Project description:RNASeq data for mPB or CB-derived CD34+ exposed to UM171 human mobilized peripheral blood or cord blood-derived CD34(+) cells were cultured for 16 hours with vehicle (DMSO), dose response of UM171 [11.9nM, 19nM, 30.5nM, 48.8nM, 78.1nM and 125nM], SR1 [500nM] and combination of( UM171 [48.8nM]+SR1 [500nM])
Project description:mRNA profiling of CD34+ human cord blood-derived cell treated with UM171, SR1 or both mRNA profiles of CD34+ human cord blood-derived cell treated with DMSO (control), SR1 [500nM], UM171 [35nM] or combination SR1 [500nM]+ UM171 [35nM] for 30min, 3hr, 12hr, 24hr, 48hr, 72hr were generated by deep sequencing
Project description:While gene therapy (GT) provides a potentially curative treatment option for patients with sickle cell disease (SCD), the occurrence of myeloid malignancies in clinical trials has prompted concern. To interrogate potential mechanisms underlying increased cancer risk, we used hematopoietic stem cell (HSC) clonal tracking by whole genome sequencing (WGS) to map the somatic mutation and clonal landscape of 2,592 gene modified as well as unmodified single stem and progenitor cells from six SCD patients undergoing gene therapy (7-26 years old, average 12.7× depth). Pre-GT phylogenetic trees in SCD were highly polyclonal and mutation burdens per cell were elevated in some, but not all, patients. Post-GT, no clonal expansions were identified. However, an increased frequency of driver mutations associated with myeloid neoplasms or clonal hematopoiesis (DNMT3A- and EZH2-mutated clones in particular) were seen in both genetically modified and unmodified cells suggested positive selection of mutant clones during gene therapy. This work sheds light on the mutation landscape and HSC clonal dynamics in gene therapy for SCD and highlights enhanced fitness of some HSCs harboring pre-existing driver mutations following gene therapy. Future studies should define the long-term fate of mutant clones including any contribution to expansions associated with myeloid neoplasms.
Project description:While gene therapy (GT) provides a potentially curative treatment option for patients with sickle cell disease (SCD), the occurrence of myeloid malignancies in clinical trials has prompted concern. To interrogate potential mechanisms underlying increased cancer risk, we used hematopoietic stem cell (HSC) clonal tracking by whole genome sequencing (WGS) to map the somatic mutation and clonal landscape of 2,592 gene modified as well as unmodified single stem and progenitor cells from six SCD patients undergoing gene therapy (7-26 years old, average 12.7× depth). Pre-GT phylogenetic trees in SCD were highly polyclonal and mutation burdens per cell were elevated in some, but not all, patients. Post-GT, no clonal expansions were identified. However, an increased frequency of driver mutations associated with myeloid neoplasms or clonal hematopoiesis (DNMT3A- and EZH2-mutated clones in particular) were seen in both genetically modified and unmodified cells suggested positive selection of mutant clones during gene therapy. This work sheds light on the mutation landscape and HSC clonal dynamics in gene therapy for SCD and highlights enhanced fitness of some HSCs harboring pre-existing driver mutations following gene therapy. Future studies should define the long-term fate of mutant clones including any contribution to expansions associated with myeloid neoplasms.
Project description:The ability of cancer cells to switch phenotype in response to a dynamic intra-tumor microenvironment is a major barrier to effective therapy. In melanoma, down-regulation of the lineage addiction oncogene MITF (Microphthalmia-associated transcription factor) is a hallmark of the proliferative-to-invasive phenotype switch. Yet how MITF promotes proliferation and suppresses invasion is poorly understood. Here we show that expression of the key lipogenic enzyme stearoyl-CoA desaturase (SCD) is activated by MITF, but suppressed by the stress-responsive transcription factor ATF4. SCD expression is required for MITF-positive melanoma cell proliferation,. By contrast, MITF-low cells express reduced levels of SCD and are insensitive to its inhibition, indicating that cell phenotype dictates response to drugs targeting lipid metabolism. Since SCD suppresses inflammatory signalling and ATF4 expression, the results identify a positive feedback-loop that can maintain an invasive phenotype, uncover a key role for MITF and ATF4 in metabolic reprograming, and reveal fatty acid composition as a driver of melanoma phenotype-switching.
Project description:Sickle cell disease (SCD) is a genetic disorder caused by a mutation in the beta hemoglobin gene, resulting in red blood cell distortion, hemolysis, and severe pain episodes. Chronic pain in SCD is believed to be largely driven by neuroinflammation and central sensitization, yet the exact neurobiological mechanisms remain unclear. Hemorphins, opioid peptides derived from beta-hemoglobin, may bridge this gap by influencing opioid signaling pathways that could alleviate the pain experienced in SCD. In this study, we investigated the levels of hemorphins in both plasma and brain tissues of transgenic SCD mice using liquid chromatography-mass spectrometry (LC-MS).
Project description:Ex-vivo expansion of hematopoietic stem cells (HSCs) is gaining in importance for cell and gene therapy and requires a shift from dormancy state to activation and cycling. However, abnormal or excessive HSC activation results in reduced self-renewal ability and increased propensity for myeloid-biased differentiation. To date, the threshold of HSC activation that marks “the point of no return” is undetermined. Identifying the molecular determinants that restrain or control HSC activation is essential for preventing accelerated exhaustion of cultured-HSCs. We now report that activation of the E3 ligase complex CRL3KBTBD4 by UM171 not only induces epigenetic changes through CoREST1 degradation but also control chromatin bound MYC levels to prevent excessive activation and maintain lympho-myeloid potential of expanded populations. Furthermore, reconstitution activity and multipotency of UM171-treated HSC is specifically compromised when MYC levels are experimentally increased despite degradation of CoREST1.
Project description:Earlier we identified the protein degradation properties of small molecule UM171 (Subramaniam et al., 2020, Blood). Here we employed quantitative proteomics approach to map the global targets of UM171. Our study revealed multiple targets including the members of CoREST complex such as RCOR1 and LSD1.
Project description:Earlier we identified the protein degradation properties of small molecule UM171 (Subramaniam et al., 2020, Blood). Here we employed quantitative proteomics approach to map the global targets of UM171. Our study revealed multiple targets including the members of CoREST complex such as RCOR1 and LSD1.