Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
1.
Rep Prog Phys ; 87(5)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38608453

RESUMO

Active matter systems, which convert internal chemical energy or energy from the environment into directed motion, are ubiquitous in nature and exhibit a range of emerging non-equilibrium behaviors. However, most of the current works on active matter have been devoted to particles, and the study of active polymers has only recently come into the spotlight due to their prevalence within living organisms. The intricate interplay between activity and conformational degrees of freedom gives rise to novel structural and dynamical behaviors of active polymers. Research in active polymers remarkably broadens diverse concepts of polymer physics, such as molecular architecture, dynamics, scaling and so on, which is of significant importance for the development of new polymer materials with unique performance. Furthermore, active polymers are often found in strongly interacting and crowded systems and in complex environments, so that the understanding of this behavior is essential for future developments of novel polymer-based biomaterials. This review thereby focuses on the study of active polymers in complex and crowded environments, and aims to provide insights into the fundamental physics underlying the adaptive and collective behaviors far from equilibrium, as well as the open challenges that the field is currently facing.

2.
J Phys Chem Lett ; 15(9): 2453-2461, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38407025

RESUMO

The organic-inorganic halide perovskite has become one of the most promising candidates for next-generation memory devices, i.e. memristors, with excellent performance and solution-processable preparation. Yet, the mechanism of resistive switching in perovskite-based memristors remains ambiguous due to a lack of in situ visualized characterization methods. Here, we directly observe the switching process of perovskite memristors with in situ photoluminescence (PL) imaging microscopy under an external electric field. Furthermore, the corresponding element composition of conductive filaments (CFs) is studied, indicating that the metallic CFs with respect to the activity of the top electrode are essential for device performance. Finally, electrochemical impedance spectroscopy (EIS) is conducted to reveal that the transition of ion states is associated with the formation of metallic CFs. This study provides in-depth insights into the switching mechanism of perovskite memristors, paving a pathway to develop and optimize high-performance perovskite memristors for large-scale applications.

3.
J Exp Clin Cancer Res ; 43(1): 2, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38163881

RESUMO

BACKGROUND: Cisplatin (CDDP)-based chemotherapy is a standard first-line treatment for metastatic bladder cancer (BCa) patients, and chemoresistance remains a major challenge in clinical practice. Circular RNAs (circRNAs) have emerged as essential regulators in carcinogenesis and cancer progression. However, the role of circRNAs in mediating CDDP chemosensitivity has yet to be well elucidated in BCa. METHODS: CircSTX6 (hsa_circ_0007905) was identified by mining the public circRNA datasets and verified by Sanger sequencing, agarose gel electrophoresis, RNase R treatment and qRT-PCR assays. Then, function experiments were performed to evaluate the effects of circSTX6 on BCa metastasis. Luciferase reporter assay, RNA pull-down, RNA immunoprecipitation (RIP), RNA stability assay, Fluorescence in situ hybridization (FISH) and Immunofluorescence (IF) were conducted to evaluate the interaction among circSTX6, miR-515-3p, PABPC1 and SUZ12. Animal experiments were performed to explore the function of circSTX6 in tumor metastasis and CDDP sensitivity. RESULTS: We identified that circSTX6 was significantly upregulated in clinical samples and cells of BCa. Functionally, circSTX6 promoted cell migration and invasion both in vitro and in vivo. Mechanistically, circSTX6 could act as a miR-515-3p sponge and abolish its effect on SUZ12. Moreover, circSTX6 was confirmed to increase the stability of SUZ12 mRNA by interacting with a mRNA stabilizer PABPC1 and subsequently promote the expression of SUZ12. Importantly, silencing of circSTX6 improved the chemosensitivity of CDDP-resistant bladder cancer cells to CDDP. Furthermore, in vivo analysis supported that knockdown of circSTX6 attenuated CDDP resistance in BCa tumors. CONCLUSION: These studies demonstrate that circSTX6 plays a pivotal role in BCa metastasis and chemoresistance, and has potential to serve as a therapeutic target for treatment of BCa.


