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OBJECTIVES: Hypoxia conditions promote the adaptation and progression of non-small-cell lung cancer (NSCLC) via hypoxia-inducible factors (HIF). HIF-1α may regulate estrogen receptor ß (ERß) and promote the progression of NSCLC. The phytochemical homoharringtonine (HHT) exerts strong inhibitory potency on NSCLC, with molecular mechanism under hypoxia being elusive. METHODS: The effects of HHT on NSCLC growth were determined by cell viability assay, colony formation, flow cytometry, and H460 xenograft models. Western blotting, molecular docking program, site-directed mutagenesis assay, immunohistochemical assay, and immunofluorescence assay were performed to explore the underlying mechanisms of HHT-induced growth inhibition in NSCLC. KEY FINDINGS: HIF-1α/ERß signaling-related E2F1 is highly expressed and contributes to unfavorable survival and tumor growth. The findings in hypoxic cells, HIF-1α overexpressing cells, as well as ERß- or E2F1-overexpressed and knockdown cells suggest that the HIF-1α/ERß/E2F1 feedforward loop promotes NSCLC cell growth. HHT suppresses HIF-1α/ERß/E2F1 signaling via the ubiquitin-proteasome pathway, which is dependent on the inhibition of the protein expression of HIF-1α and ERß. Molecular docking and site-directed mutagenesis revealed that HHT binds to the GLU305 site of ERß. HHT inhibits cell proliferation and colony formation and promotes apoptosis in both NSCLC cells and xenograft models. CONCLUSION: The formation of the HIF-1α/ERß/E2F1 feedforward loop promotes NSCLC growth and reveals a novel molecular mechanism by which HHT induces cell death in NSCLC.
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SUMOylation plays a crucial role in numerous cellular biological and pathophysiological processes associated with human disease; however, the mechanisms regulating the genes involved in SUMOylation remain unclear. In the present study, E2F transcription factor 4 (E2F4) was identified as an E2F member related to hepatocellular carcinoma (HCC) progression by public database analysis. It was found that E2F4 promoted the proliferation and invasiveness of HCC cells via SUMOylation using Soft agar and Transwell migration assays. Mechanistically, it was demonstrated that E2F4 upregulated the transcript and protein expression levels of baculoviral IAP repeat containing 5, cell division cycle associated 8 and DNA topoisomerase II α using western blotting. Furthermore, the interaction between E2F4 with lin9 DREAM multivulva class B core complex component (LIN9) was explored by coimmunoprecipitation, immunofluorescence colocalization and bimolecular fluorescence complementation assays. Moreover, it was demonstrated that E2F4 promoted the progression of HCC cells via LIN9. Rescue experiments revealed that LIN9 facilitated the SUMOylation and proliferation of HCC cells, which was prevented by knocking down E2F4 expression. In conclusion, the findings of the present study indicated that E2F4 plays a major role in the proliferation of HCC cells and may be a potential therapeutic target in the future.
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Carcinoma Hepatocelular , Proliferación Celular , Progresión de la Enfermedad , Factor de Transcripción E2F4 , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas , Sumoilación , Humanos , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/metabolismo , Factor de Transcripción E2F4/metabolismo , Factor de Transcripción E2F4/genética , Línea Celular Tumoral , Movimiento CelularRESUMEN
Circadian clock dominates a variety of biological activities, while its roles and regulatory mechanisms in neuroblastoma (NB), a pediatric extracranial malignancy, still remain largely elusive. Herein, through comprehensive analyses of public datasets, E2F transcription factor 1 (E2F1) and its circular RNA (circE2F1)-encoded 99-amino acid peptide (E2F1-99aa) were identified as vital regulators of circadian machinery essential for purine and pyrimidine biosynthesis during NB progression. Mechanistically, through interaction with Spi-B transcription factor (SPIB), E2F1 was transactivated to up-regulate circadian machinery genes (CRY1 and TIMELESS), resulting in relief of CLOCK/BMAL1-repressed transcription of enzymes (DHODH, PAICS, or PPAT) essential for de novo purine and pyrimidine biosynthesis. The biogenesis of circE2F1 was repressed by eukaryotic translation initiation factor 4A3 (EIF4A3), while E2F1-99aa or its truncated peptide competitively bound to SPIB, leading to decrease in SPIB-E2F1 interaction, circadian machinery and nucleotide biosynthetic gene expression, purine or pyrimidine biosynthesis, tumorigenesis, and aggresiveness of NB cells. In clinical NB cases, high EIF4A3, E2F1 or SPIB levels were correlated with low survival possibility of patients, while lower circE2F1 or E2F1-99aa levels were associated with advanced stages and tumor progression. These results indicate that circE2F1-encoded peptide inhibits circadian machinery essential for nucleotide biosynthesis and tumor progression via repressing SPIB/E2F1 axis.
