RESUMEN
Nuclear receptor action is mediated in part by the nuclear receptor corepressor 1 (NCOR1) and the silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). NCOR1 and SMRT regulate metabolic pathways that govern body mass, insulin sensitivity, and energy expenditure, representing an understudied area in the realm of metabolic health and disease. Previously, we found that NCOR1 and SMRT are essential for maintaining metabolic homeostasis and their knockout (KO) leads to rapid weight loss and hypoglycemia, which is not survivable. Because of a potential defect in glucose absorption, we sought to determine the role of NCOR1 and SMRT specifically in intestinal epithelial cells (IECs). We used a postnatal strategy to disrupt NCOR1 and SMRT throughout IECs in adult mice. These mice were characterized metabolically and underwent metabolic phenotyping, body composition analysis, and glucose tolerance testing. Jejunal IECs were isolated and profiled by bulk RNA sequencing. We found that the postnatal KO of NCOR1 and SMRT from IECs leads to rapid weight loss and hypoglycemia with a significant reduction in survival. This was accompanied by alterations in glucose metabolism and activation of fatty acid oxidation in IECs. Metabolic phenotyping confirmed a reduction in body mass driven by a loss of body fat without altered food intake. This appeared to be mediated by a reduction of key intestinal carbohydrate transporters, including SGLT1, GLUT2, and GLUT5. Intestinal NCOR1 and SMRT act in tandem to regulate glucose levels and body weight. This in part may be mediated by regulation of intestinal carbohydrate transporters.
Asunto(s)
Mucosa Intestinal , Ratones Noqueados , Co-Represor 1 de Receptor Nuclear , Co-Represor 2 de Receptor Nuclear , Animales , Co-Represor 1 de Receptor Nuclear/metabolismo , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Ratones , Mucosa Intestinal/metabolismo , Glucosa/metabolismo , Masculino , Metabolismo de los Hidratos de Carbono/genética , Ratones Endogámicos C57BL , Transportador 1 de Sodio-Glucosa/metabolismo , Transportador 1 de Sodio-Glucosa/genética , Transporte Biológico , Femenino , Metabolismo Energético , Transportador de Glucosa de Tipo 2/metabolismo , Transportador de Glucosa de Tipo 2/genéticaRESUMEN
Histone deacetylase 4 (HDAC4) contributes to gene repression by complex formation with HDAC3 and the corepressor silencing mediator for retinoid or thyroid hormone receptors (SMRT). We hypothesized that peptides derived from the class IIa specific binding site of SMRT would stabilize a specific conformation of its target protein and modulate its activity. Based on the SMRT-motif 1 (SM1) involved in the interaction of SMRT with HDAC4, we systematically developed cyclic peptides that exhibit Ki values that are 9 to 56 times lower than that of the linear SMRT peptide. The peptide macrocycles stabilize the wildtype of the catalytic domain of HDAC4 (cHDAC4) considerably better than its thermally more stable 'gain-of-function' (GOF) variant, cHDAC4-H976Y. Molecular docking and mutagenesis studies indicated that the cyclic peptides bind in a similar but not identical manner as the linear SMRT peptide to a discontinuous binding site. Ion mobility mass spectrometry showed no major changes in the protein fold upon peptide binding. Consistent with these results, preliminary hydrogen-deuterium exchange mass spectrometry measurements indicated only minor conformational changes. Taken together, the cyclic SMRT peptides most likely stabilize the apo form of cHDAC4.
Asunto(s)
Histona Desacetilasas , Proteínas Represoras , Histona Desacetilasas/metabolismo , Histona Desacetilasas/química , Humanos , Proteínas Represoras/química , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Péptidos Cíclicos/química , Péptidos Cíclicos/síntesis química , Péptidos Cíclicos/farmacología , Simulación del Acoplamiento Molecular , Estabilidad Proteica , Péptidos/química , Péptidos/síntesis química , Péptidos/metabolismo , Co-Represor 2 de Receptor Nuclear/química , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Diseño de Fármacos , Sitios de UniónRESUMEN
Nuclear receptor corepressors (NCoRs) function in multiprotein complexes containing histone deacetylase 3 (HDAC3) to alter transcriptional output primarily through repressive chromatin remodelling at target loci1-5. In the liver, loss of HDAC3 causes a marked hepatosteatosis largely because of de-repression of genes involved in lipid metabolism6,7; however, the individual roles and contribution of other complex members to hepatic and systemic metabolic regulation are unclear. Here we show that adult loss of both NCoR1 and NCoR2 (double knockout (KO)) in hepatocytes phenocopied the hepatomegalic fatty liver phenotype of HDAC3 KO. In addition, double KO livers exhibited a dramatic reduction in glycogen storage and gluconeogenic gene expression that was not observed with hepatic KO of individual NCoRs or HDAC3, resulting in profound fasting hypoglycaemia. This surprising HDAC3-independent activation function of NCoR1 and NCoR2 is due to an unexpected loss of chromatin accessibility on deletion of NCoRs that prevented glucocorticoid receptor binding and stimulatory effect on gluconeogenic genes. These studies reveal an unanticipated, non-canonical activation function of NCoRs that is required for metabolic health.
