Publications by authors named "Mahmoud A Bassal"

Coordinated initiation of DNA replication is essential to ensure efficient and timely DNA synthesis. Yet, molecular mechanism describing how replication initiation is coordinated in eukaryotic cells is not completely understood. Herein, we present data demonstrating a novel feature of RNAs transcribed in the proximity of actively replicating gene loci.

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Stem cells reside in specialized microenvironments, termed niches, at several different locations in tissues. The differential functions of heterogeneous stem cells and niches are important given the increasing clinical applications of stem-cell transplantation and immunotherapy. Whether hierarchical structures among stem cells at distinct niches exist and further control aspects of immune tolerance is unknown.

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  • β-thalassemia and sickle cell disease are common genetic blood disorders caused by mutations in the β-globin gene, leading to anemia and requiring treatments like blood transfusions and bone marrow transplants.
  • New research is exploring the potential of inducing ε-globin expression, which was previously thought non-inducible postnatally, as a way to improve treatment outcomes for these conditions.
  • The review highlights the need for further research into the mechanisms of ε-globin silencing and suggests future drug development initiatives to harness its therapeutic benefits.
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  • * Recent studies indicate that a specific TE-derived gene, POGK, functions as a tumor suppressor in triple-negative breast cancer (TNBC) by interfering with the expression of ribosomal genes.
  • * POGK’s deactivation occurs through isoform switching in patients with clinical TNBC, highlighting its importance in regulating tumor development.
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Immunomodulatory imide drugs (IMiDs) degrade specific C2H2 zinc finger degrons in transcription factors, making them effective against certain cancers. SALL4, a cancer driver, contains seven C2H2 zinc fingers in four clusters, including an IMiD degron in zinc finger cluster two (ZFC2). Surprisingly, IMiDs do not inhibit growth of SALL4 expressing cancer cells.

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Oncofetal transcription factor SALL4 is essential for cancer cell survival. Recently, several groups reported that immunomodulatory imide drugs (IMiDs) could degrade SALL4 in a proteasome-dependent manner. Intriguingly, we observed that IMiDs had no effect on SALL4-positive cancer cells.

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Cellular metabolism (or energetics) and epigenetics are tightly coupled cellular processes. It is arguable that of all the described cancer hallmarks, dysregulated cellular energetics and epigenetics are the most tightly coregulated. Cellular metabolic states regulate and drive epigenetic changes while also being capable of influencing, if not driving, epigenetic reprogramming.

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DNA methylation is a fundamental epigenetic modification regulating gene expression. Aberrant DNA methylation is the most common molecular lesion in cancer cells. However, medical intervention has been limited to the use of broadly acting, small molecule-based demethylating drugs with significant side-effects and toxicities.

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The phosphoinositide 3-kinase (PI3K) pathway represents the most hyperactivated oncogenic pathway in triple-negative breast cancer (TNBC), a highly aggressive tumor subtype encompassing ∼15% of breast cancers and which possesses no targeted therapeutics. Despite critical contributions of its signaling arms to disease pathogenesis, PI3K pathway inhibitors have not achieved expected clinical responses in TNBC, owing largely to a still-incomplete understanding of the compensatory cascades that operate downstream of PI3K. Here, we investigated the contributions of long noncoding RNAs (lncRNAs) to PI3K activities in clinical and experimental TNBC and discovered a prominent role for LINC01133 as a PI3K-AKT signaling effector.

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Despite decades of research, standard therapies remain ineffective for most leukemias, pushing toward an essential unmet need for targeted drug screens. Moreover, preclinical drug testing is an important consideration for success of clinical trials without affecting non-transformed stem cells. Using the transgenic chronic myeloid leukemia (CML) mouse model, we determine that leukemic stem cells (LSCs) are transcriptionally heterogenous with a preexistent drug-insensitive signature.

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The Ets transcription factor PU.1 is essential for inducing the differentiation of monocytes, macrophages, and B cells in fetal liver and adult bone marrow. PU.