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Epstein-Barr virus (EBV) co-infections with human papillomavirus (HPV) have been observed in oropharyngeal squamous cell carcinoma. Modeling EBV/HPV co-infection in organotypic epithelial raft cultures revealed that HPV16 E7 inhibited EBV productive replication through the facilitated degradation of the retinoblastoma protein pRb/p105. To further understand how pRb is required for EBV productive replication, we generated CRISPR-Cas9 pRb knockout (KO) normal oral keratinocytes (NOKs) in the context of wild-type and mutant K120E p53. EBV replication was examined in organotypic rafts as a physiological correlate for epithelial differentiation. In pRb KO rafts, EBV DNA copy number was statistically decreased compared to vector controls, regardless of p53 context. Loss of pRb did not affect EBV binding or internalization of calcium-treated NOKs or early infection of rafts. Rather, the block in EBV replication correlated with impaired immediate early gene expression. An EBV infection time course in rafts with mutant p53 demonstrated that pRb-positive basal cells were initially infected with delayed replication occurring in differentiated layers. Loss of pRb showed increased S-phase progression makers and elevated activator E2F activity in raft tissues. Complementation with a panel of pRb/E2F binding mutants showed that wild type or pRb∆685 mutant capable of E2F binding reduced S-phase marker gene expression, rescued EBV DNA replication, and restored BZLF1 expression in pRb KO rafts. However, pRb KO complemented with pRb661W mutant, unable to bind E2Fs, failed to rescue EBV replication in raft culture. These findings suggest that EBV productive replication in differentiated epithelium requires pRb inhibition of activator E2Fs to restrict S-phase progression.IMPORTANCEA subset of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma is co-positive for Epstein-Barr virus (EBV). Potential oncogenic viral interactions revealed that HPV16 E7 inhibited productive EBV replication within the differentiated epithelium. As E7 mediates the degradation of pRb, we aimed to establish how pRb is involved in EBV replication. In the context of differentiated epithelium using organotypic raft culture, we evaluated how the loss of pRb affects EBV lytic replication to better comprehend EBV contributions to carcinogenesis. In this study, ablation of pRb interfered with EBV replication at the level of immediate early gene expression. Loss of pRb increased activator E2Fs and associated S-phase gene expression throughout the differentiated epithelium. Complementation studies showed that wild type and pRb mutant capable of binding to E2F rescued EBV replication, while pRb mutant lacking E2F binding did not. Altogether, these studies support that in differentiated tissues, HPV16 E7-mediated degradation of pRb inhibits EBV replication through unregulated E2F activity.
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CDT1, a gene that shows excessive expression in various malignancies, functions as a pivotal regulator of replication licensing. In this study, we observed a positive correlation in expression between CDT1 and E2F2 among patients with lung adenocarcinoma (LUAD). Our findings substantiated that E2F2 directly interacted with the promoter region of CDT1, as confirmed by ChIP-qPCR assays, and depletion of E2F2 resulted in a downregulation of CDT1 expression in LUAD cell lines by gene interference technology. Furthermore, we identified an upregulation of CDT1 mRNA level in Chinese LUAD samples. Notably, in the loss-of-function assays, depletion of CDT1 in LUAD cell lines inhibited cell proliferation, migration, and invasion. Concurrently, it promoted cell apoptosis and induced G0/G1 phase arrest using MTT, flow cytometry, and Transwell assays, reinforcing its role as an oncogene.Furthermore, enhanced tumor ablation was determined in a CDT1-downregulated LUAD tumor-bearing nude mouse model. Collectively, our results strongly suggest that E2F2 positively regulates CDT1 expression and actively participates in the progression of lung adenocarcinoma, thereby providing valuable insights into identifying novel therapeutic targets for LUAD treatment.