Asunto(s)
Gluconeogénesis , Histona Desacetilasas , Hígado , Ratones Noqueados , Co-Represor 1 de Receptor Nuclear , Co-Represor 2 de Receptor Nuclear , Receptores de Glucocorticoides , Gluconeogénesis/genética , Animales , Receptores de Glucocorticoides/metabolismo , Receptores de Glucocorticoides/genética , Co-Represor 1 de Receptor Nuclear/metabolismo , Co-Represor 1 de Receptor Nuclear/genética , Ratones , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Hígado/metabolismo , Hepatocitos/metabolismo , Coactivador 2 del Receptor Nuclear/metabolismo , Coactivador 2 del Receptor Nuclear/genéticaAsunto(s)
Hígado , Co-Represor 1 de Receptor Nuclear , Co-Represor 2 de Receptor Nuclear , Receptores de Glucocorticoides , Receptores de Glucocorticoides/metabolismo , Hígado/metabolismo , Humanos , Animales , Co-Represor 1 de Receptor Nuclear/metabolismo , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , RatonesRESUMEN
Class II histone deacetylases (HDACs) are important in regulation of gene transcription during T cell development. However, our understanding of their cell-specific functions is limited. In this study, we reveal that class IIa Hdac4 and Hdac7 (Hdac4/7) are selectively induced in transcription, guiding the lineage-specific differentiation of mouse T-helper 17 (Th17) cells from naive CD4+ T cells. Importantly, Hdac4/7 are functionally dispensable in other Th subtypes. Mechanistically, Hdac4 interacts with the transcription factor (TF) JunB, facilitating the transcriptional activation of Th17 signature genes such as Il17a/f. Conversely, Hdac7 collaborates with the TF Aiolos and Smrt/Ncor1-Hdac3 corepressors to repress transcription of Th17 negative regulators, including Il2, in Th17 cell differentiation. Inhibiting Hdac4/7 through pharmacological or genetic methods effectively mitigates Th17 cell-mediated intestinal inflammation in a colitis mouse model. Our study uncovers molecular mechanisms where HDAC4 and HDAC7 function distinctively yet cooperatively in regulating ordered gene transcription during Th17 cell differentiation. These findings suggest a potential therapeutic strategy of targeting HDAC4/7 for treating Th17-related inflammatory diseases, such as ulcerative colitis.
Asunto(s)
Diferenciación Celular , Colitis , Histona Desacetilasas , Co-Represor 1 de Receptor Nuclear , Células Th17 , Animales , Células Th17/citología , Células Th17/metabolismo , Células Th17/inmunología , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Ratones , Colitis/genética , Colitis/metabolismo , Colitis/inmunología , Transcripción Genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Interleucina-17/metabolismo , Regulación de la Expresión Génica , Ratones Endogámicos C57BL , Humanos , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Interleucina-2/metabolismoRESUMEN
Despite numerous female contraceptive options, nearly half of all pregnancies are unintended. Family planning choices for men are currently limited to unreliable condoms and invasive vasectomies with questionable reversibility. Here, we report the development of an oral contraceptive approach based on transcriptional disruption of cyclical gene expression patterns during spermatogenesis. Spermatogenesis involves a continuous series of self-renewal and differentiation programs of spermatogonial stem cells (SSCs) that is regulated by retinoic acid (RA)-dependent activation of receptors (RARs), which control target gene expression through association with corepressor proteins. We have found that the interaction between RAR and the corepressor silencing mediator of retinoid and thyroid hormone receptors (SMRT) is essential for spermatogenesis. In a genetically engineered mouse model that negates SMRT-RAR binding (SMRTmRID mice), the synchronized, cyclic expression of RAR-dependent genes along the seminiferous tubules is disrupted. Notably, the presence of an RA-resistant SSC population that survives RAR de-repression suggests that the infertility attributed to the loss of SMRT-mediated repression is reversible. Supporting this notion, we show that inhibiting the action of the SMRT complex with chronic, low-dose oral administration of a histone deacetylase inhibitor reversibly blocks spermatogenesis and fertility without affecting libido. This demonstration validates pharmacologic targeting of the SMRT repressor complex for non-hormonal male contraception.
