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1.
FASEB J ; 38(8): e23625, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38661028

RESUMEN

Platinum resistance remains a major contributor to the poor prognosis of ovarian cancer. Anti-apoptotic protein myeloid cell leukemia-1 (MCL-1) has emerged as a promising target for overcoming drug resistance, but different cancer cells utilize distinct protein degradation pathways to alter MCL-1 level. We systematically investigated E3 ligases to identify novel candidates that mediate platinum resistance in ovarian cancer. Transcription Elongation Factor B (TCEB3) has been identified as a novel E3 ligase recognition subunit that targets MCL-1 in the cytoplasm during platinum treatment other than its traditional function of targeting the Pol II in the nuclear compartment. TCEB3 expression is downregulated in platinum-resistant cell lines and this low expression is associated with poor prognosis. The ubiquitination of MCL-1 induced by TCEB3 leads to cell death in ovarian cancer. Moreover, platinum treatment increased the cytoplasm proportion of TCEB3, and the cytoplasm localization of TCEB3 is important for its targeting of MCL-1. This study emphasizes the dual function of TCEB3 in homeostasis maintenance and in cell fate determination under different conditions, and provides a new insight into drug resistance in ovarian cancer.


Asunto(s)
Apoptosis , Resistencia a Antineoplásicos , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Neoplasias Ováricas , Ubiquitinación , Humanos , Femenino , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Neoplasias Ováricas/genética , Línea Celular Tumoral , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Proteolisis , Factores de Elongación Transcripcional/metabolismo , Factores de Elongación Transcripcional/genética , Animales , Ratones
2.
Nucleic Acids Res ; 52(8): 4151-4166, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38340348

RESUMEN

In cancer therapy, DNA intercalators are mainly known for their capacity to kill cells by inducing DNA damage. Recently, several DNA intercalators have attracted much interest given their ability to inhibit RNA Polymerase I transcription (BMH-21), evict histones (Aclarubicin) or induce chromatin trapping of FACT (Curaxin CBL0137). Interestingly, these DNA intercalators lack the capacity to induce DNA damage while still retaining cytotoxic effects and stabilize p53. Herein, we report that these DNA intercalators impact chromatin biology by interfering with the chromatin stability of RNA polymerases I, II and III. These three compounds have the capacity to induce degradation of RNA polymerase II and they simultaneously enable the trapping of Topoisomerases TOP2A and TOP2B on the chromatin. In addition, BMH-21 also acts as a catalytic inhibitor of Topoisomerase II, resembling Aclarubicin. Moreover, BMH-21 induces chromatin trapping of the histone chaperone FACT and propels accumulation of Z-DNA and histone eviction, similarly to Aclarubicin and CBL0137. These DNA intercalators have a cumulative impact on general transcription machinery by inducing accumulation of topological defects and impacting nuclear chromatin. Therefore, their cytotoxic capabilities may be the result of compounding deleterious effects on chromatin homeostasis.


Asunto(s)
Cromatina , ADN-Topoisomerasas de Tipo II , Sustancias Intercalantes , Proteínas de Unión a Poli-ADP-Ribosa , ARN Polimerasa II , Cromatina/metabolismo , Sustancias Intercalantes/farmacología , Sustancias Intercalantes/química , ADN-Topoisomerasas de Tipo II/metabolismo , ARN Polimerasa II/metabolismo , Humanos , Proteínas de Unión a Poli-ADP-Ribosa/metabolismo , Proteínas de Unión a Poli-ADP-Ribosa/genética , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/metabolismo , Proteínas del Grupo de Alta Movilidad/genética , Histonas/metabolismo , Inhibidores de Topoisomerasa II/farmacología , Factores de Elongación Transcripcional/metabolismo , Factores de Elongación Transcripcional/genética , Antígenos de Neoplasias/metabolismo , Antígenos de Neoplasias/genética , Daño del ADN , ADN/metabolismo , ADN/química , ARN Polimerasa I/metabolismo , ARN Polimerasa I/antagonistas & inhibidores , ARN Polimerasa III/metabolismo , Transcripción Genética/efectos de los fármacos , Carbazoles , Dicetopiperazinas
3.
Oncogene ; 43(8): 566-577, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38182897

