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Fuks F, Kharas M. Editorial overview: Epitranscriptomics: Exploring a new frontier in health and disease. Curr Opin Genet Dev 2024; 89:102271. [PMID: 39454466 DOI: 10.1016/j.gde.2024.102271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2024]
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Dao T, Xiong G, Mun SS, Meyerberg J, Korontsvit T, Xiang J, Cui Z, Chang AY, Jarvis C, Cai W, Luo H, Pierson A, Daniyan A, Yoo S, Takao S, Kharas M, Kentsis A, Liu C, Scheinberg DA. A dual-receptor T-cell platform with Ab-TCR and costimulatory receptor achieves specificity and potency against AML. Blood 2024; 143:507-521. [PMID: 38048594 PMCID: PMC10950474 DOI: 10.1182/blood.2023021054] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 12/06/2023] Open
Abstract
ABSTRACT Chimeric antigen receptor T-cell (CAR T) therapy has produced remarkable clinical responses in B-cell neoplasms. However, many challenges limit this class of agents for the treatment of other cancer types, in particular the lack of tumor-selective antigens for solid tumors and other hematological malignancies, such as acute myeloid leukemia (AML), which may be addressed without significant risk of severe toxicities while providing sufficient abundance for efficient tumor suppression. One approach to overcome this hurdle is dual targeting by an antibody-T-cell receptor (AbTCR) and a chimeric costimulatory signaling receptor (CSR) to 2 different antigens, in which both antigens are found together on the cancer cells but not together on normal cells. To explore this proof of concept in AML, we engineered a new T-cell format targeting Wilms tumor 1 protein (WT1) and CD33; both are highly expressed on most AML cells. Using an AbTCR comprising a newly developed TCR-mimic monoclonal antibody against the WT1 RMFPNAPYL (RMF) epitope/HLA-A2 complex, ESK2, and a secondary CSR comprising a single-chain variable fragment directed to CD33 linked to a truncated CD28 costimulatory fragment, this unique platform confers specific T-cell cytotoxicity to the AML cells while sparing healthy hematopoietic cells, including CD33+ myelomonocytic normal cells. These data suggest that this new platform, named AbTCR-CSR, through the combination of a AbTCR CAR and CSR could be an effective strategy to reduce toxicity and improve specificity and clinical outcomes in adoptive T-cell therapy in AML.
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Moreira ARS, Lim J, Urbaniak A, Banik J, Bronson K, Lagasse A, Hardy L, Haney A, Allensworth M, Miles TK, Gies A, Byrum SD, Wilczynska A, Boehm U, Kharas M, Lengner C, MacNicol MC, Childs GV, MacNicol AM, Odle AK. Musashi Exerts Control of Gonadotrope Target mRNA Translation During the Mouse Estrous Cycle. Endocrinology 2023; 164:bqad113. [PMID: 37477898 PMCID: PMC10402870 DOI: 10.1210/endocr/bqad113] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/30/2023] [Accepted: 07/20/2023] [Indexed: 07/22/2023]
Abstract
The anterior pituitary controls key biological processes, including growth, metabolism, reproduction, and stress responses through distinct cell types that each secrete specific hormones. The anterior pituitary cells show a remarkable level of cell type plasticity that mediates the shifts in hormone-producing cell populations that are required to meet organismal needs. The molecular mechanisms underlying pituitary cell plasticity are not well understood. Recent work has implicated the pituitary stem cell populations and specifically, the mRNA binding proteins of the Musashi family in control of pituitary cell type identity. In this study we have identified the target mRNAs that mediate Musashi function in the adult mouse pituitary and demonstrate the requirement for Musashi function in vivo. Using Musashi RNA immunoprecipitation, we identify a cohort of 1184 mRNAs that show specific Musashi binding. Identified Musashi targets include the Gnrhr mRNA, which encodes the gonadotropin-releasing hormone receptor (GnRHR), and the Fshb mRNA, encoding follicle-stimulating hormone (FSH). Reporter assays reveal that Musashi functions to exert repression of translation of the Fshb mRNA, in addition to the previously observed repression of the Gnrhr mRNA. Importantly, mice engineered to lack Musashi in gonadotropes demonstrate a failure to repress translation of the endogenous Gnrhr and Fshb mRNAs during the estrous cycle and display a significant heterogeneity in litter sizes. The range of identified target mRNAs suggests that, in addition to these key gonadotrope proteins, Musashi may exert broad regulatory control over the pituitary proteome in a cell type-specific manner.