Asunto(s)
Proteínas de Unión al ADN , Proteínas Represoras , Humanos , Femenino , Masculino , Animales , Ratones , Proteínas de Unión al ADN/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Proteínas Co-Represoras/genética , Co-Represor 2 de Receptor Nuclear/genética , Tretinoina/farmacología , Anticoncepción , Co-Represor 1 de Receptor NuclearRESUMEN
Giant cell tumors (GCTs) with high mobility group AT-Hook 2 ( HMGA2 )::nuclear receptor corepressor 2 ( NCOR2 ) fusion are rare mesenchymal tumors of controversial nosology, which have been anecdotally reported to respond to CSFR1 inhibitors. Here, we performed a comprehensive study of 6 GCTs with HMGA2::NCOR2 fusion and explored their relationship with other giant cell-rich neoplasms. Tumors occurred in 4 females and 2 males ranging in age from 17 to 32 years old (median 24). Three lesions originated in subcutaneous soft tissue and 3 in bone. Tumor size ranged from 20 to 33 mm (median 27 mm). The lesions had a nodular/multinodular architecture and were composed of sheets of mononuclear "histiocytoid" cells with uniform nuclei intermingled with multinucleated giant cells. Mitotic activity was low and nuclear atypia and metaplastic bone were absent. Variable findings included necrosis, cystic degeneration, lymphocytic infiltrate (sometimes forming nodules), and xanthogranulomatous inflammation. On immunohistochemistry, all cases focally expressed pan-keratin and were negative with SATB2 and H3.3G34W. Whole RNA-sequencing was performed in all cases of GCT with HMGA2::NCOR2 fusion and a subset of giant cell-rich tumors (tenosynovial-GCT, n = 19 and "wild-type" GCT of soft tissue, n = 9). Hierarchical clustering of RNA-sequencing data showed that GCT with HMGA2::NCOR2 fusion formed a single cluster, independent of the other 2 entities. Methylome profiling showed similar results, but the distinction from "wild-type" GCT of soft tissue was less flagrant. Gene expression analysis showed similar levels of expression of the CSF1/CSFR1 axis between GCT with HMGA2::NCOR2 fusion and tenosynovial-GCT, supporting their potential sensitivity to CSFR1 inhibitors. Clinical follow-up was available for 5 patients (range: 10 to 64 mo; median 32 mo). Three patients (60%) experienced local recurrences, whereas none had distant metastases or died of disease. Overall, our study confirms and expands previous knowledge on GCT with HMGA2::NCOR2 fusion and supports its inclusion as an independent entity.
Asunto(s)
Biomarcadores de Tumor , Tumores de Células Gigantes , Masculino , Femenino , Humanos , Adolescente , Adulto Joven , Adulto , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/análisis , Tumores de Células Gigantes/patología , Inmunohistoquímica , Huesos/patología , Epigénesis Genética , Co-Represor 2 de Receptor Nuclear/genéticaRESUMEN
PURPOSE: The significance of the non-classical G-protein-coupled estrogen receptor (GPER) as positive or negative prognostic factor for ovarian cancer patients remains still controversial. Recent results indicate that an imbalance of both co-factors and co-repressors of nuclear receptors regulates ovarian carcinogenesis by altering the transcriptional activity through chromatin remodeling. The present study aims to investigate whether the expression of the nuclear co-repressor NCOR2 plays a role in GPER signaling which thereby could positively impact overall survival rates of ovarian cancer patients. METHODS: NCOR2 expression was evaluated by immunohistochemistry in a cohort of 156 epithelial ovarian cancer (EOC) tumor samples and correlated with GPER expression. The correlation and differences in clinical and histopathological variables as well as their effect on prognosis were analyzed by Spearman's correlation, Kruskal-Wallis test and Kaplan-Meier estimates. RESULTS: Histologic subtypes were associated with different NCOR2 expression patterns. More specifically, serous and mucinous EOC demonstrated a higher NCOR2 expression (P = 0.008). In addition, high nuclear NCOR2 expression correlated significantly with high GPER expression (cc = 0.245, P = 0.008). A combined evaluation of both high NCOR2 (IRS > 6) and high GPER (IRS > 8) expression revealed an association of a significantly improved overall survival (median OS 50.9 versus 105.1 months, P = 0.048). CONCLUSION: Our results support the hypothesis that nuclear co-repressors such as NCOR2 may influence the transcription of target genes in EOC such as GPER. Understanding the role of nuclear co-repressors on signaling pathways will allow a better understanding of the factors involved in prognosis and clinical outcome of EOC patients.