Assuntos
MicroRNAs , Neoplasias da Bexiga Urinária , Animais , Humanos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , MicroRNAs/genética , RNA Circular/genética , Hibridização in Situ Fluorescente , Regulação Neoplásica da Expressão Gênica , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Proteínas de Ligação a RNA/genética , RNA Mensageiro , Proliferação de Células , Linhagem Celular Tumoral , Fator de Iniciação 4A em Eucariotos/genética , RNA Helicases DEAD-box/genética
4.
Sci Rep ; 14(1): 533, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177383

RESUMO

The prevalence of myopia (nearsightedness) is increasing to alarming levels, but its etiology remains poorly understood. Because both laboratory and clinical findings suggest an etiologic role for circadian rhythms in myopia development, we assayed gene expression by RNA-Seq in retina and choroid at the onset of unilateral experimental myopia in chick, isolating tissues every 4 h during a single 24-h period from myopic and contralateral control eyes. Occluded versus open eye gene expression differences varied considerably over the 24-h sampling period, with some occurring at multiple times of day but with others showing differences at only a single investigated timepoint. Some of the genes identified in retina or choroid of chick myopia were previously identified as candidate genes for common human myopia. Like differentially expressed genes, pathways identified by Gene Set Enrichment Analysis also varied dramatically by sampling time. Considered with other laboratory data, human genetic and epidemiology data, these findings further implicate circadian events in myopia pathogenesis. The present results emphasize a need to include time of day in mechanistic studies of myopia and to assess circadian biology directly in trying to understand better the origin of myopia and to develop more effective therapies.


Assuntos
Miopia , Retina , Humanos , Animais , Retina/metabolismo , Miopia/genética , Miopia/metabolismo , Corioide/metabolismo , Ritmo Circadiano/genética , Expressão Gênica , Biologia , Galinhas/genética
5.
Nat Commun ; 15(1): 525, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225267

RESUMO

Transport of rodlike particles in confinement environments of macromolecular networks plays crucial roles in many important biological processes and technological applications. The relevant understanding has been limited to thin rods with diameter much smaller than network mesh size, although the opposite case, of which the dynamical behaviors and underlying physical mechanisms remain unclear, is ubiquitous. Here, we solve this issue by combining experiments, simulations and theory. We find a nonmonotonic dependence of translational diffusion on rod length, characterized by length commensuration-governed unconventionally fast dynamics which is in striking contrast to the monotonic dependence for thin rods. Our results clarify that such a fast diffusion of thick rods with length of integral multiple of mesh size follows sliding dynamics and demonstrate it to be anomalous yet Brownian. Moreover, good agreement between theoretical analysis and simulations corroborates that the sliding dynamics is an intermediate regime between hopping and Brownian dynamics, and provides a mechanistic interpretation based on the rod-length dependent entropic free energy barrier. The findings yield a principle, that is, length commensuration, for optimal design of rodlike particles with highly efficient transport in confined environments of macromolecular networks, and might enrich the physics of the diffusion dynamics in heterogeneous media.

6.
Chin Med J (Engl) ; 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38275022

RESUMO

ABSTRACT: Cancer is a major global health issue. Effective therapeutic strategies can prolong patients' survival and reduce the costs of treatment. Drug repurposing, which identifies new therapeutic uses for approved drugs, is a promising approach with the advantages of reducing research costs, shortening development time, and increasing efficiency and safety. Disulfiram (DSF), an Food and Drug Administration (FDA)-approved drug used to treat chronic alcoholism, has a great potential as an anticancer drug by targeting diverse human malignancies. Several studies show the antitumor effects of DSF, particularly the combination of DSF and copper (DSF/Cu), on a wide range of cancers such as glioblastoma (GBM), breast cancer, liver cancer, pancreatic cancer, and melanoma. In this review, we summarize the antitumor mechanisms of DSF/Cu, including induction of intracellular reactive oxygen species (ROS) and various cell death signaling pathways, and inhibition of proteasome activity, as well as inhibition of nuclear factor-kappa B (NF-κB) signaling. Furthermore, we highlight the ability of DSF/Cu to target cancer stem cells (CSCs), which provides a new approach to prevent tumor recurrence and metastasis. Strikingly, DSF/Cu inhibits several molecular targets associated with drug resistance, and therefore it is becoming a novel option to increase the sensitivity of chemo-resistant and radio-resistant patients. Studies of DSF/Cu may shed light on its improved application to clinical tumor treatment.