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Nguyen D, Prieto C, Liu Z, Wheat J, Perez A, Gourkanti S, Chou T, Barin E, Velleca A, Rohwetter T, Chow A, Taggart J, Savino A, Hoskova K, Dhodapkar M, Schurer A, Barlowe T, Leslie C, Vu L, Steidl U, Rabandan R, Kharas M. 2007 – TRANSCRIPTIONAL CONTROL OF CBX5 BY THE RNA BINDING PROTEINS RBMX AND RBMXL1 MAINTAINS CHROMATIN STATE IN MYELOID LEUKEMIA. Exp Hematol 2021. [DOI: 10.1016/j.exphem.2021.12.372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Allensworth-James M, Odle A, Silva Moreira AR, Miles T, Haney A, Kharas M, Lengner C, MacNicol M, MacNicol A, Childs G. OR24-3 Persistence of Progenitor Cell Markers Following the Selective Ablation of Musashi in Somatotropes. J Endocr Soc 2019. [PMCID: PMC6554856 DOI: 10.1210/js.2019-or24-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Metabolic and reproductive demands are met and coordinated through the complex control of hormone synthesis and secretion exerted by the anterior pituitary. While pituitary cells are known to possess remarkable plasticity to change their cell fate and alter hormone production in response to ever changing environmental cues, the underlying molecular control of this plasticity has not been established. Our lab has previously introduced the Musashi (MSI) family of RNA binding proteins as important players in control of pituitary hormone levels. Musashi typically governs stem cell fate and promotes self-renewal by repressing translation of target mRNAs needed for differentiation. However, we found that MSI1 is expressed in most differentiated cells of the adult pituitary and can specifically bind to the 3’ UTRs of Prl, Tsh, and Pou1f1 and exert translational control in reporter assays. Confirmation of the requirement for MSI was demonstrated through in vivo analyses where MSI1 and MSI2 were selectively ablated in somatotropes. The mutant animals were subfertile. The mutant males showed reduced serum and pituitary content of LH and FSH, and significant decreases in serum GH and PRL despite 2-fold increases in pituitary protein content of PRL and GH. To further assess the role and downstream pathways regulated by MSI in the pituitary, we collected somatotrope MSI-null pituitaries from males and females for qPCR analysis of common somatotrope target genes. In correlation with our previous findings described above (low serum GH and high pituitary GH content), we found that GHRHR mRNA levels were reduced by 2-fold in male mutants. RNA-seq analysis followed by qPCR validation shows that Prop1 mRNA was significantly increased in male mutants, with no significant change in Pou1f1 mRNA. These data suggest that MSI may be involved in the regulation of progenitor cells giving rise to the somatotrope lineage and that MSI ablation may have caused retention of these progenitors and/or a failure to fully differentiate somatotropes. Our studies of MSI-null somatotrope function support this interpretation because the mutant somatotropes clearly stored GH proteins, but could not secrete them, as demonstrated by the low serum GH values, and the 50% reduction in GHRHR mRNA. RNA-seq evaluation of males revealed a change in the expression of 720 genes between controls and mutants (FDR <0.05). When we examined female MSI-null somatotrope animals, a much smaller cohort of genes showed a change in expression (153 genes, FDR <0.05). Interestingly, 38 genes were altered in both mutant males and females suggesting shared regulation by MSI. Further characterization of the NGS datasets will elucidate additional downstream targets and effector pathways of MSI-dependent control of anterior pituitary cell differentiation and function.