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BACKGROUND: Glioblastoma (GBM) is the most aggressive primary malignant brain tumor. Temozolomide (TMZ) is the most used first-line chemotherapeutic agent for GBM after surgery, but acquired resistance to TMZ frequently leads to treatment failure and is a major challenge in the clinical treatment of GBM. Increasing evidence suggests that E2F transcription factor 6 (E2F6) is associated with a variety of tumor malignant biological behaviors and drug resistance, but its biological function and underlying molecular mechanisms in GBM are unknown. METHODS: The study investigated the levels of E2F6 in both TMZ-sensitive and TMZ-resistant GBM cells and tissues using Western blotting and immunofluorescence assays. In vitro experiments were conducted to explore the impact of E2F6 on TMZ resistance and glioma stem cell stemness. These experiments included Western blotting, colony formation assay, flow cytometry assay, and TdT-mediated dUTP nick-end labeling (TUNEL) assay. Bioinformatic analyses were conducted to investigate the mechanism behind the high expression of E2F6 in TMZ-resistant cells and its correlation with caspase recruitment domain 6 (CARD6) and disulfide-linked cell adhesion protein (POSTN). The study employed bioinformatic analyses, messenger RNA (mRNA) sequencing, chromatin immunoprecipitation sequencing assay, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. To examine the function of E2F6, an intracranial xenograft tumor mouse model was used for in vivo experiments. RESULTS: It was found that CARD6 and POSTN were significantly associated with TMZ resistance and survival of GBM patients. E2F6 was up-regulated in TMZ-resistant cells and tissues. Knockdown of E2F6 down-regulated the expression of CARD6, promoted TMZ-induced apoptosis, and enhanced chemo-sensitivity, whereas its overexpression significantly increased TMZ resistance in vitro and in vivo. In addition, E2F6 can promote TMZ resistance through stem-like properties acquisition. We identified a signaling pathway related to E2F6 and POSTN, which maintains the self-renewal of GBM stem cells (GSCs). E2F6 concentrates in the promoter region of POSTN, thereby regulating the expression of GSCs-related genes cluster of differentiation 133 (CD133), Nestin, and sex-determining region Y-box 2 (SOX2), which may be involved in tumor metabolism and drug resistance processes. Down-regulation of E2F6 down-regulated the expression of POSTN and inhibited tumor growth in nude mice. CONCLUSIONS: These results suggest that the E2F6-CARD6/POSTN signaling axis regulates the malignant biological behaviors of GBM and TMZ resistance. These findings are expected to provide promising therapeutic targets for CARD6 overcoming GBM TMZ resistance.
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Resistencia a Antineoplásicos , Glioblastoma , Temozolomida , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Glioblastoma/patología , Temozolomida/farmacología , Temozolomida/uso terapéutico , Humanos , Ratones , Animales , Proteínas Adaptadoras de Señalización CARD/metabolismo , Proteínas Adaptadoras de Señalización CARD/genética , Regiones Promotoras Genéticas , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Línea Celular Tumoral , Antineoplásicos Alquilantes/farmacología , Antineoplásicos Alquilantes/uso terapéutico , Ratones DesnudosRESUMEN
BACKGROUND: Glioblastoma (GBM) is the most malignant brain tumor and ranks among the most lethal of all human cancers, without improvements in survival over the last 30 years. Data obtained in our group suggest that PARP1, a well-known DNA-repairing protein, could also play a key role in the regulation of cell cycle through its interaction with the transcription factor E2F1. Therefore, considering that most oncogenic processes are associated with cell cycle deregulation, we hypothesized that disruption of PARP1-E2F1 interaction would provide a novel therapeutic approach to different types of cancer. METHODS: The identification of novel compounds disrupting PARP1-E2F1 interaction was carried out by combining in silico and in vitro screening, using a rational drug design. The virtual screen was performed using a molecular library of several million compounds at the selected target site, using AtomNet® (Atomwise, San Francisco, CA, USA), the first deep learning neural network for structure-based drug design and discovery. Since there is no complete structural information of the PARP1-E2F1 protein-protein interaction, a homologous structure of the BRCT domain of BRCA1 complex with the phospho-peptide (PDBID: 1T2V) was used to identify the potential binding interface of BRCT domain of PARP-1 (PDBID: 2COK) and the E2F1 protein. Top scoring compounds were clustered and filtered to obtain a final subset of 83 compounds that were incorporated to our in vitro screening, which included both transcriptional E2F1 activity and survival studies. Complete culture medium supplemented with the compounds selected in the in silico screening (10 µM) were added and incubated for 24 hours. E2F1 activity was observed by measuring luminescence. For the viability assay, the fluorescence reading was performed (excitation 544 nm and emission 590 nm). RESULTS: The in silico and in vitro screening resulted in 12 compounds that inhibited E2F1 transcriptional activity and significantly reduced cell number. The highest inhibition of both E2F1 transcriptional activity and cell growth was observed with compound 3797, which was selected for further studies. CONCLUSIONS: Both in silico and in vitro results indicate that inhibition of PARP1-E2F1 transcriptional activity may provide a new rationale for designing novel therapeutic approaches for the treatment of GBM.