7.
BMC Biol ; 22(1): 12, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273307

RESUMO

BACKGROUND: Many viruses enter host cells by hijacking endosomal trafficking. CapZ, a canonical actin capping protein, participates in endosomal trafficking, yet its precise role in endocytosis and virus infection remains elusive. RESULTS: Here, we showed that CapZ was transiently associated with early endosomes (EEs) and was subsequently released from the matured EEs after the fusion of two EEs, which was facilitated by PI(3)P to PI(3,5)P2 conversion. Vacuolin-1 (a triazine compound) stabilized CapZ at EEs and thus blocked the transition of EEs to late endosomes (LEs). Likewise, artificially tethering CapZ to EEs via a rapamycin-induced protein-protein interaction system blocked the early-to-late endosome transition. Remarkably, CapZ knockout or artificially tethering CapZ to EEs via rapamycin significantly inhibited flaviviruses, e.g., Zika virus (ZIKV) and dengue virus (DENV), or beta-coronavirus, e.g., murine hepatitis virus (MHV), infection by preventing the escape of RNA genome from endocytic vesicles. CONCLUSIONS: These results indicate that the temporal association of CapZ with EEs facilitates early-to-late endosome transition (physiologically) and the release of the viral genome from endocytic vesicles (pathologically).


Assuntos
Fosfatos de Fosfatidilinositol , Infecção por Zika virus , Zika virus , Animais , Humanos , Camundongos , Endocitose/fisiologia , Endossomos/metabolismo , Sirolimo/farmacologia , Sirolimo/metabolismo , Vesículas Transportadoras , Internalização do Vírus , Infecção por Zika virus/metabolismo
8.
Phys Chem Chem Phys ; 26(3): 1684-1695, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38126534

RESUMO

The main class of nitrogenases has a molybdenum in its cofactor. A mechanism for Mo-nitrogenase has recently been described. In the present study, another class of nitrogenases has been studied, the one with a vanadium instead of a molybdenum in its cofactor. It is generally believed that these classes use the same general mechanism to activate nitrogen. The same methodology has been used here as the one used for Mo-nitrogenase. N2 activation is known to occur after four reductions in the catalytic cycle, in the E4 state. The main features of the mechanism for Mo-nitrogenase found in the previous study are an activation process in four steps prior to catalysis, the release of a sulfide during the activation steps and the formation of H2 from two hydrides in E4, just before N2 is activated. The same features have been found here for V-nitrogenase. A difference is that five steps are needed in the activation process, which explains why the ground state of V-nitrogenase is a triplet (even number) and the one for Mo-nitrogenase is a quartet (odd number). The reason an additional step is needed for V-nitrogenase is that V3+ can be reduced to V2+, in contrast to the case for Mo3+ in Mo-nitrogenase. The fact that V3+ is Jahn-Teller active has important consequences. N2H2 is formed in E4 with reasonably small barriers.


Assuntos
Nitrogenase , Vanádio , Nitrogenase/metabolismo , Molibdênio , Oxirredução , Nitrogênio
10.
Med ; 4(12): 898-912.e4, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-37944532