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Silva Moreira AR, Miles T, Haney A, Hardy L, Allensworth M, Kharas M, Lengner C, MacNicol M, MacNicol A, Childs G, Odle A. SAT-406 Deletion of Musashi in Gonadotropes Leads to Increased GnRHR Protein Levels and Gonadotrope Dysfunction. J Endocr Soc 2019. [PMCID: PMC6552265 DOI: 10.1210/js.2019-sat-406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Leptin is a critical mediator of metabolic regulation of the hypothalamic-pituitary gonadal (HPG) axis. We have previously shown that leptin is responsible for the optimal expression of GnRHR, a rate-limiting component of the reproductive process. Female mice lacking leptin receptors (Lepr-null) specifically on gonadotropes are sub-fertile. Their reduced GnRHR proteins and normal Gnrhr mRNA levels suggest leptin’s actions on gonadotropes are post-transcriptional. A clue about a candidate translational regulator is seen in our studies showing that Lepr-null gonadotropes have increased expression of Musashi (MSI), which has binding sites within the Gnrhr 3’ UTR. Furthermore, leptin reduced MSI expression specifically in gonadotropes and increased GnRHR expression. We hypothesized that MSI may repress Gnrhr mRNA translation and that leptin alleviates this repression. To determine the effects of MSI on the HPG axis, we developed a gonadotrope-Msi1/2-null mouse line and compared mutant females (MUT) to their littermate controls (CTL) on the morning of diestrus, when the pituitary GnRHR protein levels should reach a peak. The levels of GnRHR proteins (measured by EIA) are significantly increased (1.6X) in the pituitary of the mutant females (CTL: 1.355 ± 0.11 ng/ml vs MUT: 2.202 ± 0.16 ng/ml, p=.0006), with no change in mRNA. The gonadotrope-Msi1/2-null females are subfertile, with litter sizes of 3 ± 0.4 pups, with the first litter at around day 40 and an average of 41 day delay between litters. To understand the downstream effect of the MSI knockout on gonadotropin levels, we measured pituitary and serum LH and FSH protein levels (Luminex EIA) and mRNA (qPCR). Serum FSH levels are decreased by >50% in mutant females (CTL: 0.947 ± 0.14 ng/mL vs MUT: 0.406 ± 0.05 ng/ml, p=.0049), but FSH stores and Fsh mRNAs are unchanged. Additionally, we observed a 2.2X increase in the pituitary LH protein content in mutant females (CTL: 0.328 ± 0.11 ng/ml vs MUT: 0.729 ± 0.09 ng/ml, p=.0174), but no changes in serum LH or Lh mRNA levels. These studies thus show that, as a repressor of GnRHR translation, Musashi can also regulate expression of gonadotropins. In the gonadotrope Lepr-null model, we hypothesized that leptin signals were needed to de-repress Musashi actions and allow GnRHR translation. In contrast, the gonadotrope-MSI-null mice over-express GnRHR, which confirms this role for MSI as a GnRHR regulator. We propose that the increased expression of GnRHR in the gonadotrope MSI-null animals causes the increased LH content, and disrupted FSH secretion, resulting in a higher serum LH:FSH ratio and subfertility. Collectively these data suggest that MSI regulation is necessary for optimal fertility in the adult female mouse. Future studies will determine the impact of loss of MSI on gonadotrope function throughout the estrous cycle.
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Sengupta U, Montalbano M, McAllen S, Minuesa G, Kharas M, Kayed R. Formation of Toxic Oligomeric Assemblies of RNA-binding Protein: Musashi in Alzheimer's disease. Acta Neuropathol Commun 2018; 6:113. [PMID: 30367664 PMCID: PMC6203984 DOI: 10.1186/s40478-018-0615-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder associated with structural and functional alterations of brain cells causing progressive deterioration of memory and other cognitive functions. Recent studies demonstrate that several neurodegenerative diseases, including AD exhibit RNA-binding proteins (RBPs) pathologies, including TAR DNA -binding protein (TDP-43), fused in sarcoma (FUS), superoxide dismutase (SOD1) and T-interacting antigen-1 (TIA-1), highlighting the role of RBPs in neurodegeneration. One such group of RBPs, Musashi proteins comprised of MSI1 and MSI2, has been long studied in neurogenesis and cancer biology. Herein, we have investigated the aggregation properties of MSI1 and MSI2 by in vitro assays, their expression and accumulation as well as their possible interactions with other cellular proteins, such as tau in AD pathology. We have performed atomic force microscopy, Western blot, and immunoprecipitation to demonstrate the aggregation properties of recombinant Musashi proteins. Furthermore, we have studied cortical brain sections from AD (N = 4) and age-matched non-demented subjects (N = 4) by Western blot and immunofluorescence microscopy to investigate MSI1 and MSI2 levels and their localization in human brain tissues. Musashi proteins showed in vitro aggregation properties by forming oligomers. We have observed an increase in Musashi proteins levels in AD brain tissues as compared with age-matched non-demented subjects. Moreover, Musashi proteins are observed to form oligomers in the diseased brain tissues. Interestingly, the co-immunofluorescence study has revealed a change in fluorescence pattern of oligomeric Musashi proteins and tau with a high association in the perinuclear area of the cells suggesting changes in function of Musashi proteins. Our data have demonstrated for the first time that MSI1 and MSI2 are present in an oligomeric state in AD brains compared to the age-matched non-demented subjects and that these large assemblies co-localize with tau contributing to the neurodegenerative pathogenesis.