RESUMEN

Mutations in APC, found in 80% of colon caner, enhance ß-catenin stabilization, which is the initial step of colonic tumorigenesis. However, the core transcriptional mechanism underlying the induction of colon cancer stemness by stable ß-catenin remains unclear. Here, we found that inducible inhibition of ß-catenin suppressed elongation of Pol II and RNA polymerase-associated factor 1 complex (PAF1C) around the transcription start site (TSS) of LGR5. Moreover, stable ß-catenin enhanced the formation of active Pol II complex cooperatively with CDC73 and CDK9 by facilitating the recruitment of DRB sensitivity-inducing factor (DSIF) and negative elongation factor (NELF) complexes to the Pol II complex. Subsequently, stable ß-catenin facilitated the formation of the Pol II-DSIF-PAF1C complex, suggesting that stable ß-catenin induces cancer stemness by stimulating active Pol II complex through NELF and PAF1C. Furthermore, NELF or PAF1C inhibition recapitulated the changes in cancer stemness-related gene expression induced by the inhibition of stable ß-catenin and suppressed colon cancer stemness. Additionally, the chemical inhibition of CDK12 (a downstream transcription CDK of PAF1C) suppressed colon cancer stemness. These results suggest that NELF and PAF1C are the core transcriptional machineries that control expression of colon cancer stemness-inducing genes and may be therapeutic targets for colon cancer.


Asunto(s)
Neoplasias del Colon , Factores de Transcripción , beta Catenina , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Neoplasias del Colon/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , ARN Polimerasa II/metabolismo , Transcripción Genética , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo
4.
Blood Adv ; 8(5): 1305-1319, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38029383

RESUMEN

ABSTRACT: Circular RNAs (circRNAs) are emerging molecular players in leukemogenesis and promising therapeutic targets. In KMT2A::AFF1 (MLL::AF4)-rearranged leukemia, an aggressive disease compared with other pediatric B-cell precursor (BCP) acute lymphoblastic leukemia (ALL), data about circRNAs are limited. Here, we disclose the circRNA landscape of infant patients with KMT2A::AFF1 translocated BCP-ALL showing dysregulated, mostly ectopically expressed, circRNAs in leukemia cells. Most of these circRNAs, apart from circHIPK3 and circZNF609, previously associated with oncogenic behavior in ALL, are still uncharacterized. An in vitro loss-of-function screening identified an oncogenic role of circFKBP5, circKLHL2, circNR3C1, and circPAN3 in KMT2A::AFF1 ALL, whose silencing affected cell proliferation and apoptosis. Further study in an extended cohort disclosed a significantly correlated expression of these oncogenic circRNAs and their putative involvement in common regulatory networks. Moreover, it showed that circAFF1 upregulation occurs in a subset of cases with HOXA KMT2A::AFF1 ALL. Collectively, functional analyses and patient data reveal oncogenic circRNA upregulation as a relevant mechanism that sustains the malignant cell phenotype in KMT2A::AFF1 ALL.


Asunto(s)
Leucemia , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Niño , Humanos , Lactante , Proteínas de Unión al ADN/metabolismo , ARN Circular/genética , Factores de Elongación Transcripcional/metabolismo , Regulación hacia Arriba
5.
Life Sci Alliance ; 7(1)2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37935464

RESUMEN

The transcription factor SPT5 physically interacts with MYC oncoproteins and is essential for efficient transcriptional activation of MYC targets in cultured cells. Here, we use Drosophila to address the relevance of this interaction in a living organism. Spt5 displays moderate synergy with Myc in fast proliferating young imaginal disc cells. During later development, Spt5-knockdown has no detectable consequences on its own, but strongly enhances eye defects caused by Myc overexpression. Similarly, Spt5-knockdown in larval type 2 neuroblasts has only mild effects on brain development and survival of control flies, but dramatically shrinks the volumes of experimentally induced neuroblast tumors and significantly extends the lifespan of tumor-bearing animals. This beneficial effect is still observed when Spt5 is knocked down systemically and after tumor initiation, highlighting SPT5 as a potential drug target in human oncology.


