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1.
Sci Rep ; 14(1): 8286, 2024 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-38594331

RESUMEN

Despite great efforts in improving existing therapies, the outcome of patients with advanced radioresistant HPV-negative head and neck squamous cell carcinoma (HNSCC) remains poor. The chromatin remodeler Chromodomain helicase DNA binding protein 4 (CHD4) is involved in different DNA-repair mechanisms, but the role and potential in HNSCC has not been explored yet. In the present study, we evaluated the prognostic significance of CHD4 expression using in silico analysis of the pan-cancer dataset. Furthermore, we established a monoclonal HNSCC CHD4 knockdown cell clone utilizing the CRISPR/Cas9 system. Effects of lower CHD4 expression on radiosensitivity after increasing doses of ionizing radiation were characterized using clonogenic assays and cell numbers. The in silico analysis revealed that high CHD4 expression is associated with significant poorer overall survival of HPV-negative HNSCC patients. Additionally, the knockdown of CHD4 significantly increased the radiosensitivity of HNSCC cells. Therefore, CHD4 might be involved in promoting radioresistance in hard-to-treat HPV-negative HNSCC entities. We conclude that CHD4 could serve as a prognostic factor in HPV-negative HNSCC tumors and is a potential target protein overcoming radioresistance in HNSCC. Our results and the newly established cell clone laid the foundation to further characterize the underlying mechanisms and ultimately use CHD4 in HNSCC therapies.


Asunto(s)
Neoplasias de Cabeza y Cuello , Infecciones por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/radioterapia , Carcinoma de Células Escamosas de Cabeza y Cuello/complicaciones , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de Cabeza y Cuello/complicaciones , Pronóstico , Línea Celular Tumoral , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2
2.
Life Sci Alliance ; 7(7)2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38649186

RESUMEN

Numerous long non-coding RNAs (lncRNAs) were shown to have a functional impact on cellular processes such as human epidermal homeostasis. However, the mechanism of action for many lncRNAs remains unclear to date. Here, we report that lncRNA LINC00941 regulates keratinocyte differentiation on an epigenetic level through association with the NuRD complex, one of the major chromatin remodelers in cells. We find that LINC00941 interacts with NuRD-associated MTA2 and CHD4 in human primary keratinocytes. LINC00941 perturbation changes MTA2/NuRD occupancy at bivalent chromatin domains in close proximity to transcriptional regulator genes, including the EGR3 gene coding for a transcription factor regulating epidermal differentiation. Notably, LINC00941 depletion resulted in reduced NuRD occupancy at the EGR3 gene locus, increased EGR3 expression in human primary keratinocytes, and increased abundance of EGR3-regulated epidermal differentiation genes in cells and human organotypic epidermal tissues. Our results therefore indicate a role of LINC00941/NuRD in repressing EGR3 expression in non-differentiated keratinocytes, consequentially preventing premature differentiation of human epidermal tissues.


Asunto(s)
Diferenciación Celular , Epidermis , Histona Desacetilasas , Queratinocitos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , ARN Largo no Codificante , Proteínas Represoras , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Diferenciación Celular/genética , Queratinocitos/metabolismo , Queratinocitos/citología , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Epidermis/metabolismo , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Proteína 3 de la Respuesta de Crecimiento Precoz/genética , Proteína 3 de la Respuesta de Crecimiento Precoz/metabolismo , Epigénesis Genética , Células Epidérmicas/metabolismo , Células Epidérmicas/citología , Cromatina/metabolismo , Cromatina/genética , Regulación de la Expresión Génica , Células Cultivadas
3.
Development ; 151(8)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619323

RESUMEN

Regulation of chromatin states is essential for proper temporal and spatial gene expression. Chromatin states are modulated by remodeling complexes composed of components that have enzymatic activities. CHD4 is the catalytic core of the nucleosome remodeling and deacetylase (NuRD) complex, which represses gene transcription. However, it remains to be determined how CHD4, a ubiquitous enzyme that remodels chromatin structure, functions in cardiomyocytes to maintain heart development. In particular, whether other proteins besides the NuRD components interact with CHD4 in the heart is controversial. Using quantitative proteomics, we identified that CHD4 interacts with SMYD1, a striated muscle-restricted histone methyltransferase that is essential for cardiomyocyte differentiation and cardiac morphogenesis. Comprehensive transcriptomic and chromatin accessibility studies of Smyd1 and Chd4 null embryonic mouse hearts revealed that SMYD1 and CHD4 repress a group of common genes and pathways involved in glycolysis, response to hypoxia, and angiogenesis. Our study reveals a mechanism by which CHD4 functions during heart development, and a previously uncharacterized mechanism regarding how SMYD1 represses cardiac transcription in the developing heart.