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Bosch A, Li Z, Bergamaschi A, Ellis H, Toska E, Prat A, Tao JJ, Spratt DE, Viola-Villegas NT, Castel P, Minuesa G, Morse N, Rodón J, Ibrahim Y, Cortes J, Perez-Garcia J, Galvan P, Grueso J, Guzman M, Katzenellenbogen JA, Kharas M, Lewis JS, Dickler M, Serra V, Rosen N, Chandarlapaty S, Scaltriti M, Baselga J. PI3K inhibition results in enhanced estrogen receptor function and dependence in hormone receptor-positive breast cancer. Sci Transl Med 2016; 7:283ra51. [PMID: 25877889 DOI: 10.1126/scitranslmed.aaa4442] [Citation(s) in RCA: 261] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Activating mutations of PIK3CA are the most frequent genomic alterations in estrogen receptor (ER)-positive breast tumors, and selective phosphatidylinositol 3-kinase α (PI3Kα) inhibitors are in clinical development. The activity of these agents, however, is not homogeneous, and only a fraction of patients bearing PIK3CA-mutant ER-positive tumors benefit from single-agent administration. Searching for mechanisms of resistance, we observed that suppression of PI3K signaling results in induction of ER-dependent transcriptional activity, as demonstrated by changes in expression of genes containing ER-binding sites and increased occupancy by the ER of promoter regions of up-regulated genes. Furthermore, expression of ESR1 mRNA and ER protein were also increased upon PI3K inhibition. These changes in gene expression were confirmed in vivo in xenografts and patient-derived models and in tumors from patients undergoing treatment with the PI3Kα inhibitor BYL719. The observed effects on transcription were enhanced by the addition of estradiol and suppressed by the anti-ER therapies fulvestrant and tamoxifen. Fulvestrant markedly sensitized ER-positive tumors to PI3Kα inhibition, resulting in major tumor regressions in vivo. We propose that increased ER transcriptional activity may be a reactive mechanism that limits the activity of PI3K inhibitors and that combined PI3K and ER inhibition is a rational approach to target these tumors.
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Morgan K, Kharas M, Dzierzak E, Gilliland DG. Isolation of early hematopoietic stem cells from murine yolk sac and AGM. J Vis Exp 2008:789. [PMID: 19066546 DOI: 10.3791/789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
In the mouse embryo, early hematopoiesis occurs simultaneously in multiple organs, which includes the yolk sac and aorta-gonad-mesonephros region. These regions are crucial in establishing the blood system in the embryos and leads to the eventual movement of stem cells into the fetal liver and then development of adult stem cells in the bonemarrow. Early hematopoietic stem cells can be isolated from these organs through microdissection of the embryo followed by flow cytometric sorting to obtain a more pure population. It remains unclear how these stem cell populations contribute to the fetal and adult stem cell pool. Also, our lab investigates how early stem cells functionally differ from fetal and adult hematopoietic stem cells. Furthermore, our lab sorts different populations of hematopoietic stem cells and test their functional role in the context of a variety of genetic models. In this video, we demonstrate the micro-dissection procedure we commonly use and also show the results of a typical FACS plotfter isolating these rare populations, it is possible to perform a variety of functional assays including: colony assays and bone marrow transplants.
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Funk PE, Pifer J, Kharas M, Crisafi G, Johnson A. The avian chB6 alloantigen induces apoptosis in DT40 B cells. Cell Immunol 2004; 226:95-104. [PMID: 14962497 DOI: 10.1016/j.cellimm.2003.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Accepted: 11/25/2003] [Indexed: 02/06/2023]
Abstract
In avian species, B-lymphocytes develop in the bursa of Fabricius. Cells developing in the bursa are subject to signals regulating their survival, with the majority of cells dying by apoptosis within the bursa. However, the molecules delivering the signals influencing this life and death decision remain enigmatic. We have previously shown that antibodies against the chB6 alloantigen present on avian B-lymphocytes can induce a rapid form of cell death. Here we extend this finding by showing that anti-chB6 antibodies induce true apoptosis in DT40 cells without visible membrane damage. This apoptosis results in DNA degradation and morphologic changes characteristic of apoptosis. Furthermore, this apoptosis is coincident with a loss of mitochondrial membrane potential and is inhibited by either overexpression of bcl-x(L) or the presence of inhibitors of caspase 8, 9, or 3 activity. Collectively these data argue that chB6 may function as a novel death receptor on avian B-lymphocytes and support the use of DT40 as an amenable model to study the signaling involved in chB6-induced apoptosis.
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