Asunto(s)
Neoplasias Encefálicas , Drosophila , Animales , Humanos , Encéfalo/metabolismo , Neoplasias Encefálicas/genética , Drosophila/genética , Drosophila/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factores de Elongación Transcripcional/metabolismo
6.
Cell Physiol Biochem ; 57(5): 395-408, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37876219

RESUMEN

Suppressor of Ty homolog-5 (SPT5) discovered in the yeast mutant screens as a suppressor of mutation caused by the insertion of the Transposons of yeast (Ty) element along with SPT4, with which it forms a holoenzyme complex known as DRB sensitivity-inducing factor (DSIF) and plays an essential role in the regulation of transcription. SPT5 is a highly conserved protein across all three domains of life and performs critical functions in transcription, starting from promoter-proximal pausing to termination. We also highlight the emerging role of SPT5 in other non-canonical functions, such as the regulation of post-translational modifications (PTM) and the transcriptional regulation of non-coding genes. Also, in brief, we highlight the clinical implications of SPT5 dysregulation.


Asunto(s)
Proteínas Nucleares , Proteínas de Saccharomyces cerevisiae , Proteínas Nucleares/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Transcripción Genética
7.
Biochem Cell Biol ; 101(4): 361-376, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37084412

RESUMEN

Epigenetic regulation contributes to human health and disease, especially cancer, but the mechanisms of many epigenetic regulators remain obscure. Most research is focused on gene regulatory processes, such as mRNA translation and DNA damage repair, rather than the effects on biological functions like mitochondrial activity and oxidative phosphorylation. Here, we identified an essential role for the histone chaperone structure-specific recognition protein 1 (SSRP1) in mitochondrial oxidative respiration in hepatocellular carcinoma, and found that SSRP1 suppression led to mitochondrial damage and decreased oxidative respiration. Further, we focused on TNF receptor-associated protein 1 (TRAP1), the only member of the heat shock protein 90 (HSP90) family, which directly interacts with selected respiratory complexes and affects their stability and activity. We confirmed that SSRP1 downregulation caused a decrease in TRAP1 expression at both the mRNA and protein levels. A chromatin immunoprecipitation assay also showed that SSRP1 could deposit in the TRAP1 promoter region, indicating that SSRP1 maintains mitochondrial function and reactive oxygen species levels through TRAP1. Additionally, rescue experiments and animal experiments confirmed the mechanism of SSRP1 and TRAP1 interaction. In summary, we identified a new mechanism that connects mitochondrial respiration and apoptosis, via SSRP1.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Humanos , Carcinoma Hepatocelular/metabolismo , Factor 1 Asociado a Receptor de TNF/metabolismo , Chaperonas de Histonas/metabolismo , Epigénesis Genética , Neoplasias Hepáticas/metabolismo , Mitocondrias/metabolismo , Apoptosis/fisiología , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/metabolismo , Factores de Elongación Transcripcional/metabolismo , Proteínas HSP90 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/metabolismo
8.
Int J Biol Sci ; 19(6): 1968-1982, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37063434

RESUMEN

MLL-AFF4 fusion gene has been discovered in acute leukemia, whether AFF4 alone plays a role in tumor, especially pancreatic tumorigenesis, is still elusive. Increasing evidence suggests that cancer cells altered nucleotide metabolism during tumorigenesis. In present study, we observed AFF4 overexpression promoted cell proliferation, colony formation and cell cycle progression while loss of AFF4 impairs above phenotypes of pancreatic ductal carcinoma (PDAC) cells. Using RNA-profiling, we revealed that HPRT1 and IMPDH2, two enzymes in the nucleotide metabolism pathway, were upregulated following AFF4 overexpression. Simultaneous expression of HPRT1 and IMPDH2 would mainly rescue the phenotypes of cells lacking AFF4. Additionally, xenograft study proved HPRT1 and IMPDH2 genetically function in the downstream of AFF4, which was recruited by PAX2 when CDK9 mediated AFF4 phosphorylation at S388 and drove HPRT1 and IMPDH2 expression. We further discovered PI3K/c-Myc axis is required for AFF4 expression in PDAC cells. Finally, we obtained the positive correlation between c-Myc and AFF4 or AFF4 and HPRT1/IMPDH2 in clinical PDAC samples. Otherwise, we conducted data-mining and found that the expression levels of AFF4 and HPRT1/IMPDH2 are correlated with patients' prognosis, establishing AFF4 as a potential biomarker and therapeutic target for PDAC.