Asunto(s)
Neoplasias Ováricas , Receptores de Estrógenos , Humanos , Femenino , Pronóstico , Proteínas Co-Represoras , Receptores Acoplados a Proteínas G , Neoplasias Ováricas/patología , Carcinoma Epitelial de Ovario , Línea Celular Tumoral , Co-Represor 2 de Receptor Nuclear/genéticaRESUMEN
BACKGROUND: Silencing Mediator of Retinoid and Thyroid hormone receptors (SMRT; NCoR2) is a transcriptional corepressor (CoR) which has been recognized as an important player in the regulation of hepatic lipogenesis and in somatic development in mouse embryo. SMRT protein is also widely expressed in mouse connective tissues, for example adipocytes and muscle. We recently reported that mice with global deletion of SMRT develop significant obesity and muscle wasting which are independent from thyroid hormone (TH) signaling and thermogenesis. However, the tissue specific role of SMRT in skeletal muscle is still not clear. METHODS: To clarify role of SMRT in muscle differentiation, we made myogenic C2C12 clones which lack SMRT protein (C2C12-SKO) by using CRISPR-Cas9. Wild-type C2C12 (C2C12-WT) and C2C12-SKO cells were cultured in differentiation medium, and the resulting gene and protein profiles were compared between the two cell lines both before and after differentiation. We also analyzed muscle tissues which were dissected from whole body SMRT knockout (KO) mice and their controls. RESULTS: We found significant up-regulation of muscle specific ß-oxidation markers; Peroxisome proliferator-activated receptor δ (PPARδ) and PPARγ coactivator-1α (PGC-1α) in the C2C12-SKO cells, suggesting that the cells had a similar gene profile to what is found in exercised rodent skeletal muscle. On the other hand, confocal microscopic analysis showed the significant loss of myotubes in C2C12-SKO cells similar to the morphology found in immature myoblasts. Proteomics analysis also confirmed that the C2C12-SKO cells had higher expression of markers of fibrosis (ex. Collagen1A1; COL1A1 and Fibroblast growth factor-2; FGF-2), indicating the up-regulation of Transforming growth factor-ß (TGF-ß) receptor signaling. Consistent with this, treatment with a specific TGF-ß receptor inhibitor ameliorated both the defects in myotube differentiation and fibrosis. CONCLUSION: Taken together, we demonstrate that SMRT functions as a pivotal transcriptional mediator for both ß-oxidation and the prevention for the fibrosis via TGF-ß receptor signaling in the differentiation of C2C12 myoblasts. In contrast to the results from C2C12 cells, SMRT does not appear to play a role in adult skeletal muscle of whole body SMRT KO mice. Thus, SMRT plays a significant role in the differentiation of myoblasts.
Asunto(s)
Fibras Musculares Esqueléticas , Co-Represor 2 de Receptor Nuclear , PPAR delta , Animales , Ratones , Diferenciación Celular , Factor 2 de Crecimiento de Fibroblastos , Fibrosis , Músculo Esquelético , Co-Represor 2 de Receptor Nuclear/genéticaRESUMEN
The nuclear corepressors NCOR1 and NCOR2 interact with transcription factors involved in B cell development and potentially link these factors to alterations in chromatin structure and gene expression. Herein, we demonstrate that Ncor1/2 deletion limits B cell differentiation via impaired recombination, attenuates pre-BCR signaling and enhances STAT5-dependent transcription. Furthermore, NCOR1/2-deficient B cells exhibited derepression of EZH2-repressed gene modules, including the p53 pathway. These alterations resulted in aberrant Rag1 and Rag2 expression and accessibility. Whole-genome sequencing of Ncor1/2 DKO B cells identified increased number of structural variants with cryptic recombination signal sequences. Finally, deletion of Ncor1 alleles in mice facilitated leukemic transformation, whereas human leukemias with less NCOR1 correlated with worse survival. NCOR1/2 mutations in human leukemia correlated with increased RAG expression and number of structural variants. These studies illuminate how the corepressors NCOR1/2 regulate B cell differentiation and provide insights into how NCOR1/2 mutations may promote B cell transformation.
