RESUMO
NRAS mutations are most frequently observed in hematological malignancies and are also common in some solid tumors such as melanoma and colon cancer. Despite its pivotal role in oncogenesis, no effective therapies targeting NRAS has been developed. Targeting NRAS localization to the plasma membrane (PM) is a promising strategy for cancer therapy, as its signaling requires PM localization. However, the process governing NRAS translocation from the Golgi apparatus to the PM after lipid modification remains elusive. This study identifies GOLGA7 as a crucial factor controlling NRAS' PM translocation, demonstrating that its depletion blocks NRAS, but not HRAS, KRAS4A and KRAS4B, translocating to PM. GOLGA7 is known to stabilize the palmitoyltransferase ZDHHC9 for NRAS and HRAS palmitoylation, but we found that GOLGA7 depletion does not affect NRAS' palmitoylation level. Further studies show that loss of GOLGA7 disrupts NRAS anterograde trafficking, leading to its cis-Golgi accumulation. Remarkably, depleting GOLGA7 effectively inhibits cell proliferation in multiple NRAS-mutant cancer cell lines and attenuates NRASG12D-induced oncogenic transformation in vivo. These findings elucidate a specific intracellular trafficking route for NRAS under GOLGA7 regulation, highlighting GOLGA7 as a promising therapeutic target for NRAS-driven cancers.
Assuntos
Lipoilação , Transdução de Sinais , Membrana Celular/metabolismo , Linhagem Celular , Mutação , Complexo de Golgi/metabolismoRESUMO
Hepatitis B virus (HBV) infection of hepatocytes begins by binding to its cellular receptor sodium taurocholate cotransporting polypeptide (NTCP), followed by the internalization of viral nucleocapsid into the cytoplasm. The viral relaxed circular (rc) DNA genome in nucleocapsid is transported into the nucleus and converted into covalently closed circular (ccc) DNA to serve as a viral persistence reservoir that is refractory to current antiviral therapies. Host DNA repair enzymes have been speculated to catalyze the conversion of rcDNA to cccDNA, however, the DNA polymerase(s) that fills the gap in the plus strand of rcDNA remains to be determined. Here we conducted targeted genetic screening in combination with chemical inhibition to identify the cellular DNA polymerase(s) responsible for cccDNA formation, and exploited recombinant HBV with capsid coding deficiency which infects HepG2-NTCP cells with similar efficiency of wild-type HBV to assure cccDNA synthesis is exclusively from de novo HBV infection. We found that DNA polymerase κ (POLK), a Y-family DNA polymerase with maximum activity in non-dividing cells, substantially contributes to cccDNA formation during de novo HBV infection. Depleting gene expression of POLK in HepG2-NTCP cells by either siRNA knockdown or CRISPR/Cas9 knockout inhibited the conversion of rcDNA into cccDNA, while the diminished cccDNA formation in, and hence the viral infection of, the knockout cells could be effectively rescued by ectopic expression of POLK. These studies revealed that POLK is a crucial host factor required for cccDNA formation during a de novo HBV infection and suggest that POLK may be a potential target for developing antivirals against HBV.
Assuntos
DNA Circular/genética , DNA Viral/genética , DNA Polimerase Dirigida por DNA/metabolismo , Hepatite B/genética , Southern Blotting , Linhagem Celular , DNA Circular/metabolismo , DNA Viral/metabolismo , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Técnicas de Inativação de Genes , Hepatite B/metabolismo , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Hepatócitos/virologia , Humanos , Reação em Cadeia da Polimerase , RNA Interferente Pequeno , Transfecção , Replicação Viral/genéticaRESUMO
Bimetallic Au75Pd25 nanocrystals with shapes of icosahedron and octahedron were synthesized by adding different amounts of iodide ions, and were employed as catalysts for solvent-free aerobic oxidation of cyclohexane. Although both icosahedrons and octahedrons were bounded by {111} facets, the turnover frequency number of Au75Pd25 icosahedrons reached 15,106 h(-1), almost three times as high as that of Au75Pd25 octahedrons. The conversion of cyclohexane reached 28.1% after 48 h using Au75Pd25 icosahedrons, with the selectivity of 84.3% to cyclohexanone. Density functional theory calculations along with X-ray photoelectron spectroscopy examinations reveal that the excellent catalytic performance of AuPd icosahedrons could be ascribed to twin-induced strain and highly negative charge density of Au atoms on the surface.
