Publications by authors named "Michal Sheffer"

Background: Cytokine induced memory-like natural killer (CIML NK) cells combined with an IL-15 super-agonist (N-803) are a novel modality to treat relapsed/refractory head and neck cancer.

Methods: We report data from a phase I trial of haploidentical CIML NK cells combined with N-803 with or without ipilimumab (IPI) in relapsed/refractory head and neck cancer patients after a median of 6 prior lines of therapy. The trial adhered to a 3 + 3 dose de-escalation design, with primary endpoint being safety.

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The tumor microenvironment can inhibit the efficacy of cancer therapies through mechanisms such as poor trafficking and exhaustion of immune cells. Here, to address this challenge, we exploited the safety, tumor tropism and ease of genetic manipulation of non-pathogenic Escherichia coli (E. coli) to deliver key immune-activating cytokines to tumors via surface display on the outer membrane of E.

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  • Epithelial ovarian cancer (EOC) is a highly deadly gynecological cancer, but recent studies have shown that cytokine-induced memory-like (CIML) natural killer (NK) cells can effectively target EOC cells and enhance immune responses.
  • The research indicates that CIML NK cells not only increase activation receptor expression but also improve antitumor effects when engineered with a chimeric antigen receptor (CAR) aimed at mesothelin (MSLN) found on EOC cells.
  • These CAR-modified CIML NK cells significantly inhibited tumor growth and metastasis in animal models, suggesting they could be a promising new treatment approach for EOC patients.
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Background: To accelerate the translation of novel immunotherapeutic treatment approaches, the development of analytic methods to assess their efficacy at early in vitro stages is necessary. Using a droplet-based microfluidic platform, we have established a method for multiparameter quantifiable phenotypic and genomic observations of immunotherapies. Chimeric antigen receptor (CAR) natural killer (NK) cells are of increased interest in the current immunotherapy landscape and thus provide an optimal model for evaluating our novel methodology.

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  • The research introduces a new method using non-pathogenic bacteria (K-12 DH5α) to deliver immune-activating cytokines, improving immune cell function in tumors.
  • The engineered bacteria stimulated strong immune responses, leading to significant tumor control and increased survival rates in mice with colorectal carcinoma and melanoma.
  • The bacteria's ability to enhance the effectiveness of CAR NK cells against resistant tumors suggests promising potential for clinical application in treating stubborn solid tumors.
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Cancer cells can evade natural killer (NK) cell activity, thereby limiting anti-tumor immunity. To reveal genetic determinants of susceptibility to NK cell activity, we examined interacting NK cells and blood cancer cells using single-cell and genome-scale functional genomics screens. Interaction of NK and cancer cells induced distinct activation and type I interferon (IFN) states in both cell types depending on the cancer cell lineage and molecular phenotype, ranging from more sensitive myeloid to less sensitive B-lymphoid cancers.

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Clinical progress in multiple myeloma (MM), an incurable plasma cell (PC) neoplasia, has been driven by therapies that have limited applications beyond MM/PC neoplasias and do not target specific oncogenic mutations in MM. Instead, these agents target pathways critical for PC biology yet largely dispensable for malignant or normal cells of most other lineages. Here we systematically characterized the lineage-preferential molecular dependencies of MM through genome-scale clustered regularly interspaced short palindromic repeats (CRISPR) studies in 19 MM versus hundreds of non-MM lines and identified 116 genes whose disruption more significantly affects MM cell fitness compared with other malignancies.