RESUMO

BACKGROUND: Meningeal lymphatic vessels (mLVs) have proven to bear a relationship with tumor immunity and therapeutic efficacy of intracranial malignant tumors in pre-clinical animal studies. We aimed to explore the association between mLV function and intracranial malignant tumors in clinical participants. METHODS: The participants were allocated to a control group or a group of patients with intracranial tumors. Dynamic enhanced magnetic resonance was used to evaluate the wash-in and wash-out functions of mLVs around the superior sagittal sinus and the sigmoid sinus. FINDINGS: A total of 246 individuals were recruited for our study. The area under curve and wash-in rate of mLVs in the intracranial tumor group were higher than in the control group (2,749 vs. 2,110, p < 0.001 and 3.72 vs. 2.87, p < 0.001, respectively). The wash-out ratio of mLVs was lower in the intracranial tumor group than in the control group (0.65 vs. 0.73, p < 0.001). Decreased wash-out of mLVs was associated with tumor progression (ß = -0.118; p < 0.001). High-grade glioma and isocitrate dehydrogenase wild type were associated with a lower mLV wash-out function (ß = -0.057, p = 0.044 and ß = -0.069, p = 0.047, respectively). CONCLUSIONS: Intracranial malignant tumors were associated with elevated wash-in function and decreased wash-out function of mLVs. High-grade glioma and isocitrate dehydrogenase wild type were associated with low mLV wash-out function, and long-term decreased mLV wash-out function was a risk factor for tumor progression. FUNDING: There was no funding.


Assuntos
Neoplasias Encefálicas , Glioma , Vasos Linfáticos , Animais , Humanos , Isocitrato Desidrogenase , Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética
11.
Infect Drug Resist ; 16: 7305-7311, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023396

RESUMO

In the available reports on clinical medicine, the infection sites of Mycobacterium porcinum include wounds, bone marrow, respiratory tract, and catheters. A 61-year-old woman was admitted to our hospital; her hilar and mediastinal lymph nodes were found to be enlarged during health examination, but there was no specific discomfort. Initially, she had undergone a mediastinal lymph node biopsy and pathology, but the diagnosis was not confirmed. However, 16S rRNA gene sequencing revealed M. porcinum infection of hilar and mediastinal lymph nodes. Subsequently, she was treated with clarithromycin, amikacin, imipenem, and tigecycline. After 2 months, chest computed tomography showed a significant reduction in lymph nodes. M. porcinum infection was considered to be the cause of disease.

13.
Chaos ; 33(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37352505

RESUMO

The optimization of synchronization on distributed power grids is an important topic in recent years. We extensively study the optimization by restructuring grid topology in terms of connection rewirings. Due to the node-link dual property of power networks, i.e., the intrinsic generator-load dynamics of nodes and the multiple-attribute connections, we propose the frequency-correlation-optimization scheme to get grid topology with the largest anti-correlation by targeting the frequency-correlation function among nodes. The topology optimizations on both sparse and dense networks are successfully realized. The optimized topology exhibits more generator-consumer connections, indicating that a decentralization of the distribution of generator nodes on power grids favors synchronizability. The benefits of these frequency-correlation-optimized power grids to synchrony are verified. By comparing with the phase-coherence-optimization scheme that favors both the optimal topology and efficient synchronizability, we show that the frequency-correlation optimization and the phase-coherence optimization of power grids are usually compatible, while the former is more efficient and simpler in avoiding tedious simulations of high-dimensional nonlinear dynamics. Our explorations may shed light on the predesign and construction of modern distributed power grids, which are composed of decentralized miscellaneous power sources.


Assuntos
Algoritmos , Modelos Teóricos , Simulação por Computador , Dinâmica não Linear , Eletrodos
14.
Curr Med Sci ; 43(3): 560-571, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37142816

RESUMO

OBJECTIVE: Cisplatin (CDDP)-based chemotherapy is a first-line, drug regimen for muscle-invasive bladder cancer (BC) and metastatic bladder cancer. Clinically, resistance to CDDP restricts the clinical benefit of some bladder cancer patients. AT-rich interaction domain 1A (ARID1A) gene mutation occurs frequently in bladder cancer; however, the role of CDDP sensitivity in BC has not been studied. METHODS: We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology. IC50 determination, flow cytometry analysis of apoptosis, and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A. qRT-PCR, Western blotting, RNA interference, bioinformatic analysis, and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC. RESULTS: It was found that ARID1A inactivation was associated with CDDP resistance in BC cells. Mechanically, loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3 (EIF4A3) through epigenetic regulation. Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399 (circ0008399), a novel circular RNA (circRNA) identified in our previous study, which, to some extent, showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells. Importantly, EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP. CONCLUSION: Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.