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Recently, metal nanoframes have received increased attention due to their unique spatial and physicochemical, e.g., catalytic and plasmonic properties. So far, a variety of synthetic procedures have been developed to fabricate metal nanoframes with different shapes, sizes and compositions. Typical synthesis of metal nanoframes involves two stages: 1) formation of solid nanocrystals and 2) hollowing out the interiors and side faces. In this review, solution-phase synthetic strategies are summarized, based on galvanic replacement reactions, oxidative etching, the Kirkendall effect, electrodeposition, and template-assisted growth, as well as one-pot synthesis. Their potential applications in catalysis and optical sensing are overviewed as well.
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Severe fever with thrombocytopenia syndrome virus (SFTSV) is a novel phlebovirus in the Bunyaviridae family. Most patients infected by SFTSV present with fever and thrombocytopenia, and up to 30% die due to multiple-organ dysfunction. The mechanisms by which SFTSV enters multiple cell types are unknown. SFTSV contains two species of envelope glycoproteins, Gn (44.2 kDa) and Gc (56 kDa), both of which are encoded by the M segment and are cleaved from a precursor polypeptide (about 116 kDa) in the endoplasmic reticulum (ER). Gn fused with an immunoglobulin Fc tag at its C terminus (Gn-Fc) bound to multiple cells susceptible to the infection of SFTSV and blocked viral infection of human umbilical vein endothelial cells (HUVECs). Immunoprecipitation assays following mass spectrometry analysis showed that Gn binds to nonmuscle myosin heavy chain IIA (NMMHC-IIA), a cellular protein with surface expression in multiple cell types. Small interfering RNA (siRNA) knockdown of NMMHC-IIA, but not the closely related NMMHC-IIB or NMMHC-IIC, reduced SFTSV infection, and NMMHC-IIA specific antibody blocked infection by SFTSV but not other control viruses. Overexpression of NMMHC-IIA in HeLa cells, which show limited susceptivity to SFTSV, markedly enhanced SFTSV infection of the cells. These results show that NMMHC-IIA is critical for the cellular entry of SFTSV. As NMMHC-IIA is essential for the normal functions of platelets and human vascular endothelial cells, it is conceivable that NMMHC-IIA directly contributes to the pathogenesis of SFTSV and may be a useful target for antiviral interventions against the viral infection.
Assuntos
Febre/virologia , Cadeias Pesadas de Miosina/fisiologia , Phlebovirus/patogenicidade , Trombocitopenia/virologia , Animais , Sequência de Bases , Western Blotting , Linhagem Celular , Primers do DNA , Humanos , Microscopia Confocal , Cadeias Pesadas de Miosina/genética , Reação em Cadeia da Polimerase , RNA Interferente Pequeno/genéticaRESUMO
BACKGROUND: The current standard of care for locally advanced gastric cancer (GC) involves neoadjuvant chemotherapy followed by radical surgery. Recently, neoadjuvant treatment for this condition has involved the exploration of immunotherapy plus chemotherapy as a potential approach. However, the efficacy remains uncertain. METHODS: A single-arm, phase 2 study was conducted to evaluate the efficacy and tolerability of neoadjuvant camrelizumab combined with mFOLFOX6 and identify potential biomarkers of response through multi-omics analysis in patients with resectable locally advanced GC. The primary endpoint was the pathological complete response (pCR) rate. Secondary endpoints included the R0 rate, near pCR rate, progression-free survival (PFS), disease-free survival (DFS), and overall survival (OS). Multi-omics analysis was assessed by whole-exome sequencing, transcriptome sequencing, and multiplex immunofluorescence (mIF) using biopsies pre- and post-neoadjuvant therapy. RESULTS: This study involved 60 patients, of which 55 underwent gastrectomy. Among these, five (9.1%) attained a pathological complete response (pCR), and 11 (20.0%) reached near pCR. No unexpected treatment-emergent adverse events or perioperative mortality were observed, and the regimen presented a manageable safety profile. Molecular changes identified through multi-omics analysis correlated with treatment response, highlighting associations between HER2-positive and CTNNB1 mutations with treatment sensitivity and a favourable prognosis. This finding was further supported by immune cell infiltration analysis and mIF. Expression data uncovered a risk model with four genes (RALYL, SCGN, CCKBR, NTS) linked to poor response. Additionally, post-treatment infiltration of CD8+ T lymphocytes positively correlates with pathological response. CONCLUSION: The findings suggest the combination of PD-1-inhibitor and mFOLFOX6 showed efficacy and acceptable toxicity for locally advanced GC. Extended follow-up is required to determine the duration of the response. This study lays essential groundwork for developing precise neoadjuvant regimens.
Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Terapia Neoadjuvante , Neoplasias Gástricas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fluoruracila/uso terapêutico , Leucovorina/uso terapêutico , Multiômica , Terapia Neoadjuvante/métodos , Compostos Organoplatínicos/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Resultado do TratamentoRESUMO
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with varied clinical and histopathological features between individuals, particularly across races. As an autoimmune disease, IgAN arises from consequences of increased circulating levels of galactose-deficient IgA1 and mesangial deposition of IgA-containing immune complexes, which are recognized as key events in the widely accepted "multi-hit" pathogenesis of IgAN. The emerging evidence further provides insights into the role of genes, environment, mucosal immunity and complement system. These developments are paralleled by the increasing availability of diagnostic tools, potential biomarkers and therapeutic agents. In this review, we summarize current evidence and outline novel findings in the prognosis, clinical trials and translational research from the updated perspectives of IgAN pathogenesis.
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CDH1 deficiency is common in diffuse gastric cancer and triple negative breast cancer patients, both of which still lack effective therapeutics. ROS1 inhibition results in synthetic lethality in CDH1-deficient cancers, but often leads to adaptive resistance. Here, we demonstrate that upregulation of the FAK activity accompanies the emergence of resistance to ROS1 inhibitor therapy in gastric and breast CDH1-deficient cancers. FAK inhibition, either by FAK inhibitors or by knocking down its expression, resulted in higher cytotoxicity potency of the ROS1 inhibitor in CDH1-deficient cancer cell lines. Co-treatment of mice with the FAK inhibitor and ROS1 inhibitors also showed synergistic effects against CDH1-deficient cancers. Mechanistically, ROS1 inhibitors induce the FAK-YAP-TRX signaling, decreasing oxidative stress-related DNA damage and consequently reducing their anti-cancer effects. The FAK inhibitor suppresses the aberrant FAK-YAP-TRX signaling, reinforcing ROS1 inhibitor's cytotoxicity towards cancer cells. These findings support the use of FAK and ROS1 inhibitors as a combination therapeutic strategy in CDH1-deficient triple negative breast cancer and diffuse gastric cancer patients.
Assuntos
Neoplasias Gástricas , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Linhagem Celular Tumoral , Proteínas Proto-Oncogênicas/metabolismo , Antígenos CD , Caderinas/genéticaRESUMO
A two-way 224-Gbit/s four-level pulse amplitude modulation (PAM4)-based fibre-free-space optical (FSO) converged system through a 25-km single-mode fibre (SMF) transport with 500-m free-space transmission is successfully constructed, which adopts injection-locked vertical-cavity surface-emitting lasers with polarisation-multiplexing mechanism for a demonstration. Compared with one-way transmission, two-way transmission is an attractive architecture for fibre-FSO converged system. Two-way transmission over SMF transport with free-space transmission not only reduces the required number of fibres and the setups of free-space transmission, but also provides the advantage of capacity doubling. Incorporating dual-wavelength four-level pulse amplitude modulation (PAM4) modulation with polarisation-multiplexing mechanism, the transmission capacity of fibre-FSO converged system is significantly enhanced to 224 Gbit/s (56 Gbit/s PAM4/wavelength × 2-wavelength × 2-polarisation) for downlink/uplink transmission. Bit error rate and PAM4 eye diagrams (downstream/upstream) perform well over 25-km SMF transport with 500-m free-space transmission. This proposed two-way fibre-FSO converged system is a prominent one not only because of its development in the integration of fibre backbone with optical wireless extension, but also because of its advantage in two-way transmission for affording high downlink/uplink data rate with good transmission performance.
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FLT3 mutations are the most frequently identified genetic alterations in acute myeloid leukemia (AML) and are associated with poor prognosis. Multiple FLT3 inhibitors are in various stages of clinical evaluation. However, resistance to FLT3 inhibitors resulting from acquired point mutations in tyrosine kinase domain (TKD) have limited the sustained efficacy of treatments, and a "gatekeeper" mutation (F691L) is resistant to most available FLT3 inhibitors. Thus, new FLT3 inhibitors against both FLT3 internal tandem duplication (FLT3-ITD) and FLT3-TKD mutations (including F691L) are urgently sought. Herein, we identified KX2-391 as a dual FLT3 and tubulin inhibitor and investigated its efficacy and mechanisms in overcoming drug-resistant FLT3-ITD-TKD mutations in AML. KX2-391 exhibited potent growth inhibitory and apoptosis promoting effects on diverse AML cell lines harboring FLT3-ITD mutations and AC220-resistant mutations at the D835 and F691 residues in TKD and inhibited FLT3 phosphorylation and its downstream signaling targets. Orally administered KX2-391 significantly prolonged the survival of a murine leukemia model induced by FLT3-ITD-F691L. KX2-391 also significantly inhibited the growth of 4 primary AML cells expressing FLT3-ITD and 2 primary AML cells expressing FLT3-ITD-D835Y. Our preclinical data highlight KX2-391 as a promising FLT3 inhibitor for the treatment of AML patients harboring FLT3 mutations, especially refractory/relapsed patients with F691L and other FLT3-TKD mutations.
