Publications by authors named "Marc R Mansour"

Neoantigen immunogenicity prediction is a highly challenging problem in the development of personalised medicines. Low reactivity rates in called neoantigens result in a difficult prediction scenario with limited training datasets. Here we describe ImmugenX, a modular protein language modelling approach to immunogenicity prediction for CD8+ reactive epitopes.

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Article Synopsis
  • Oncogenes can become activated through mechanisms like enhancer hijacking and mutations that generate new enhancers or promoters, helping researchers understand variations in noncoding cancer genomes.
  • A new mechanism is identified where the loss of an intronic element in the FTO gene causes abnormal expression of the IRX3 oncogene in T cell acute lymphoblastic leukemia (T-ALL).
  • The study suggests that 'promoter tethering' helps keep oncogenes inactive by linking them to non-functioning parts of the genome, which may act as a safeguard against tumor development.
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T-ALL relapse usually occurs early but can occur much later, which has been suggested to represent a de novo leukemia. However, we conclusively demonstrate late relapse can evolve from a pre-leukemic subclone harbouring a non-coding mutation that evades initial chemotherapy.

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T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) are rare aggressive hematologic malignancies. Current treatment consists of intensive chemotherapy leading to 80% overall survival but is associated with severe toxic side effects. Furthermore, 10-20% of patients still die from relapsed or refractory disease providing a strong rationale for more specific, targeted therapeutic strategies with less toxicities.

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Purpose: Failure to respond to induction chemotherapy portends a poor outcome in childhood acute lymphoblastic leukemia (ALL) and is more frequent in T-cell ALL (T-ALL) than B-cell ALL. We aimed to address the limited understanding of clinical and genetic factors that influence outcome in a cohort of patients with T-ALL induction failure (IF).

Methods: We studied all cases of T-ALL IF on two consecutive multinational randomized trials, UKALL2003 and UKALL2011, to define risk factors, treatment, and outcomes.

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T-cell lymphoblastic lymphoma (T-LBL) is a rare and aggressive lymphatic cancer, often diagnosed at a young age. Patients are treated with intensive chemotherapy, potentially followed by a hematopoietic stem cell transplantation. Although prognosis of T-LBL has improved with intensified treatment protocols, they are associated with side effects and 10-20% of patients still die from relapsed or refractory disease.

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Article Synopsis
  • - T cell acute lymphoblastic leukemia (T-ALL) is a severe cancer of immature T lymphocytes, with a higher chance of treatment failure compared to B cell acute lymphoblastic leukemia, making effective treatment difficult.
  • - Immunotherapies that work well for B cell leukemia face challenges in T-ALL due to the lack of unique target antigens on malignant T cells and the harmful effects of depleting healthy T cells.
  • - The study identifies the CCR9 chemokine receptor as present in over 70% of T-ALL cases, and proposes that CAR T-cells targeting CCR9 could be a promising treatment, offering potent anti-leukemic effects without the serious side effects associated with current therapies.
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c-MYC controls global gene expression and regulates cell proliferation, cell differentiation, cell cycle, metabolism and apoptosis. According to some estimates, MYC is dysregulated in ≈70% of human cancers and strong evidence implicates aberrantly expressed MYC in both tumor initiation and maintenance. In vivo studies show that MYC inhibition elicits a prominent anti-proliferative effect and sustained tumor regression while any alteration on healthy tissue remains reversible.

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Melanomas driven by loss of the NF1 tumor suppressor have a high risk of treatment failure and effective therapies have not been developed. Here we show that loss-of-function mutations of nf1 and pten result in aggressive melanomas in zebrafish, representing the first animal model of NF1-mutant melanomas harboring PTEN loss. MEK or PI3K inhibitors show little activity when given alone due to cross-talk between the pathways, and high toxicity when given together.

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T-cell ALL (T-ALL) is an aggressive malignancy of T-cell progenitors. Although survival outcomes in T-ALL have greatly improved over the past 50 years, relapsed and refractory cases remain extremely challenging to treat and those who cannot tolerate intensive treatment continue to have poor outcomes. Furthermore, T-ALL has proven a more challenging immunotherapeutic target than B-ALL.

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Cancer cells display DNA hypermethylation at specific CpG islands in comparison to their normal healthy counterparts, but the mechanism that drives this so-called CpG island methylator phenotype (CIMP) remains poorly understood. Here, we show that CpG island methylation in human T-cell acute lymphoblastic leukemia (T-ALL) mainly occurs at promoters of Polycomb Repressor Complex 2 (PRC2) target genes that are not expressed in normal or malignant T-cells and which display a reciprocal association with H3K27me3 binding. In addition, we revealed that this aberrant methylation profile reflects the epigenetic history of T-ALL and is established already in pre-leukemic, self-renewing thymocytes that precede T-ALL development.

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Article Synopsis
  • Loss-of-function mutations in PRC2's EZH2 component are linked to poor outcomes and chemotherapy resistance in T-cell acute lymphoblastic leukemia (T-ALL).
  • A study using edited T-ALL cells showed that EZH2-deficient cells are more sensitive to CHK1 inhibitors, which can delay tumor growth in models with EZH2 mutations.
  • This research suggests that EZH2 loss leads to immature T-ALL characteristics and increased reliance on CHK1 for survival, revealing a potential therapeutic target for treating high-risk T-ALL cases.
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T-cell acute lymphoblastic leukemia (T-ALL) and T-cell acute lymphoblastic lymphoma (T-LBL) are aggressive hematological malignancies that are currently treated with high-dose chemotherapy. Over the last several years, the search toward novel and less-toxic therapeutic strategies for T-ALL/T-LBL patients has largely focused on the identification of cell-intrinsic properties of the tumor cell. However, non-cell-autonomous activation of specific oncogenic pathways might also offer opportunities that could be exploited at the therapeutic level.

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The search for oncogenic mutations in haematological malignancies has largely focused on coding sequence variants. These variants have been critical in understanding these complex cancers in greater detail, ultimately leading to better disease monitoring, subtyping and prognostication. In contrast, the search for oncogenic variants in the noncoding genome has proven to be challenging given the vastness of the search space, the intrinsic difficulty in assessing the impact of variants that do not code for functional proteins, and our still primitive understanding of the function harboured by large parts of the noncoding genome.

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