Asunto(s)
ADN Helicasas , Proteínas de Unión al ADN , Regulación del Desarrollo de la Expresión Génica , Corazón , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Miocitos Cardíacos , Factores de Transcripción , Animales , Ratones , Corazón/embriología , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Miocitos Cardíacos/metabolismo , Transcripción Genética , N-Metiltransferasa de Histona-Lisina/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Humanos , Ratones Noqueados , Glucólisis/genética , Cromatina/metabolismo , Diferenciación Celular/genética , Proteómica
4.
Anticancer Res ; 44(4): 1739-1750, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38538000

RESUMEN

BACKGROUND/AIM: Only a few studies have examined the expression of nucleosome remodeling and deacetylase complex in endometrial carcinoma (EC). The aim of this study was to analyze the expressions of histone deacetylase (HDAC1), HDAC2, and chromodomain helicase DNA-binding protein 4 (CHD4) in EC. PATIENTS AND METHODS: Sixty cases of EC were categorized into two clusters based on the expression levels of the three proteins. RESULTS: Cluster 1 (C1) exhibited elevated expressions of HDAC2 and CHD4 compared with cluster 2 (C2). Notably, 75% of cases in C2 represented non-aggressive histological types, whereas 37.5% of cases in C1 manifested aggressive types. C2 exclusively comprised pathological tumor stage 1 (pT1) tumors, whereas C1 included pT2 and pT3 tumors. In C1, 25% of cases displayed aberrant p53 expression, contrasting with the absence of such expression in C2. Furthermore, only one patient in C2 experienced disease recurrence, whereas 20.8% of patients in C1 developed recurrent tumors. CONCLUSION: High HDAC2 and CHD4 expression may be associated with adverse clinicopathological characteristics in EC. Further studies are needed to validate these results.


Asunto(s)
Neoplasias Endometriales , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Humanos , Femenino , Nucleosomas , Recurrencia Local de Neoplasia , Histona Desacetilasas/metabolismo , Histona Desacetilasa 1
5.
Biochem Biophys Res Commun ; 701: 149555, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38325179

RESUMEN

Fetal-to-adult hemoglobin switching is controlled by programmed silencing of γ-globin while the re-activation of fetal hemoglobin (HbF) is an effective strategy for ameliorating the clinical severity of ß-thalassemia and sickle cell disease. The identification of enhancer RNAs (eRNAs) related to the fetal (α2γ2) to adult hemoglobin (α2ß2) switching remains incomplete. In this study, the transcriptomes of GYPA+ cells from six ß-thalassemia patients with extreme HbF levels were sequenced to identify differences in patterns of noncoding RNA expression. It is interesting that an enhancer upstream of CHD4, an HbF-related core subunit of the NuRD complex, was differentially transcribed. We found a significantly positive correlation of eRNA-CHD4 enhancer-gene interaction using the public database of FANTOM5. Specifically, the eRNA-CHD4 expression was found to be significantly higher in both CD34+ HSPCs and HUDEP-2 than those in K562 cells which commonly expressed high level of HbF, suggesting a correlation between eRNA and HbF expression. Furthermore, prediction of transcription binding sites of cis-eQTLs and the CHD4 genomic region revealed a putative interaction site between rs73264846 and ZNF410, a known transcription factor regulating HbF expression. Moreover, in-vitro validation showed that the inhibition of eRNA could reduce the expression of HBG expression in HUDEP-2 cells. Taken together, the findings of this study demonstrate that a distal enhancer contributes to stage-specific silencing of γ-globin genes through direct modulation of CHD4 expression and provide insights into the epigenetic mechanisms of NuRD-mediated hemoglobin switching.