Assuntos
Cisplatino , Resistencia a Medicamentos Antineoplásicos , Neoplasias da Bexiga Urinária , Humanos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Cisplatino/uso terapêutico , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/farmacologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Epigênese Genética , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Fator de Iniciação 4A em Eucariotos/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/farmacologia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/genética
15.
Nanotechnology ; 34(31)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37116476

RESUMO

Last decades have witnessed the rapid development of ultraviolet (UV) photodetectors in diversity of applications. The III-nitride semiconductor and metal halide perovskite have both performed promising UV-sensing optoelectronic properties. However, they are still suffering from either the high temperature epitaxial-growth or low photocurrent generated in UV range. In this work, we demonstrate an innovative MAPbCl3/GaN particle hybrid device with all-solution-processed deposition methods. Comparing to the control MAPbCl3photoconductors, the photo-sensing ability of the hybrid device with the optimal concentration of GaN particles is more than one order of magnitude enhanced, and report a responsivity of 86 mA W-1, a detectivity of 3.1 × 1011Jones and a rise/fall time of 1.1/10.7 ms at 360 nm. The photocurrent increment could be attributed to the enhanced UV absorption of GaN particles and facilitated charge separation and photoconductive gain at MAPbCl3/GaN heterojunction. This work paves a pathway towards the large-scale low-cost UV photodetectors in versatile applications.

16.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 39(4): 332-338, 2023 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-37087551

RESUMO

Objective To observe the role of tumor necrosis factor-α (TNF-α) and platelet-derived growth factor-B (PDGF-B) in kiwi fruit essence-mediated protection of radiation-induced lung injury (RILI) in rats. Methods 96 male healthy Sprague-Dawley rats were divided into normal control group, model group, and kiwi fruit essence treatment group(60 and 240 mg/kg) by the random number table method, with 24 animals in each group. The whole lungs underwent 6 MV X-ray irradiation (18 Gy) to induce RILI animal models in rats of the latter three groups. On the next day after irradiation, rats in the latter two groups were intragastrically administrated with 60 or 240 mg/kg kiwi fruit essence, once a day. The rats in the normal control and model groups were treated with 9 g/L sodium chloride solution. Eight rats in the latter three groups were randomly sacrificed on days 14, 28, and 56, while normal control rats were sacrificed on day 56 as the overall control. Blood samples were collected and separated. Serum concentrations of TNF-α and PDGF-B were detected using ELISA. The lung tissues were isolated for HE and Masson staining to evaluate alveolitis and pulmonary fibrosis (PF). The hydroxyproline (HYP) content in lung tissues was detected. The mRNA and protein expression of pulmonary TNF-α and PDGF-B were determined by quantitative real-time PCR and immunohistochemistry. Results Compared with the model group, treatment with 60 and 240 mg/kg kiwi fruit essence group significantly reduced alveolitis on days 14 and 28 as well as PF lesions on days 28 and 56. Compared with the normal control group, HYP content in the lung tissue of the model group increased on day 28 and day 56, while TNF-α and PDGF-B levels in the serum and lung tissues increased at each time point. Compared with the model group during the same period, 60 and 240 mg/kg kiwi fruit essence element treatment group reported the diminished levels of serum and pulmonary TNF-α on day 14 and day 28. Consistently, the lung tissue HYP content and serum and pulmonary PDGF-B levels on day 28 and day 56 were reduced. In addition, the above indicators in the 240 mg/kg kiwi fruit essence treatment group were lower than those for the 60 mg/kg kiwi fruit essence treatment group. Conclusion Kiwi fruit essence can alleviate RILI in rats, which is related to the down-regulation of TNF-α expression at the early stage and decreased PDGF-B level at the middle and late stages.