Asunto(s)
Hematopoyesis , Transducción de Señal , Ratones , Humanos , Animales , Proteínas Co-Represoras , Núcleo Celular , Genómica , Co-Represor 2 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/genéticaRESUMEN
Brown adipose tissue (BAT) is a key thermogenic organ whose expression of uncoupling protein 1 (UCP1) and ability to maintain body temperature in response to acute cold exposure require histone deacetylase 3 (HDAC3). HDAC3 exists in tight association with nuclear receptor corepressors (NCoRs) NCoR1 and NCoR2 (also known as silencing mediator of retinoid and thyroid receptors [SMRT]), but the functions of NCoR1/2 in BAT have not been established. Here we report that as expected, genetic loss of NCoR1/2 in BAT (NCoR1/2 BAT-dKO) leads to loss of HDAC3 activity. In addition, HDAC3 is no longer bound at its physiological genomic sites in the absence of NCoR1/2, leading to a shared deregulation of BAT lipid metabolism between NCoR1/2 BAT-dKO and HDAC3 BAT-KO mice. Despite these commonalities, loss of NCoR1/2 in BAT does not phenocopy the cold sensitivity observed in HDAC3 BAT-KO, nor does loss of either corepressor alone. Instead, BAT lacking NCoR1/2 is inflamed, particularly with respect to the interleukin-17 axis that increases thermogenic capacity by enhancing innervation. Integration of BAT RNA sequencing and chromatin immunoprecipitation sequencing data revealed that NCoR1/2 directly regulate Mmp9, which integrates extracellular matrix remodeling and inflammation. These findings reveal pleiotropic functions of the NCoR/HDAC3 corepressor complex in BAT, such that HDAC3-independent suppression of BAT inflammation counterbalances stimulation of HDAC3 activity in the control of thermogenesis.
Asunto(s)
Tejido Adiposo Pardo , Co-Represor 1 de Receptor Nuclear , Co-Represor 2 de Receptor Nuclear , Termogénesis , Tejido Adiposo Pardo/metabolismo , Animales , Histona Desacetilasas/metabolismo , Inflamación/metabolismo , Ratones , Ratones Noqueados , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Receptores de Ácido Retinoico/metabolismo , Termogénesis/genética , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismoRESUMEN
Xanthogranulomatous epithelial tumor (XGET) and keratin-positive giant cell-rich soft tissue tumor with HMGA2-NCOR2 fusion (KPGCT) are two recently described neoplasms with both distinct and overlapping clinical and histopathologic features. We hypothesized that XGET and KPGCT may be related and represent a histologic spectrum of a single entity. To test this, we sought to characterize the clinical, radiographic, immunohistochemical, ultrastructural and molecular features of additional tumors with features of XGET and/or KPGCT, which we refer to descriptively as keratin-positive xanthogranulomatous/giant cell-rich tumors (KPXG/GCT). The archives were searched for potential cases of KPXG/GCT. Clinical and imaging features were noted. Slides were assessed for histologic and immunohistochemical findings. Ultrastructural and next generation RNA sequencing-based analysis were also performed. Nine cases were identified arising in seven women and two men [median age of 33 years (range: 12-87)]. Median tumor size was 4 cm (range: 2.4-14.0 cm) and tumors presented in the thigh (2), buttock (1), forearm (2), groin (1), cranial fossa (1), ilium (1), and tibia (1). Morphologically, tumors were most frequently characterized by a fibrous capsule, with associated lymphoid reaction, enclosing a polymorphous proliferation of histiocytes, giant cells (Touton and osteoclast-types), mixed inflammatory infiltrate, hemorrhage and hemosiderin deposition, which imparted a variably xanthogranulomatous to giant cell tumor-like appearance. One case clearly showed mononuclear cells with eosinophilic cytoplasm characteristic of XGET. All cases expressed keratin and 7 of 9 were found to harbor HMGA2-NCOR2 fusions including cases with xanthogranulomatous appearance. One patient developed local recurrence and multifocal pulmonary lesions, which were radiographically suspicious for metastases. Shared clinical, histologic and immunohistochemical features, and the shared presence of HMGA2-NCOR2 fusions supports interpretation of KPXG/GCT as a single entity which includes XGET and KPGCT. Given limited clinical follow-up to date and rare cases with apparently aggressive findings, we provisionally regard these tumors as having uncertain biologic potential.