Asunto(s)
Anemia de Células Falciformes , Talasemia beta , Adulto , Humanos , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , gamma-Globinas/genética , gamma-Globinas/metabolismo , Talasemia beta/genética , Regulación de la Expresión Génica , Anemia de Células Falciformes/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo
6.
Nucleic Acids Res ; 52(7): 3607-3622, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38281186

RESUMEN

Biologically precise enhancer licensing by lineage-determining transcription factors enables activation of transcripts appropriate to biological demand and prevents deleterious gene activation. This essential process is challenged by the millions of matches to most transcription factor binding motifs present in many eukaryotic genomes, leading to questions about how transcription factors achieve the exquisite specificity required. The importance of chromatin remodeling factors to enhancer activation is highlighted by their frequent mutation in developmental disorders and in cancer. Here, we determine the roles of CHD4 in enhancer licensing and maintenance in breast cancer cells and during cellular reprogramming. In unchallenged basal breast cancer cells, CHD4 modulates chromatin accessibility. Its depletion leads to redistribution of transcription factors to previously unoccupied sites. During cellular reprogramming induced by the pioneer factor GATA3, CHD4 activity is necessary to prevent inappropriate chromatin opening. Mechanistically, CHD4 promotes nucleosome positioning over GATA3 binding motifs to compete with transcription factor-DNA interaction. We propose that CHD4 acts as a chromatin proof-reading enzyme that prevents unnecessary gene expression by editing chromatin binding activities of transcription factors.


Asunto(s)
Cromatina , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Femenino , Humanos , Sitios de Unión , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Reprogramación Celular/genética , Cromatina/metabolismo , Ensamble y Desensamble de Cromatina , Elementos de Facilitación Genéticos , Factor de Transcripción GATA3/metabolismo , Factor de Transcripción GATA3/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Nucleosomas/metabolismo , Nucleosomas/genética , Unión Proteica , Factores de Transcripción/metabolismo
7.
J Transl Med ; 22(1): 99, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38268032

RESUMEN

BACKGROUND: Cancer stem cells (CSCs) are a small population of cells in tumor tissues that can drive tumor initiation and promote tumor progression. A small number of previous studies indirectly mentioned the role of F-box and WD repeat domain-containing 7 (FBXW7) as a tumor suppressor in Triple-negative breast cancer (TNBC). However, few studies have focused on the function of FBXW7 in cancer stemness in TNBC and the related mechanism. METHODS: We detected FBXW7 by immunohistochemistry (IHC) in 80 TNBC patients. FBXW7 knockdown and overexpression in MD-MBA-231 and HCC1937 cell models were constructed. The effect of FBXW7 on malignant phenotype and stemness was assessed by colony assays, flow cytometry, transwell assays, western blot, and sphere formation assays. Immunoprecipitation-Mass Spectrometry (IP-MS) and ubiquitination experiments were used to find and verify potential downstream substrate proteins of FBXW7. Animal experiments were constructed to examine the effect of FBXW7 on tumorigenic potential and cancer stemness of TNBC cells in vivo. RESULTS: The results showed that FBXW7 was expressed at low levels in TNBC tissues and positively correlated with prognosis of TNBC patients. In vitro, FBXW7 significantly inhibited colony formation, cell cycle progression, cell migration, EMT process, cancer stemness and promotes apoptosis. Further experiments confirmed that chromodomain-helicase-DNA-binding protein 4 (CHD4) is a novel downstream target of FBXW7 and is downregulated by FBXW7 via proteasomal degradation. Moreover, CHD4 could promote the nuclear translocation of ß-catenin and reverse the inhibitory effect of FBXW7 on ß-catenin, and ultimately activate the Wnt/ß-catenin pathway. Rescue experiments confirmed that the FBXW7-CHD4-Wnt/ß-catenin axis was involved in regulating the maintenance of CSC in TNBC cells. In animal experiments, FBXW7 reduced CSC marker expression and suppressed TNBC cell tumorigenesis in vivo. CONCLUSIONS: Taken together, these results highlight that FBXW7 degrades CHD4 protein through ubiquitination, thereby blocking the activation of the Wnt/ß-catenin pathway to inhibit the stemness of TNBC cells. Thus, targeting FBXW7 may be a promising strategy for therapeutic intervention against TNBC.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Animales , Humanos , beta Catenina , Carcinogénesis , Transformación Celular Neoplásica , Proteína 7 que Contiene Repeticiones F-Box-WD/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Neoplasias de la Mama Triple Negativas/genética
8.
Oncogene ; 43(6): 420-433, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38092960