Assuntos
Actinidia , Lesão Pulmonar , Óleos Voláteis , Proteínas Proto-Oncogênicas c-sis , Fibrose Pulmonar , Fator de Necrose Tumoral alfa , Animais , Masculino , Ratos , Frutas/metabolismo , Pulmão/patologia , Pulmão/efeitos da radiação , Lesão Pulmonar/etiologia , Lesão Pulmonar/prevenção & controle , Proteínas Proto-Oncogênicas c-sis/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-sis/metabolismo , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Actinidia/química
17.
Oncogene ; 42(15): 1247-1262, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36869127

RESUMO

The limited success of immunotherapies targeting immune checkpoint inhibitors is largely ascribed to the lack of infiltrating CD8+ T lymphocytes. Circular RNAs (circRNAs) are a novel type of prevalent noncoding RNA that have been implicated in tumorigenesis and progression, while their roles in modulating CD8+ T cells infiltration and immunotherapy in bladder cancer have not yet been investigated. Herein, we uncover circMGA as a tumor-suppressing circRNA triggering CD8+ T cells chemoattraction and boosting the immunotherapy efficacy. Mechanistically, circMGA functions to stabilize CCL5 mRNA by interacting with HNRNPL. In turn, HNRNPL increases the stability of circMGA, forming a feedback loop that enhances the function of circMGA/HNRNPL complex. Intriguingly, therapeutic synergy between circMGA and anti-PD-1 could significantly suppress xenograft bladder cancer growth. Taken together, the results demonstrate that circMGA/HNRNPL complex may be targetable for cancer immunotherapy and the study advances our understanding of the physiological roles of circRNAs in antitumor immunity.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo L , Neoplasias da Bexiga Urinária , Humanos , Linfócitos T CD8-Positivos , RNA Circular/genética , Imunoterapia/métodos , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/terapia , Microambiente Tumoral/genética
18.
Adv Sci (Weinh) ; 10(6): e2206411, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36567273

RESUMO

The aberrant regulation of PD-L1 in tumor cells remains poorly understood. Here, the authors systematically investigate the endosomal trafficking of plasma membrane PD-L1 in tumor cells. They show that plasma membrane PD-L1 is continuously internalized, and then trafficked from early endosomes to multivesicular bodies/late endosomes, recycling endosomes, lysosomes, and/or extracellular vesicles (EVs). This constitutive endocytic trafficking of PD-L1 is Rab5- and clathrin-dependent. Triazine compound 6J1 blocks the endosomal trafficking of PD-L1 and induces its accumulation in endocytic vesicles by activating Rab5. 6J1 also promotes exosomal PD-L1 secretion by activating Rab27. Together, these effects result in a decrease in the membrane level of PD-L1 in 6J1-treated tumor cells and enables tumor cells to be more susceptible to the tumor-killing activity of T cells in vitro. 6J1 also increases tumor-infiltrating cytotoxic T cells and promotes chemokines secretion in the tumor microenvironment. Rab27 knockdown abolishes 6J1-induced PD-L1 secretion in EVs and revokes the exhausted tumor-infiltrating T cells in tumors, thereby improving the anticancer efficacy of 6J1. Furthermore, a combination of 6J1 and an anti-PD-1 antibody significantly improves the anticancer immune response. Therefore, manipulating PD-L1 endosomal trafficking provides a promising means to promote an anticancer immune response in addition to the immune checkpoint-blocking antibody therapy.


Assuntos
Antígeno B7-H1 , Neoplasias , Humanos , Antígeno B7-H1/metabolismo , Endossomos/metabolismo , Neoplasias/metabolismo , Linfócitos T Citotóxicos , Membrana Celular/metabolismo , Microambiente Tumoral
19.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 38(11): 1011-1017, 2022 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-36328432