Asunto(s)
Tumores de Células Gigantes , Neoplasias Glandulares y Epiteliales , Proteínas de Fusión Oncogénica , Neoplasias de los Tejidos Blandos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Células Gigantes/patología , Hemosiderina , Queratinas , Neoplasias Glandulares y Epiteliales/patología , Co-Represor 2 de Receptor Nuclear/genética , Neoplasias de los Tejidos Blandos/genética , Neoplasias de los Tejidos Blandos/patología , Proteínas de Fusión Oncogénica/genética , Proteína HMGA2/genéticaRESUMEN
Resistance to antitumor treatment contributes to patient mortality. Functional proteomic screening of organoids derived from chemotherapy-treated patients with breast cancer identified nuclear receptor corepressor 2 (NCOR2) histone deacetylase as an inhibitor of cytotoxic stress response and antitumor immunity. High NCOR2 in the tumors of patients with breast cancer predicted chemotherapy refractoriness, tumor recurrence and poor prognosis. Molecular studies revealed that NCOR2 inhibits antitumor treatment by regulating histone deacetylase 3 (HDAC3) to repress interferon regulatory factor 1 (IRF-1)-dependent gene expression and interferon (IFN) signaling. Reducing NCOR2 or impeding its epigenetic activity by modifying its interaction with HDAC3 enhanced chemotherapy responsiveness and restored antitumor immunity. An adeno-associated viral NCOR2-HDAC3 competitor potentiated chemotherapy and immune checkpoint therapy in culture and in vivo by permitting transcription of IRF-1-regulated proapoptosis and inflammatory genes to increase IFN-γ signaling. The findings illustrate the utility of patient-derived organoids for drug discovery and suggest that targeting stress and inflammatory-repressor complexes such as NCOR2-HDAC3 could overcome treatment resistance and improve the outcome of patients with cancer.
Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Detección Precoz del Cáncer , Femenino , Humanos , Recurrencia Local de Neoplasia , Co-Represor 2 de Receptor Nuclear/genética , Organoides/metabolismo , ProteómicaRESUMEN
BACKGROUND/AIM: Chimeras involving the high-mobility group AT-hook 2 gene (HMGA2 in 12q14.3) have been found in lipomas and other benign mesenchymal tumors. We report here a fusion of HMGA2 with the nuclear receptor co-repressor 2 gene (NCOR2 in 12q24.31) repeatedly found in tumors of bone and the first cytogenetic investigation of this fusion. MATERIALS AND METHODS: Six osteoclastic giant cell-rich tumors were investigated using G-banding, RNA sequencing, reverse transcription polymerase chain reaction, Sanger sequencing, and fluorescence in situ hybridization. RESULTS: Four tumors had structural chromosomal aberrations of 12q. The pathogenic variant c.103_104GG>AT (p.Gly35Met) in the H3.3 histone A gene was found in a tumor without 12q aberration. In-frame HMGA2-NCOR2 fusion transcripts were found in all tumors. In two cases, the presence of an HMGA2-NCOR2 fusion gene was confirmed by FISH on metaphase spreads. CONCLUSION: Our results demonstrate that a subset of osteoclastic giant cell-rich tumors of bone are characterized by an HMGA2-NCOR2 fusion gene.
