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BACKGROUND: Colorectal cancer (CRC) commonly exhibits tolerance to cisplatin treatment, but the underlying mechanisms remain unclear. Within the tumor microenvironment, macrophages play a role in resisting the cytotoxic effects of chemotherapy by engaging in efferocytosis to clear apoptotic cells induced by chemotherapeutic agents. The involvement of extracellular vesicles (EVs), an intercellular communicator within the tumor microenvironment, in regulating the efferocytosis for the promotion of drug resistance has not been thoroughly investigated. METHODS: We constructed GFP fluorescent-expressing CRC cell lines (including GFP-CT26 and GFP-MC38) to detect macrophage efferocytosis through flow cytometric analysis. We isolated and purified CRC-secreted EVs using a multi-step ultracentrifugation method and identified them through electron microscopy and nanoflow cytometry. Proteomic analysis was conducted to identify the protein molecules carried by CRC-EVs. MFGE8 knockout CRC cell lines were constructed using CRISPR-Cas9, and their effects were validated through in vitro and in vivo experiments using Western blotting, immunofluorescence, and flow cytometric analysis, confirming that these EVs activate the macrophage αvß3-Src-FAK-STAT3 signaling pathway, thereby promoting efferocytosis. RESULTS: In this study, we found that CRC-derived EVs (CRC-EVs) enhanced macrophage efferocytosis of cisplatin-induced apoptotic CRC cells. Analysis of The Cancer Genome Atlas (TCGA) database revealed a high expression of the efferocytosis-associated gene MFGE8 in CRC patients, suggesting a poorer prognosis. Additionally, mass spectrometry-based proteomic analysis identified a high abundance of MFGE8 protein in CRC-EVs. Utilizing CRISPR-Cas9 gene edition system, we generated MFGE8-knockout CRC cells, demonstrating that their EVs fail to upregulate macrophage efferocytosis in vitro and in vivo. Furthermore, we demonstrated that MFGE8 in CRC-EVs stimulated macrophage efferocytosis by increasing the expression of αvß3 on the cell surface, thereby activating the intracellular Src-FAK-STAT3 signaling pathway. CONCLUSIONS: Therefore, this study highlighted a mechanism in CRC-EVs carrying MFGE8 activated the macrophage efferocytosis. This activation promoted the clearance of cisplatin-induced apoptotic CRC cells, contributing to CRC resistance against cisplatin. These findings provide novel insights into the potential synergistic application of chemotherapy drugs, EVs inhibitors, and efferocytosis antagonists for CRC treatment.
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Neoplasias Colorretais , Vesículas Extracelulares , Macrófagos , Fagocitose , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Macrófagos/metabolismo , Humanos , Animais , Linhagem Celular Tumoral , Camundongos , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Transdução de Sinais , Cisplatino/farmacologia , Integrina alfaVbeta3/metabolismo , Integrina alfaVbeta3/genética , EferocitoseRESUMO
Tumor-initiating cells (TICs) resilience and an immunosuppressive microenvironment are aggressive oncogenic phenotypes that contribute to unsatisfactory long-term outcomes in lung adenocarcinoma (LUAD) patients. The molecular mechanisms mediating the interaction between TICs and immune tolerance have not been elucidated. The role of Galectin-9 in oncogenesis and immunosuppressive microenvironment is still unknown. This study explored the potential role of galectin-9 in TIC regulation and immune modulation in LUAD. The results show that galectin-9 supports TIC properties in LUAD. Co-culture of patient-derived organoids and matched peripheral blood mononuclear cells showed that tumor-secreted galectin-9 suppressed T cell cytotoxicity and induced regulatory T cells (Tregs). Clinically, galectin-9 is upregulated in human LUAD. High expression of galectin-9 predicted poor recurrence-free survival and correlated with high levels of Treg infiltration. LGALS9, the gene encoding galectin-9, is found to be transcriptionally regulated by the nuclear factor of activated T cells 2 (NFATc2), a previously reported TIC regulator, via in silico prediction and luciferase reporter assays. Overall, the results suggest that the NFATc2/galectin-9 axis plays a dual role in TIC regulation and immune suppression.
