Publications by authors named "Amin Sobh"

Despite the success of B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T cells (CAR-Ts) in multiple myeloma, patients with high-risk cytogenetic features continue to relapse most quickly and are in urgent need of additional therapeutic options. Here, we identify CD70, widely recognized as a favorable immunotherapy target in other cancers, as a specifically upregulated cell surface antigen in high-risk myeloma tumors. We use a structure-guided design to define a CD27-based anti-CD70 CAR-T design that outperforms all tested single-chain variable fragment-based CARs, leading to >80-fold improved CAR-T expansion in vivo.

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Iron is an essential nutrient required for various physiological processes in the body. However, iron imbalance can potentially contribute to initiating and promoting cancer development. Epidemiological studies have investigated the relationship between dietary iron intake and the risk of different types of cancer, yet, not all studies have consistently shown a significant association between dietary iron and cancer risk.

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The histone H3 at lysine 27 (H3K27) demethylase lysine demethylase 6A (KDM6A) is a tumor suppressor in multiple cancers, including multiple myeloma (MM). We created isogenic MM cells disrupted for KDM6A and tagged the endogenous protein to facilitate genome-wide studies. KDM6A binds genes associated with immune recognition and cytokine signaling.

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Chromosomal translocation (4;14), an adverse prognostic factor in multiple myeloma (MM), drives overexpression of the histone methyltransferase nuclear receptor binding SET domain protein 2 (NSD2). A genome-wide CRISPR screen in MM cells identified adenylate kinase 2 (AK2), an enzyme critical for high-energy phosphate transfer from the mitochondria, as an NSD2-driven vulnerability. AK2 suppression in t(4;14) MM cells decreased nicotinamide adenine dinucleotide phosphate (NADP[H]) critical for conversion of ribonucleotides to deoxyribonucleosides, leading to replication stress, DNA damage, and apoptosis.

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Despite the success of BCMA-targeting CAR-Ts in multiple myeloma, patients with high-risk cytogenetic features still relapse most quickly and are in urgent need of additional therapeutic options. Here, we identify CD70, widely recognized as a favorable immunotherapy target in other cancers, as a specifically upregulated cell surface antigen in high risk myeloma tumors. We use a structure-guided design to define a CD27-based anti-CD70 CAR-T design that outperforms all tested scFv-based CARs, leading to >80-fold improved CAR-T expansion in vivo.

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Unlabelled: The histone H3K27 demethylase KDM6A is a tumor suppressor in multiple cancers, including multiple myeloma (MM). We created isogenic MM cells disrupted for KDM6A and tagged the endogenous protein to facilitate genome wide studies. KDM6A binds genes associated with immune recognition and cytokine signaling.

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Nuclear receptor-binding SET domain-containing 2 (NSD2) plays important roles in gene regulation, largely through its ability to dimethylate lysine 36 of histone 3 (H3K36me2). Despite aberrant activity of NSD2 reported in numerous cancers, efforts to selectively inhibit the catalytic activity of this protein with small molecules have been unsuccessful to date. Here, we report the development of UNC8153, a novel NSD2-targeted degrader that potently and selectively reduces the cellular levels of both NSD2 protein and the H3K36me2 chromatin mark.

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Article Synopsis
  • PROTACs are special molecules that help break down unwanted proteins in our bodies by using another type of protein called E3 ligases.
  • In this study, researchers found a natural compound called piperlongumine (PL) that helps recruit E3 ligases to destroy a specific protein called CDK9 when combined with another drug.
  • The research showed that this combination is really good at destroying CDK9 in cancer cells and might also work to break down other harmful proteins, making it a promising tool for treating cancer.
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Etoposide is used to treat a wide range of malignant cancers, including acute myeloid leukemia (AML) in children. Despite the use of intensive chemotherapeutic regimens containing etoposide, a significant proportion of pediatric patients with AML become resistant to treatment and relapse, leading to poor survival. This poses a pressing clinical challenge to identify mechanisms underlying drug resistance to enable effective pharmacologic targeting.

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Metabolic dysfunction mutations can impair energy sensing and cause cancer. Loss of function of the mitochondrial tricarboxylic acid (TCA) cycle enzyme subunit succinate dehydrogenase B (SDHB) results in various forms of cancer typified by pheochromocytoma (PC). Here we delineate a signaling cascade where the loss of SDHB induces the Warburg effect, triggers dysregulation of [Ca], and aberrantly activates calpain and protein kinase Cdk5, through conversion of its cofactor from p35 to p25.