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  • Anti-GD2 antibody immunotherapy has improved outcomes for high-risk neuroblastoma in children, but nearly 50% of patients still relapse, highlighting a need to understand resistance mechanisms.
  • Research shows that lower GD2 expression is linked to a mesenchymal cell state in neuroblastoma, leading to decreased sensitivity to anti-GD2 therapy due to reduced expression of the enzyme ST8SIA1, which is crucial for GD2 synthesis.
  • Targeting the EZH2 enzyme with pharmacological inhibitors can restore GD2 expression and re-sensitize mesenchymal neuroblastoma cells to anti-GD2 therapy, suggesting a potential combined treatment strategy to improve patient outcomes.
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  • Conventional donor lymphocyte infusion has low effectiveness for treating relapses after hematopoietic cell transplantation, prompting a trial of cytokine-induced memory-like (CIML) NK cell therapy in patients with myeloid malignancies.
  • In a phase I trial, 6 patients received donor-derived NK cells, resulting in rapid and sustained expansion of these cells post-infusion without serious adverse effects, although mild fever and pancytopenia were noted.
  • The successful expansion and long-term presence of CIML NK cells indicate their potential for treating relapses after transplantation, and further research is needed to understand their interactions with other immune cells and the tumor environment.
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  • The study aimed to identify molecular features in human tumor cells that affect their sensitivity to natural killer (NK) cells by analyzing various solid tumor cell lines with a focus on genetic factors.
  • High NK cell responsiveness was associated with tumor cells exhibiting 'mesenchymal-like' traits, significant expression of chromatin remodeling complexes, increased levels of B7-H6, and decreased expression of HLA-E and antigen presentation genes.
  • The findings suggest that the characteristics of NK cell-sensitive tumors also correlate with resistance to immune checkpoint inhibitors, indicating potential for developing biomarkers to enhance NK cell immunotherapy strategies.
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Immune checkpoint inhibitors (ICIs) have improved overall survival for cancer patients, however, optimal duration of ICI therapy has yet to be defined. Given ICIs were first used to treat patients with metastatic melanoma, a condition that at the time was incurable, little attention was initially paid to how much therapy would be needed for a durable response. As the early immunotherapy trials have matured past 10 years, a significant per cent of patients have demonstrated durable responses; it is now time to determine whether patients have been overtreated, and if durable remissions can still be achieved with less therapy, limiting the physical and financial toxicity associated with years of treatment.

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Heterobifunctional proteolysis-targeting chimeric compounds leverage the activity of E3 ligases to induce degradation of target oncoproteins and exhibit potent preclinical antitumor activity. To dissect the mechanisms regulating tumor cell sensitivity to different classes of pharmacological "degraders" of oncoproteins, we performed genome-scale CRISPR-Cas9-based gene editing studies. We observed that myeloma cell resistance to degraders of different targets (BET bromodomain proteins, CDK9) and operating through CRBN (degronimids) or VHL is primarily mediated by prevention of, rather than adaptation to, breakdown of the target oncoprotein; and this involves loss of function of the cognate E3 ligase or interactors/regulators of the respective cullin-RING ligase (CRL) complex.

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  • Mutations similar to those caused by growth factors lead to increased proliferation and movement in aggressive types of breast tumors, prompting the need to explore new players in this process.
  • Researchers conducted a phosphoproteomic analysis on normal mammary cells treated with epidermal growth factor (EGF) and identified a protein called ladinin-1 (LAD1) that plays a critical role in mediating responses in the EGF-to-ERK pathway.
  • Further studies showed that LAD1 is involved in cell proliferation and migration, interacts with actin and related proteins, and its depletion negatively impacts cell survival, making it a potential predictor of poor prognosis in aggressive breast cancer types like triple-negative and HER2-positive tumors.
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The microRNA miR-504 targets TP53 mRNA encoding the p53 tumor suppressor. miR-504 resides within the fibroblast growth factor 13 (FGF13) gene, which is overexpressed in various cancers. We report that the FGF13 locus, comprising FGF13 and miR-504, is transcriptionally repressed by p53, defining an additional negative feedback loop in the p53 network.

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The nuclear factor-κB (NF-κB) transcription factor family plays critical roles in the pathophysiology of hematologic neoplasias, including multiple myeloma. The current review examines the roles that this transcription factor system plays in multiple myeloma cells and the nonmalignant accessory cells of the local microenvironment; as well as the evidence indicating that a large proportion of myeloma patients harbor genomic lesions which perturb diverse genes regulating the activity of NF-κB. This article also discusses the therapeutic targeting of the NF-κB pathway using proteasome inhibitors, a pharmacological class that has become a cornerstone in the therapeutic management of myeloma; and reviews some of the future challenges and opportunities for NF-κB-related research in myeloma.