RESUMEN

Dysregulated expression of long-stranded non-coding RNAs is strongly associated with carcinogenesis. However, the precise mechanisms underlying their involvement in ovarian cancer pathogenesis remain poorly defined. Here, we found that lncRNA RUNX1-IT1 plays a crucial role in the progression of ovarian cancer. Patients with high RUNX1-IT1 expression had shorter survival and poorer outcomes. Notably, knockdown of RUNX1-IT1 suppressed the proliferation, migration and invasion of ovarian cancer cells in vitro, and reduced the formation of peritoneum metastasis in vivo. Mechanistically, RUNX1-IT1 bound to HDAC1, the core component of the NuRD complex, and STAT1, acting as a molecular scaffold of the STAT1 and NuRD complex to regulate intracellular reactive oxygen homeostasis by altering the histone modification status of downstream targets including GPX1. Consequently, RUNX1-IT1 activated NF-κB signaling and altered the biology of ovarian cancer cells. In conclusion, our findings demonstrate that RUNX1-IT1 promotes ovarian malignancy and suggest that targeting RUNX1-IT1 represents a promising therapeutic strategy for ovarian cancer treatment.


Asunto(s)
Neoplasias Ováricas , ARN Largo no Codificante , Humanos , Femenino , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proliferación Celular/genética , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Histona Desacetilasas/genética , ARN Largo no Codificante/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Movimiento Celular/genética , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/metabolismo
9.
Cancer Res ; 84(2): 241-257, 2024 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-37963210

RESUMEN

Ewing sarcoma is an aggressive cancer with a defective response to DNA damage leading to an enhanced sensitivity to genotoxic agents. Mechanistically, Ewing sarcoma is driven by the fusion transcription factor EWS-FLI1, which reprograms the tumor cell epigenome. The nucleosome remodeling and deacetylase (NuRD) complex is an important regulator of chromatin function, controlling both gene expression and DNA damage repair, and has been associated with EWS-FLI1 activity. Here, a NuRD-focused CRISPR/Cas9 inactivation screen identified the helicase CHD4 as essential for Ewing sarcoma cell proliferation. CHD4 silencing induced tumor cell death by apoptosis and abolished colony formation. Although CHD4 and NuRD colocalized with EWS-FLI1 at enhancers and super-enhancers, CHD4 promoted Ewing sarcoma cell survival not by modulating EWS-FLI1 activity and its oncogenic gene expression program but by regulating chromatin structure. CHD4 depletion led to a global increase in DNA accessibility and induction of spontaneous DNA damage, resulting in an increased susceptibility to DNA-damaging agents. CHD4 loss delayed tumor growth in vivo, increased overall survival, and combination with PARP inhibition by olaparib treatment further suppressed tumor growth. Collectively, these findings highlight the NuRD subunit CHD4 as a therapeutic target in Ewing sarcoma that can potentiate the antitumor activity of genotoxic agents. SIGNIFICANCE: CRISPR/Cas9 screening in Ewing sarcoma identifies a dependency on CHD4, which is crucial for the maintenance of chromatin architecture to suppress DNA damage and a promising therapeutic target for DNA damage repair-deficient malignancies.


Asunto(s)
Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Sarcoma de Ewing , Humanos , Línea Celular Tumoral , Supervivencia Celular , Cromatina/genética , ADN , Regulación Neoplásica de la Expresión Génica , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteína Proto-Oncogénica c-fli-1/genética , Proteína EWS de Unión a ARN , Sarcoma de Ewing/genética , Sarcoma de Ewing/patología
10.
Mol Biol Cell ; 35(1): ar13, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37938928

RESUMEN

The nucleosome remodeling and deacetylase (NuRD) complex is essential for gene expression and cell fate determination, and missense mutations of NuRD caused neurodevelopmental diseases. However, the molecular pathogenesis of clinic NuRD variants is unknown. Here, we introduced a clinic CHD3 (L915F) variant into Caenorhabditis elegans homologue LET-418, impairing germline and vulva development and ultimately causing animal sterility. Our ATAC-seq and RNA-seq analyses revealed that this variant generated an abnormal open chromatin structure and disrupted the expression of developmental genes. Through genetic suppressor screens, we uncovered that intragenic mutations, likely renovating NuRD activity, restored animal viability. We also found that intergenic mutations in nucleosome remodeling factor NURF that counteracts NuRD rescued abnormal chromatin structure, gene expression, and animal sterility. We propose that two antagonistic chromatin-remodeling factors coordinate to establish the proper chromatin status and transcriptome and that inhibiting NURF may provide insights for treatment of NuRD mutation-related diseases.


