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1.
Mol Cell ; 70(3): 395-407.e4, 2018 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-29727616

RESUMEN

Telomeres and telomere-binding proteins form complex secondary nucleoprotein structures that are critical for genome integrity but can present serious challenges during telomere DNA replication. It remains unclear how telomere replication stress is resolved during S phase. Here, we show that the BUB3-BUB1 complex, a component in spindle assembly checkpoint, binds to telomeres during S phase and promotes telomere DNA replication. Loss of the BUB3-BUB1 complex results in telomere replication defects, including fragile and shortened telomeres. We also demonstrate that the telomere-binding ability of BUB3 and kinase activity of BUB1 are indispensable to BUB3-BUB1 function at telomeres. TRF2 targets BUB1-BUB3 to telomeres, and BUB1 can directly phosphorylate TRF1 and promote TRF1 recruitment of BLM helicase to overcome replication stress. Our findings have uncovered previously unknown roles for the BUB3-BUB1 complex in S phase and shed light on how proteins from diverse pathways function coordinately to ensure proper telomere replication and maintenance.


Asunto(s)
Proteínas de Ciclo Celular/genética , Replicación del ADN/genética , Proteínas de Unión a Poli-ADP-Ribosa/genética , Proteínas Serina-Treonina Quinasas/genética , Telómero/genética , Línea Celular , Línea Celular Tumoral , ADN Helicasas/genética , Células HEK293 , Células HeLa , Humanos , Puntos de Control de la Fase M del Ciclo Celular/genética , Fase S/genética , Huso Acromático/genética , Proteínas de Unión a Telómeros/genética
2.
PLoS Genet ; 19(9): e1010937, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37756323

RESUMEN

Telomeric repeat-containing RNA (TERRA) is a class of long noncoding RNAs (lncRNAs) that are transcribed from subtelomeric to telomeric region of chromosome ends. TERRA is prone to form R-loop structures at telomeres by invading into telomeric DNA. Excessive telomere R-loops result in telomere instability, so the TERRA level needs to be delicately modulated. However, the molecular mechanisms and factors controlling TERRA level are still largely unknown. In this study, we report that the RNA binding protein RBMX is a novel regulator of TERRA level and telomere integrity. The expression level of TERRA is significantly elevated in RBMX depleted cells, leading to enhanced telomere R-loop formation, replication stress, and telomere instability. We also found that RBMX binds to TERRA and the nuclear exosome targeting protein ZCCHC8 simultaneously, and that TERRA degradation slows down upon RBMX depletion, implying that RBMX promotes TERRA degradation by regulating its transportation to the nuclear exosome, which decays nuclear RNAs. Altogether, these findings uncover a new role of RBMX in TERRA expression regulation and telomere integrity maintenance, and raising RBMX as a potential target of cancer therapy.


Asunto(s)
Exosomas , ARN Largo no Codificante , Exosomas/genética , Heterocromatina , Proteínas Nucleares , ARN Largo no Codificante/genética , Telómero/genética , Humanos
3.
Eur J Nucl Med Mol Imaging ; 51(6): 1703-1712, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38191817

RESUMEN

PURPOSE: Boramino acids are a class of amino acid biomimics that replace the carboxylate group with trifluoroborate and can achieve the 18F-labeled positron emission tomography (PET) and boron neutron capture therapy (BNCT) with identical chemical structure. METHODS: This study reports a trifluoroborate-derived boronophenylalanine (BBPA), a derived boronophenylalanine (BPA) for BNCT, as a promising PET tracer for tumor imaging. RESULTS: Competition inhibition assays in cancer cells suggested the cell accumulation of [18F]BBPA is through large neutral amino acid transporter type-1 (LAT-1). Of note, [18F]BBPA is a pan-cancer probe that shows notable tumor uptake in B16-F10 tumor-bearing mice. In the patients with gliomas and metastatic brain tumors, [18F]BBPA-PET shows good tumor uptake and notable tumor-to-normal brain ratio (T/N ratio, 18.7 ± 5.5, n = 11), higher than common amino acid PET tracers. The [18F]BBPA-PET quantitative parameters exhibited no difference in diverse contrast-enhanced status (P = 0.115-0.687) suggesting the [18F]BBPA uptake was independent from MRI contrast-enhancement. CONCLUSION: This study outlines a clinical trial with [18F]BBPA to achieve higher tumor-specific accumulation for PET, provides a potential technique for brain tumor diagnosis, and might facilitate the BNCT of brain tumors.