Assuntos
Acetamidas/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Morfolinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Moduladores de Tubulina/farmacologia , Tirosina Quinase 3 Semelhante a fms/genética , Acetamidas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/genética , Camundongos , Morfolinas/uso terapêutico , Mutação/efeitos dos fármacos , Mutação Puntual/efeitos dos fármacos , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Moduladores de Tubulina/uso terapêutico , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidoresRESUMO
A 400-Gb/s wavelength-division-multiplexing (WDM) four-level pulse amplitude modulation (PAM4) optical wireless communication (OWC) system through a 200-m free-space transmission with either an 8.8-m piped water-air-piped water link or a 6.5-m turbid water-air-turbid water link is successfully constructed. Incorporating PAM4 modulation with an 8-wavelength WDM scheme greatly increases the total transmission rate of the WDM-PAM4 OWC system to 400 Gb/s (50 Gb/s/λ × 8 λs). By adopting doublet lenses in free-space transmission, a laser beam reducer/expander and a reflective spatial light modulator (SLM) with an angle expander through the water-air-water link, good bit error rate performance and acceptable PAM4 eye diagrams are obtained. Using a reflective SLM with an angle expander not only adaptively adjusts the laser beam, but also effectively solves the oceanic engineering problems. This demonstrates WDM-PAM4 OWC system outperforms existing OWC systems through the free-space transmission with an air-water-air link because it can solve the practical engineering problems in actual oceanic environments.
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IRF8 is a key regulator of innate immunity receptor signaling and plays diverse functions in the development of hematopoietic cells. The effects of IRF8 on hematopoietic stem cells (HSCs) are still unknown. Here, it is demonstrated that IRF8 deficiency results in a decreased number of long-term HSCs (LT-HSCs) in mice. However, the repopulation capacity of individual HSCs is significantly increased. Transcriptomic analysis shows that IFN-γ and IFN-α signaling is downregulated in IRF8-deficient HSCs, while their response to proinflammatory cytokines is unchanged ex vivo. Further tests show that Irf8-/- HSCs can not respond to CpG, an agonist of Toll-like receptor 9 (TLR9) in mice, while long-term CpG stimulation increases wild-type HSC abundance and decreases their bone marrow colony-forming capacity. Mechanistically, as the primary producer of proinflammatory cytokines in response to CpG stimulation, dendritic cells has a blocked TLR9 signaling due to developmental defect in Irf8-/- mice. Macrophages remain functionally intact but severely reduce in Irf8-/- mice. In NK cells, IRF8 directly regulates the expression of Tlr9 and its deficiency leads to no increased IFNγ production upon CpG stimulation. These results indicate that IRF8 regulates HSCs, at least in part, through controlling TLR9 signaling in diverse innate immune cells.
Assuntos
Células-Tronco Hematopoéticas/metabolismo , Imunidade Inata/imunologia , Fatores Reguladores de Interferon/imunologia , Fatores Reguladores de Interferon/metabolismo , Receptor Toll-Like 9/imunologia , Receptor Toll-Like 9/metabolismo , Animais , Perfilação da Expressão Gênica/métodos , Células-Tronco Hematopoéticas/imunologia , Imunidade Inata/genética , Fatores Reguladores de Interferon/genética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor Toll-Like 9/genéticaRESUMO
Sodium taurocholate cotransporting polypeptide (NTCP) is a functional receptor for human hepatitis B virus (HBV) and its satellite virus Hepatitis D virus (HDV). Physiologically, NTCP is responsible for the majority of sodium-dependent bile acids uptake by hepatocytes. The p.Ser267Phe (S267F) variant of NTCP is a single nucleotide polymorphism (SNP) previously found to cause substantial loss of ability to support HBV and HDV infection and its taurocholic acid uptake function in vitro. Intriguingly, ten individuals were identified as S267F homozygotes in population studies of chronic hepatitis B (CHB) patients. In this study, we identified new HBV isolates from one homozygous S267F mutation carrier and confirmed new isolates also use wildtype-NTCP as a cellular receptor. Furthermore, we demonstrated S267F variant of NTCP, though inefficient, is still a functional receptor for HBV entry. This study advances our understanding of NTCP-mediated HBV infection.