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Naive T cell stimulation activates anabolic metabolism to fuel the transition from quiescence to growth and proliferation. Here we show that naive CD4(+) T cell activation induces a unique program of mitochondrial biogenesis and remodeling. Using mass spectrometry, we quantified protein dynamics during T cell activation.

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Unlabelled: Differences among individuals in susceptibility to infectious diseases can be modulated by host genetics. Much of the research in this field has aimed to identify loci within the host genome that are associated with these differences. In mice, A/J (AJ) and C57BL/6J (B6) mice show differential susceptibilities to various pathogens, including the intracellular pathogen Francisella tularensis.

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p53 is a well-known tumor suppressor that is mutated in over 50% of human cancers. These mutations were shown to exhibit gain of oncogenic function compared with the deletion of the gene. Additionally, p53 has fundamental roles in differentiation and development; nevertheless, mutant p53 mice are viable and develop malignant tumors only on adulthood.

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The transmembrane neural cell adhesion receptor L1 is a Wnt/β-catenin target gene expressed in many tumor types. In human colorectal cancer, L1 localizes preferentially to the invasive front of tumors and when overexpressed in colorectal cancer cells, it facilitates their metastasis to the liver. In this study, we investigated genes that are regulated in human colorectal cancer and by the L1-NF-κB pathway that has been implicated in liver metastasis.

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HIG2 (hypoxia-inducible gene 2) is a biomarker of hypoxia and elevated in several cancers. Here, we show that HIG2 also upregulated HIF-1α expression under hypoxic conditions and enhanced AP-1 expression under normoxic conditions, which affects colorectal cancer cell survival. Importantly, over-expression of HIG2 promoted tumor growth by suppressing apoptosis in a mouse orthotopic model.

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We introduce Pathifier, an algorithm that infers pathway deregulation scores for each tumor sample on the basis of expression data. This score is determined, in a context-specific manner, for every particular dataset and type of cancer that is being investigated. The algorithm transforms gene-level information into pathway-level information, generating a compact and biologically relevant representation of each sample.

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  • - Cancer chromosomal instability (CIN) leads to frequent changes in chromosome number and structure, resulting in diverse tumor cell populations and is linked to poor outcomes and drug resistance.
  • - In this study, researchers found that CIN(+) colorectal cancer (CRC) cells experience impaired DNA replication and increased replication stress compared to CIN(-) CRC cells, contributing to chromosome missegregation during cell division.
  • - The researchers identified three new genes that suppress CIN, which are often lost in CIN(+) CRC, and showed that addressing replication stress could reduce chromosome segregation errors, suggesting potential new treatment strategies to improve cancer outcomes.
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Vimentin, a mesenchymal marker, is frequently overexpressed in epithelial carcinomas undergoing epithelial to mesenchymal transition (EMT), a condition correlated with invasiveness and poor prognosis. Therefore, vimentin is a potential molecular target for anticancer therapy. Emerging studies in experimental models underscore the functions of homeodomain-interacting protein kinase 2 (HIPK2) as potential oncosuppressor by acting as transcriptional corepressor or catalytic activator of molecules involved in apoptosis and response to antitumor drugs.

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Hypoxia-inducible factor 1 (HIF-1), the major transcription factor specifically activated during hypoxia, regulates genes involved in critical aspects of cancer biology, including angiogenesis, cell proliferation, glycolysis and invasion. The HIF-1a subunit is stabilized by low oxygen, genetic alteration and cobaltous ions, and its over-expression correlates with drug resistance and increased cancer mortality in various cancer types, therefore representing an important anticancer target. Zinc supplementation has been shown to counteract the hypoxic phenotype in cancer cells, in vitro and in vivo, hence, understanding the molecular pathways modulated by zinc under hypoxia may provide the basis for reprogramming signalling pathways for anticancer therapy.

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