Asunto(s)
Compuestos de Boro , Neoplasias Encefálicas , Radioisótopos de Flúor , Fenilalanina , Tomografía Computarizada por Tomografía de Emisión de Positrones , Trazadores Radiactivos , Animales , Femenino , Humanos , Ratones , Compuestos de Boro/análisis , Compuestos de Boro/metabolismo , Compuestos de Boro/farmacocinética , Terapia por Captura de Neutrón de Boro , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/metabolismo , Radioisótopos de Flúor/análisis , Radioisótopos de Flúor/metabolismo , Radioisótopos de Flúor/farmacocinética , Voluntarios Sanos , Transportador de Aminoácidos Neutros Grandes 1/metabolismo , Imagen por Resonancia Magnética , Melanoma Experimental , Ratones Endogámicos C57BL , Sondas Moleculares/análisis , Sondas Moleculares/metabolismo , Sondas Moleculares/farmacocinética , Fenilalanina/análogos & derivados , Fenilalanina/análisis , Fenilalanina/metabolismo , Fenilalanina/farmacocinética , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Cell Commun Signal ; 22(1): 333, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890642

RESUMEN

Glioblastoma (GBM) is the most common malignant brain tumor and has a dismal prognosis even under the current first-line treatment, with a 5-year survival rate less than 7%. Therefore, it is important to understand the mechanism of treatment resistance and develop new anti-tumor strategies. Induction of programmed cell death (PCD) has become a promising anti-tumor strategy, but its effectiveness in treating GBM remains controversial. On the one hand, PCD triggers tumor cell death and then release mediators to draw in immune cells, creating a pro-inflammatory tumor microenvironment (TME). One the other hand, mounting evidence suggests that PCD and inflammatory TME will force tumor cells to evolve under survival stress, leading to tumor recurrence. The purpose of this review is to summarize the role of PCD and inflammatory TME in the tumor evolution of GBM and promising methods to overcome tumor evolution.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Inflamación , Microambiente Tumoral , Glioblastoma/patología , Glioblastoma/genética , Humanos , Inflamación/patología , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/genética , Apoptosis , Animales
5.
Purinergic Signal ; 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38421486

RESUMEN

For many years, there has been ongoing research on the P2X7 receptor (P2X7R). A comprehensive, systematic, and objective evaluation of the scientific output and status of P2X7R will be instrumental in guiding future research directions. This study aims to present the status and trends of P2X7R research from 2002 to 2023. Publications related to P2X7R were retrieved from the Web of Science Core Collection database. Quantitative analysis and visualization tools were Microsoft Excel, VOSviewer, and CiteSpace software. The analysis content included publication trends, literature co-citation, and keywords. 3282 records were included in total, with the majority of papers published within the last 10 years. Based on literature co-citation and keyword analysis, neuroinflammation, neuropathic pain, gastrointestinal diseases, tumor microenvironment, rheumatoid arthritis, age-related macular degeneration, and P2X7R antagonists were considered to be the hotspots and frontiers of P2X7R research. Researchers will get a more intuitive understanding of the status and trends of P2X7R research from this study.