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Factor de Transcripción E2F1 , Glioblastoma , Poli(ADP-Ribosa) Polimerasa-1 , Humanos , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Factor de Transcripción E2F1/metabolismo , Desarrollo de Medicamentos/métodos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Línea Celular Tumoral , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéuticoRESUMEN
OBJECTIVE: This investigation was to determine the relationship between changes in the expression levels of miR-134 and the E2F transcription factor 6 (E2F6) in mediating control of apoptosis in N-methyl-D-aspartate (NMDA)-induced glaucomatous mice. METHODS: Morphological and structural changes were quantitatively analyzed along with apoptosis in the retinal ganglion cell (RGC) layer, internal plexiform layer and RGCs. Glaucomatous RGCs were transfected, and cell viability and apoptosis were examined. The targeting relationship between miR-134 and E2F6 was analyzed, as well as their expression pattern. RESULTS: Intravitreal injection of NMDA induced a significant reduction in the number of RGCs and thinning of IPL thickness. miR-134 was highly expressed and E2F6 was lowly expressed in glaucoma mice. Suppression of miR-134 or E2F6 overexpression inhibited apoptosis in the glaucomatous RGCs and instead their proliferative activity. MiR-134 targeted inhibition of E2F6 expression. Suppressing rises in E2F6 expression reduced the interfering effect of miR-134 on glaucomatous RGC development. CONCLUSION: Depleting miR134 expression increases, in turn, E2F6 expression levels and in turn reduces glaucomatous RGC apoptosis expression.
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Apoptosis , Factor de Transcripción E2F6 , Glaucoma , MicroARNs , N-Metilaspartato , Células Ganglionares de la Retina , Animales , MicroARNs/genética , MicroARNs/metabolismo , Apoptosis/efectos de los fármacos , Apoptosis/genética , Células Ganglionares de la Retina/patología , Células Ganglionares de la Retina/metabolismo , Células Ganglionares de la Retina/efectos de los fármacos , Glaucoma/genética , Glaucoma/patología , Glaucoma/metabolismo , Glaucoma/inducido químicamente , N-Metilaspartato/toxicidad , Ratones , Factor de Transcripción E2F6/genética , Factor de Transcripción E2F6/metabolismo , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Masculino , Inyecciones Intravítreas , Supervivencia Celular/efectos de los fármacosRESUMEN
Background: E2F7 is a recently discovered member of the E2F family. Investigating the function and mechanism of E2F7 in the growth of tumors is significant for the clinical diagnosis and therapy of these malignancies. Objective: The purpose of this review is to provide theoretical basis for the diagnosis and treatment of malignant tumors by exploring E2F7. Methods: The relevant information was collected through the PubMed database using keyword searches "E2F7" and "cancer". Results: On the one hand, E2F7 plays an essential role in embryonic development, angiogenesis, and the nervous system. On the other hand, E2F7 is also linked to the occurrence and growth of various malignant tumors. Conclusion: E2F7 has potential as a therapeutic target in future cancer treatments.