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Adenocarcinoma de Pulmão , Galectinas , Neoplasias Pulmonares , Fatores de Transcrição NFATC , Células-Tronco Neoplásicas , Humanos , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/metabolismo , Linhagem Celular Tumoral , Galectinas/genética , Galectinas/metabolismo , Galectinas/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/metabolismo , Fatores de Transcrição NFATC/metabolismo , Fatores de Transcrição NFATC/genética , Fenótipo , Microambiente TumoralRESUMO
BACKGROUND: Small extracellular vesicles (sEVs) mediate intercellular communication that contributes to hepatocellular carcinoma (HCC) progression via multifaceted pathways. The success of cell entry determines the effect of sEV on recipient cells. Here, we aimed to delineate the mechanisms underlying the uptake of sEV in HCC. METHODS: Macropinocytosis was examined by the ability of cells to internalize dextran and sEV. Macropinocytosis was analyzed in Na(+)/H(+) exchanger 7 (NHE7)-knockdown and -overexpressing cells. The properties of cells were studied using functional assays. pH biosensor was used to evaluate the intracellular and endosomal pH. The expression of NHE7 in patients' liver tissues was examined by immunofluorescent staining. Inducible silencing of NHE7 in established tumors was performed to reveal the therapeutic potential of targeting NHE7. RESULTS: The data revealed that macropinocytosis controlled the internalization of sEVs and their oncogenic effect on recipient cells. It was found that metastatic HCC cells exhibited the highest efficiency of sEV uptake relative to normal liver cells and non-metastatic HCC cells. Attenuation of macropinocytic activity by 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) limited the entry of sEVs and compromised cell aggressiveness. Mechanistically, we delineated that high level of NHE7, a sodium-hydrogen exchanger, alkalized intracellular pH and acidized endosomal pH, leading to the maturation of macropinosomes. Inducible inhibition of NHE7 in established tumors developed in mice delayed tumor development and suppressed lung metastasis. Clinically, NHE7 expression was upregulated and linked to dismal prognosis of HCC. CONCLUSIONS: This study advances the understanding that NHE7 enhances sEV uptake by macropinocytosis to promote the malignant properties of HCC cells. Inhibition of sEV uptake via macropinocytosis can be exploited as a treatment alone or in combination with conventional therapeutic approaches for HCC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/genética , Linhagem Celular , Neoplasias Hepáticas/genética , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo , Regulação para CimaRESUMO
Hepatocellular carcinoma (HCC) is a hypervascular malignancy by which its growth and dissemination are largely driven by the modulation of tumor-derived small extracellular vesicles (sEVs). Proteomic profiling of circulating sEVs of control individuals and HCC patients identifies von Willibrand factor (vWF) to be upregulated progressively along HCC stages. Elevated sEV-vWF levels are found in a larger cohort of HCC-sEV samples and metastatic HCC cell lines compared to their respective normal counterparts. Circulating sEVs of late-stage HCC patients markedly augment angiogenesis, tumor-endothelial adhesion, pulmonary vascular leakiness, and metastasis, which are significantly compromised by anti-vWF antibody. The role of vWF is further corroborated by the enhanced promoting effect of sEVs collected from vWF-overexpressing cells. sEV-vWF modulates endothelial cells through an elevated level of vascular endothelial growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF2). Mechanistically, secreted FGF2 elicits a positive feedback response in HCC via the FGFR4/ERK1 signaling pathway. The co-administration of anti-vWF antibody or FGFR inhibitor significantly improves the treatment outcome of sorafenib in a patient-derived xenograft mouse model. This study reveals mutual stimulation between HCC and endothelial cells by tumor-derived sEVs and endothelial angiogenic factors, facilitating angiogenesis and metastasis. It also provides insights into a new therapeutic strategy involving blocking tumor-endothelial intercellular communication.