6.
BMC Neurol ; 24(1): 202, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38877400

RESUMEN

BACKGROUND: Intratumoral hemorrhage, though less common, could be the first clinical manifestation of glioma and is detectable via MRI; however, its exact impacts on patient outcomes remain unclear and controversial. The 2021 WHO CNS 5 classification emphasised genetic and molecular features, initiating the necessity to establish the correlation between hemorrhage and molecular alterations. This study aims to determine the prevalence of intratumoral hemorrhage in glioma subtypes and identify associated molecular and clinical characteristics to improve patient management. METHODS: Integrated clinical data and imaging studies of patients who underwent surgery at the Department of Neurosurgery at Peking Union Medical College Hospital from January 2011 to January 2022 with pathological confirmation of glioma were retrospectively reviewed. Patients were divided into hemorrhage and non-hemorrhage groups based on preoperative magnetic resonance imaging. A comparison and survival analysis were conducted with the two groups. In terms of subgroup analysis, we classified patients into astrocytoma, IDH-mutant; oligodendroglioma, IDH-mutant, 1p/19q-codeleted; glioblastoma, IDH-wildtype; pediatric-type gliomas; or circumscribed glioma using integrated histological and molecular characteristics, according to WHO CNS 5 classifications. RESULTS: 457 patients were enrolled in the analysis, including 67 (14.7%) patients with intratumoral hemorrhage. The hemorrhage group was significantly older and had worse preoperative Karnofsky performance scores. The hemorrhage group had a higher occurrence of neurological impairment and a higher Ki-67 index. Molecular analysis indicated that CDKN2B, KMT5B, and PIK3CA alteration occurred more in the hemorrhage group (CDKN2B, 84.4% vs. 62.2%, p = 0.029; KMT5B, 25.0% vs. 8.9%, p = 0.029; and PIK3CA, 81.3% vs. 58.5%, p = 0.029). Survival analysis showed significantly worse prognoses for the hemorrhage group (hemorrhage 18.4 months vs. non-hemorrhage 39.1 months, p = 0.01). In subgroup analysis, the multivariate analysis showed that intra-tumoral hemorrhage is an independent risk factor only in glioblastoma, IDH-wildtype (162 cases of 457 overall, HR = 1.72, p = 0.026), but not in other types of gliomas. The molecular alteration of CDK6 (hemorrhage group p = 0.004, non-hemorrhage group p < 0.001), EGFR (hemorrhage group p = 0.003, non-hemorrhage group p = 0.001), and FGFR2 (hemorrhage group p = 0.007, non-hemorrhage group p = 0.001) was associated with shorter overall survival time in both hemorrhage and non-hemorrhage groups. CONCLUSIONS: Glioma patients with preoperative intratumoral hemorrhage had unfavorable prognoses compared to their nonhemorrhage counterparts. CDKN2B, KMT5B, and PIK3CA alterations were associated with an increased occurrence of intratumoral hemorrhage, which might be future targets for further investigation of intratumoral hemorrhage.


Asunto(s)
Neoplasias Encefálicas , Glioma , Humanos , Masculino , Femenino , Glioma/complicaciones , Glioma/genética , Glioma/cirugía , Glioma/patología , Persona de Mediana Edad , Estudios Retrospectivos , Pronóstico , Adulto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Neoplasias Encefálicas/patología , Anciano , Estudios de Cohortes , Adulto Joven
7.
BMC Med Imaging ; 24(1): 142, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862900

RESUMEN

BACKGROUND: To investigate whether the intraoperative superb microvascular imaging(SMI) technique helps evaluate lesion boundaries compared with conventional grayscale ultrasound in brain tumor surgery and to explore factors that may be associated with complete radiographic resection. METHODS: This study enrolled 57 consecutive brain tumor patients undergoing surgery. During the operation, B-mode and SMI ultrasound evaluated the boundaries of brain tumors. MRI before and within 48h after surgery was used as the gold standard to evaluate gross-total resection(GTR). The ultrasound findings and GTR results were analyzed to determine the imaging factors related to GTR. RESULTS: A total of 57 patients were enrolled in the study, including 32 males and 25 females, with an average age of 53.4 ± 14.1 years old(range 19 ~ 80). According to the assessment criteria of MRI, before and within 48 h after the operation, 37(63.9%) cases were classified as GTR, and 20(35.1%) cases were classified as GTR. In comparing tumor interface definition between B-mode and SMI mode, SMI improved HGG boundary recognition in 5 cases(P = 0.033). The results showed that the tumor size ≥ 5 cm and unclear ultrasonic boundary were independent risk factors for nGTR (OR>1, P<0.05). CONCLUSIONS: As an innovative intraoperative doppler technique in neurosurgery, SMI can effectively demarcate the tumor's boundary and help achieve GTR as much as possible.


Asunto(s)
Neoplasias Encefálicas , Imagen por Resonancia Magnética , Humanos , Femenino , Persona de Mediana Edad , Masculino , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Adulto , Anciano , Imagen por Resonancia Magnética/métodos , Anciano de 80 o más Años , Microvasos/diagnóstico por imagen , Adulto Joven , Ultrasonografía/métodos
8.
Nucleic Acids Res ; 50(20): 11619-11634, 2022 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-36399511

RESUMEN

Telomeric repeat-containing RNA (TERRA) is a type of long non-coding RNA transcribed from telomeres, and it forms R-loops by invasion into telomeric DNA. Since either an excessive or inadequate number of R-loops leads to telomere instability, the TERRA levels need to be delicately modulated. In this study, we found that m6A modification presents on the subtelomeric regions of TERRA and stabilizes it, and the loss of METTL3 impacts telomere stability. Mechanically, the m6A modification on TERRA is catalyzed by METTL3, recognized and stabilized by the m6A reader YTHDC1. Knockdown of either METTL3 or YTHDC1 enhances TERRA degradation. The m6A-modified TERRA forms R-loops and promotes homologous recombination which is essential for the alternative lengthening of telomeres (ALT) pathway in cancer cells. METTL3 depletion leads to R-loop reduction, telomere shortening and instability. Altogether, these findings reveal that METTL3 protects telomeres by catalyzing m6A modification on TERRA, indicating that inhibition or deletion of METTL3 is potentially a new avenue for ALT cancer therapy.