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Cellular senescence, traditionally viewed as a consequence of proliferating and growing cells overwhelmed by extensive stresses and damage, has long been recognized as a critical cellular aging mechanism. Recent research, however, has revealed a novel pathway termed "quiescence-origin senescence", where cells directly transition into senescence from the quiescent state, bypassing cell proliferation and growth. This opinion paper presents a framework conceptualizing a continuum between quiescence and senescence with quiescence deepening as a precursor to senescence entry. We explore the triggers and controllers of this process and discuss its biological implications. Given that the majority of cells in the human body are dormant rather than proliferative, understanding quiescence-origin senescence has significant implications for tissue homeostasis, aging, cancer, and various disease processes. The new paradigm in exploring this previously overlooked senescent cell population may reshape our intervention strategies for age-related diseases and tissue regeneration.
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BACKGROUND: Circular RNAs (circRNAs) are capable of affecting breast cancer (BC) development. However, the role and underneath mechanism of circFKBP8 (also known as hsa_circ_0000915) in BC remain largely unknown. METHODS: Expression analyses were performed using quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry (IHC) assays. Effects on cell functional phenotypes were determined by assessing cell proliferation, migratory capacity, invasion, and stemness in vitro. The relationship between microRNA (miR)-432-5p and circFKBP8 or E2F transcription factor 7 (E2F7) was examined by RNA pull-down, dual-luciferase reporter, and RNA immunoprecipitation (RIP) assays. Xenograft assays were used to identify the function of circFKBP8 in vivo. RESULTS: CircFKBP8 was presented at high levels in BC tissues and cells. High circFKBP8 expression was associated with worse overall survival in BC patients. CircFKBP8 suppression inhibited BC cell proliferation, migratory capacity, invasion and stemness in vitro. CircFKBP8 suppression blocked xenograft tumor growth in vivo. Mechanistically, circFKBP8 functioned as a miR-432-5p sponge to modulate E2F7 expression. CircFKBP8 modulated BC cell malignant behaviors by miR-432-5p, and miR-432-5p affected these cell phenotypes through E2F7. CONCLUSION: Our observations prove that circFKBP8 promotes BC malignant phenotypes through the miR-432-5p/E2F7 cascade, offering a promising therapeutic and prognostic target for BC.
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Neoplasias de la Mama , Proliferación Celular , Factor de Transcripción E2F7 , Regulación Neoplásica de la Expresión Génica , MicroARNs , ARN Circular , MicroARNs/genética , Humanos , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , ARN Circular/genética , Femenino , Animales , Línea Celular Tumoral , Factor de Transcripción E2F7/genética , Factor de Transcripción E2F7/metabolismo , Ratones , Movimiento Celular , Redes Reguladoras de GenesRESUMEN
BACKGROUND: Hepatocellular carcinoma (HCC) stands as the prevailing manifestation of primary liver cancer. Previous studies have implicated ARHGEF39 in various cancer progression processes, but its impact on HCC metastasis remains unclear. METHODS: Bioinformatics analysis and qRT-PCR were employed to test ARHGEF39 expression in HCC tissues and cells, identified enriched pathways associated with ARHGEF39, and investigated its regulatory relationship with E2F1. The impact of ARHGEF39 overexpression or knockdown on cellular phenotypes in HCC was assessed through the implementation of CCK-8 and Transwell assays. Accumulation of neutral lipids was determined by BODIPY 493/503 staining, while levels of triglycerides and phospholipids were measured using specific assay kits. Expression of E-cadherin, Vimentin, MMP-2, MMP-9, and FASN were analyzed by Western blot. The interaction between ARHGEF39 and E2F1 was validated through ChIP and dual-luciferase reporter assays. RESULTS: Our study demonstrated upregulated expression of both ARHGEF39 and E2F1 in HCC, with ARHGEF39 being associated with fatty acid metabolism (FAM) pathways. Additionally, ARHGEF39 was identified as a downstream target gene of E2F1. Cell-based experiments unmasked that high expression of ARHGEF39 mediated the promotion of HCC cell viability, migration, and invasion via enhanced FAM. Moreover, rescue assays demonstrated that the promotion of HCC cell metastasis by high ARHGEF39 expression was attenuated upon treatment with Orlistat. Conversely, the knockdown of E2F1 suppressed HCC cell metastasis and FAM, while the upregulation of ARHGEF39 counteracted the repressive effects of E2F1 downregulation on the metastatic potential of HCC cells. CONCLUSION: Our findings confirmed the critical role of ARHGEF39 in HCC metastasis and unmasked potential molecular mechanisms through which ARHGEF39 fostered HCC metastasis via FAM, providing a theoretical basis for exploring novel molecular markers and preventive strategies for HCC metastasis.
