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BACKGROUND: Lipid droplet formation is a prominent histological feature in clear cell renal cell carcinoma (ccRCC), but the significance and mechanisms underlying lipid droplet accumulation remain unclear. METHODS: Expression and clinical significance of MT1G in ccRCC were analyzed by using TCGA data, GEO data and scRNASeq data. MT1G overexpression or knockdown ccRCC cell lines were constructed and in situ ccRCC model, lung metastasis assay, metabolomics and lipid droplets staining were performed to explore the role of MT1G on lipid droplet accumulation in ccRCC. RESULTS: Initially, we observed low MT1G expression in ccRCC tissues, whereas high MT1G expression correlated with advanced disease stage and poorer prognosis. Elevated MT1G expression promoted ccRCC growth and metastasis both in vitro and in vivo. Mechanistically, MT1G significantly suppressed acylcarnitine levels and downstream tricarboxylic acid (TCA) cycle activity, resulting in increased fatty acid and lipid accumulation without affecting cholesterol metabolism. Notably, MT1G inhibited H3K14 trimethylation (H3K14me3) modification. Under these conditions, MT1G-mediated H3K14me3 was recruited to the CPT1B promoter through direct interaction with specific promoter regions, leading to reduced CPT1B transcription and translation. CONCLUSIONS: Our study unveils a novel mechanism of lipid droplet accumulation in ccRCC, where MT1G inhibits CPT1B expression through modulation of H3K14 trimethylation, consequently enhancing lipid droplet accumulation and promoting ccRCC progression. Graphical abstract figure Schematic diagram illustrating MT1G/H3K14me3/CPT1B-mediated lipid droplet accumulation promoted ccRCC progression via FAO inhibition.
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Carcinoma de Células Renais , Progressão da Doença , Neoplasias Renais , Gotículas Lipídicas , Animais , Feminino , Humanos , Masculino , Camundongos , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/genética , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Histonas/genética , Neoplasias Renais/patologia , Neoplasias Renais/metabolismo , Neoplasias Renais/genética , Gotículas Lipídicas/metabolismo , Metilação , Camundongos Nus , Prognóstico , Metalotioneína/genética , Metalotioneína/metabolismoRESUMO
Spirotryprostatins are representative members of medicinally interesting bioactive molecules of the spirooxindole natural products. In this communication, we present a novel enantioselective total synthesis of the spirooxindole alkaloid dihydrospirotryprostatin B. The synthesis takes advantage of copper-catalyzed tandem reaction of o-iodoanilide chiral sulfinamide derivatives with alkynone to rapidly construct the key quaternary carbon stereocenter of the natural product dihydrospirotryprostatin B.
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Compostos de Espiro , Estereoisomerismo , Estrutura Molecular , Compostos de Espiro/química , Compostos de Espiro/síntese química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Catálise , Cobre/química , Alcaloides/síntese química , Alcaloides/químicaRESUMO
Carboxymethyl poria polysaccharide plays important anti-tumor, antioxidant, and anti-inflammatory roles. Therefore, this study aimed to compare the healing impacts of two different sources of carboxymethyl poria polysaccharides [Carboxymethylat Poria Polysaccharides I (CMP I) and Carboxymethylat Poria Polysaccharides II (CMP II)] on ulcerative colitis in mice caused by dextran sulfate sodium (DSS). All the mice were arbitrarily split into five groups (n = 6): (a) control (CTRL), (b) DSS, (c) SAZ (sulfasalazine), (d) CMP I, and (e) CMP II. The experiment lasted for 21 days, and the body weight and final colon length were monitored. A histological analysis of the mouse colon tissue was carried out using H&E staining to assess the degree of inflammatory infiltration. The levels of inflammatory cytokines [interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-4 (IL-4)] and enzymes [superoxide dismutase (SOD) and myeloperoxidase (MPO)] in the serum were examined using ELISA. Additionally, 16S ribosomal RNA sequencing was used to analyze the microorganisms in the colon. The results indicated that both CMP I and CMP II alleviated weight loss, colonic shortening, and inflammatory factor infestation in colonic tissues caused by DSS (p < 0.05). Furthermore, the ELISA results revealed that both CMP I and CMP II reduced the expression of IL-1ß, IL-6, TNF-α, and MPO, and elevated the expression of IL-4 and SOD in the sera of the mice (p < 0.05). Moreover, 16S rRNA sequencing showed that CMP I and CMP II increased the plenitude of microorganisms in the mouse colon relative to that in the DSS group. The results also indicated that the therapeutic effect of CMP I on DSS-induced colitis in the mice was superior to that of CMP II. This study demonstrated that carboxymethyl poria polysaccharide from Poria cocos had therapeutic effects on DSS-induced colitis in mice, with CMP I being more effective than CMP II.
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Colite Ulcerativa , Colite , Poria , Animais , Camundongos , Interleucina-4/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , RNA Ribossômico 16S/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Colite Ulcerativa/tratamento farmacológico , Colo/patologia , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Polissacarídeos/metabolismo , Sulfato de Dextrana/toxicidade , Camundongos Endogâmicos C57BL , Modelos Animais de DoençasRESUMO
INTRODUCTION: Cancer stem cells have been implicated angiogenesis of tumor and invasiveness, drug resistance in tumors. Yes-associated protein 1 (YAP) owns carcinogenic roles in various organs, but the role of YAP in cancer stem cells of gastric cancer (GC) remains unclear. In this study, we explored the function and mechanism of YAP in GC cancer stem cells. MATERIALS AND METHODS, AND RESULTS: First, we confirmed that the expression of YAP mRNA and protein in GC tissues was higher than in adjacent tissues by RT-PCR, western blot and immunohistochemistry. Immunofluorescence staining of the GC tissues revealed that the region of YAP expression coincided with the region of expression of the cancer stem cell marker SALL4 but did not overlap with that of the epithelial marker cytokeratin 14 (CK14). Additional research revealed that spherical cells expressed relatively high levels of YAP protein, and YAP overexpression reinforced self-renewal and expression of stem cell markers in the GC cells. Knockdown the expression of YAP reversed this phenomenon. Second, we examined the expression patterns of lipocalin-type prostaglandin D2 synthase (L-PTGDS) and prostaglandin D2 receptor 2 (PTGDR2) in GC tissues and proved that there was negatively correlation between the expression of L-PTGDS and PTGDR2 and YAP in GC tissues. Finally, we confirmed that YAP inhibited the expression of L-PTGDS and PTGDR2 by gain- and loss-of-function experiments. Moreover, the overexpression of L-PTGDS and PTGDR2 suppressed the proliferation and self-renewal induced by YAP in vitro and reversed the pro-tumor effect of YAP in vivo. CONCLUSION: Our results revealed a novel function of YAP and the mechanism underlying cancer stem cell regulation by YAP.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Oxirredutases Intramoleculares/genética , Lipocalinas/genética , Receptores Imunológicos/genética , Receptores de Prostaglandina/genética , Neoplasias Gástricas/patologia , Fatores de Transcrição/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Autorrenovação Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Oxirredutases Intramoleculares/metabolismo , Lipocalinas/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Células-Tronco Neoplásicas/patologia , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas de Sinalização YAPRESUMO
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of Editors-in-Chief and first Author. The article duplicates significant parts of a paper that had already appeared in Fish & Shellfish Immunology, Volume 93 (2019) 726-731, https://doi.org/10.1016/j.fsi.2019.06.052. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents a misuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. The first author informed the journal that the article was published without the knowledge of the co-authors.
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Ração Animal , Peixes-Gato/imunologia , Imunidade Inata , Punica granatum/química , Aeromonas hydrophila , Animais , Antioxidantes/análise , Suplementos Nutricionais , Resistência à Doença , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Transdução de SinaisRESUMO
In this study, the effects of Rhodopseudomonas capsulata present in wastewater effluent on the biodegradation of carbaryl in soil and improvement of soil fertility were investigated. Compared to control treatment, carbaryl was removed efficiently and soil fertility was remediated with the addition of effluent containing R. capsulata. Molecular analysis revealed that carbaryl induced carbaryl hydrolase gene expression to synthesize carbaryl hydrolase through activating MAPKKKs, MAPKKs, MAPKs genes in MAPK signal transduction pathway. The induction and secretion of carbaryl hydrolase occur after one day in R. capsulata, which can be attributed to its characteristics as an ancient bacteria, which require acclimatization to carbaryl before gene induction. However, lack of organics in soil and control treatment could not maintain R. capsulata growth for over one day. The residual organics in the effluent provided sufficient carbon source and energy for R. capsulata under four effluent treatments. This new method resulted in the remediation of carbaryl pollution and improvement of soil fertility and soybean processing wastewater treatment simultaneously, as well as the reutilization of wastewater and R. capsulata as sludge. Meanwhile, the high-order non-linear mathematical model about carbaryl removal rate was established.
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Rhodobacter capsulatus , Águas Residuárias , Biodegradação Ambiental , Carbaril , SoloRESUMO
Clostridium butyricum (CB) and Phellinus igniarius (PI) have anti-inflammatory, immune regulation, anti-tumor, and other functions. This study aimed to explore the therapeutic effect of CB and mycelium of PI (MPI) alone and in combination on colitis mice induced by dextran sodium sulfate (DSS). Mice were randomly assigned to five groups: (1) control (CTRL), (2) DSS, (3) CB, (4) MPI, and (5) CB + MPI (CON). The weight of the mice was recorded daily during the experiment, and the length of the colon was measured on the last day of the experiment. The colons were collected for hematoxylin and eosin staining, colon contents were collected for intestinal flora analysis, and serum was collected for metabolite analysis. The results showed that compared with the DSS group, CB, MPI, and CON treatments inhibited the weight loss and colon length shortening caused by DSS, significantly increased the concentrations of interleukin (IL)-4, IL-10, and superoxide dismutase, and significantly decreased the concentrations of IL-6, tumor necrosis factor-α, and myeloperoxidase. Gene sequence analysis of 16S rRNA showed that CB, MPI, and CON treatments changed the composition and structure of intestinal microorganisms. Metabolome results showed that CB, MPI, and CON treatments changed serum metabolites in DSS-treated mice, including dodecenoylcarnitine, L-urobilinogen, and citric acid. In conclusion, CB, MPI, and CON treatments alleviated DSS-induced colitis in mice by regulating intestinal flora and metabolites, with the CON group having the best effect.
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Clostridium butyricum , Colite , Microbioma Gastrointestinal , Phellinus , Animais , Camundongos , RNA Ribossômico 16S/genética , Colite/induzido quimicamente , Colite/tratamento farmacológico , MicélioRESUMO
Phellinus igniarius is a valuable medicinal and edible mushroom, and its polysaccharides exhibit excellent anti-inflammatory activity. During liquid fermentation to produce P. igniarius mycelia, the fermentation liquid is often discarded, but it contains extracellular polysaccharides. To better utilize these resources, P. igniarius SH-1 was fermented in a 100 L fermenter, and PIPS-2 was isolated and purified from the fermentation broth. The structural characteristics and anti-inflammatory activity of PIPS-2 were determined. PIPS-2 had a molecular weight of 22.855 kDa and was composed of galactose and mannose in a molar ratio of 0.38:0.62. Structural analysis revealed that the main chain of PIPS-2 involved â2)-α-D-Manp-(1 â 3)-ß-D-Galf-(1â, and the side chains involved α-D-Manp-(1 â 6)-α-D-Manp-(1â, α-D-Manp-(1 â 3)-α-D-Manp-(1â, and α-D-Manp-(1. PIPS-2 alleviated the symptoms of dextran sodium sulfate (DSS)-induced colitis in mice, improved the imbalance of inflammatory factors and antioxidant enzymes, and increased short-chain fatty acid contents. Combining the intestinal flora and metabolite results, PIPS-2 was found to regulate the abundance of Firmicutes, Lachnospiraceae_NK4A136_group, Proteobacteria, Bacteroides, and many serum metabolites including hexadecenal, copalic acid, 8-hydroxyeicosatetraenoic acid, artepillin C, and uric acid, thereby ameliorating metabolite related disorders in mice with colitis. In summary, PIPS-2 may improve colitis in mice by regulating the gut microbiota and metabolites.
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Basidiomycota , Colite , Sulfato de Dextrana , Animais , Camundongos , Colite/induzido quimicamente , Colite/tratamento farmacológico , Basidiomycota/química , Polissacarídeos Fúngicos/química , Polissacarídeos Fúngicos/farmacologia , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Masculino , Polissacarídeos/química , Polissacarídeos/farmacologia , Peso Molecular , Modelos Animais de Doenças , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
Key gene mutations are essential for colorectal cancer (CRC) development; however, how the mutated tumor cells impact the surrounding normal cells to promote tumor progression has not been well defined. Here, we report that PIK3CA mutant tumor cells transmit oncogenic signals and result in malignant transformation of intestinal epithelial cells (IECs) via paracrine exosomal arachidonic acid (AA)-induced H3K4 trimethylation. Mechanistically, PIK3CA mutations sustain SGK3-FBW7-mediated stability of the cPLA2 protein, leading to the synthetic increase in AA, which is transported through exosome and accumulated in IECs. Transferred AA directly binds Menin and strengthens the interactions of Menin and MLL1/2 methyltransferase. Finally, the combination of VTP50469, an inhibitor of the Menin-MLL interaction, and alpelisib synergistically represses PDX tumors harboring PIK3CA mutations. Together, these findings unveil the metabolic link between PIK3CA mutant tumor cells and the IECs, highlighting AA as the potential target for the treatment of patients with CRC harboring PIK3CA mutations.
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Ácido Araquidônico , Transformação Celular Neoplásica , Montagem e Desmontagem da Cromatina , Classe I de Fosfatidilinositol 3-Quinases , Mutação , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Humanos , Ácido Araquidônico/metabolismo , Animais , Mutação/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Montagem e Desmontagem da Cromatina/genética , Camundongos , Linhagem Celular Tumoral , Colo/patologia , Colo/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Exossomos/metabolismo , Exossomos/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Histonas/metabolismo , Histonas/genéticaRESUMO
Regulatory T cells (Tregs) are an important component of the tumor microenvironment; however, the interaction between Tregs and gastric cancer cells is not completely understood. Recent studies have shown that Tregs participate in cancer cell stemness maintenance. In this study, we performed single-cell RNA sequencing of gastric cancer and adjacent tissues and found that Tregs with high TNF expression were recruited to gastric cancer tissues and were significantly correlated with patient survival. TNF+ Tregs significantly contribute to tumor growth and progression. Our studies have further demonstrated that TNF+ Tregs promote the stemness of gastric cancer cells through the IL13/STAT3 pathway. Therefore, blocking the interaction between TNF+ Tregs and gastric cancer cells may be a new approach in the treatment of gastric cancer.
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Background: Hepatocellular carcinoma (HCC) is one of the most common type of cancers, but there is still a lack of known biomarkers for the effective diagnosis or prognosis of HCC. Myristoylated alanine-rich C-kinase substrate (MARCKS) is a substrate of protein kinase C, which was located in the cell plasma membrane. The purpose of our study was to evaluate the role of MARCKS in HCC. Methods: The role of MARCKS in HCC was explored by bioinformatics and experiment. Results: We demonstrated that MARCKS expression was significantly elevated in HCC datasets of TCGA. MARCKS was up-regulated in tumor sample in HCC. Functional enrichment indicated that MARCKS-related differentially expressed genes (DEGs) were mainly enriched in cell junction tissue, response to growth factors and cell population proliferation. Tumor and ECM-receptor interactions related pathways were enriched by the KEGG. MARCKS expression in HCC patients was higher in females, younger individuals, and those at worse clinical stages. Cox regression analysis showed that MARCKS expression was a risk factor for overall survival and disease-specific survival of patients. Conclusion: MARCKS was up-regulated in HCC, may play a crucial role in HCCs, and has prognostic value for clinical outcomes.
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BACKGROUND: Cancer stem cells (CSCs) are regarded as the "seed cells" for tumorigenesis, metastasis, recurrence and drug resistance. However, specific surface markers of CSCs of different origins have not been documented. METHODS: Single-cell sequencing was used to analyze the highly expressed genes in cancer stem cells of gastric cancer patients, and it was verified that AQP5 was specifically highly expressed in gastric cancer stem cells (GC-CSCs) in vivo and in vitro. The effect of AQP5-promoting LGR5 on the malignant biological function of GC-CSCs was investigated. The mechanism by which AQP5 affects GC-CSCs was explored through transcriptome sequencing, proteomic detection, mass spectrometry, etc. RESULTS: We report the identification and validation of AQP5 as a potentially specific surface marker of GC-CSCs. AQP5 was significantly upregulated in CSCs isolated from gastric cancer patients and in spheroid cells, and AQP5 was coexpressed with the canonical stem marker LGR5. Biologically, AQP5 promoted the sphere formation, proliferation, migration and invasion of GC cells in vitro and enhanced tumorigenesis in vivo. Furthermore, AQP5 coordinated with LGR5 and synergistically promoted the tumorigenesis of GC-CSCs. At the mechanistic level, AQP5 activated autophagy by inducing the LC3I/LC3II transformation in GC-CSCs, which was crucial for the biological functions of AQP5. Finally, we demonstrated that AQP5 recruited the E3 ligase TRIM21 to the key autophagy protein ULK1 and induced the K63-mediated ubiquitination of ULK1. CONCLUSIONS: We elucidate a novel surface marker, AQP5, which is specifically expressed by GC-CSCs. Furthermore, our study creates a link between AQP5 and LGR5 and highlights the necessity of targeting both surface markers simultaneously as a promising approach for the treatment of gastric cancer patients.
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Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Proteômica , Células-Tronco Neoplásicas/metabolismo , Transformação Celular Neoplásica/metabolismo , Carcinogênese/metabolismo , Ubiquitinação , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Aquaporina 5/genética , Aquaporina 5/metabolismoRESUMO
BACKGROUND: Metabolic reprogramming is a hallmark of cancer. However, the roles of long noncoding RNAs (lncRNAs) in cancer metabolism, especially glucose metabolism remain largely unknown. RESULTS: In this study, we identified and functionally characterized a novel metabolism-related lncRNA, LINC00930, which was upregulated and associated with tumorigenesis, lymphatic invasion, metastasis, and poor prognosis in nasopharyngeal carcinoma (NPC). Functionally, LINC00930 was required for increased glycolysis activity and cell proliferation in multiple NPC models in vitro and in vivo. Mechanistically, LINC00930 served as a scaffold to recruit the RBBP5 and GCN5 complex to the PFKFB3 promoter and increased H3K4 trimethylation and H3K9 acetylation levels in the PFKFB3 promoter region, which epigenetically transactivating PFKFB3, and thus promoting glycolytic flux and cell cycle progression. Clinically, targeting LINC00930 and PFKFB3 in combination with radiotherapy induced tumor regression. CONCLUSIONS: Collectively, LINC00930 is mechanistically, functionally and clinically oncogenic in NPC. Targeting LINC00930 and its pathway may be meaningful for treating patients with NPC.
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Glicólise/genética , Neoplasias Nasofaríngeas/genética , Oncogenes/genética , Fosfofrutoquinase-2/metabolismo , RNA Longo não Codificante/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Neoplasias Nasofaríngeas/patologia , TransfecçãoRESUMO
Cancer stem cells (CSCs) are characterized by robust self-renewal and tumorigenesis and are responsible for metastasis, drug resistance, and angiogenesis. However, the molecular mechanisms for the regulation of CSC homeostasis are incompletely understood. This study demonstrated that the interleukin-17 (IL-17)B/IL-17RB signaling cascade promotes the self-renewal and tumorigenesis of CSCs by inducing Beclin-1 ubiquitination. We found that IL-17RB expression was significantly upregulated in spheroid cells and Lgr5-positive cells from the same tumor tissues of patients with gastric cancer (GC), which was closely correlated with the degree of cancer cell differentiation. Recombinant IL-17B (rIL-17B) promoted the sphere-formation ability of CSCs in vitro and enhanced tumor growth and metastasis in vivo. Interestingly, IL-17B induced autophagosome formation and cleavage-mediated transformation of LC3 in CSCs and 293T cells. Furthermore, inhibition of autophagy activation by ATG7 knockdown reversed rIL-17B-induced self-renewal of GC cells. In addition, we showed that IL-17B also promoted K63-mediated ubiquitination of Beclin-1 by mediating the binding of tumor necrosis factor receptor-associated factor 6 to Beclin-1. Silencing IL-17RB expression abrogated the effects of IL-17B on Beclin-1 ubiquitination and autophagy activation in GC cells. Finally, we showed that IL-17B level in the serum of GC patients was positively correlated with IL-17RB expression in GC tissues, and IL-17B could induce IL-17RB expression in GC cells. Overall, the results elucidate the novel functions of IL-17B for CSCs and suggest that the intervention of the IL-17B/IL-17RB signaling pathway may provide new therapeutic targets for the treatment of cancer.
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Proteína Beclina-1/genética , Carcinogênese/genética , Interleucina-17/genética , Morfogênese/genética , Receptores de Interleucina-17/genética , Autofagia/genética , Diferenciação Celular/genética , Autorrenovação Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Homeostase , Humanos , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Ubiquitinação/genéticaRESUMO
Mesenchymal stem cells (MSCs) are a class of adult stem cells derived from the mesoderm. They can self-renew, have multidirectional differentiation potential, and can differentiate into a variety of mesenchymal tissues. MSCs can produce a large number of exosomes, which can mediate information exchange and transmission between cells in the tumor microenvironment under conditions of rest or stress. Recent studies have reported conflicting findings regarding the effect of MSC-derived exosomes on tumors. Some studies have suggested that MSC-derived exosomes can promote tumor growth and metastasis, but others have reported that they can inhibit tumor cell growth. Here, we investigate the two sides of the debate regarding the effect of MSC-derived exosomes on tumors and analyze the reasons for the divergent findings.
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Human cytomegalovirus (HCMV), a ubiquitous pathogen, can cause severe illness in immunocompromised individuals. Typically, glioma is one of the most common malignant primary brain tumors and originates in the central nervous system. The IE86 gene of HCMV exerts a major role in regulating virus replication. By using coimmunoprecipitation combined with mass spectrometry, the components of the IE86 complex were identified, and the heterogeneous ribonucleoprotein A2/B1 (hnRNP A2/B1) was recognized as one of the IE86 complex components. hnRNP A2/B1 is highly expressed in U251 cells, and the data suggest that IE86 can promote hnRNP A2/B1 expression. Furthermore, the knockdown of hnRNP A2/B1 significantly attenuates IE86-mediated apoptosis and cell proliferation. Importantly, IE86 can also inhibit the alternative splicing of Bcl-x by decreasing the Bcl-xS/Bcl-xL ratio, which is closely related to apoptosis. Meanwhile, the knockdown of hnRNP A2/B1 can mitigate the inhibitory effect of IE86 on the alternative splicing of Bcl-x. In conclusion, the inhibition of apoptosis and enhancement of cell proliferation by IE86 may be related to the hnRNP A2/B1-mediated alternative splicing of Bcl-x.
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Glioblastoma is the most aggressive intracranial tumor and diffuse migration is the leading cause of death. Recent evidence has indicated that heterogeneous nuclear ribonucleoprotein A2B1 (hnRNP A2B1) is overexpressed in human glioblastoma tissue and enhances glioblastoma invasion in vitro. We found by mass spectrometry that hnRNP A2B1 interacts with human cytomegalovirus (HCMV) immediate early 86 protein (IE86, ie2 gene-encoded) in malignant glioma cells (U87MG) infected with HCMV. However, the role of hnRNP A2 B1 in glioblastoma development remains poorly understood. Here, we report that hnRNP A2B1 is highly expressed in the HCMV·ie2 transgenic mice model. This phenomenon was confirmed in U87MG cell lines transfected with pEGFP-N3-ie2 plasmid. In addition, hnRNP A2B1 knockdown in U87MG cells inhibited tumor migration, and this effect might be mediated by hnRNP A2B1 through effects on splicing patterns of RON. Our data suggested that HCMV· ie2 promotes glioblastoma migration by regulating hnRNP A2B1 expression.