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Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/metabolismo , Células Endoteliais/metabolismo , Vesículas Extracelulares/metabolismo , Retroalimentação , Fator 2 de Crescimento de Fibroblastos/metabolismo , Neoplasias Hepáticas/metabolismo , Proteômica , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator de von Willebrand/metabolismoRESUMO
In recent years, we have realized that extracellular vesicles (EVs) play a critical role in regulating the intercellular communication between tumor and immune cells in the tumor microenvironment (TME). Tumor-derived extracellular vesicles (TDEVs) profoundly affect the functional changes of tumor-associated macrophages (TAMs) and promote their M2 polarization. Meanwhile, macrophages have a strong phagocytic ability in phagocytosing apoptotic cells. Especially in the course of chemotherapy or radiotherapy, TAMs can phagocytose and remove apoptotic tumor cells, showing anti-inflammatory and pro-tumor effects. However, the underlying mechanisms by which TDEVs regulate macrophage phagocytosis of apoptotic tumor cells have not been fully elucidated. In this study, we focused on the effect of colorectal cancer-derived extracellular vesicles (CRC-EVs) on macrophages. We demonstrated that CRC-EVs enhanced macrophage phagocytosis of apoptotic CRC cells. We then determined that heat shock protein 70 (HSP70) carried in CRC-EVs was responsible for this effect by using mass spectrometry-based proteomic analysis and the CRISPR-Cas9 system. Through transcriptome sequencing of macrophages, we found that the enhanced phagocytosis of macrophages was mainly due to the up-regulation of the macrophage receptor with collagenous structure (MARCO). In addition, we confirmed that the up-regulation of MARCO was mediated by the AKT-STAT3 signaling pathway. Taken together, this study revealed a novel EVs-mediated macrophage phagocytosis mechanism involved in the clearance of apoptotic tumor cells in the TME. Targeting TDEVs may have potential therapeutic applications in tumor treatment.
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Neoplasias Colorretais , Vesículas Extracelulares , Humanos , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Proteômica , Macrófagos/metabolismo , Fagocitose , Vesículas Extracelulares/metabolismo , Neoplasias Colorretais/metabolismo , Microambiente TumoralRESUMO
Glutathione S-transferase pi (GSTP1), a phase II detoxification enzyme, is known to be overexpressed and mediates chemotherapeutic resistance in lung cancer. However, whether GSTP1 supports cancer stem cells (CSCs) and the underlying mechanisms in lung adenocarcinoma (LUAD) remain largely unknown. This study unveiled that GSTP1 is upregulated in lung CSCs and supports tumor self-renewal, metastasis, and resistance to targeted tyrosine kinase inhibitors of LUAD both in vitro and in vivo. Mechanistically, CaMK2A (calcium/calmodulin-dependent protein kinase 2 isoform A)/NRF2 (nuclear factor erythroid 2-related factor 2)/GSTP1 is uncovered as a regulatory axis under hypoxia. CaMK2A increased GSTP1 expression through phosphorylating the Sersine558 residue of NRF2 and promoting its nuclear translocation, a novel mechanism for NRF2 activation apart from conventional oxidization-dependent activation. Upregulation of GSTP1 in turn suppressed reactive oxygen species levels and supported CSC phenotypes. Clinically, GSTP1 analyzed by immunohistochemistry is upregulated in a proportion of LUAD and serves as a prognostic marker for survival. Using patient-derived organoids from an ALK-translocated LUAD, the therapeutic potential of a specific GSTP1 inhibitor ezatiostat in combination treatment with the ALK inhibitor crizotinib is demonstrated. This study demonstrates GSTP1 to be a promising therapeutic target for long-term control of LUAD through targeting CSCs.