Asunto(s)
Proteínas de Drosophila , Infertilidad , Animales , Femenino , Nucleosomas , Ensamble y Desensamble de Cromatina , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Cromatina , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Proteínas de Drosophila/metabolismo , Caenorhabditis elegans/metabolismo
11.
Biol Open ; 13(1)2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38149716

RESUMEN

As cells exit the pluripotent state and begin to commit to a specific lineage they must activate genes appropriate for that lineage while silencing genes associated with pluripotency and preventing activation of lineage-inappropriate genes. The Nucleosome Remodelling and Deacetylation (NuRD) complex is essential for pluripotent cells to successfully undergo lineage commitment. NuRD controls nucleosome density at regulatory sequences to facilitate transcriptional responses, and also has been shown to prevent unscheduled transcription (transcriptional noise) in undifferentiated pluripotent cells. How these activities combine to ensure cells engage a gene expression program suitable for successful lineage commitment has not been determined. Here, we show that NuRD is not required to silence all genes. Rather, it restricts expression of genes primed for activation upon exit from the pluripotent state, but maintains them in a transcriptionally permissive state in self-renewing conditions, which facilitates their subsequent activation upon exit from naïve pluripotency. We further show that NuRD coordinates gene expression changes, which acts to maintain a barrier between different stable states. Thus NuRD-mediated chromatin remodelling serves multiple functions, including reducing transcriptional noise, priming genes for activation and coordinating the transcriptional response to facilitate lineage commitment.


Asunto(s)
Proteínas de Unión al ADN , Factores de Transcripción , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Unión al ADN/metabolismo , Nucleosomas , Diferenciación Celular/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética
12.
Am J Med Genet A ; 194(4): e63503, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38116750

RESUMEN

CHD3 heterozygous variants are associated with Snijders Blok-Campeau syndrome (SBCS) which consists of intellectual disability (ID), macrocephaly, and dysmorphic facies. Most reported variants are missense or loss of function clustered within the ATPase/helicase domain of the protein. We report a severe neurocognitive phenotype caused by biallelic CHD3 variants in two siblings, each inherited from a mildly affected parent. Male and female siblings were referred to the Genetics Clinic due to severe ID and profound dysmorphism. The parents are first cousins of Iranian descent with borderline intellectual abilities. Exome sequencing was performed for the affected female and her parents. A single homozygous candidate variant in the CHD3 gene was detected in the proband: c.5384_5389dup. p.Arg1796_Phe1797insTrpArg, resulting in an in-frame insertion of 2 amino acids located outside the ATPase/helicase domain at the C-terminal region of CHD3-encoding residues. This variant is classified as likely pathogenic according to ACMG guidelines. The variant was detected in a heterozygous state in each parent. Both affected siblings were homozygous, while their unaffected brother did not carry the variant. Biallelic CHD3 variants cause a severe neurodevelopmental syndrome that is distinguishable from SBCS. We assume that the variant type (in-frame insertion) and location may enable CHD3 biallelic variants.


Asunto(s)
Discapacidades del Desarrollo , Facies , Hipertelorismo , Discapacidad Intelectual , Hermanos , Humanos , Masculino , Femenino , Irán , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Discapacidad Intelectual/patología , Fenotipo , ADN Helicasas/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética
13.
Braz J Med Biol Res ; 56: e12854, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37970920

RESUMEN

During the tumorigenic process, cancer cells may become overly dependent on the activity of backup cellular pathways for their survival, representing vulnerabilities that could be exploited as therapeutic targets. Certain molecular vulnerabilities manifest as a synthetic lethality relationship, and the identification and characterization of new synthetic lethal interactions may pave the way for the development of new therapeutic approaches for human cancer. Our goal was to investigate a possible synthetic lethal interaction between a member of the Chromodomain Helicase DNA binding proteins family (CHD4) and a member of the histone methyltransferases family (SETDB1) in the molecular context of a cell line (Hs578T) representing the triple negative breast cancer (TNBC), a subtype of breast cancer lacking validated molecular targets for treatment. Therefore, we employed the CRISPR-Cas9 gene editing tool to individually or simultaneously introduce indels in the genomic loci corresponding to the catalytic domains of SETDB1 and CHD4 in the Hs578T cell line. Our main findings included: a) introduction of indels in exon 22 of SETDB1 sensitized Hs578T to the action of the genotoxic chemotherapy doxorubicin; b) by sequentially introducing indels in exon 22 of SETDB1 and exon 23 of CHD4 and tracking the percentage of the remaining wild-type sequences in the mixed cell populations generated, we obtained evidence of the existence of a synthetic lethality interaction between these genes. Considering the lack of molecular targets in TNBC, our findings provided valuable insights for development of new therapeutic approaches not only for TNBC but also for other cancer types.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Histona Metiltransferasas/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Ensamble y Desensamble de Cromatina/genética , Mutaciones Letales Sintéticas/genética , Línea Celular , Factores de Transcripción/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo
16.
Cell Rep ; 42(11): 113322, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37883227