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Glioma, a prevalent primary tumor of the central nervous system, is targeted by molecular therapies aiming to intervene in specific genes and signaling pathways to inhibit tumor growth and spread. Our previous bioinformatics study revealed that significant CDC6 overexpression in gliomas was closely correlated with poor patient prognosis. Through qPCR, western blotting, and immunohistochemistry, we will further validate CDC6 expression in clinical glioma specimens, while the effects of silencing and overexpressing CDC6 in the U87 and LN229 glioma cell lines on malignancy will be assessed through MTS, EdU, transwell, and migration assays. Luciferase reporter assays, ChIP, qPCR, and western blotting were used to explore the upstream and downstream molecular mechanisms of CDC6. Our study confirmed the abnormal overexpression of CDC6 in gliomas, particularly in glioblastomas. CDC6 promotes glioma cell activity, proliferation, invasion, and migration by activating the IL6-mediated JAK2/STAT3 signaling pathway. The transcription Factor E2F8 directly regulates CDC6 transcription, playing a crucial role in its abnormal overexpression in gliomas. This research provides vital evidence supporting CDC6 as a molecular target for glioma therapy.
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Long noncoding RNAs (lncRNAs) constitute a distinctive subset of RNA molecules with limited protein-coding potential, which exert crucial impacts on various biological activities. In the context of cancer, dysregulated lncRNAs function as essential regulators that affect tumor initiation and malignant progression. These lncRNAs serve as competitive endogenous RNAs (ceRNAs) through sponging microRNAs and regulating the expression of targeted genes. Moreover, they also directly bind to RNA-binding proteins, which can be integrated into a complex mechanistic network. E2F1, an extensively studied transcription factor, mediates multiple malignant behaviors by regulating cell cycle progression, tumor metastasis, and therapeutic response. Emerging evidence suggests that lncRNAs play a pivotal role in regulating the E2F1 pathway. This review aims to elucidate the intricate gene regulatory programs between lncRNAs and E2F1 in cancer progression. We elaborate on distinct mechanistic networks involved in cancer progression, emphasizing the potential of the lncRNAs/E2F1 axes as promising targets for cancer therapy. Additionally, we provide novel perspectives on current evidence, limitations, and future directions for targeting lncRNAs in human cancers. Fully deciphering the intricate network of lncRNA/E2F1-mediated regulatory mechanisms in cancer could facilitate the translation of current findings into clinical course, such efforts ultimately significantly improve the clinical prognosis of cancer patients.
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BACKGROUND: Gastric cancer (GC) stands as a prevalent and challenging malignancy within the gastrointestinal tract. The potential of long non-coding RNAs (lncRNAs) as biomarkers and therapeutic targets in oncology has garnered immense research interest. This study aims to elucidate the relevance, biological roles, and mechanistic pathways of LncRNA HAGLR in the context of GC. METHODS: The assessments of cell proliferation, migration, and invasion were executed using CCK-8, wound healing, and Transwell assays. The interactions between HAGLR, miR-20a-5p, and E2F1 were appraised through luciferase reporter assays, fluorescence in situ hybridization (FISH), and RNA immunoprecipitation (RIP). A tumor xenograft model provided in vivo validation for in vitro findings. RESULTS: Elevated levels of HAGLR in GC cells and tissue specimens were linked to worse patient outcomes. The inhibition of HAGLR led to a decrease in GC cell proliferation, migration, and invasion, whereas its activation prompted contrary effects. The impact of HAGLR on cell migration and invasion was notably associated with epithelial-mesenchymal transition (EMT). Through bioinformatics, luciferase reporter assays, FISH, RIP, and Western blot analyses, it was revealed that HAGLR acts as a molecular sponge for miR-20a-5p, consequently augmenting E2F1 levels. CONCLUSIONS: The data suggest that the HAGLR/miR-20a-5p/E2F1 regulatory cascade is implicated in GC pathogenesis, offering a novel therapeutic avenue for GC management.
