p>
Project description:Chronic myeloid leukemia (CML) is a hematopoetic stem cell disease with distinct biological and clinical features. The biological foundation of the stereotypical progression from chronic phase through accelerated phase to blast crisis is poorly understood. We used DNA microarrays to compare gene expression in 91 cases of CML in chronic (42 cases), accelerated (17 cases), and blast phases (32 cases). Three thousand genes were found to be significantly (p<10-10) associated with the progression from chronic to blast phase. A comparison of the gene signatures of chronic, accelerated, and blast phases suggest that the progression of chronic phase CML from chronic advanced phase (accelerated and blast crisis) CML is a two-step rather than a three-step process, with new gene expression changes occurring early in accelerated phase before the accumulation of increased leukemia blast cells. The genetic signature of advanced phase CML is similar to that of normal CD34+ cells; however, progression also involved novel genes not expressed in normal CD34+ cells. Especially noteworthy is deregulation of the WNT/b-catenin pathway, the decreased expression of both JunB and Fos, and dysregulation of genes under the control of MZF1 and delta EF1 zinc finger transcription factors. Studies of CML patients who relapsed after initially successful treatment with imatinib mesylate demonstrated a gene expression pattern closely related to advanced phase disease. Take together, these data suggest that CML progression begins relative early and before clinical and pathological detection, and features distinct genetic differences compared to normal hematpoetic cells that might provide diagnostic and therapeutic targets. Samples from different phases of CML were hybridized against the pool of chronic phases of samples.
Project description:Despite the advanced understanding of disease mechanisms, the current therapeutic regimens fail to cure most patients with acute myeloid leukemia (AML). In the present study, we address the role of protein synthesis control in AML leukemia stem cell (LSC) function and leukemia propagation. We apply a murine model of mixed-lineage leukemia-rearranged AML to demonstrate that LSCs synthesize more proteins per hour compared with the bulk of leukemia. Using a genetic model that permits inducible and graded regulation of ribosomal subunit joining, we show that defective ribosome assembly leads to a significant survival advantage by selectively eradicating LSCs but not normal hematopoietic stem and progenitor cells. Finally, transcriptomic and proteomic analyses identify a rare subset of LSCs with immature stem cell signature and high ribosome content that underlies the resistance to defective ribosome assembly. Collectively, our study unveils a critical requirement of high protein synthesis rate for LSC function, highlighting ribosome assembly as a therapeutic target in AML.