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Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Glutationa S-Transferase pi/genética , Glutationa S-Transferase pi/metabolismo , Fator 2 Relacionado a NF-E2 , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Adenocarcinoma de Pulmão/tratamento farmacológico , Receptores Proteína Tirosina QuinasesRESUMO
Based on the problems of high carbon emission and high cost of traditional mining methods and filling materials, the tailings powder modified Coal Gangue-based Cementitious Backfill Material (CGCBM) was used for paste filling mining. In this study, the samples were prepared with different tailings powder content and different curing ages. The compressive strength test, XRD, SEM test, and NMR test were used to explore the changes of macroscopic strength and microstructure of the material. The results show that adding 50% tailings powder has the most obvious optimization effect on the performance of CGCBM. Tailings powder particles fill the surface holes of the fine aggregate of coal gangue in the early cement hydration process, reduce the water absorption of the aggregate. In addition, the active substances such as Ca2SiO4 play the pozzolanic effect, stimulate the secondary hydration of slurry, make the microstructure closely, and thus improve the macroscopic mechanical strength.
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Minas de Carvão , Pós , Água/química , Carvão Mineral/análiseRESUMO
As a main producer of complement, the environment in the liver is greatly affected by the complement system. Although the complement system is considered to have the ability of nonself discrimination, remarkable studies have revealed the tight association between improper complement activation in tumour initiation and progression. As complement activation predominantly occurs within the liver, the protumourigenic role of the complement system may contribute to the development of hepatocellular carcinoma (HCC). Improvement in the understanding of the molecular targets involved in complement-mediated tumour development, metastasis, and tumour-promoting inflammation in HCC would certainly aid in the development of better treatments. This minireview is focused on recent findings of the protumourigenic role of the complement system in HCC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , InflamaçãoRESUMO
OBJECTIVE: Disc degeneration has long been associated with excessive mechanical loading or acute disc injury. Our goal is to perform a shock load on the functional units of the cynomolgus monkey intervertebral disc and analyze the degree of degeneration of the intervertebral disc through image analysis and comprehensive analysis. The organ model establishes a standard organ culture model and a non-invasive biomechanical evaluation protocol close to the early degeneration of the human intervertebral disc. METHODS: After modeling, the cynomolgus monkey intervertebral discs were collected and loaded into the dynamic mechanical culture system. The physiological group was loaded with 10% high compressive deformation load for one second, the injury group was punctured with annulus fibrosus, the model group was loaded with 20-50% high compressive deformation, and the nutritional components were a high-glucose group and low-glucose group. After day 3 (short term) and day 10 (long term), samples were collected to analyze cell viability, histomorphology, image analysis for imaging and biomechanical changes. RESULTS: Both the injury group and the 30-50% strain model group showed signs of early degeneration, including decreased instantaneous compressive stiffness, percent change in gray value, decreased cell viability, AF fissure, and percent increase in dynamic elastic modulus. The glucose-restricted group also showed signs of early disc degeneration in long-term cultures. CONCLUSION: This study shows that a single shock load can induce early degeneration of healthy cynomolgus monkey intervertebral discs, and 30% strain may be the nociceptive threshold for early degeneration of healthy intervertebral discs. More importantly, a non-invasive biomechanical evaluation scheme of Percentage change in dynamic modulus of elasticity is established, which solves the key scientific problem of how to non-invasively, quantitatively and sensitively detect the development process of early intervertebral disc degeneration and its degree of degeneration in an in vitro organ model.
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Degeneração do Disco Intervertebral , Disco Intervertebral , Animais , Módulo de Elasticidade , Glucose , Humanos , Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/diagnóstico por imagem , Macaca fascicularisRESUMO
OBJECTIVE: This study investigated the effects of acute or chronic ketamine administration on learning and memory function as well as levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and blood in order to explore the potential correlation between learning-memory dysfunction and ketamine. METHODS: Rats were treated with 25 mg/kg ketamine for 3 d (n = 20) or 14 d (n = 20). Saline-treated rats were used as controls. The Morris water maze test was used to evaluate spatial learning and memory after 10 d of withdrawal. The level of BDNF in serum and the hippocampus were measured by ELISA. RESULTS: The number of platform crossings and residence time in the target platform quadrant were significantly reduced in ketamine 3 d and 14 d groups than in the saline controls (both p < 0.05). In addition, the average escape latency of ketamine 3 d and 14 d groups were significantly longer than that of the saline 3 d and 14 d groups (p < 0.0001), respectively. Further examination found that only serum samples from ketamine 14 d group showed significantly decreased BDNF level compared to that from saline 14 d groups (p < 0.05). However, no differences were detected in hippocampus samples. CONCLUSION: Chronic ketamine exposure (25 mg/kg) causes spatial learning and memory deficits in SD rats, which may be associated with decreased serum BDNF levels.