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Background: The COVID-19 pandemic has resulted in 275 million infections and 5.4 million deaths as of December 2021. While effective vaccines are being administered globally, there is still a great need for antiviral therapies as antigenically novel SARS-CoV-2 variants continue to emerge across the globe.

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Pancreatic cancer is the third most common cause of cancer-related deaths in the United States. Although gemcitabine is the standard of care for most patients with pancreatic cancer, its efficacy is limited by the development of resistance. This resistance may be attributable to the evasion of apoptosis caused by the overexpression of BCL-2 family antiapoptotic proteins.

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The HIV-protease inhibitor nelfinavir has shown broad anticancer activity in various preclinical and clinical contexts. In patients with advanced, proteasome inhibitor (PI)-refractory multiple myeloma, nelfinavir-based therapy resulted in 65% partial response or better, suggesting that this may be a highly active chemotherapeutic option in this setting. The broad anticancer mechanism of action of nelfinavir implies that it interferes with fundamental aspects of cancer cell biology.

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The use of genome editing tools is expanding our understanding of various human diseases by providing insight into gene-disease interactions. Despite the recognized role of toxicants in the development of human health issues and conditions, there is currently limited characterization of their mechanisms of action, and the application of CRISPR-based genome editing to the study of toxicants could help in the identification of novel gene-environment interactions. CRISPR-based functional screens enable identification of cellular mechanisms fundamental for response and susceptibility to a given toxicant.

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We report a novel platform [native capillary zone electrophoresis-top-down mass spectrometry (nCZE-TDMS)] for the separation and characterization of whole nucleosomes, their histone subunits, and post-translational modifications (PTMs). As the repeating unit of chromatin, mononucleosomes (Nucs) are an ∼200 kDa complex of DNA and histone proteins involved in the regulation of key cellular processes central to human health and disease. Unraveling the covalent modification landscape of histones and their defined stoichiometries within Nucs helps to explain epigenetic regulatory mechanisms.

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Formaldehyde (FA), a ubiquitous environmental pollutant, is classified as a Group I human carcinogen by the International Agency for Research on Cancer. Previously, we reported that FA induced hematotoxicity and chromosomal aneuploidy in exposed workers and toxicity in bone marrow and hematopoietic stem cells of experimental animals. Using functional toxicogenomic profiling in yeast, we identified genes and cellular processes modulating eukaryotic FA cytotoxicity.

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Transferrin-bound iron (TBI), the physiological circulating iron form, is acquired by cells through the transferrin receptor (TfR1) by endocytosis. In erythroid cells, most of the acquired iron is incorporated into heme in the mitochondria. Cellular trafficking of heme is indispensable for erythropoiesis and many other essential biological processes.

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Organochlorine pesticides, once widely used, are extremely persistent and bio-accumulative in the environment. Epidemiological studies have implicated that environmental exposure to organochlorine pesticides including dieldrin is a risk factor for the development of Parkinson's disease. However, the pertinent mechanisms of action remain poorly understood.

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Acetaldehyde, a metabolite of ethanol, is a cellular toxicant and a human carcinogen. A genome-wide CRISPR-based loss-of-function screen in erythroleukemic K562 cells revealed candidate genetic contributors affecting acetaldehyde cytotoxicity. Secondary screening exposing cells to a lower acetaldehyde dose simultaneously validated multiple candidate genes whose loss results in increased sensitivity to acetaldehyde.

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CCCTC-binding factor (CTCF)-mediated stable topologically associating domains (TADs) play a critical role in constraining interactions of DNA elements that are located in neighboring TADs. CTCF plays an important role in regulating the spatial and temporal expression of HOX genes that control embryonic development, body patterning, hematopoiesis, and leukemogenesis. However, it remains largely unknown whether and how HOX loci associated CTCF boundaries regulate chromatin organization and HOX gene expression.

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Arsenic exposure is a worldwide health concern associated with an increased risk of skin, lung, and bladder cancer but arsenic trioxide (AsIII) is also an effective chemotherapeutic agent. The current use of AsIII in chemotherapy is limited to acute promyelocytic leukemia (APL). However, AsIII was suggested as a potential therapy for other cancer types including chronic myeloid leukemia (CML), especially when combined with other drugs.

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gene dysregulation is a common feature of acute myeloid leukemia (AML). The molecular mechanisms underlying aberrant gene expression and associated AML pathogenesis remain unclear. The nuclear protein CCCTC-binding factor (CTCF), when bound to insulator sequences, constrains temporal gene-expression patterns within confined chromatin domains for normal development.

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