Asunto(s)
ARN Largo no Codificante , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Telómero/genética , Telómero/metabolismo , Acortamiento del Telómero , Recombinación Homóloga , ADN , Homeostasis del Telómero
9.
Metab Brain Dis ; 39(5): 719-729, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38687460

RESUMEN

BACKGROUND: Glioma is the main subtype of primary central nervous system (CNS) tumor with high malignancy and poor prognosis under current therapeutic approaches. Glycolysis and suppressive tumor microenvironment (TME) are key markers of glioma with great importance for aggressive features of glioma and inferior clinical outcomes. Hexokinase 3 (HK3) is an important rate-limiting enzyme in glycolysis, but its function in glioma remains unknown. METHODS: This study comprehensively assessed the expression distribution and immunological effect of HK3 via pan-cancer analysis based on datasets from Genotype Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE), and The Cancer Genome Atlas (TCGA). Furthermore, it explored the malignant phenotype and genomic landscape between low-HK3 and high-HK3 expression groups in gliomas from Chinese Glioma Genome Atlas (CGGA) and TCGA. Moreover, data from the TIMER website predicted the relationship between macrophage infiltration and HK3 expression. Also, single-cell sequencing data were used to validate the relationship. RESULTS: For pan-cancer patients, HK3 was expressed in various cancers. The results showed that HK3 was highly expressed in gliomas and positively correlated with tumor-infiltrating immune cells (TIICs), immune checkpoints, immunomodulators, and chemokines. Meanwhile, HK3 expression was highest in normal immune cells and tissues. In gliomas, the expression of HK3 was found to be closely correlated with the malignant clinical characteristics and the infiltration of macrophages. Also, HK3 was proven to be positively associated with macrophage through single-cell sequencing data and immunohistochemistry techniques. Finally, it is predicted that samples with high HK3 expression are often malignant entities and also significant genomic aberrations of driver oncogenes. CONCLUSIONS: This is the first comprehensive research to figure out the relationship between HK3 and TME characteristics in gliomas. HK3 is positively associated with macrophage infiltration and can induce the immunosuppressive TME and malignant phenotype of gliomas.


Asunto(s)
Neoplasias Encefálicas , Glioma , Hexoquinasa , Microambiente Tumoral , Humanos , Glioma/patología , Glioma/genética , Glioma/inmunología , Glioma/enzimología , Hexoquinasa/metabolismo , Hexoquinasa/genética , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/inmunología , Microambiente Tumoral/inmunología , Macrófagos/metabolismo , Macrófagos/patología , Regulación Neoplásica de la Expresión Génica
10.
Postgrad Med J ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38652265

RESUMEN

PURPOSE: Umeclidinium plus vilanterol (UMEC/VI) is an inhaled long-acting muscarinic antagonist/long-acting beta2-agonist (LAMA/LABA), recently approved as once-daily maintenance therapy for chronic obstructive pulmonary disease (COPD). This meta-analysis aims to assess the efficacy and safety of UMEC/VI compared with fluticasone propionate plus salmeterol (FP/SAL). METHODS: A systematic search was conducted by a trained medical research librarian across MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese Biomedical Literature Database (CBM) for randomized controlled trials comparing UMEC/VI with FP/SAL in COPD patients. Two reviewers independently assessed the risk of bias and extracted data. The primary outcome was 0-24 h weighted mean (wm) forced expiratory volume in the first second (FEV1), trough FEV1. The secondary outcomes were other lung functions, symptoms, quality of life, and safety. RESULTS: Three studies with 2119 patients were included in the meta-analysis. UMEC/VI showed improvement in 0-24 h wm FEV1 (mean difference (MD) 0.08 L, 95% confidence interval (CI) 0.06 to 0.10, P < 0.01, moderate quality) and trough FEV1 (MD 0.09 L, 95% CI 0.07 to 0.11, P < 0.01, moderate quality) in comparison with FP/SAL. UMEC/VI statistically significantly improved all other lung functions compared with FP/SAL. However, there were no significant differences between UMEC/VI and FP/SAL in rescue-medication use, symptomatic endpoints, and health outcomes. UMEC/VI also demonstrated fewer drug-related adverse effects (risk ratio 0.47, 95% CI 0.27 to 0.82, P = 0.01, low quality). CONCLUSIONS: UMEC/VI, when compared with FP/SAL, demonstrated significant improvements in lung functions with fewer drug-related adverse effects. However, the conclusion was limited by the scarcity of studies and long-term trials.