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Tumor initiating cells (TIC) of lung cancer are mainly induced by stress-related plasticity. Calcium/Calmodulin dependent protein kinase II alpha (CAMK2A) is a key calcium signaling molecule activated by exogenous and endogenous stimuli with effects on multiple cell functions but little is known about its role on TIC. In human lung adenocarcinomas (AD), CAMK2A was aberrantly activated in a proportion of cases and was an independent risk factor predicting shorter survivals. Functionally, CAMK2A enhanced TIC phenotypes in vitro and in vivo. CAMK2A regulated SOX2 expression by reducing H3K27me3 and EZH2 occupancy at SOX2 regulatory regions, leading to its epigenetic de-repression with functional consequences. Further, CAMK2A caused kinase-dependent phosphorylation of EZH2 at T487 with suppression of EZH2 activity. Together, the data demonstrated the CAMK2A-EZH2-SOX2 axis on TIC regulation. This study provided phenotypic and mechanistic evidence for the TIC supportive role of CAMK2A, implicating a novel predictive and therapeutic target for lung cancer.
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Adenocarcinoma de Pulmão/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Células-Tronco Neoplásicas/patologia , Fatores de Transcrição SOXB1/genética , Regulação para Cima/genética , Adenocarcinoma de Pulmão/patologia , Animais , Apoptose/genética , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Autorrenovação Celular/genética , Humanos , Neoplasias Pulmonares/patologia , Camundongos SCID , Terapia de Alvo Molecular , Células-Tronco Neoplásicas/metabolismo , Fosforilação , Fosfotreonina/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Fatores de Transcrição SOXB1/metabolismo , Análise de SobrevidaRESUMO
A catalytic asymmetric conjugate addition/Schmidt-type rearrangement of vinyl azides and (E)-alkenyloxindoles was realized. It afforded a variety of optically active 3,2'-pyrrolinyl spirooxindoles with high yields (up to 98%), and excellent diastereo- and enantioselectivities (up to 98% ee, >19 : 1 dr), even at the gram-scale in the presence of a chiral N,N'-dioxide-nickel(ii) complex. In addition, a possible catalytic cycle and transition state model were proposed to rationalize the stereoselectivity.
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Statins are effective cholesterol-lowering drugs for reducing the risks of mortality and morbidity of cardiovascular diseases. Increasing evidence has shown that statin use is associated with a significant beneficial effect in patients with ischemic stroke. Both pre-stroke and post-stroke statin use has been found to be beneficial in ischemic stroke. Furthermore, good adherence is associated with a better clinical outcome, and statin withdrawal is associated with a poor functional outcome in patients with ischemic stroke. High-intensity statin therapy is advocated for the treatment of ischemic stroke. However, there are concerns regarding the adverse effects associated with statin use in ischemic stroke such as intracranial hemorrhage. In this review, we summarize the beneficial effect of statin use in ischemic stroke and discuss the potential risks associated with statin therapy.