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  • Hypomethylating agents are used in cancer treatment, but their potential to reactivate oncogenes remains unclear.
  • In a study of myelodysplastic syndrome patients, 40% and 30% showed up-regulation of a specific oncogene after treatment, which correlated with worse outcomes.
  • CRISPR-DiR technology identified a critical CpG island for oncogene expression; this highlights the need for further research into the effects of hypomethylating agents on cancer treatment.
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  • * It finds that mutations in complex I genes are mutually exclusive with IDH1 mutations but not with IDH2 mutations, indicating a unique relationship that affects how the cancer cells metabolize nutrients.
  • * The research highlights that IDH1 mutations create a specific weakness in metabolism, making IDH1-mutant cells more sensitive to treatments that target complex I, revealing potential new therapy strategies for AML patients.
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Chromatin immunoprecipitation coupled with sequencing (ChIP-seq) is a technique used to identify protein-DNA interaction sites through antibody pull-down, sequencing and analysis; with enrichment 'peak' calling being the most critical analytical step. Benchmarking studies have consistently shown that peak callers have distinct selectivity and specificity characteristics that are not additive and seldom completely overlap in many scenarios, even after parameter optimization. We therefore developed ChIP-AP, an integrated ChIP-seq analysis pipeline utilizing four independent peak callers, which seamlessly processes raw sequencing files to final result.

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Nutritional intake impacts the human epigenome by directing epigenetic pathways in normal cell development via as yet unknown molecular mechanisms. Consequently, imbalance in the nutritional intake is able to dysregulate the epigenetic profile and drive cells towards malignant transformation. Here we present a novel epigenetic effect of the essential nutrient, NAD.

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  • Pseudogenes, once thought to be useless remnants of evolution, are now linked to cancer prognosis and subtypes, with only a small fraction studied in cancer so far.
  • The study reveals that pseudogenes can act as epigenetic regulators that demethylate and activate oncogenes, specifically focusing on the oncogene SALL4 and its related pseudogenes in hepatocellular carcinoma (HCC).
  • Key findings show that pseudogene 5 enhances SALL4 expression by demethylating a critical CpG region, and both are significantly increased in patients with hepatitis B virus-related HCC, suggesting a new mechanism for oncogene activation in cancer.
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CUT&RUN is a recently developed chromatin profiling technique that enables high-resolution chromatin mapping and probing. Herein, we describe our adapted CUT&RUN protocol for transcription factors (TFs). Our protocol outlines all necessary steps for TF profiling including the procedure to obtain proteinA-Mnase, while also outlining the bioinformatic pipeline steps required to process, analyze, and identify novel binding sites and sequences.

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Leukemic stem cells (LSCs) can acquire non-mutational resistance following drug treatment leading to therapeutic failure and relapse. However, oncogene-independent mechanisms of drug persistence in LSCs are incompletely understood, which is the primary focus of this study. We integrated proteomics, transcriptomics, and metabolomics to determine the contribution of STAT3 in promoting metabolic changes in tyrosine kinase inhibitor (TKI) persistent chronic myeloid leukemia (CML) cells.

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Compelling evidence supports vascular contributions to cognitive impairment and dementia (VCID) including Alzheimer's disease (AD), but the underlying pathogenic mechanisms and treatments are not fully understood. Cis P-tau is an early driver of neurodegeneration resulting from traumatic brain injury, but its role in VCID remains unclear. Here, we found robust cis P-tau despite no tau tangles in patients with VCID and in mice modeling key aspects of clinical VCID, likely because of the inhibition of its isomerase Pin1 by DAPK1.

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The mechanism underlying cell type-specific gene induction conferred by ubiquitous transcription factors as well as disruptions caused by their chimeric derivatives in leukemia is not well understood. Here, we investigate whether RNAs coordinate with transcription factors to drive myeloid gene transcription. In an integrated genome-wide approach surveying for gene loci exhibiting concurrent RNA and DNA interactions with the broadly expressed Runt-related transcription factor 1 (RUNX1), we identified the long noncoding RNA (lncRNA) originating from the upstream regulatory element of PU.

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Lung cancer is the leading cause of cancer deaths. Tumor heterogeneity, which hampers development of targeted therapies, was herein deconvoluted via single cell RNA sequencing in aggressive human adenocarcinomas (carrying Kras-mutations) and comparable murine model. We identified a tumor-specific, mutant-KRAS-associated subpopulation which is conserved in both human and murine lung cancer.

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E-cadherin is a calcium-dependent cell-cell adhesion molecule extensively studied for its involvement in tissue formation, epithelial cell behavior, and suppression of cancer. However, E-cadherin expression in the hematopoietic system has not been fully elucidated. Combining single-cell RNA-sequencing analyses and immunophenotyping, we revealed that progenitors expressing high levels of E-cadherin and contained within the granulocyte-monocyte progenitors (GMPs) fraction have an enriched capacity to differentiate into basophils and mast cells.

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The zinc finger transcription factor SALL4 is highly expressed in embryonic stem cells, downregulated in most adult tissues, but reactivated in many aggressive cancers. This unique expression pattern makes SALL4 an attractive therapeutic target. However, whether SALL4 binds DNA directly to regulate gene expression is unclear, and many of its targets in cancer cells remain elusive.

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