Asunto(s)
Neoplasias Óseas , Fusión Génica , Tumores de Células Gigantes , Proteína HMGA2 , Lipoma , Co-Represor 2 de Receptor Nuclear , Osteoclastos , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Tumores de Células Gigantes/genética , Tumores de Células Gigantes/patología , Células Gigantes/patología , Proteína HMGA2/genética , Humanos , Hibridación Fluorescente in Situ , Lipoma/genética , Lipoma/patología , Co-Represor 2 de Receptor Nuclear/genética , Osteoclastos/patologíaRESUMEN
HYPOTHESIS: To identify genetic factors predisposing to migraine-epilepsy phenotype utilizing a multi-generational family with known linkage to chr12q24.2-q24.3. METHODS: We used single nucleotide polymorphism (SNP) genotyping and next-generation sequencing technologies to perform linkage, haplotype, and variant analyses in an extended Finnish migraine-epilepsy family (n = 120). In addition, we used a large genome-wide association study (GWAS) dataset of migraine and two biobank studies, UK Biobank and FinnGen, to test whether variants within the susceptibility region associate with migraine or epilepsy related phenotypes in a population setting. RESULTS: The family showed the highest evidence of linkage (LOD 3.42) between rs7966411 and epilepsy. The haplotype shared among 12 out of 13 epilepsy patients in the family covers almost the entire NCOR2 and co-localizes with one of the risk loci of the recent GWAS on migraine. The haplotype harbors nine low-frequency variants with potential regulatory functions. Three of them, in addition to two common variants, show nominal associations with neurological disorders in either UK Biobank or FinnGen. CONCLUSION: We provide several independent lines of evidence supporting association between migraine-epilepsy phenotype and NCOR2. Our study suggests that NCOR2 may have a role in both migraine and epilepsy and thus would provide evidence for shared pathophysiology underlying these two diseases.
Asunto(s)
Epilepsia , Trastornos Migrañosos , Epilepsia/genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Humanos , Trastornos Migrañosos/genética , Co-Represor 2 de Receptor Nuclear/genética , Fenotipo , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Individual cell types of human tissues have their own CpG site methylation profiles, which might be utilized for the development of methylation markers to denote tumor-infiltrating lymphocytes (TILs). We aimed to develop DNA methylation markers that recapitulate the densities of TILs in gastric carcinoma (GC). Through genome-wide methylation profiling, NCOR2, PARK2, and ZSCAN12 were found to be highly methylated in CD3-positive and CD8-positive cells and rarely methylated in tumor cells. Scores of the three methylation markers were analyzed for their relationship with the overall survival and recurrence-free survival of patients with advanced GC (n = 471). The scores of three methylation markers were closely associated with densities of CD3-positive or CD8-positive cells at the tumor center or invasive front of GCs and found to be a significant prognostic factor in univariate analysis of overall survival and recurrence-free survival. In multivariate analysis, the highest score showed hazard ratios of 0.513 (CI 0.306-0.857) and 0.434 (CI 0.261-0.720) for overall survival and recurrence-free survival, respectively. The findings suggest that methylation markers signifying TILs might be utilized for the recapitulation of TIL density in GCs and serve as biomarkers for predicting prognosis in patients with GC.
Asunto(s)
Carcinoma/genética , Carcinoma/patología , Metilación de ADN/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Linfocitos Infiltrantes de Tumor/metabolismo , Linfocitos Infiltrantes de Tumor/patología , Co-Represor 2 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Biomarcadores/metabolismo , Linfocitos T CD8-positivos/metabolismo , Carcinoma/mortalidad , Femenino , Predicción , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Neoplasias Gástricas/mortalidad , Tasa de Supervivencia , Microambiente Tumoral/genéticaRESUMEN
MYC upregulation is associated with multidrug refractory disease in patients with multiple myeloma (MM). We, isolated patient-derived MM cells with high MYC expression and discovered that NCOR2 was down-regulated in these cells. NCOR2 is a transcriptional coregulatory protein and its role in MM remains unknown. To define the role of NCOR2 in MM, we created NCOR2 knockout human myeloma cell lines and demonstrated that NCOR2 knockout led to high MYC expression. Furthermore, NCOR2 knockout conferred resistance to pomalidomide, BET and HDAC inhibitors, independent of Cereblon (CRBN), indicating high MYC expression as a cause of multidrug resistance. Moreover, NCOR2 interacted with the nucleosome remodeling and deacetylase (NuRD) complex and repressed the expression of CD180 by directly binding to its promoter and inducing MYC expression. Next, we generated lenalidomide-resistant and pomalidomide-resistant human myeloma cell lines. Whole-exome sequencing revealed that these cell lines acquired the same exonic mutations of NCOR2. These cell lines showed NCOR2 downregulation and MYC upregulation independent of CRBN and demonstrated resistance to BET and HDAC inhibitors. Our findings reveal a novel CRBN independent molecular mechanism associated with drug resistance. Low NCOR2 expression can serve as a potential biomarker for drug resistance and needs further validation in larger prospective studies.