RESUMEN

Fibrosis, characterized by sustained activation of myofibroblasts and excessive extracellular matrix (ECM) deposition, is known to be associated with chronic inflammation. Receptor-interacting protein kinase 3 (RIPK3), the central kinase of necroptosis signaling, is upregulated in fibrosis and contributes to tumor necrosis factor (TNF)-mediated inflammation. In bile-duct-ligation-induced liver fibrosis, we found that myofibroblasts are the major cell type expressing RIPK3. Genetic ablation of ß1 integrin, the major profibrotic ECM receptor in fibroblasts, not only abolished ECM fibrillogenesis but also blunted RIPK3 expression via a mechanism mediated by the chromatin-remodeling factor chromodomain helicase DNA-binding protein 4 (CHD4). While the function of CHD4 has been conventionally linked to the nucleosome-remodeling deacetylase (NuRD) and CHD4-ADNP-HP1(ChAHP) complexes, we found that CHD4 potently repressed a set of genes, including Ripk3, with high locus specificity but independent of either the NuRD or the ChAHP complex. Thus, our data uncover that ß1 integrin intrinsically links fibrotic signaling to RIPK3-driven inflammation via a novel mode of action of CHD4.


Asunto(s)
Integrina beta1 , Necroptosis , Humanos , Integrina beta1/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Factores de Transcripción/genética , Nucleosomas , Fibrosis , Inflamación
17.
Genes (Basel) ; 14(9)2023 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-37761804

RESUMEN

Snijders Blok-Campeau syndrome (SNIBCPS, OMIM# 618205) is an extremely infrequent disease with only approximately 60 cases reported so far. SNIBCPS belongs to the group of neurodevelopmental disorders (NDDs). Clinical features of patients with SNIBCPS include global developmental delay, intellectual disability, speech and language difficulties and behavioral disorders like autism spectrum disorder. In addition, patients with SNIBCPS exhibit typical dysmorphic features including macrocephaly, hypertelorism, sparse eyebrows, broad forehead, prominent nose and pointed chin. The severity of the neurological effects as well as the presence of other features is variable among subjects. SNIBCPS is caused likely by pathogenic and pathogenic variants in CHD3 (Chromodomain Helicase DNA Binding Protein 3), which seems to be involved in chromatin remodeling by deacetylating histones. Here, we report 20 additional patients with clinical features compatible with SNIBCPS from 17 unrelated families with confirmed likely pathogenic/pathogenic variants in CHD3. Patients were analyzed by whole exome sequencing and segregation studies were performed by Sanger sequencing. Patients in this study showed different pathogenic variants affecting several functional domains of the protein. Additionally, none of the variants described here were reported in control population databases, and most computational predictors suggest that they are deleterious. The most common clinical features of the whole cohort of patients are global developmental delay (98%) and speech disorder/delay (92%). Other frequent features (51-74%) include intellectual disability, hypotonia, hypertelorism, abnormality of vision, macrocephaly and prominent forehead, among others. This study expands the number of individuals with confirmed SNIBCPS due to pathogenic or likely pathogenic variants in CHD3. Furthermore, we add evidence of the importance of the application of massive parallel sequencing for NDD patients for whom the clinical diagnosis might be challenging and where deep phenotyping is extremely useful to accurately manage and follow up the patients.