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Carcinogénesis/genética , Carcinoma Ductal Pancreático/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular/genética , Transformación Celular Neoplásica/genética , Regulación Neoplásica de la Expresión Génica , Nucleótidos , Neoplasias Pancreáticas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo
9.
Sci Adv ; 9(13): eadf0005, 2023 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-36989355

RESUMEN

MYCN amplification in neuroblastoma leads to aberrant expression of MYCN oncoprotein, which binds active genes promoting transcriptional amplification. Yet, how MYCN coordinates transcription elongation to meet productive transcriptional amplification and which elongation machinery represents MYCN-driven vulnerability remain to be identified. We conducted a targeted screen of transcription elongation factors and identified the super elongation complex (SEC) as a unique vulnerability in MYCN-amplified neuroblastomas. MYCN directly binds EAF1 and recruits SEC to enhance processive transcription elongation. Depletion of EAF1 or AFF1/AFF4, another core subunit of SEC, leads to a global reduction in transcription elongation and elicits selective apoptosis of MYCN-amplified neuroblastoma cells. A combination screen reveals SEC inhibition synergistically potentiates the therapeutic efficacies of FDA-approved BCL-2 antagonist ABT-199, in part due to suppression of MCL1 expression, both in MYCN-amplified neuroblastoma cells and in patient-derived xenografts. These findings identify disruption of the MYCN-SEC regulatory axis as a promising therapeutic strategy in neuroblastoma.


Asunto(s)
Neuroblastoma , Proteínas Nucleares , Humanos , Proteína Proto-Oncogénica N-Myc/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , Neuroblastoma/genética , Neuroblastoma/metabolismo , Factores de Transcripción
10.
Adv Cancer Res ; 158: 387-421, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36990537

RESUMEN

Oncogenic transcription activation is associated with tumor development and resistance derived from chemotherapy or target therapy. The super elongation complex (SEC) is an important complex regulating gene transcription and expression in metazoans closely related to physiological activities. In normal transcriptional regulation, SEC can trigger promoter escape, limit proteolytic degradation of transcription elongation factors and increase the synthesis of RNA polymerase II (POL II), and regulate many normal human genes to stimulate RNA elongation. Dysregulation of SEC accompanied by multiple transcription factors in cancer promotes rapid transcription of oncogenes and induce cancer development. In this review, we summarized recent progress in understanding the mechanisms of SEC in regulating normal transcription, and importantly its roles in cancer development. We also highlighted the discovery of SEC complex target related inhibitors and their potential applications in cancer treatment.


Asunto(s)
Neoplasias , Factor B de Elongación Transcripcional Positiva , Humanos , Factor B de Elongación Transcripcional Positiva/genética , Factor B de Elongación Transcripcional Positiva/metabolismo , Transcripción Genética , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/genética
11.
Oncogene ; 42(1): 11-25, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36357572

RESUMEN

EWS/ETS fusion transcription factors, most commonly EWSR1::FLI1, drives initiation and progression of Ewing sarcoma (EwS). Even though direct targeting EWSR1::FLI1 is a formidable challenge, epigenetic/transcriptional modulators have been proved to be promising therapeutic targets for indirectly disrupting its expression and/or function. Here, we identified structure-specific recognition protein 1 (SSRP1), a subunit of the Facilitates Chromatin Transcription (FACT) complex, to be an essential tumor-dependent gene directly induced by EWSR1::FLI1 in EwS. The FACT-targeted drug CBL0137 exhibits potent therapeutic efficacy against multiple EwS preclinical models both in vitro and in vivo. Mechanistically, SSRP1 and EWSR1::FLI1 form oncogenic positive feedback loop via mutual transcriptional regulation and activation, and cooperatively promote cell cycle/DNA replication process and IGF1R-PI3K-AKT-mTOR pathway to drive EwS oncogenesis. The FACT inhibitor drug CBL0137 effectively targets the EWSR1::FLI1-FACT circuit, resulting in transcriptional disruption of EWSR1::FLI1, SSRP1 and their downstream effector oncogenic signatures. Our study illustrates a crucial role of the FACT complex in facilitating the expression and function of EWSR1::FLI1 and demonstrates FACT inhibition as a novel and effective epigenetic/transcriptional-targeted therapeutic strategy against EwS, providing preclinical support for adding EwS to CBL0137's future clinical trials.