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Movimiento Celular , Proliferación Celular , Factor de Transcripción E2F1 , Regulación Neoplásica de la Expresión Génica , MicroARNs , ARN Largo no Codificante , Neoplasias Gástricas , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Neoplasias Gástricas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Factor de Transcripción E2F1/metabolismo , Factor de Transcripción E2F1/genética , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/genética , Movimiento Celular/genética , Ratones , Transición Epitelial-Mesenquimal/genética , Progresión de la Enfermedad , Masculino , Femenino , Invasividad Neoplásica/genética , Ratones DesnudosRESUMEN
Studying the mechanisms underlying clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer, may address an unmet need in ccRCC-targeted drug research. Growing evidences indicate that protein phosphatase 4 (PP4) plays an important role in cancer biology. Here, we characterized the upregulation of PP4 core component SMEK1 in ccRCC using tissue microarrays and revealed that its high expression is closely associated with reduced patient survival. We then conducted cell function experiments and animal experiments to prove the tumor-promoting effect of SMEK1. Next, RNA-seq was performed to explore its underlying mechanism, and the results revealed that SMEK1-regulated genes were extensively involved in cell motility, and the canonical tyrosine kinase receptor EGFR was one of its targets. Moreover, we verified the regulatory effect of SMEK1 on EGFR and its downstream MAPK and AKT pathway through molecular experiments, in which erlotinib, a tyrosine kinase inhibitor, can partially block this regulation, demonstrating that SMEK1 mediates its effects dependent on the tyrosine kinase activity of EGFR. Mechanistically, SMEK1 bond to PRMT5 and facilitated PRMT5-mediated histone methylation to promote the transcription of EGFR. Furthermore, we studied the upstream regulators of SMEK1 and demonstrated that the transcription factor E2F1 could directly bind to the SMEK1 promoter by chromatin immunoprecipitation. Functionally, E2F1 could also induce ccRCC progression by manipulating the expression of SMEK1. Collectively, our findings demonstrate the overexpression of SMEK1 in ccRCC, and reveal a novel E2F1/SMEK1/PRMT5/EGFR-tyrosine-kinase-dependent pathway for ccRCC progression.
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Carcinoma de Células Renales , Progresión de la Enfermedad , Receptores ErbB , Regulación Neoplásica de la Expresión Génica , Neoplasias Renales , Humanos , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Receptores ErbB/metabolismo , Receptores ErbB/genética , Neoplasias Renales/patología , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , Animales , Línea Celular Tumoral , Ratones , Transducción de Señal , Movimiento Celular , Masculino , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Femenino , Factor de Transcripción E2F1/metabolismo , Factor de Transcripción E2F1/genéticaRESUMEN
The bromodomain and extraterminal domain (BET) family proteins serve as primary readers of acetylated lysine residues and play crucial roles in cell proliferation and differentiation. Dysregulation of BET proteins has been implicated in tumorigenesis, making them important therapeutic targets. BET-bromodomain (BD) inhibitors and BET-targeting degraders have been developed to inhibit BET proteins. In this study, we found that the BET inhibitor MS645 exhibited superior antiproliferative activity than BET degraders including ARV771, AT1, MZ1 and dBET1 in triple-negative breast cancer (TNBC) cells. Treatment with MS645 led to the dissociation of BETs, MED1 and RNA polymerase II from the E2F1-3 promoter, resulting in the suppression of E2F1-3 transcription and subsequent inhibition of cell growth in TNBC. In contrast, while ARV771 displaced BET proteins from chromatin, it did not significantly alter E2F1-3 expression. Mechanistically, ARV771 induced BRD4 depletion at protein level, which markedly increased EGR1 expression. This elevation of EGR1 subsequently recruited septin 2 and septin 9 to E2F1-3 promoters, enhancing E2F1-3 transcription and promoting cell proliferation rate in vitro and in vivo. Our findings provide valuable insights into differential mechanisms of BET inhibition and highlight potential of developing BET-targeting molecules as therapeutic strategies for TNBC.