11.
J Neurophysiol ; 129(4): 862-871, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36919939

RESUMEN

Intracerebral hemorrhage (ICH) is classified as a lethal neurological injury associated with cerebrovascular disorders. Ferroptosis is a unique form of cell death and participates in ICH pathogenesis. Herein, the role of SRY-box transcription factor 10 (SOX10) in ferroptosis of hippocampal neurons after ICH was investigated. The in vitro ICH models were established by treating immortalized mouse hippocampal cell line HT-22 with Hemin. Quantitative real-time polymerase chain reaction and Western blotting revealed that the transcription factor SOX10 and microRNA (miR)-29a-3p were decreased whereas acyl-CoA synthetase long-chain family member 4 (ACSL4) was increased in the ICH cell models. Subsequently, the assays of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, the commercial kits, and fluorescent labeling revealed that SOX10 overexpression improved cell viability, decreased the amount of reactive oxygen species (ROS) and Fe2+, and increased the amount of glutathione (GSH) and glutathione peroxidase 4 (GPX4) in ICH models. Thereafter, chromatin immunoprecipitation and dual-luciferase assays showed that SOX10 binding to the miR-29a-3p promoter region increased miR-29a-3p expression, and miR-29a-3p targeted and limited ACSL4 transcription. Rescue experiments showed that miR-29a-3p downregulation or ACSL4 overexpression expedited ferroptosis of Hemin-treated HT-22 cells. Taken together, SOX10 contributed to ferroptosis of hippocampal neurons after ICH via increasing miR-29a-3p to limit ACSL4 transcription.NEW & NOTEWORTHY SOX10 promotes the expression of Mir-29a-3p by binding to the promoter region of Mir-29a-3p, thereby targeting the expression of ACSL4 and inhibiting the iron death of hippocampal neuronal cells in mice with ICH.


Asunto(s)
Ferroptosis , MicroARNs , Ratones , Animales , MicroARNs/genética , MicroARNs/metabolismo , Hemina/metabolismo , Hemorragia Cerebral/genética , Hemorragia Cerebral/metabolismo , Neuronas/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción SOXE/metabolismo , Coenzima A Ligasas/genética , Coenzima A Ligasas/metabolismo
12.
Brief Bioinform ; 22(5)2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-33839757

RESUMEN

Glioblastoma (GBM) is the most malignant and lethal intracranial tumor, with extremely limited treatment options. Immunotherapy has been widely studied in GBM, but none can significantly prolong the overall survival (OS) of patients without selection. Considering that GBM cancer stem cells (CSCs) play a non-negligible role in tumorigenesis and chemoradiotherapy resistance, we proposed a novel stemness-based classification of GBM and screened out certain population more responsive to immunotherapy. The one-class logistic regression algorithm was used to calculate the stemness index (mRNAsi) of 518 GBM patients from The Cancer Genome Atlas (TCGA) database based on transcriptomics of GBM and pluripotent stem cells. Based on their stemness signature, GBM patients were divided into two subtypes via consensus clustering, and patients in Stemness Subtype I presented significantly better OS but poorer progression-free survival than Stemness Subtype II. Genomic variations revealed patients in Stemness Subtype I had higher somatic mutation loads and copy number alteration burdens. Additionally, two stemness subtypes had distinct tumor immune microenvironment patterns. Tumor Immune Dysfunction and Exclusion and subclass mapping analysis further demonstrated patients in Stemness Subtype I were more likely to respond to immunotherapy, especially anti-PD1 treatment. The pRRophetic algorithm also indicated patients in Stemness Subtype I were more resistant to temozolomide therapy. Finally, multiple machine learning algorithms were used to develop a 7-gene Stemness Subtype Predictor, which were further validated in two external independent GBM cohorts. This novel stemness-based classification could provide a promising prognostic predictor for GBM and may guide physicians in selecting potential responders for preferential use of immunotherapy.