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Isquemia Encefálica/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hemorragias Intracranianas/induzido quimicamente , Avaliação de Resultados em Cuidados de Saúde , Acidente Vascular Cerebral/tratamento farmacológico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversosRESUMO
Rationale: Abnormal Wnt/ß-catenin signaling in the endometrium can lead to both embryo implantation failure and severe pathogenic changes of the endometrium such as endometrial cancer and endometriosis. However, how Wnt/ß-catenin signaling is regulated in the endometrium remains elusive. We explored possible regulation of Wnt/ß-catenin signaling by multi-drug resistance protein 4 (MRP4), a potential target in cancer chemotherapy, and investigated the mechanism. Methods: Knockdown of MRP4 was performed in human endometrial cells in vitro or in a mouse embryo-implantation model in vivo. Immunoprecipitation, immunoblotting and immunofluorescence were used to assess protein interaction and stability. Wnt/ß-catenin signaling was assessed by TOPflash reporter assay and quantitative PCR array. Normal and endometriotic human endometrial tissues were examined. Data from human microarray or RNAseq databases of more than 100 participants with endometriosis, endometrial cancer or IVF were analyzed. In vitro and in vivo tumorigenesis was performed. Results: MRP4-knockdown, but not its transporter-function-inhibition, accelerates ß-catenin degradation in human endometrial cells. MRP4 and ß-catenin are co-localized and co-immunoprecipitated in mouse and human endometrium. MRP4-knockdown in mouse uterus reduces ß-catenin levels, downregulates a series of Wnt/ß-catenin target genes and impairs embryo implantation, which are all reversed by blocking ß-catenin degradation. Analysis of human endometrial biopsy samples and available databases reveals significant and positive correlations of MRP4 with ß-catenin and Wnt/ß-catenin target genes in the receptive endometrium in IVF, ectopic endometriotic lesions and endometrial cancers. Knockdown of MRP4 also inhibits in vitro and in vivo endometrial tumorigenesis. Conclusion: A previously undefined role of MRP4 in stabilizing ß-catenin to sustain Wnt/ß-catenin signaling in endometrial cells is revealed for both embryo implantation and endometrial disorders, suggesting MRP4 as a theranostic target for endometrial diseases associated with Wnt/ß-catenin signaling abnormality.
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Neoplasias do Endométrio/metabolismo , Endometriose/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Gravidez/metabolismo , Via de Sinalização Wnt , Adulto , Animais , Linhagem Celular Tumoral , Endométrio/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos ICR , Camundongos Nus , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , beta Catenina/metabolismoRESUMO
OBJECTIVE: Stroke-associated pneumonia (SAP) is a spectrum of pulmonary infections in non-mechanical ventilation patients within 7 days of stroke. SAP is one of the most common complications after stroke, with an incidence of 7%-38%, which is significantly associated with poor prognosis of stroke. Stroke-induced immune-depression syndrome (SIDS) is one of the main pathogenesis of SAP, which is closely related to autoimmune, sympathetic nervous system (SNS), hypothalamic-pituitary-adrenalin axis (HPA axis), parasympathetic nervous system (PNS), and damage-related molecular patterns (DAMPs). It is unclear how the lungs and brain interact during the development of SAP. Some clinical studies have found that some clinical indicators such as monocyte human leukocyte antigen-DR (mHLA-DR), neutrophil to lymphocyte ratio (NLR) and heart rate variability (HRV) can be used to predict SAP occurrence. Old age, male, and diabetes are currently considered risk factors for SAP. Furthermore, a variety of SAP risk scales such as A2DS2 scale (age, atrial fibrillation, dysphagia, gender and stroke severity), preventive antibacterial therapy in acute ischemic stroke (PANTHERIS) scale, acute ischemic stroke-associated pneumonia scale (AIS-APS), and ISAN scale (pre-stroke independence, gender, age, and stroke severity) have been developed. According to the opinion of Pneumonia in Stroke Consensus in 2015, it is recommended to use the modified Centers for Disease Control and Prevention (CDC) pneumonia clinical diagnostic criteria for the diagnosis of SAP. Prevention of SAP is the most important part of clinical practice. Preventive antibiotics are not recommended, and once SAP is diagnosed, the antibiotic strategies should be followed. Neuroprotective and anti-inflammatory treatments are still being studied.