Asunto(s)
Resistencia a Antineoplásicos , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Co-Represor 2 de Receptor Nuclear/genética , Proteínas Proto-Oncogénicas c-myc/genética , Antineoplásicos/farmacología , Línea Celular Tumoral , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos/efectos de los fármacos , Técnicas de Inactivación de Genes , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Talidomida/análogos & derivados , Talidomida/farmacología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
This study addresses the roles of nuclear receptor corepressor 2 (NCOR2) in prostate cancer (PC) progression in response to androgen deprivation therapy (ADT). Reduced NCOR2 expression significantly associates with shorter disease-free survival in patients with PC receiving adjuvant ADT. Utilizing the CWR22 xenograft model, we demonstrate that stably reduced NCOR2 expression accelerates disease recurrence following ADT, associates with gene expression patterns that include neuroendocrine features, and induces DNA hypermethylation. Stably reduced NCOR2 expression in isogenic LNCaP (androgen-sensitive) and LNCaP-C4-2 (androgen-independent) cells revealed that NCOR2 reduction phenocopies the impact of androgen treatment and induces global DNA hypermethylation patterns. NCOR2 genomic binding is greatest in LNCaP-C4-2 cells and most clearly associates with forkhead box (FOX) transcription factor FOXA1 binding. NCOR2 binding significantly associates with transcriptional regulation most when in active enhancer regions. These studies reveal robust roles for NCOR2 in regulating the PC transcriptome and epigenome and underscore recent mutational studies linking NCOR2 loss of function to PC disease progression.
Asunto(s)
Antagonistas de Andrógenos/farmacología , Andrógenos/deficiencia , Biomarcadores de Tumor/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Recurrencia Local de Neoplasia/patología , Co-Represor 2 de Receptor Nuclear/antagonistas & inhibidores , Neoplasias de la Próstata/patología , Animales , Apoptosis , Biomarcadores de Tumor/genética , Proliferación Celular , Humanos , Masculino , Ratones , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/metabolismo , Co-Represor 2 de Receptor Nuclear/genética , Co-Represor 2 de Receptor Nuclear/metabolismo , Pronóstico , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/metabolismo , Tasa de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The life cycle of human papillomavirus (HPV) depends on keratinocyte differentiation as the virus modulates and takes advantage of cellular pathways to replicate its genome and assemble viral particles in differentiated cells. Viral genomes are amplified in nuclear replication foci in differentiated keratinocytes, and DNA repair factors from the DNA damage response signaling pathway are recruited to replicate viral DNA. The HPV genome is associated with cellular histones at all stages of the infectious cycle, and here, we show that the histone variant macroH2A1 is bound to the HPV genome and enriched in viral replication foci in differentiated cells. macroH2A1 isoforms play important roles in cellular transcriptional repression, double-strand break repair, and replication stress. The viral E8^E2 protein also binds to the HPV genome and inhibits viral replication and gene expression by recruiting NCoR/SMRT complexes. We show here that E8^E2 and SMRT also localize within replication foci, though independently from macroH2A1. Conversely, transcription complexes containing RNA polymerase II and Brd4 are located on the surface of the foci. Foci generated with an HPV16 E8^E2 mutant genome are not enriched for SMRT or macroH2A1 but contain transcriptional complexes throughout the foci. We propose that both the cellular macroH2A1 protein and viral E8^E2 protein help to spatially separate replication and transcription activities within viral replication foci. IMPORTANCE Human papillomaviruses are small DNA viruses that cause chronic infection of cutaneous and mucosal epithelium. In some cases, persistent infection with HPV can result in cancer, and 5% of human cancers are the result of HPV infection. In differentiated cells, HPV amplifies viral DNA in nuclear replication factories and transcribes late mRNAs to produce capsid proteins. However, very little is known about the spatial organization of these activities in the nucleus. Here, we show that repressive viral and cellular factors localize within the foci to suppress viral transcription, while active transcription takes place on the surface. The cellular histone variant macroH2A1 is important for this spatial organization.