Asunto(s)
Antineoplásicos Alquilantes/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Aprendizaje Automático , Células Madre Neoplásicas/efectos de los fármacos , Temozolomida/uso terapéutico , Transcriptoma , Adulto , Anciano , Atlas como Asunto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Glioblastoma/mortalidad , Glioblastoma/patología , Humanos , Inmunoterapia/métodos , Masculino , Persona de Mediana Edad , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/patología , Selección de Paciente , Pronóstico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/genética , Receptor de Muerte Celular Programada 1/inmunología , Análisis de Supervivencia , Resultado del Tratamiento , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/genética , Microambiente Tumoral/inmunología
13.
Opt Express ; 31(8): 13125-13139, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37157457

RESUMEN

Active devices play a critical role in modern electromagnetic and photonics systems. To date, the epsilon (ε)-near-zero (ENZ) is usually integrated with the low Q-factor resonant metasurface to achieve active devices, and enhance the light-matter interaction significantly at the nanoscale. However, the low Q-factor resonance may limit the optical modulation. Less work has been focused on the optical modulation in the low-loss and high Q-factor metasurfaces. Recently, the emerging optical bound states in the continuum (BICs) provides an effective way for achieving high Q-factor resonators. In this work, we numerically demonstrate a tunable quasi-BICs (QBICs) by integrating a silicon metasurface with ENZ ITO thin film. Such a metasurface is composed of five square holes in a unit cell, and hosts multiple BICs by engineering the position of centre hole. We also reveal the nature of these QBICs by performing multipole decomposition and calculating near field distribution. Thanks to the large tunability of ITO's permittivity by external bias and high-Q factor enabled by QBICs, we demonstrate an active control on the resonant peak position and intensity of transmission spectrum by integrating ENZ ITO thin films with QBICs supported by silicon metasurfaces. We find that all QBICs show excellent performance on modulating the optical response of such a hybrid structure. The modulation depth can be up to 14.8 dB. We also investigate how the carrier density of ITO film influence the near-field trapping and far-field scattering, which in turn influence the performance of optical modulation based on this structure. Our results may find promising applications in developing active high-performance optical devices.

14.
Opt Lett ; 48(8): 2158-2161, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37058666

RESUMEN

Bound states in the continuum (BICs) hold great promise in enhancing light-matter interaction as they have an infinite Q-factor. To date, the symmetry-protected BIC (SP-BIC) is one of the most intensively studied BICs because it is easily found in a dielectric metasurface satisfying certain group symmetry. To convert SP-BICs into quasi-BICs (QBICs), structural symmetry shall be broken so that external excitation can access them. Usually, the unit cell's asymmetry is created by removing or adding parts of dielectric nanostructures. The QBICs are usually excited only by s-polarized or p-polarized light because of the symmetry-breaking of the structure. In this work, we investigate the excited QBIC properties by introducing double notches on the edges of highly symmetrical silicon nanodisks. The QBIC shares the same optical response under the s-polarized and p-polarized light. The effect of polarization on coupling efficiency between the QBIC mode and incident light is studied, and the highest coupling efficiency occurs at a polarization angle of 135 ∘, which corresponds to the radiative channel. Moreover, the near-field distribution and multipole decomposition confirm that the QBIC is dominated by the magnetic dipole along the z direction. It is noted that the QBIC covers a wide spectrum region. Finally, we present an experimental confirmation; the measured spectrum shows a sharp Fano resonance with a Q-factor of 260. Our results suggest promising applications in enhancing light-matter interaction, such as lasing, sensing, and nonlinear harmonic generation.