Asunto(s)
Sarcoma de Ewing , Humanos , Línea Celular Tumoral , Cromatina , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Proteínas del Grupo de Alta Movilidad/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteína Proto-Oncogénica c-fli-1/genética , Proteína Proto-Oncogénica c-fli-1/metabolismo , Proteína EWS de Unión a ARN/genética , Sarcoma de Ewing/tratamiento farmacológico , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Factores de Elongación Transcripcional/metabolismo
12.
Nat Commun ; 13(1): 4408, 2022 07 29.
Artículo en Inglés | MEDLINE | ID: mdl-35906225

RESUMEN

Progenitors in epithelial tissues, such as human skin epidermis, continuously make fate decisions between self-renewal and differentiation. Here we show that the Super Elongation Complex (SEC) controls progenitor fate decisions by directly suppressing a group of "rapid response" genes, which feature high enrichment of paused Pol II in the progenitor state and robust Pol II elongation in differentiation. SEC's repressive role is dependent on the AFF1 scaffold, but not AFF4. In the progenitor state, AFF1-SEC associates with the HEXIM1-containing inactive CDK9 to suppress these rapid-response genes. A key rapid-response SEC target is ATF3, which promotes the upregulation of differentiation-activating transcription factors (GRHL3, OVOL1, PRDM1, ZNF750) to advance terminal differentiation. SEC peptidomimetic inhibitors or PKC signaling activates CDK9 and rapidly induces these transcription factors within hours in keratinocytes. Thus, our data suggest that the activity switch of SEC-associated CDK9 underlies the initial processes bifurcating progenitor fates between self-renewal and differentiation.


Asunto(s)
Factor B de Elongación Transcripcional Positiva , Factores de Elongación Transcripcional , Quinasa 9 Dependiente de la Ciclina/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Epidermis/metabolismo , Humanos , Factor B de Elongación Transcripcional Positiva/metabolismo , ARN Polimerasa II , Proteínas de Unión al ARN , Factores de Transcripción/genética , Factores de Elongación Transcripcional/metabolismo , Proteínas Supresoras de Tumor
13.
Sci Rep ; 12(1): 11852, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35831348

RESUMEN

Gastric cancer is the common type of malignancy positioned at second in mortality rate causing burden worldwide with increasing treatment options. More accurate and reliable diagnostic methods/biomarkers are urgently needed. The application of transcriptomics technologies possesses the high efficiency of identifying key metabolic pathways and functional genes in cancer research. In this study, we performed a transcriptome analysis on Prunetin treated AGS cells. A total of 1,118 differentially expressed (DE) genes on Prunetin treated AGS cancer cells, among which 463 were up-regulated and 655 were down-regulated. Notably, around 40 genes were found to be related with necroptosis, among which 16 genes were found to be in close association with Receptor Interacting Protein Kinase (RIPK) family. Validation of the RIPK genes through GEPIA identified 8 genes (NRP1, MNX1, SSRP1, PRDX2, PLRG1, LGALS4, SNX5 and FXYD3) which are highly expressed in stomach cancer were significantly down-regulated in PRU treated samples. In conclusion, the sequencing data explores the expression of RIPK mediated genes through necroptosis signaling network in treating gastric cancer. The futuristic validations on the 8 genes as candidate biomarkers will offer a treatment approach against gastric cancer using PRU.


Asunto(s)
Neoplasias Gástricas , Biomarcadores , Biología Computacional , Proteínas de Unión al ADN/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Proteínas del Grupo de Alta Movilidad/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Proteínas de Homeodominio , Humanos , Péptidos y Proteínas de Señalización Intracelular , Isoflavonas , Proteínas de la Membrana/metabolismo , Proteínas de Neoplasias/genética , Proteínas Nucleares , Neoplasias Gástricas/patología , Factores de Transcripción , Factores de Elongación Transcripcional/metabolismo
14.
Bioengineered ; 13(5): 13815-13828, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35706403