Asunto(s)
Discapacidades del Desarrollo , Hipertelorismo , Discapacidad Intelectual , Trastornos del Desarrollo del Lenguaje , Megalencefalia , Humanos , ADN Helicasas/genética , Histonas , Discapacidad Intelectual/genética , Megalencefalia/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Discapacidades del Desarrollo/genética
18.
EMBO J ; 42(21): e113448, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37737560

RESUMEN

The nucleosome remodeling and histone deacetylase (NuRD) complex physically associates with BCL11B to regulate murine T-cell development. However, the function of NuRD complex in mature T cells remains unclear. Here, we characterize the fate and metabolism of human T cells in which key subunits of the NuRD complex or BCL11B are ablated. BCL11B and the NuRD complex bind to each other and repress natural killer (NK)-cell fate in T cells. In addition, T cells upregulate the NK cell-associated receptors and transcription factors, lyse NK-cell targets, and are reprogrammed into NK-like cells (ITNKs) upon deletion of MTA2, MBD2, CHD4, or BCL11B. ITNKs increase OPA1 expression and exhibit characteristically elongated mitochondria with augmented oxidative phosphorylation (OXPHOS) activity. OPA1-mediated elevated OXPHOS enhances cellular acetyl-CoA levels, thereby promoting the reprogramming efficiency and antitumor effects of ITNKs via regulating H3K27 acetylation at specific targets. In conclusion, our findings demonstrate that the NuRD complex and BCL11B cooperatively maintain T-cell fate directly by repressing NK cell-associated transcription and indirectly through a metabolic-epigenetic axis, providing strategies to improve the reprogramming efficiency and antitumor effects of ITNKs.


Asunto(s)
Histonas , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Animales , Humanos , Ratones , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Dinámicas Mitocondriales , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Linfocitos T/metabolismo , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo
19.
Nat Struct Mol Biol ; 30(11): 1628-1639, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37770717

RESUMEN

To understand how the nucleosome remodeling and deacetylase (NuRD) complex regulates enhancers and enhancer-promoter interactions, we have developed an approach to segment and extract key biophysical parameters from live-cell three-dimensional single-molecule trajectories. Unexpectedly, this has revealed that NuRD binds to chromatin for minutes, decompacts chromatin structure and increases enhancer dynamics. We also uncovered a rare fast-diffusing state of enhancers and found that NuRD restricts the time spent in this state. Hi-C and Cut&Run experiments revealed that NuRD modulates enhancer-promoter interactions in active chromatin, allowing them to contact each other over longer distances. Furthermore, NuRD leads to a marked redistribution of CTCF and, in particular, cohesin. We propose that NuRD promotes a decondensed chromatin environment, where enhancers and promoters can contact each other over longer distances, and where the resetting of enhancer-promoter interactions brought about by the fast decondensed chromatin motions is reduced, leading to more stable, long-lived enhancer-promoter relationships.


Asunto(s)
Cromatina , Nucleosomas , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Regiones Promotoras Genéticas , Elementos de Facilitación Genéticos
20.
Proc Natl Acad Sci U S A ; 120(33): e2307287120, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37552759

RESUMEN

The nucleosome remodeling and deacetylase (NuRD) complex modifies nucleosome positioning and chromatin compaction to regulate gene expression. The methyl-CpG-binding domain proteins 2 and 3 (MBD2 and MBD3) play a critical role in complex formation; however, the molecular details of how they interact with other NuRD components have yet to be fully elucidated. We previously showed that an intrinsically disordered region (IDR) of MBD2 is necessary and sufficient to bind to the histone deacetylase core of NuRD. Building on that work, we have measured the inherent structural propensity of the MBD2-IDR using solvent and site-specific paramagnetic relaxation enhancement measurements. We then used the AlphaFold2 machine learning software to generate a model of the complex between MBD2 and the histone deacetylase core of NuRD. This model is remarkably consistent with our previous studies, including the current paramagnetic relaxation enhancement data. The latter suggests that the free MBD2-IDR samples conformations similar to the bound structure. We tested this model of the complex extensively by mutating key contact residues and measuring binding using an intracellular bioluminescent resonance energy transfer assay. Furthermore, we identified protein contacts that, when mutated, disrupted gene silencing by NuRD in a cell model of fetal hemoglobin regulation. Hence, this work provides insights into the formation of NuRD and highlights critical binding pockets that may be targeted to block gene silencing for therapy. Importantly, we show that AlphaFold2 can generate a credible model of a large complex that involves an IDR that folds upon binding.


Asunto(s)
Histona Desacetilasas , Nucleosomas , Histona Desacetilasas/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Silenciador del Gen , Cromatina , Histona Desacetilasa 1/genética
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