Publications by authors named "Rolf Marschalek"

KMT2A rearrangements are associated with a poor clinical outcome in infant, pediatric, and adult acute lymphoblastic and myeloid leukemia. Here, we present a protocol to reconstruct chromosomal translocations with different partner genes of KMT2A in vitro. We describe steps for patient-specific single guide RNA (sgRNA) design, optimized sgRNA in vitro transcription, detailed purification of hematopoietic stem and progenitor cells (HSPCs) from umbilical cord blood (UCB), and CRISPR-Cas9 editing of the test cell line K562 as well as UCB HSPCs.

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Rearrangement of NUTM1 gene (NUTM1r) is one of the most frequent aberrations occurring in infants (younger than 1 year at diagnosis) with B-cell precursor Acute Lymphoblastic Leukaemia (BCP-ALL). In this study we had the unique opportunity to analyze the umbilical cord blood (UCB) sample from one infant patient with NUTM1r BCP-ALL. Herein we reported for the first time that NUTM1r infant ALL arise prenatally, as both the patient-specific CUX1::NUTM1 fusion gene, as well as two IG/TR leukaemic markers were already present and detectable in the patient's UCB at birth.

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B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer, with long-term overall survival rates of ∼85%. However, B-ALL harboring rearrangements of the MLL gene (also known as KMT2A), referred to as MLLr B-ALL, is common in infants and is associated with poor 5-year survival, relapses, and refractoriness to glucocorticoids (GCs). GCs are an essential part of the treatment backbone for B-ALL, and GC resistance is a major clinical predictor of poor outcome.

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Article Synopsis
  • - The study focuses on hnRNPA0, a protein that is influenced by type I interferons, and examines its role as a host factor in HIV-1 replication, finding that reducing hnRNPA0 levels boosts HIV-1 activity and infectivity while increasing hnRNPA0 decreases it.
  • - High levels of hnRNPA0 were shown to impair specific processes vital for HIV-1 replication, including the efficiency of viral mRNA production and the balance of viral protein ratios, indicating its significance in controlling HIV-1 spread.
  • - The research highlights that lower hnRNPA0 levels are present in untreated HIV-1-infected individuals compared to healthy people, pointing to its potential role in enhancing HIV-1 viral fitness in
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Measurable residual disease (MRD) monitoring in childhood acute myeloid leukemia (AML) is used to assess response to treatment and for early detection of imminent relapse. In childhood AML, MRD is typically evaluated using flow cytometry, or by quantitative detection of leukemia-specific aberrations at the mRNA level. Both methods, however, have significant limitations.

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Since the end of 2019, the SARS-CoV-2 virus started to spread in different countries, leading to a world-wide pandemia, with today's infection numbers of more than 690 million and with a case fatality rate of more than 6.9 million. In addition, about 65 million patients suffer from post/long-Covid syndromes after having infections with the SARS-CoV-2 virus or variants thereof.

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Induction of alternative, non-apoptotic cell death programs such as cell-lethal autophagy and mitophagy represent possible strategies to combat glioblastoma (GBM). Here we report that VLX600, a novel iron chelator and oxidative phosphorylation (OXPHOS) inhibitor, induces a caspase-independent type of cell death that is partially rescued in adherent U251 (autophagy related 5/7) knockout (KO) GBM cells and NCH644 knockdown (KD) glioma stem-like cells (GSCs), suggesting that VLX600 induces an autophagy-dependent cell death (ADCD) in GBM. This ADCD is accompanied by decreased oxygen consumption, increased expression/mitochondrial localization of BNIP3 (BCL2 interacting protein 3) and BNIP3L (BCL2 interacting protein 3 like), the induction of mitophagy as demonstrated by diminished levels of mitochondrial marker proteins [e.

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Haematopoietic stem cells (HSC) reside in the bone marrow microenvironment (BMM), where they respond to extracellular calcium [eCa] via the G-protein coupled calcium-sensing receptor (CaSR). Here we show that a calcium gradient exists in this BMM, and that [eCa] and response to [eCa] differ between leukaemias. CaSR influences the location of MLL-AF9 acute myeloid leukaemia (AML) cells within this niche and differentially impacts MLL-AF9 AML versus BCR-ABL1 leukaemias.

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Cellular ontogeny and MLL breakpoint site influence the capacity of MLL-edited CD34+ hematopoietic cells to initiate and recapitulate infant patients' features in pro-B-cell acute lymphoblastic leukemia (B-ALL). We provide key insights into the leukemogenic determinants of MLL-AF4+ infant B-ALL.