RESUMEN

The circular RNA, hsa_circ_0057452, is highly expressed in keloids, but its specific mechanism of action remains unknown. The levels of hsa_circ_0057452, microRNA (miR)-1225-3p, and AF4/FMR2 family member 4 (AFF4) in keloid tissues and keloid fibroblasts (KFs) were determined using quantitative reverse transcription-polymerase chain reaction. Changes in KFs viability, proliferation, apoptosis, and migration were investigated using the cell counting kit-8, bromodeoxyuridine, flow cytometry, and Transwell assays. Luciferase, RNA immunoprecipitation, and RNA pull-down assays were performed to identify the binding relationship among hsa_circ_0057452, miR-1225-3p, and AFF4. We found that hsa_circ_0057452 and AFF4 expression levels were upregulated, whereas miR-1225-3p expression levels were downregulated in keloids. Knockdown of hsa_circ_0057452 or AFF4 suppressed the viability, proliferation, and migration of KFs and induced apoptosis, whereas hsa_circ_0057452 overexpression and miR-1225-3p knockdown showed the opposite trend. Furthermore, hsa_circ_0057452 affected the biological behavior of KFs by releasing AFF4 via sponging of miR-1225-3p. Therefore, our results show that hsa_circ_0057452 promotes keloid progression by targeting miR-1225-3p and regulating AFF4 levels.


Asunto(s)
Queloide , MicroARNs , Proliferación Celular/genética , Familia , Regulación Neoplásica de la Expresión Génica , Humanos , Queloide/genética , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , Factores de Transcripción/metabolismo , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo
15.
J Hematol Oncol ; 15(1): 41, 2022 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-35395864

RESUMEN

BACKGROUND: Chromosome translocations involving mixed lineage leukemia 1 (MLL1) cause acute leukemia in most infants and 5-10% children/adults with dismal clinical outcomes. Most frequent MLL1-fusion partners AF4/AFF4, AF9/ENL and ELL, together with CDK9/cyclin-T1, constitute super elongation complexes (SEC), which promote aberrant gene transcription, oncogenesis and maintenance of MLL1-rearranged (MLL1-r) leukemia. Notably, ENL, but not its paralog AF9, is essential for MLL1-r leukemia (and several other cancers) and therefore a drug target. Moreover, recurrent ENL mutations are found in Wilms tumor, the most common pediatric kidney cancer, and play critical roles in oncogenesis. METHODS: Proteolysis-Targeting Chimera (PROTAC) molecules were designed and synthesized to degrade ENL. Biological activities of these compounds were characterized in cell and mouse models of MLL1-r leukemia and other cancers. RESULTS: Compound 1 efficiently degraded ENL with DC50 of 37 nM and almost depleted it at ~ 500 nM in blood and solid tumor cells. AF9 (as well as other proteins in SEC) was not significantly decreased. Compound 1-mediated ENL reduction significantly suppressed malignant gene signatures, selectively inhibited cell proliferation of MLL1-r leukemia and Myc-driven cancer cells with EC50s as low as 320 nM, and induced cell differentiation and apoptosis. It exhibited significant antitumor activity in a mouse model of MLL1-r leukemia. Compound 1 can also degrade a mutant ENL in Wilms tumor and suppress its mediated gene transcription. CONCLUSION: Compound 1 is a novel chemical probe for cellular and in vivo studies of ENL (including its oncogenic mutants) and a lead compound for further anticancer drug development.


Asunto(s)
Neoplasias Renales , Leucemia Mieloide Aguda , Tumor de Wilms , Animales , Humanos , Ratones , Carcinogénesis , Expresión Génica , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/genética , Leucemia Mieloide Aguda/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Proteolisis , Factores de Elongación Transcripcional/química , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , Tumor de Wilms/tratamiento farmacológico , Tumor de Wilms/genética
16.
J Healthc Eng ; 2022: 3528786, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35463672

RESUMEN

Methods: We search PubMed and Web of Sciences with keywords "SSRP1" and "Cancer." Only English literature was included, and conference papers and abstract were all excluded. Results: Transcription factors are classified into three groups based on their DNA binding motifs: simple helix-loop-helix (bHLH), classical zinc fingers (ZF-TFs), and homeodomains. The tumor-suppressive miR-497 (microRNA-497) acted as an undesirable regulator of SSRP1 upregulation, which led to tumor growth. The siRNA (small interfering RNA) knockdown of SSRP1 hindered cell proliferation along with incursion and glioma cell migration. Through the AKT (also known as protein kinase B) signaling pathway, SSRP1 silencing affected cancer apoptosis and cell proliferation. Conclusion: The MAPK (mitogen-activated protein kinase) signaling pathway's phosphorylation was suppressed when SSRP1 was depleted. The effect of curaxins on p53 and NF-B (nuclear factor-κB), and their toxicity to cancer cells, is attributable to the FACT (facilitates chromatin transcription) complex's chromatin trapping.