RESUMO

Objective To observe the role of connective tissue growth factor (CTGF) and collagen synthesis in anti-pulmonary fibrosis (PF) by Kiwi fruit essence(unsaturated fatty acid of actinidia chinesis planch seed oil)in rats. Methods Sixty male SD rats were randomly divided into control group, model group, Kiwi fruit essence (60, 120, 240 mg/kg) treatment groups, and 5 mg/kg prednisone acetate group, with 10 animals in each group. Rats in control group were intratracheally administered with 9 g/L sodium chloride solution, and animals in other groups were intratracheally administered with bleomycin A5 to establish PF model. From the second day on, rats in the latter 4 groups were intragastrically treated with Kiwi fruit essence of 60, 120 and 240 mg/kg and prednisone acetate of 5 mg/kg, respectively. Rats in control and model groups were treated with 9 g/L sodium chloride solution once a day. All rats were sacrificed on day 28, and then pulmonary tissues were removed. The extent of PF lesions were evaluated using HE and Masson staining. The contents of hydroxyproline (HYP) were measured by a commercial kit. The mRNA expressions of CTGF and α-smooth muscle actin (α-SMA) in pulmonary tissues was detected by quantitative real-time PCR. The protein expressions of CTGF, α-SMA, collagen type 1 (Col1) and Col3 were measured by Western blotting. The protein levels of CTGF were analyzed using immunohistochemical staining. Results Compared with the model group, the alveolitis and PF extent in 60, 120, 240 mg/kg Kiwi fruit essence treatment groups as well as 5 mg/kg prednisone acetate group were significantly alleviated, and the content of HYP and the expression of CTGF, α-SMA, Col1 and Col3 decreased. The changes of above indicators were dose-dependent among the (60, 120, 240) mg/kg Kiwi fruit essence treatment groups. Moreover, the above indicators were found higher in (60, 120) mg/kg Kiwi fruit essence treatment groups than those in 5 mg/kg prednisone acetate group, which, however, showed no significantly difference between 240 mg/kg Kiwi fruit essence treatment group and 5 mg/kg prednisone acetate group. Conclusion Kiwi fruit essence down-regulates CTGF expression and decreases the levels of α-SMA, leading to inhibition of Col1 and Col3 synthesis and alleviation of PF.


Assuntos
Actinidia , Óleos Voláteis , Fibrose Pulmonar , Ratos , Masculino , Animais , Actinidia/metabolismo , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Prednisona , Cloreto de Sódio , Ratos Sprague-Dawley , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/prevenção & controle , Fibrose Pulmonar/genética , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Ácidos Graxos Insaturados , Óleos de Plantas/farmacologia , Acetatos
20.
Onco Targets Ther ; 15: 1057-1062, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36186153

RESUMO

Colonic metastases of lung adenocarcinoma are extremely rare. Signet ring cell adenocarcinoma (SRCA) has not been described in patients with gastrointestinal metastasis of lung adenocarcinoma. SRCA is a unique subtype of adenocarcinoma with strong invasion and a poor prognosis, and most SRCA found in the lung are due to gastrointestinal metastases. This report describes a rare case of colonic metastasis from primary lung SRCA. A 64-year-old female was admitted to Sun Yat-sen University Cancer Center for feeling of nausea and malaise. Following a positron emission tomography CT (PET-CT) scan, widespread metastases of tumor cells were found in the bilateral lung, liver, bone, and multiple lymph nodes, but there was no evidence of metastasis to the colon. Two months later, the patient received a liver biopsy at Tongji Hospital in Wuhan. Pathology revealed a poorly differentiated adenocarcinoma with SRCA conformation, but immunohistochemical staining did not identify the original source of tumor cells. Considering that SRCA mainly derives from the gastrointestinal tract and that serum gastrointestinal tumor markers were elevated, we performed gastrointestinal endoscopy on the patient. The results showed an isolated polyp in the colon, and the pathology results indicated a poorly differentiated adenocarcinoma that was considered to originate from the lung based on immunohistochemical staining. Meanwhile, genetic tests identified a BRAF V600E mutation. The final diagnosis was colonic metastasis of BRAFV 600E mutated lung SRCA. Considering the positive expression of EGFR in this case, cetuximab was innovatively added to the first-line treatment regime (dabrafenib and trametinib). To date, the patient has received thirty-two weeks of treatment. Interestingly, lung and liver tumors shrank and tumor markers in the blood normalized. Our findings offer valuable diagnostic and therapeutic information for colonic metastasis of BRAFV600E mutant primary lung adenocarcinoma with signet ring cell features.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA