RESUMEN
Hepatocellular carcinoma (HCC) is the major cause of liver cancer-associated morality. Metformin, used for treating type 2 diabetes, has antitumor activity and reduces the risk of some diabetes-related tumors, such as liver and breast cancer. However, the mechanisms underlying metformin's effects in HCC remain unclear. To identify genes associated with metformin treatment in HCC, we conducted transcriptomic and proteomic analyses in HCC cells treated with or without metformin. We identified 41 differentially expressed genes upon metformin treatment. Among them, Ataxin 7 Like 3B (ATXN7L3B), which is a negative regulator of the Spt-Ada-Gcn5 acetyltransferase (SAGA) deubiquitinase (DUB) module and has relatively unknown functions in cancer, attracted our attention. We observed that metformin reduced ATXN7L3B level in HCC cells. ATXN7L3B expression was significantly negatively correlated with survival in liver cancer patients. We also demonstrated that ATXN7L3B promoted HCC stemness. Metformin treatment decreased ATXN7L3B-induced tumor-initiating ability in a HCC mouse model, implying that metformin may inhibit cancer stemness by downregulating ATXN7L3B. Our study supports the antitumor activity of metformin and its potential as an anticancer drug for HCC treatment.
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Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Factores de Transcripción/metabolismo , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Femenino , Humanos , Hipoglucemiantes/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/patología , Metformina/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genéticaRESUMEN
Hypoxia-inducible factor-1α (HIF-1α) induces cancer metastasis. We previously demonstrated that HIF-1α-induced membrane-type 4 matrix metalloproteinase (MT4-MMP) is involved in hypoxia-mediated metastasis in head and neck squamous cell carcinoma (HNSCC). However, the functions and detailed mechanisms of MT4-MMP in cancer metastasis are not well understood. In this study, we investigated whether MT4-MMP regulates invadopodia formation or individual cell movement-both critical to cancer migration and invasion-in three-dimensional (3D) environments. By expressing MT4-MMP in the HNSCC cell line FaDu, we demonstrated that MT4-MMP increases invadopodia formation and gelatin degradation. Furthermore, the amoeboid-like cell movement on collagen gel was increased by MT4-MMP expression in FaDu cells. Mechanistically, MT4-MMP may induce invadopodia formation by binding with Tks5 and PDGFRα to result in Src activation and promote amoeboid-like movement by stimulating the small GTPases Rho and Cdc42. Altogether, our data indicate that MT4-MMP induces two crucial mechanisms of cancer dissemination, invadopodia formation and amoeboid movement, and elucidate the prometastatic role of MT4-MMP in hypoxia-mediated cancer metastasis.
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Movimiento Celular , Neoplasias de Cabeza y Cuello/enzimología , Neoplasias de Cabeza y Cuello/patología , Metaloproteinasas de la Matriz Asociadas a la Membrana/metabolismo , Podosomas/patología , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Miosinas Cardíacas/metabolismo , Línea Celular Tumoral , Gelatina/metabolismo , Células HEK293 , Humanos , Cadenas Ligeras de Miosina/metabolismo , Invasividad Neoplásica , Fosforilación , Fosfotirosina/metabolismo , Unión Proteica , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Transducción de Señal , Proteína de Unión al GTP cdc42/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Familia-src Quinasas/metabolismoRESUMEN
BACKGROUND: spontaneous esophageal rupture (Boerhaave's syndrome) is a rare and challenging clinical condition. OBJECTIVE: to evaluate the outcome of different surgical treatments for patients with Boerhaave's syndrome with an early diagnosis (< 24 h) and delayed diagnosis (> 24 h), using a retrospective cohort study in a tertiary referral center. PATIENTS AND METHODS: eighty-eight patients with Boerhaave's syndrome who underwent surgical treatment were identified from March 1994 to March 2019 in the First Hospital of Shanxi Medical University. Subsequently, they were retrospectively divided into two groups according to time from symptom onset to diagnosis (group 1, < 24 h, n = 16; group 2, > 24 h, n = 72). Primary suture repair was used in group 1 and reinforcement with a vascular muscle flap was used in group 2, in order to reduce the incidence of fistula. Patients in group 2 were further divided into two subgroups according to reinforcement using diaphragmatic flaps (subgroup 1) or intercostal muscle flaps (subgroup 2). RESULTS: the duration of hospitalization and stay in Intensive Care Unit (ICU) was significantly shorter in group 1 (p = 0.027 and p = 0.001). Group 1 had fewer postoperative esophageal leaks (p = 0.037) compared to group 2. Various aspects were compared in the two subgroups and the differences were not statistically significant (p > 0.05). CONCLUSIONS: it is very important to establish an early diagnosis for patients with Boerhaave's syndrome. Early (< 24 h) and primary suture repair is superior to delayed (> 24 h) primary repair, even for those reinforced with vascular muscle flaps. Furthermore, repair reinforcement with different muscle flaps appears to render similar results for patients with delayed diagnosis.
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Enfermedades del Esófago , Perforación del Esófago , Adulto , Diagnóstico Tardío , Humanos , Enfermedades del Mediastino , Estudios Retrospectivos , Rotura Espontánea , Resultado del TratamientoRESUMEN
Ectoparasites repress host immune responses while they obtain nutrition from their hosts. Understanding the immunosuppressive mechanisms between ectoparasites and their hosts will provide new strategies to develop potential immunosuppressive drugs against immune disorder diseases. Previously, we have discovered that a small peptide, immunoregulin HA, from the horsefly (Hybomitra atriperoides) may play an immunosuppressive role in rat splenocytes. However, the targeting cells and detailed mechanisms of immunoregulin HA in immunosuppressive reactions are not well defined. Here, we show that immunoregulin HA reduces the secretion of proinflammatory cytokines upon lipopolysaccharide (LPS) stimulation. Interestingly, we discover that the major cytokines repressed by immunoregulin HA are secreted by macrophages, rather than by T cells. Furthermore, immunoregulin HA inhibits macrophage maturation and phagocytosis. Mechanically, the activations of c-JUN N-terminal kinase and extracellular signal-regulated kinase upon LPS stimulation are decreased by immunoregulin HA. Consistently, immunoregulin HA treatment exhibits an anti-inflammatory activity in a mouse model of adjuvant-induced paw inflammation. Taken together, our data reveal that immunoregulin HA conducts the anti-inflammatory activity by blocking macrophage functions.
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Diferenciación Celular/efectos de los fármacos , Dípteros/química , Inmunosupresores/farmacología , Inflamación/patología , Macrófagos/patología , Péptidos/farmacología , Fagocitosis/efectos de los fármacos , Animales , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Células RAW 264.7RESUMEN
Spiders are the most successful insect predators given that they use their venom containing insecticidal peptides as biochemical weapons for preying. Due to the high specificity and potency of peptidic toxins, discoveries of insecticidal toxins from spider venom have provided an opportunity to obtain natural compounds for agricultural applications without affecting human health. In this study, a novel insecticidal toxin (µ-NPTX-Nc1a) was identified and characterized from the venom of Nephila clavata. Its primary sequence is GCNPDCTGIQCGWPRCPGGQNPVMDKCVSCCPFCPPKSAQG which was determined by automated Edman degradation, cDNA cloning, and MS/MS analysis. BLAST search indicated that Nc1a shows no similarity with known peptides or proteins, indicating that Nc1a belongs to a novel family of insecticidal peptide. Nc1a displayed inhibitory effects on NaV and KV channels in cockroach dorsal unpaired median neurons. The median lethal dose (LD50) of Nc1a on cockroach was 573 ng/g. Herein, a study that identifies a novel insecticidal toxin, which can be a potential candidate and/or template for the development of bioinsecticides, is presented.
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Proteínas de Artrópodos/química , Insecticidas/química , Venenos de Araña/química , Arañas/química , Animales , Proteínas de Artrópodos/genética , Venenos de Araña/genética , Arañas/genéticaRESUMEN
UNLABELLED: Gene clusters coding for the chaperone/usher (CU) pathway are widely distributed in many important environmental and pathogenic microbes; however, information about the regulatory machineries controlling CU gene expression during multicellular morphogenesis is missing. The Myxococcus xanthus Mcu system, encoded by the mcuABCD gene cluster, represents a prototype of the archaic CU family that functions in spore coat formation. Using genome-wide transposon mutagenesis, we identified MXAN2872 to be a potential regulator of the mcuABC operon and demonstrated the necessity of MXAN2872 for mcuABC expression and fruiting body morphogenesis in early development. In silico, biochemical, and genetic analyses suggest that MXAN2872 encodes a Baeyer-Villiger monooxygenase (BVMO) of flavoproteins, and the potential cofactor-binding site as well as the BVMO fingerprint sequence is important for the regulatory role of the MXAN2872 protein. The expression profile of mcuA in strains with an MXAN2872 deletion and point mutation agrees well with the timing of cell aggregation of these mutants. Furthermore, McuA could not be detected either in a fruA-null mutant, where starvation-induced aggregation was completely blocked, or in the glycerol-induced spores, where sporulation was uncoupled from cell aggregation. In sum, the present work uncovers a positive role for MXAN2872, a metabolic enzyme-encoding gene, in controlling M. xanthus development. MXAN2872 functions by affecting the onset of cell aggregation, thereby leading to a secondary effect on the timing of mcuABC expression of this model organism. IMPORTANCE: Identification of the players that drive Myxococcus xanthus fruiting body formation is necessary for studying the mechanism of multicellular morphogenesis in this model organism. This study identifies MXAN2872, a gene encoding a putative flavin adenine dinucleotide-binding monooxygenase, to be a new interesting regulator regulating the timing of developmental aggregation. In addition, MXAN2872 seems to affect the expression of the chaperone/usher gene cluster mcu in a manner that is aggregation dependent. Thus, in organisms characterized by a developmental cycle, expression of the chaperone/usher pathway can be controlled by morphological checkpoints, demonstrating another layer of complexity in the regulation of this conserved protein secretion pathway.
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Proteínas Bacterianas/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Oxigenasas de Función Mixta/metabolismo , Myxococcus xanthus/enzimología , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Oxigenasas de Función Mixta/genética , Datos de Secuencia Molecular , Myxococcus xanthus/metabolismoRESUMEN
OBJECTIVE: To explore the role of the basic fibroblast growth factor (bFGF) in the directional differentiation of bone marrow mesenchymal stem cells (BMSCs) into Leydig cells. METHODS: After purification and identification, we inoculated the third-generation BMSCs of SD rats onto a six-orifice board and then randomly divided them into groups A (normal saline control), B (human chorionic gonadotropin [hCG] + platelet-derived growth factor [PDGF] induction), C (hCG + PDGF + 5.0 ng/ml bFGF induction), D (hCG + PDGF + 10.0 ng/ml bFGF induction), and E (hCG + PDGF + 20.0 ng/ml bFGF induction). On the 7th, 14th and 21st day of induction, we observed the morphological changes of the cells and measured the level of testosterone (T) and expression of 3 beta hydroxy steroid dehydrogenase (3ß-HSD) in the supernatant by immunofluorescence staining. RESULTS: After induction, the BMSCs of groups B, C, D, and E exhibited microscopic features of enlarged size, inter-connection, long-shuttle or irregular shape, adherent growth, and large round nuclei, all characteristic of Leydig cells. With the prolonging of time and enhanced concentration of bFGF, gradual increases were observed in the T level and the count of 3ß-HSD-positive BMSCs in the four induction groups, with statistically significant differences between group B and groups C, D, and E (P < 0.05), as well as between group C and groups D and E (P < 0.05), but not between D and E (P > 0.05). CONCLUSION: The bFGF has an obvious promoting effect in the in vitro induced differentiation of rat BMSCs into Leydig cells.
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Células de la Médula Ósea/efectos de los fármacos , Diferenciación Celular , Factor 2 de Crecimiento de Fibroblastos/farmacología , Células Intersticiales del Testículo/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Células Cultivadas , Gonadotropina Coriónica/metabolismo , Humanos , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Testosterona/metabolismoRESUMEN
Most of amphibians belonging to family Rhacophoridae live in arboreal habitats. A large number of antimicrobial peptides (AMPs) have been identified from amphibian skins. No antimicrobial peptide from Rhacophoridae amphibians has been reported. In this study, we purified and characterized a novel antimicrobial peptide, pleurain-a1-thel from skin secretions of the tree frog, Theloderma kwangsiensis. Its amino acid sequence was determined as RILTMTKRVKMPQLYKQIVCRLFKTC by Edman degradation, mass spectrometry analysis and cDNA cloning. There are two cysteines, which form an intra-molecular disulfide bridge, in the sequence of pleurain-a1-thel. Pleurain-a1-thel exerted potential antimicrobial activities against wide spectrum of microorganisms, including Gram-negative and -positive bacteria and fungi. It exerted little hemolytic activity in human or rabbit red cells. To the best of our knowledge, this is the first report of antimicrobial peptide from Rhacophoridae amphibians.
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Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Ranidae/fisiología , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/química , Secuencia de Bases , ADN Complementario/genética , Datos de Secuencia MolecularRESUMEN
Tea consumption has been linked to a decreased risk of cardiovascular disease (CVD) mortality, which imposes a heavy burden on the healthcare system; however, which components in tea cause this beneficial effect is not fully understood. Here we uncovered a cystatin (namely CsCPI1), which is a cysteine proteinase inhibitor (CPI) of the tea plant (Camellia sinensis) that promotes antithrombotic activity. Since thrombosis is a common pathogenesis of fatal CVDs, we investigated the effects of CsCPI1, which showed good therapeutic effects in mouse models of thrombotic disease and ischemic stroke. CsCPI1 significantly increases endothelial cell production of nitric oxide (NO) and inhibits platelet aggregation. Notably, CsCPI1 exhibited no cytotoxicity or resistance to pH and temperature changes, which indicates that CsCPI1 might be a potent antithrombotic agent that contributes to the therapeutic effects of tea consumption against CVD. Specifically, the antithrombotic effects of CsCPI1 are distinct from the classical function of plant cystatins against herbivorous insects. Therefore, our study proposes a new potential role of cystatins in CVD prevention and treatment, which requires further study.
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Camellia sinensis , Enfermedades Cardiovasculares , Cistatinas , Fibrinolíticos , Animales , Ratones , Camellia sinensis/química , Cistatinas/farmacología , Fibrinolíticos/farmacología , Hojas de la Planta/químicaRESUMEN
T cells play a crucial role in the regulation of immune response and are integral to the efficacy of cancer immunotherapy. Because immunotherapy has emerged as a promising treatment for cancer, increasing attention has been focused on the differentiation and function of T cells in immune response. In this review, we describe the research progress on T-cell exhaustion and stemness in the field of cancer immunotherapy and summarize advances in potential strategies to intervene and treat chronic infection and cancer by reversing T-cell exhaustion and maintaining and increasing T-cell stemness. Moreover, we discuss therapeutic strategies to overcome T-cell immunodeficiency in the tumor microenvironment and promote continuous breakthroughs in the anticancer activity of T cells.
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Neoplasias , Agotamiento de Células T , Humanos , Neoplasias/terapia , Linfocitos T , Inmunoterapia , Diferenciación Celular , Microambiente TumoralRESUMEN
Cancer immunotherapy has been acknowledged as a new paradigm for cancer treatment, with notable therapeutic effects on certain cancer types. Despite their significant potential, clinical studies over the past decade have revealed that cancer immunotherapy has low response rates in the majority of solid tumors. One of the key causes for poor responses is known to be the relatively low immunogenicity of solid tumors. Because most solid tumors are immune desert 'cold tumors' with antitumor immunity blocked from the onset of innate immunity, combination therapies that combine validated T-based therapies with approaches that can increase tumor-immunogenicity are being considered as relevant therapeutic options. This review paper focuses on immunogenic cell death (ICD) as a way of enhancing immunogenicity in tumor tissues. We will thoroughly review how ICDs such as necroptosis, pyroptosis, and ferroptosis can improve anti-tumor immunity and outline clinical trials targeting ICD. Finally, we will discuss the potential of ICD inducers. as an adjuvant for cancer immunotherapy.[BMB Reports 2023; 56(5): 275-286].
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Antineoplásicos , Neoplasias , Humanos , Muerte Celular , Muerte Celular Inmunogénica , Inmunoterapia , Antineoplásicos/farmacologíaRESUMEN
There is increasing evidence that long non-coding RNAs (lncRNAs) are involved in the pathogenesis and progression of gastric cancer (GC), however, the underlying mechanisms remain poorly understood. In this study, we identified lncRNA BC002811 as a critical regulator of GC development and progression. BC002811 was upregulated in GC tissues and cell lines, and that high expression of BC002811 was indicative of a reduction in overall survival of GC patients. Our research reveals that BC002811 promoted GC cell proliferation, migration, invasion, and inhibition of apoptosis in vitro, as well as accelerated tumor growth and metastasis in vivo. We also found that BC002811 upregulated MMP2 and MMP9 and promoted GC cell metastasis partially through downregulating PTEN expression. BC002811 may act as a molecular decoy for the transcription factor SOX2, thereby inhibiting the transcription of PTEN by blocking SOX2 binding to the PTEN promoter. Our study advances the understanding of the role of BC002811 in the pathogenesis of GC and provides new molecular targets for therapeutic intervention against GC metastasis.
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ARN Largo no Codificante , Neoplasias Gástricas , Humanos , ARN Largo no Codificante/genética , Neoplasias Gástricas/metabolismo , Línea Celular Tumoral , Movimiento Celular/genética , Apoptosis/genética , Regulación Neoplásica de la Expresión Génica/genética , Proliferación Celular/genética , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismoRESUMEN
INTRODUCTION: By displaying tumor-specific neoangiogenesis, narrow band imaging (NBI), a novel imaging approach, enhances the diagnosis of head and neck cancers and makes it more accurate OBJECTIVE: To determine the effect of NBI in combination with white light endoscopy (WLE) for diagnosis of preneoplastic or neoplastic laryngeal cancers according to Ni classification and to conclude if higher Ni classification and tumor stage are related. METHODS: We enrolled 114 patients with various laryngeal cancer between December 2018 and June 2021. Patients were examined with WLE and NBI. Squamous cell carcinoma (SCC) accounted for 46 cases, benign lesions 30 cases, and nondysplastic, low-grade, and severe dysplasias for 38 cases. Based on characteristics of the intraepithelial papillary capillary loop (IPCL), endoscopic NBI results were divided into five categories (I, II, III, IV, and V). Type I-IV are regarded to be benign, while type V is considered to be cancerous. An incisional biopsy was conducted to assess histopathology, and the histopathology was compared to the NBI results. We assessed the negative predictive value (NPV), positive predictive value (PPV), specificity, and sensitivity for WLE alone and WLE combined with NBI. Analyses were conducted using SPSS software version 26. RESULTS: The WLE combined with NBI showed excellent sensitivity (96%) compared to WLE (86.4%). Specificity was higher in the WLE combined with NBI (96.4%) than WLE alone (91.7%). WLE combined with NBI saw a NPV of 89% as compared with WLE with 88%. WLE and WLE in combination with NBI, recorded a PPV of 90% and 98%, respectively. CONCLUSION: The accuracy of detecting laryngeal cancer increases when WLE and NBI are combined. Combined NBI with WLE remains highly sensitive to early glottis cancer. Accuracy of preoperative NBI was high. In the diagnosis of laryngeal cancer, a higher Ni classification closely correlates with the late stages of the glottis tumor.
RESUMEN
Amphibian skins act as the first line against noxious aggression by microorganisms, parasites, and predators. Anti-microorganism activity is an important task of amphibian skins. A large amount of gene-encoded antimicrobial peptides (AMPs) has been identified from amphibian skins. Only a few of small protease inhibitors have been found in amphibian skins. From skin secretions of 5 species (Odorrana livida, Hylarana nigrovittata, Limnonectes kuhlii, Odorrana grahami, and Amolops loloensis) of Ranidae frogs, 16 small serine protease inhibitor peptides have been purified and characterized. They have lengths of 17-20 amino acid residues (aa). All of them are encoded by precursors with length of 65-70 aa. These small peptides show strong trypsin-inhibitory abilities. Some of them can exert antimicrobial activities. They share the conserved GCWTKSXXPKPC fragment in their primary structures, suggesting they belong to the same families of peptide. Signal peptides of precursors encoding these serine protease inhibitors share obvious sequence similarity with those of precursors encoding AMPs from Ranidae frogs. The current results suggest that these small serine protease inhibitors are the common defensive compounds in frog skin of Ranidae as amphibian skin AMPs.
Asunto(s)
Péptidos Catiónicos Antimicrobianos , Inhibidores de Serina Proteinasa , Piel/química , Piel/metabolismo , Inhibidores de Tripsina , Secuencia de Aminoácidos , Proteínas Anfibias/química , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/metabolismo , Inmunidad Innata , Pruebas de Sensibilidad Microbiana , Péptidos/química , Péptidos/metabolismo , Ranidae , Alineación de Secuencia , Inhibidores de Serina Proteinasa/química , Inhibidores de Serina Proteinasa/aislamiento & purificación , Inhibidores de Serina Proteinasa/metabolismo , Tripsina/metabolismo , Inhibidores de Tripsina/química , Inhibidores de Tripsina/aislamiento & purificación , Inhibidores de Tripsina/metabolismoRESUMEN
Cancer stem cells (CSCs) are a subset of highly tumorigenic cells in tumors. They have enhanced self-renewal properties, are usually chemo-radioresistant, and can promote tumor recurrence and metastasis. They can recruit macrophages into the tumor microenvironment and differentiate them into tumor-associated macrophages (TAMs). TAMs maintain CSC stemness and construct niches that are favorable for CSC survival. However, how CSCs and TAMs interact is not completely understood. An understanding on these mechanisms can provide additional targeting strategies for eliminating CSCs. In this review, we comprehensively summarize the reported mechanisms of crosstalk between CSCs and TAMs and update the related signaling pathways involved in tumor progression. In addition, we discuss potential therapies targeting CSC-TAM interaction, including targeting macrophage recruitment and polarization by CSCs and inhibiting the TAM-induced promotion of CSC stemness. This review also provides the perspective on the major challenge for developing potential therapeutic strategies to overcome CSC-TAM crosstalk.
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Neoplasias , Macrófagos Asociados a Tumores , Humanos , Macrófagos/metabolismo , Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Transducción de Señal , Microambiente TumoralRESUMEN
Mammalian peptide transporters, PepT1 and PepT2, mediate uptake of small peptides and are essential for their absorption. PepT also mediates absorption of many drugs and prodrugs to enhance their bioavailability. PepT has twelve transmembrane (TM) helices that fold into an N-terminal domain (NTD, TM1-6) and a C-terminal domain (CTD, TM7-12) and has a large extracellular domain (ECD) between TM9-10. It is well recognized that peptide transport requires movements of the NTD and CTD, but the role of the ECD in PepT1 remains unclear. Here we report the structure of horse PepT1 encircled in lipid nanodiscs and captured in the inward-open apo conformation. The structure shows that the ECD bridges the NTD and CTD by interacting with TM1. Deletion of ECD or mutations to the ECD-TM1 interface impairs the transport activity. These results demonstrate an important role of ECD in PepT1 and enhance our understanding of the transport mechanism in PepT1.
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Simportadores , Animales , Transporte Biológico , Caballos , Mamíferos/metabolismo , Conformación Molecular , Transportador de Péptidos 1/genética , Péptidos , Simportadores/genética , Simportadores/metabolismoRESUMEN
Liver cancer stem cells (LCSCs) are a small subset of oncogenic cells with a self-renewal ability and drug resistance, and they promote the recurrence and metastasis of hepatocellular carcinoma (HCC). However, the mechanisms regulating LCSCs have not been fully explored. By enriching LCSCs from spheroid cultures and performing transcriptomic analysis, we determined that alanine-glyoxylate aminotransferase (AGXT), which participates in the metabolism of serine and glycine, was significantly upregulated in spheroid cultures, and its function in LCSCs remains unknown. Through the exogenous overexpression or short hairpin RNA knockdown of AGXT in HCC cells, we observed that changes in the AGXT level did not affect the spheroid ability and population of LCSCs. The knockdown of AGXT in LCSCs reduced the number of spheroids and the population of LCSCs; this implies that AGXT is required for the maintenance of cancer stemness rather than as a driver of LCSCs. Mechanistically, AGXT may sustain the self-renewal potential of LCSCs by upregulating the expression of SRY-box transcription factor 2 (SOX2) and octamer-binding transcription factor 4 (OCT4), two well-known master regulators of cancer stemness. Taken together, our study demonstrates the role of AGXT in supporting LCSCs; thus, AGXT merits further exploration.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Carcinoma Hepatocelular/metabolismo , Línea Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Transaminasas , Regulación hacia ArribaRESUMEN
Background: The mechanism through which death-associated protein kinase 1 (DAPK1) causes hepatocellular carcinoma (HCC) progression remains unclear. In this study, we aimed to identify key proteins that were altered after DAPK1 knockout. Methods: Stable DAPK1 knockout HCC cell lines were established, then the differentially expressed genes (DEGs) of HCC were screened using the NetworkAnalyst database and enriched using the Metascape software. Protein-protein interaction networks (PPIs) were analyzed and visualized using the STRING database expansion. Results: In total, 732 differentially expressed genes were identified, including 415 upregulated genes and 317 downregulated genes. Through Cytoscape software scoring, 10 pivotal genes were found to be closely related to changes in DAPK1 expression; Kininogen-1 (KNG1), Complement C3 (C3), Metalloproteinase inhibitor 1 (TIMP1), and Alpha-2-HS-glycoprotein (AHSG) were the most strongly associated with DAPK1 expression changes. Moreover, western blot analysis results revealed that changes in the levels of proteins encoded by the four key genes after DAPK1 knockout were consistent with those seen in the database screening. Conclusions: These results provide a direction for further studies on the DAPK1 gene and on the mechanism through which DAPK1 leads to hepatocellular carcinoma development.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Perfilación de la Expresión Génica/métodos , Biología Computacional/métodos , Mapas de Interacción de Proteínas/genética , Proteínas Quinasas Asociadas a Muerte Celular/genéticaRESUMEN
Cancer immunotherapies, including immune checkpoint inhibitors and immune pathway-targeted therapies, are promising clinical strategies for treating cancer. However, drug resistance and adverse reactions remain the main challenges for immunotherapy management. The future direction of immunotherapy is mainly to reduce side effects and improve the treatment response rate by finding new targets and new methods of combination therapy. Ubiquitination plays a crucial role in regulating the degradation of immune checkpoints and the activation of immune-related pathways. Some drugs that target E3 ubiquitin ligases have exhibited beneficial effects in preclinical and clinical antitumor treatments. In this review, we discuss mechanisms through which E3 ligases regulate tumor immune checkpoints and immune-related pathways as well as the opportunities and challenges for integrating E3 ligases targeting drugs into cancer immunotherapy.
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Neoplasias/enzimología , Neoplasias/inmunología , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Humanos , Inmunomodulación , Inmunoterapia , Terapia Molecular Dirigida , UbiquitinaciónRESUMEN
Estrogen and progesterone regulate the growth and development of human tissues, including the reproductive system and breasts, through estrogen and progesterone receptors, respectively. These receptors are also important indicators for the clinical prognosis of breast cancer and various reproductive cancers. Many studies have reported that cancer stem cells (CSCs) play a key role in tumor initiation, progression, metastasis, and recurrence. Although the role of estrogen and progesterone in human organs and various cancers has been studied, the molecular mechanisms underlying the action of these hormones on CSCs remain unclear. Therefore, further elucidation of the effects of estrogen and progesterone on CSCs should provide a new direction for developing pertinent therapies. In this review, we summarize the current knowledge on the estrogen and progesterone axis involved in cancer stemness and discuss potential therapeutic strategies to inhibit CSCs by targeting relevant pathways.