Asunto(s)
Glioma , MicroARNs , Apoptosis , Línea Celular Tumoral , Cromatina , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Humanos , MicroARNs/genética , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo
17.
Clin Transl Med ; 12(4): e691, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35474446

RESUMEN

BACKGROUND: Gastric carcinoma (GC) is one of the most deadly diseases due to tumour metastasis and resistance to therapy. Understanding the molecular mechanism of tumour progression and drug resistance will improve therapeutic efficacy and develop novel intervention strategies. METHODS: Differentially expressed long non-coding RNAs (lncRNAs) in clinical specimens were identified by LncRNA microarrays and validated in different clinical cohorts by quantitative real-time polymerase chain reaction (qRT-PCR), in situ hybridisation and bioinformatics analysis. Biological functions of lncRNA were investigated by using cell proliferation assays, migration assays, xenograft tumour models and bioinformatics analysis. Effects of lncSLCO1C1 on GC cell survival were assessed by comet assays and immunofluorescence assays. Underlying molecular mechanisms were further explored by using a number of technologies including RNA pull-down, mass spectrometry analysis, RNA immunoprecipitation, co-immunoprecipitation, miRNA sequencing, luciferase reporter assays and molecular modelling. RESULTS: LncSLCO1C1 was highly upregulated in GC tissue samples and associated with GC patients' poor overall survival. Overexpression of lncSLCO1C1 promoted proliferation and migration, whereas decreased lncSLCO1C1 expression produced the opposite effects. lncSLCO1C1 also mediated tumour resistance to chemotherapy with oxaliplatin by reducing DNA damage and increasing cell proliferation. Despite sequence overlapping between lncSLCO1C1 and PDE3A, alternations of PDE3A expression had no effect on the GC cell progression, indicating that lncSLCO1C1, not PDE3A, related with the progression of GC cells. Mechanistically, lncSLCO1C1 serves as a scaffold for the structure-specific recognition protein 1 (SSRP1)/H2A/H2B complex and regulates the function of SSRP1 in reducing DNA damage. Meanwhile, lncSLCO1C1 functions as a sponge to adsorb miR-204-5p and miR-211-5p that target SSRP1 mRNA, and thus increases SSRP1 expression. Patients with high expressions of both lncSLCO1C1 and SSRP1 have poor overall survival, highlighting the role of lncSLCO1C1 in GC progression. CONCLUSIONS: LncSLCO1C1 promotes GC progression by enhancing cell growth and preventing DNA damage via interacting and scaffolding the SSRP1/H2A/H2b complex and absorbing both miR-211-5p and miR-204-5p to increase SSRP1 expression.


Asunto(s)
MicroARNs , ARN Largo no Codificante , Neoplasias Gástricas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Progresión de la Enfermedad , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Transportadores de Anión Orgánico , Oxaliplatino/farmacología , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo
18.
Transcription ; 13(1-3): 16-38, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35485711

RESUMEN

The identification of FACT as a histone chaperone enabling transcription through chromatin in vitro has strongly shaped how its roles are envisioned. However, FACT has been implicated in essentially all aspects of chromatin biology, from transcription to DNA replication, DNA repair, and chromosome segregation. In this review, we focus on recent literature describing the role and mechanisms of FACT during transcription. We highlight the prime importance of FACT in preserving chromatin integrity during transcription and challenge its role as an elongation factor. We also review evidence for FACT's role as a cell-type/gene-specific regulator of gene expression and briefly summarize current efforts at using FACT inhibition as an anti-cancer strategy.


Asunto(s)
Proteínas del Grupo de Alta Movilidad , Chaperonas de Histonas , Cromatina/genética , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/química , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Chaperonas de Histonas/química , Chaperonas de Histonas/genética , Chaperonas de Histonas/metabolismo , Nucleosomas , Factores de Elongación Transcripcional/metabolismo
19.
Cell Cycle ; 21(14): 1532-1542, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35343377

RESUMEN

As part of the development of an infectious bursal disease virus (IBDV) subunit vaccine, this study was designed to improve the expression of highly soluble VP2-LS3 (Haemophilus parasuis lumazine synthase 3, LS3) protein by using different tagged vectors in E. coli. IBDV VP2-LS3 gene was designed and synthesized. Fusion tags, GST, NusA, MBP, Ppi, γ-crystallin, ArsC, and Grifin were joined to the N-terminus of VP2-LS3 protein. Seven expression plasmids were constructed, and each plasmid was transformed into E. coli BL21 (DE3) competent cells. After induction by IPTG, the solubility and expression levels of the various VP2-LS3 proteins were analyzed by SDS-PAGE and Western Blot analysis. The fusion tag that significantly promoted soluble expression of the VP2-LS3 protein was selected. Recombinant proteins were purified using Ni-NTA affinity chromatography, then cleaved by using TEV protease and detected by using transmission electron microscopy. Gel electrophoresis and sequencing analysis showed that all seven recombinant vectors were successfully constructed. GST, NusA, MBP, Ppi, γ-crystallin, ArsC, and Grifin enhanced the expression and solubility of VP2 protein; however, MBP was more effective for the high-purity production of VP2-LS3. Western Blot analysis confirmed successful generation of VP2-LS3 fusion protein in E. coli. The result of transmission electron microscopy showed that VP2-LS3 formed nano-sized particles with homogeneous shape and relatively uniform size. This study established a method to generate VP2-LS3 recombinant protein, which may lay a foundation for the development and subsequent study of IBDV subunit vaccines.


Asunto(s)
Proteínas de Escherichia coli , Virus de la Enfermedad Infecciosa de la Bolsa , gamma-Cristalinas , Animales , Proteínas de la Cápside/genética , Proteínas de la Cápside/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Nanoestructuras , Proteínas Recombinantes/genética , Factores de Elongación Transcripcional/metabolismo , Proteínas Estructurales Virales/genética , gamma-Cristalinas/metabolismo
20.
Cell Mol Life Sci ; 79(3): 183, 2022 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-35279775

RESUMEN

The so-called Yaf9, ENL, AF9, Taf14, and Sas5 (YEATS) domain-containing proteins, hereafter referred to as YD proteins, take control over the transcription by multiple steps of regulation either involving epigenetic remodelling of chromatin or guiding the processivity of RNA polymerase II to facilitate elongation-coupled mRNA 3' processing. Interestingly, an increasing amount of evidence suggest a wider repertoire of YD protein's functions spanning from non-coding RNA regulation, RNA-binding proteins networking, post-translational regulation of a few signalling transduction proteins and the spindle pole formation. However, such a large set of non-canonical roles is still poorly characterized. Notably, four paralogous of human YEATS domain family members, namely eleven-nineteen-leukaemia (ENL), ALL1-fused gene from chromosome 9 protein (AF9), YEATS2 and glioma amplified sequence 41 (GAS41), have a strong link to cancer yet new findings also highlight a potential novel role in neurological diseases. Here, in an attempt to more comprehensively understand the complexity of four YD proteins and to gain more insight into the novel functions they may accomplish in the neurons, we summarized the YD protein's networks, systematically searched and reviewed the YD genetic variants associated with neurodevelopmental disorders and finally interrogated the model organism Drosophila melanogaster.


Asunto(s)
Proteínas Cromosómicas no Histona/metabolismo , Enfermedades del Sistema Nervioso/patología , Factores de Transcripción/metabolismo , Factores de Elongación Transcripcional/metabolismo , Animales , Proteínas Cromosómicas no Histona/química , Proteínas Cromosómicas no Histona/genética , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Epigénesis Genética , Evolución Molecular , Humanos , Enfermedades del Sistema Nervioso/metabolismo , Dominios Proteicos , Factores de Transcripción/química , Factores de Transcripción/genética , Factores de Elongación Transcripcional/química , Factores de Elongación Transcripcional/genética
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