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Isquemia Encefálica , Pneumonia , Acidente Vascular Cerebral , Humanos , Sistema Hipotálamo-Hipofisário , Masculino , Sistema Hipófise-Suprarrenal , Fatores de RiscoRESUMO
The evidence that gene mutations in the polarity determinant Crumbs homologs-2 (CRB2) cause congenital nephrotic syndrome suggests the functional importance of this gene product in podocyte development. Because another isoform, CRB3, was reported to repress the mechanistic/mammalian target of the rapamycin complex 1 (mTORC1) pathway, we examined the role of CRB2 function in developing podocytes in relation to mTORC1. In HEK-293 and MDCK cells constitutively expressing CRB2, we found that the protein localized to the apicolateral side of the cell plasma membrane and that this plasma membrane assembly required N-glycosylation. Confocal microscopy of the neonate mouse kidney revealed that both the tyrosine-phosphorylated form and non-phosphorylated form of CRB2 commence at the S-shaped body stage at the apicolateral side of podocyte precursor cells and move to foot processes in a capillary tuft pattern. The pattern of phosphorylated mTOR in developing podocytes was similar to that of CRB2 tyrosine phosphorylation. Additionally, the lack of a tyrosine phosphorylation site on CRB2 led to the reduced sensitivity of mTORC1 activation in response to energy starvation. CRB2 may play an important role in the mechanistic pathway of developing podocytes through tyrosine phosphorylation by associating with mTORC1 activation.
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Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas de Membrana/metabolismo , Podócitos/metabolismo , Células-Tronco/metabolismo , Animais , Proteínas de Transporte/genética , Membrana Celular/genética , Cães , Glicosilação , Células HEK293 , Humanos , Células Madin Darby de Rim Canino , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Proteínas de Membrana/genética , Camundongos , Fosforilação/genética , Podócitos/citologia , Células-Tronco/citologiaRESUMO
Arsenic trioxide (ATO) is used as a chemotherapeutic agent for the treatment of acute promyelocytic leukemia. However, increasing drug resistance is reducing its efficacy. Therefore, a better understanding of ATO resistance mechanism is required. In this study, we established an ATO-resistant human epidermoid carcinoma cell line, KB/ATO, from its parental KB-3-1 cells. In addition to ATO, KB/ATO cells also exhibited cross-resistance to other anticancer drugs such as cisplatin, antimony potassium tartrate, and 6-mercaptopurine. The arsenic accumulation in KB/ATO cells was significantly lower than that in KB-3-1 cells. Further analysis indicated that neither application of P-glycoprotein inhibitor, breast cancer resistant protein (BCRP) inhibitor, or multidrug resistance protein 1 (MRP1) inhibitor could eliminate ATO resistance. We found that the expression level of ABCB6 was increased in KB/ATO cells. In conclusion, ABCB6 could be an important factor for ATO resistance in KB/ATO cells. The ABCB6 level may serve as a predictive biomarker for the effectiveness of ATO therapy.
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Tumor-initiating cells (TIC) are dynamic cancer cell subsets that display enhanced tumor functions and resilience to treatment but the mechanism of TIC induction or maintenance in lung cancer is not fully understood. In this study, we show the calcium pathway transcription factor NFATc2 is a novel regulator of lung TIC phenotypes, including tumorspheres, cell motility, tumorigenesis, as well as in vitro and in vivo responses to chemotherapy and targeted therapy. In human lung cancers, high NFATc2 expression predicted poor tumor differentiation, adverse recurrence-free and cancer-specific overall survivals. Mechanistic investigations identified NFATc2 response elements in the 3' enhancer region of SOX2, and NFATc2/SOX2 coupling upregulates ALDH1A1 by binding to its 5' enhancer. Through this axis, oxidative stress induced by cancer drug treatment is attenuated, leading to increased resistance in a mutation-independent manner. Targeting this axis provides a novel approach for the long-term treatment of lung cancer through TIC elimination.