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RNA-binding proteins (RBPs) are a class of proteins that primarily function by interacting with different types of RNAs and play a critical role in regulating the transcription and translation of cancer-related genes. However, their role in the progression of hepatocellular carcinoma (HCC) remains unclear. In this study, we analyzed RNA sequencing data and the corresponding clinical information of patients with HCC to screen for prognostic RBPs. Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) was identified as an independent prognostic factor for liver cancer. It is upregulated in HCC and is associated with a poor prognosis. Elevated IGF2BP3 expression was validated via immunohistochemical analysis using a tissue microarray of patients with HCC. IGF2BP3 knockdown inhibited the proliferation of Hep3B and HepG2 cells, whereas IGF2BP3 overexpression promoted the expansion of HuH-7 and MHCC97H cells. Mechanistically, IGF2BP3 modulates cell proliferation by regulating E2F1 expression. DNA hypomethylation of the IGF2BP3 gene may increase the expression of IGF2BP3, thereby enhancing cell proliferation in HCC. Therefore, IGF2BP3 may act as a novel prognostic biomarker and a potential therapeutic target for HCC.
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Carcinoma Hepatocelular , Proliferación Celular , Metilación de ADN , Factor de Transcripción E2F1 , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas , Proteínas de Unión al ARN , Regulación hacia Arriba , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , Proliferación Celular/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Factor de Transcripción E2F1/metabolismo , Factor de Transcripción E2F1/genética , Masculino , Regulación hacia Arriba/genética , Femenino , Pronóstico , Línea Celular Tumoral , Persona de Mediana Edad , Células Hep G2 , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismoRESUMEN
OBJECTIVE: Metastases in the advanced stages of colorectal cancer (CRC) present a major challenge to its treatment. Epithelial-Mesenchymal Transition (EMT) plays a crucial role in enhancing the metastasis and invasion ability of cancer cells. However, the progress of E2F transcription factor 1 (E2F1) and Regulator of chromatin condensation 1 (RCCD1) in CRC on EMT has not been studied. METHODS: The CRC differential expression data from The Cancer Genome Atlas database were analyzed by Gene Set Enrichment Analysis to verify the difference in expression of E2F1 and RCCD1 in cancerous and para-cancerous tissues.DNA-pull down and dual luciferase experiments confirmed that E2F1 regulates RCCD1. Western-blot and q-PCR experiments confirmed that E2F1 regulates RCCD1 and participates in the EMT-related progress of CRC.EDU, Wound healing and Transwell experiments verified the effects of regulation of E2F1 and RCCD1 on the proliferation, migration and invasion of CRC cells. RESULTS: E2F1 and RCCD1 are highly expressed in cancer tissues and cancer cells. E2F1 binds to the upstream promoter of RCCD1 to regulate RCCD1 and affect the expression of EMT-related targets in CRC cells. It also affects the proliferation, migration and invasion of CRC cells. CONCLUSIONS: E2F1 regulates the involvement of RCCD1 in CRC EMT and affects the proliferation, migration and invasion ability of CRC cells.
Asunto(s)
Neoplasias Colorrectales , Factor de Transcripción E2F1 , Transición Epitelial-Mesenquimal , Regulación Neoplásica de la Expresión Génica , Humanos , Transición Epitelial-Mesenquimal/genética , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Factor de Transcripción E2F1/metabolismo , Factor de Transcripción E2F1/genética , Movimiento Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proliferación Celular/genética , Invasividad Neoplásica/genética , Progresión de la Enfermedad , Línea Celular TumoralRESUMEN
Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis of the skin and multiple vital organs, but the immunological pathogenesis of SSc remains unclear. We show here that miR-19b promotes Th9 cells that exacerbate SSc. Specifically, miR-19b and interleukin (IL)-9 increase in CD4+ T cells in experimental SSc in mice induced with bleomycin. Inhibiting miR-19b reduces Th9 cells and ameliorates the disease. Mechanistically, transforming growth factor beta (TGF-ß) plus IL-4 activates pSmad3-Ser213 and TRAF6-K63 ubiquitination by suppressing NLRC3. Activated TRAF6 sequentially promotes TGF-ß-activated kinase 1 (TAK1) and nuclear factor κB (NF-κB) p65 phosphorylation, leading to the upregulation of miR-19b. Notably, miR-19b activated Il9 gene expression by directly suppressing atypical E2F family member E2f8. In patients with SSc, higher levels of IL9 and MIR-19B correlate with worse disease progression. Our findings reveal miR-19b as a key factor in Th9 cell-mediated SSc pathogenesis and should have clinical implications for patients with SSc.