15.
Cancer Cell Int ; 23(1): 227, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37779195

RESUMEN

BACKGROUND: Glioma is the most common and lethal type of brain tumor, and it is characterized by unfavorable prognosis and high recurrence rates. The reprogramming of energy metabolism and an immunosuppressive tumor microenvironment (TME) are two hallmarks of tumors. Complex and dynamic interactions between neoplastic cells and the surrounding microenvironment can generate an immunosuppressive TME, which can accelerate the malignant progression of glioma. Therefore, it is crucial to explore associations between energy metabolism and the immunosuppressive TME and to identify new biomarkers for glioma prognosis. METHODS: In our work, we analyzed the co-expression relationship between glycolytic genes and immune checkpoints based on the transcriptomic data from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) and found the correlation between HK3 expression and glioma tumor immune status. To investigate the biological role of HK3 in glioma, we performed bioinformatics analysis and established a mouse glioblastoma (GBM) xenograft model. RESULTS: Our study showed that HK3 significantly stimulated immune cell infiltration into the glioma TME. Tissue samples with higher HK3 expressive level showed increasing levels of immune cells infiltration, including M2 macrophages, neutrophils, and various subtypes of activated memory CD4+ T cells. Furthermore, HK3 expression was significantly increasing along with the elevated tumor grade, had a higher level in the mesenchymal subtype compared with those in other subtypes of GBM and could independently predict poor outcomes of GBM patients. CONCLUSION: The present work mainly concentrated on the biological role of HK3 in glioma and offered a novel insight of HK3 regulating the activation of immune cells in the glioma microenvironment. These findings could provide a new theoretical evidence for understanding the metabolic molecular within the glioma microenvironment and identifying new therapeutic targets.

16.
Cancer Cell Int ; 23(1): 156, 2023 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-37542290

RESUMEN

BACKGROUND: N6-methyladenosine (m6A), 5-methylcytosine (m5C) and N1-methyladenosine (m1A) are the main RNA methylation modifications involved in the progression of cancer. However, it is still unclear whether RNA methylation-related long noncoding RNAs (lncRNAs) affect the prognosis of glioma. METHODS: We summarized 32 m6A/m5C/m1A-related genes and downloaded RNA-seq data and clinical information from The Cancer Genome Atlas (TCGA) database. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were used to identify differentially expressed (DE-) RNA methylation-related lncRNAs in order to construct a prognostic signature of glioma and in order to determine their correlation with immune function, immune therapy and drug sensitivity. In vitro and in vivo assays were performed to elucidate the effects of RNA methylation-related lncRNAs on glioma. RESULTS: A total of ten RNA methylation-related lncRNAs were used to construct a survival and prognosis signature, which had good independent prediction ability for patients. It was found that the high-risk group had worse overall survival (OS) than the low-risk group in all cohorts. In addition, the risk group informed the immune function, immunotherapy response and drug sensitivity of patients with glioma in different subgroups. Knockdown of RP11-98I9.4 and RP11-752G15.8 induced a more invasive phenotype, accelerated cell growth and apparent resistance to temozolomide (TMZ) both in vitro and in vivo. We observed significantly elevated global RNA m5C and m6A levels in glioma cells. CONCLUSION: Our study determined the prognostic implication of RNA methylation-related lncRNAs in gliomas, established an RNA methylation-related lncRNA prognostic model, and elucidated that RP11-98I9.4 and RP11-752G15.8 could suppress glioma proliferation, migration and TMZ resistance. In the future, these RNA methylation-related lncRNAs may become a new choice for immunotherapy of glioma.

17.
Cell Commun Signal ; 21(1): 74, 2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-37046332

RESUMEN

Glioblastoma (GBM) is the most malignant CNS tumor with a highest incidence rate, and most patients would undergo a recurrence. Recurrent GBM (rGBM) shows an increasing resistance to chemotherapy and radiotherapy, leading to a significantly poorer prognosis and the urgent need for novel treatments. Immunotherapy, a rapidly developing anti-tumor therapy in recent years, has shown its potential value in rGBM. Recent studies on PD-1 immunotherapy and CAR-T therapy have shown some efficacy, but the outcome was not as expected. Tumor vaccination is the oldest approach of immunotherapies, which has returned to the research focus because of the failure of other strategies and subversive understanding of CNS. The isolation effect of blood brain barrier and the immunosuppressive cell infiltration could lead to resistance existing in all phases of the anti-tumor immune response, where novel tumor vaccines have been designed to overcome these problems through new tumor antigenic targets and regulatory of the systematic immune response. In this review, the immunological characteristics of CNS and GBM would be discussed and summarized, as well as the mechanism of each novel tumor vaccine for rGBM. And through the review of completed early-phase studies and ongoing large-scale phase III clinical trials, evaluation could be conducted for potential immune response, biosecurity and initial clinical outcome, which further draw a panorama of this vital research field and provide some deep thoughts for the prospective tendency of vaccination strategy. Video Abstract.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/patología , Estudios Prospectivos , Neoplasias Encefálicas/patología , Inmunoterapia
18.
Eur Radiol ; 33(6): 4052-4062, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36472694