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Article Synopsis
  • * In a study of 1091 adult patients, 12.9% had KMT2A-r, with a 5-year relapse rate of 40.7% and overall survival rate of 53.3%. The presence of specific gene alterations like TP53 and IKZF1 correlated with significantly worse outcomes.
  • * The analysis showed that measuring minimal residual disease (MRD) using KMT2A markers was more reliable than other methods, indicating that patients responding well early
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Chromosomal translocations (CTs) are a genetic hallmark of cancer. They could be identified as recurrent genetic aberrations in hemato-malignancies and solid tumors. More than 40% of all "cancer genes" were identified in recurrent CTs.

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Pediatric acute myeloid leukemia (AML) is a highly heterogeneous disease making standardized measurable residual disease (MRD) assessment challenging. Currently, patient-specific DNA-based assays are only rarely applied for MRD assessment in pediatric AML. We tested whether quantification of genomic breakpoint-specific sequences via quantitative polymerase chain reaction (gDNA-PCR) provides a reliable means of MRD quantification in children with non-standardrisk AML and compared its results to those obtained with state-of-the-art ten-color flow cytometry (FCM).

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"RNA-templated/directed DNA repair" is a biological mechanism that has been experimentally demonstrated in bacteria, yeast, and mammalian cells. Recent study has shown that small noncoding RNAs (DDRNAs) and/or newly RNAPII transcribed RNAs (dilncRNAs) are orchestrating the initial steps of double-strand break (DSB) repair. In this study, we demonstrate that also pre-mRNA could be used as direct or indirect substrate for DSB repair.

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KMT2A-rearranged acute lymphoblastic infant leukemia (KMT2A-r iALL) is associated with outsize risk of relapse and relapse mortality. We previously reported strong upregulation of the immediate early gene EGR3 in KMT2A::AFF1 iALL at relapse; now we provide analyses of the EGR3 regulome, which we assessed through binding and expression target analysis of an EGR3-overexpressing t(4;11) cell culture model. Our data identify EGR3 as a regulator of early B-lineage commitment.

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Mesenchymal stromal cells (MSCs) have the potential to suppress pathological activation of immune cells and have therefore been considered for the treatment of Graft-versus-Host-Disease. The clinical application of MSCs requires a process validation to ensure consistent quality. A flow cytometry-based mixed lymphocyte reaction (MLR) was developed to analyse the inhibitory effect of MSCs on T cell proliferation.

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MLL (KMT2a) translocations are found in ~10% of acute leukemia patients, giving rise to oncogenic MLL-fusion proteins. A common MLL translocation partner is ENL and associated with a poor prognosis in t(11;19) patients. ENL contains a highly conserved N-terminal YEATS domain that binds acetylated histones and interacts with the PAF1c, an epigenetic regulator protein complex essential for MLL-fusion leukemogenesis.

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Article Synopsis
  • - The study investigates how hematopoietic stem and progenitor cells (HSPCs) may serve as reservoirs for HIV-1, which complicates finding a cure for the virus.
  • - Experiments showed that various HSPC subpopulations could be infected by HIV-1, mainly through the CXCR4 and CCR5 entry pathways, indicating their vulnerability to the virus.
  • - Analysis of bone marrow samples from HIV-positive individuals revealed the presence of HIV-1 genetic material in some CD34+ cells, supporting the idea that these primitive HSPCs contribute to the HIV-1 reservoir.
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The expansion of regulatory T cells (Tregs) is known to be mediated by cytokines including IL-10 and TGFβ but has additionally been shown to depend on the interaction of the immune receptors ICOSLG and ICOS. Here, we describe a co-culture system which enables quantification of the ability of leukemia cells to induce Treg expansion through secreted cytokines and direct receptor interactions. The protocol is applicable for MHC-matched and -unmatched experiments and allows assessment of Treg expansion without using a mouse model.

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Article Synopsis
  • The MLL/AF4 fusion gene is linked to a high-risk form of pro-B acute lymphoblastic leukemia, where relapses may switch the cancer type to acute myeloid leukemia, complicating treatment.
  • Research shows that during these relapses, the cancer cells retain specific genetic characteristics from the original leukemia and can develop from different stages of cell development.
  • Changes in chromatin accessibility and gene regulation, particularly involving the CHD4 gene, contribute to this lineage switching, suggesting that the cancer's development is driven by faulty epigenetic control.
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Background: In recent months, Omicron variants of SARS-CoV-2 have become dominant in many regions of the world, and case numbers with Omicron subvariants BA.1 and BA.2 continue to increase.

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Article Synopsis
  • * Infants with this type of leukemia often have a poor chance of recovery because the cancer returns frequently, even when they are getting treatment, and there isn’t a clear reason why.
  • * Research showed that high levels of a molecule called ICOSLG at the time of diagnosis are linked to worse outcomes, and it might help the cancer resist treatments, making it a possible target for new therapies.
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