RESUMEN

OBJECTIVES: Preventing the expansion of perihematomal edema (PHE) represents a novel strategy for the improvement of neurological outcomes in intracerebral hemorrhage (ICH) patients. Our goal was to predict early and delayed PHE expansion using a machine learning approach. METHODS: We enrolled 550 patients with spontaneous ICH to study early PHE expansion, and 389 patients to study delayed expansion. Two imaging researchers rated the shape and density of hematoma in non-contrast computed tomography (NCCT). We trained a radiological machine learning (ML) model, a radiomics ML model, and a combined ML model, using data from radiomics, traditional imaging, and clinical indicators. We then validated these models on an independent dataset by using a nested 4-fold cross-validation approach. We compared models with respect to their predictive performance, which was assessed using the receiver operating characteristic curve. RESULTS: For both early and delayed PHE expansion, the combined ML model was most predictive (early/delayed AUC values were 0.840/0.705), followed by the radiomics ML model (0.799/0.663), the radiological ML model (0.779/0.631), and the imaging readers (reader 1: 0.668/0.565, reader 2: 0.700/0.617). CONCLUSION: We validated a machine learning approach with high interpretability for the prediction of early and delayed PHE expansion. This new technique may assist clinical practice for the management of neurocritical patients with ICH. KEY POINTS: • This is the first study to use artificial intelligence technology for the prediction of perihematomal edema expansion. • A combined machine learning model, trained on data from radiomics, clinical indicators, and imaging features associated with hematoma expansion, outperformed all other methods.


Asunto(s)
Inteligencia Artificial , Edema Encefálico , Humanos , Edema Encefálico/diagnóstico por imagen , Edema Encefálico/etiología , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/diagnóstico por imagen , Edema/diagnóstico por imagen , Edema/complicaciones , Aprendizaje Automático , Hematoma/complicaciones , Hematoma/diagnóstico por imagen
19.
Org Biomol Chem ; 21(47): 9459-9462, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-37997156

RESUMEN

Deoxofluor-promoted intramolecular cyclopropanation of 1,2-(3-indole)fullerenols has been developed as a straightforward and efficient protocol for the synthesis of various spiro[indolenine]-methanofullerenes. This approach exhibits low cost, operational simplicity, and convenient conditions, and thus has potential application value.

20.
Cardiovasc Drugs Ther ; 37(5): 877-889, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-35670983

RESUMEN

BACKGROUND: Human aortic vascular smooth muscle cells (HA-VSMCs) play vital roles in the pathogenesis of vascular diseases. Circular RNAs (circRNAs) have been reported to regulate the biological functions of HA-VSMCs. In this study, the functions of circRNA pecanex homolog (circPCNX) in platelet-derived growth factor-BB (PDGF-BB)-induced HA-VSMCs were investigated. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the expression of circPCNX, DNA methyltransferase 1 (DNMT1), and microRNA-1278 (miR-1278). 5'-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry analysis, wound healing assay, and transwell assay were used to examine cell proliferation, cell cycle, and migration. Western blot assay was utilized to measure protein levels. RNA immunoprecipitation (RIP) assay, RNA pull down assay, and dual-luciferase reporter assay were adopted to analyze the relationships among circPCNX, miR-1278, and DNMT1. RESULTS: CircPCNX was upregulated in PDGF-BB-treated HA-VSMCs in a dose- or time-dependent manner. CircPCNX knockdown alleviated PDGF-BB-induced cell proliferation, cell cycle progression, and migration in HA-VSMCs. CircPCNX knockdown could reverse PDGF-BB-induced HA-VSMC progression by regulating DNMT1. Moreover, circPCNX was identified to regulate DNMT1 expression by sponging miR-1278. Inhibition of miR-1278 reversed circPCNX knockdown-mediated effects on cell proliferation and migration in PDGF-BB-induced HA-VSMCs. MiR-1278 overexpression suppressed PDGF-BB-stimulated HA-VSMC proliferation and migration by targeting DNMT1. CONCLUSION: CircPCNX promoted PDGF-BB-induced HA-VSMC proliferation and migration by elevating DNMT1 expression through sponging miR-1278.


Asunto(s)
Becaplermina , MicroARNs , Músculo Liso Vascular , Humanos , Becaplermina/farmacología , Movimiento Celular , Proliferación Celular , Células Cultivadas , MicroARNs/genética , MicroARNs/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Transducción de Señal
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