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Adenosine deaminases acting on RNA1 (ADAR1) are involved in the occurrence and development of cancers. Although the role of ADAR1 in gastric cancer metastasis has been reported, the role of ADAR1 in the mechanism of cisplatin resistance in gastric cancer is not clear. In this study, human gastric cancer tissue specimens were used to construct cisplatin-resistant gastric cancer cells; the results indicated that the mechanism underlying the inhibition of gastric cancer metastasis and reversal of cisplatin-resistant gastric cancer by ADAR1 inhibits gastric cancer occurs through the antizyme inhibitor 1 (AZIN1) pathway. We assessed ADAR1 and AZIN1 expression in the tissues of patients with low to moderately differentiated gastric cancer. Gastric cancer cells (human gastric adenocarcinoma cell line [AGS] and HGC-27 cells) and gastric cancer cisplatin-resistant cells (AGS CDDP and HGC-27 CDDP ) were selected, and the protein expression of ADAR1 and AZIN1 was detected using immunocytochemistry and immunocytofluorescence. The effects of ADAR1 small interfering RNA (siRNA) on the invasion, migration and proliferation of cisplatin-resistant gastric cancer cells were investigated. Western blot assays were used to assess the protein expression levels of ADAR1, AZIN1 and epithelial-mesenchymal transition (EMT)-related markers. In-vivo experiments, a subcutaneous tumor formation model of nude mice was established, and the effects of ADAR1 on tumor growth and AZIN1 expression level were detected by hematoxylin and eosin, immunohistochemistry and western blot. The expression of ADAR1 and AZIN1 in human gastric cancer tissue was significantly higher than that in paracancerous tissues. The colocalization of ADAR1, AZIN1 and E-cadherin expression in immunofluorescence assays indicated a significant correlation between the three. In in-vitro experiments, ADAR1 knockout not only reduced the invasion and migration ability of AGS and HGC-27 cells but also reduced that of cisplatin-resistant gastric cancer cells. ADAR1 siRNA inhibited the proliferation and decreased the colony number of cisplatin-resistant gastric cancer cells. ADAR1 siRNA decreased the expression of AZIN1 and EMT-related marker proteins (vimentin, N-cadherin, ß-catenin, MMP9, MMP2 and TWIST). The effect of ADAR1 siRNA combined with AZIN1 siRNA was more significant. In-vivo, the knockdown of ADAR1 significantly inhibited tumor growth and AZIN1 expression. ADAR1 and AZIN1 are antimetastatic targets of gastric cancer, and AZIN1 is a downstream regulatory target of ADAR1. ADAR1 knockout can inhibit the metastasis of gastric cancer cells and reverse the cisplatin resistance of gastric cancer cells by downregulating the expression of AZIN1, potentially resulting in increased treatment efficacy.
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L-Homoserine is a valuable amino acid as a platform chemical in the synthesis of various important compounds. Development of microbial strains for high-level L-homoserine production is an attractive research direction in recent years. Herein, we converted a wild-type Escherichia coli to a non-auxotrophic and plasmid-free hyperproducer of L-homoserine using systematically metabolic engineer strategies. First, an initial strain was obtained through regulating L-homoserine degradation pathway and enhancing synthetic flow. To facilitate L-homoserine production, flux-control genes were tuned by optimizing the copy numbers in chromosome, and transport system was modified to promote L-homoserine efflux. Subsequently, a strategy of cofactors synergistic utilization was proposed and successfully applied to achieve L-homoserine hyperproduction. The final engineered strain could efficiently produce 85.29 g/L L-homoserine, which was the highest production level ever reported from a plasmid-free, antibiotic-free, inducer-free and nonauxotrophic strain. These strategies used here can be considered for developing microbial cell factory of other L-aspartate derivatives.
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Proteínas de Escherichia coli , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Homosserina/genética , Homosserina/metabolismo , Plasmídeos/genéticaRESUMO
The peritoneum, especially the omentum, is a common site for gastric cancer (GC) metastasis. Our aim was to expound the role and mechanisms of Piezo1 on GC omentum metastasis. A series of functional assays were performed to examine cell proliferation, clone formation, apoptosis, Ca2+ influx, mitochondrial membrane potential (MMP) and migration after overexpression or knockdown of Piezo1. A GC peritoneal implantation and metastasis model was conducted. After infection by si-Piezo1, the number and growth of tumours were observed in abdominal cavity. Fibre and angiogenesis were tested in metastatic tumour tissues. Piezo1 had higher expression in GC tissues with omentum metastasis and metastatic lymph node tissues than in GC tissues among 110 patients. High Piezo1 expression was associated with lymph metastasis, TNM and distant metastasis. Overexpressed Piezo1 facilitated cell proliferation and suppressed cell apoptosis in GC cells. Moreover, Ca2+ influx was elevated after up-regulation of Piezo1. Piezo1 promoted cell migration and Calpain1/2 expression via up-regulation of HIF-1α in GC cells. In vivo, Piezo1 knockdown significantly inhibited peritoneal metastasis of GC cells and blocked EMT process and angiogenesis. Our findings suggested that Piezo1 is a key component during GC omentum metastasis, which could be related to up-regulation of HIF-1α.
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Regulação Neoplásica da Expressão Gênica , Canais Iônicos/genética , Canais Iônicos/metabolismo , Mecanotransdução Celular , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Animais , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal , Feminino , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Imunofenotipagem , Masculino , Mecanotransdução Celular/genética , Potencial da Membrana Mitocondrial , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Omento/patologia , Neoplasias Gástricas/patologiaRESUMO
Background: Gastric cancer (GC) is a malignant tumor with a high global mortality rate that is currently difficult to treat. Dextran sulfate (DS), a safe anti-tumor agent, can effectively inhibit the malignant biological behavior of gastric cancer; however, its mechanism of action is not fully understood. Therefore, this study aimed at elucidate the potential mechanisms of action. Methods: In this study we used DS to intervene in lentivirus-transfected gastric cancer cells to observe the effect of DS on miR-34c-5p. RT-qPCR, CCK-8, clone formation assay, wound healing assay, transwell assay and western blot were used to examine whether DS affects the proliferation and metastasis of gastric cancer cells via miR-34c-5p. The results were validated using in vivo experiments. Results: Our data confirmed that DS up-regulated miR-34c-5p expression in human gastric cancer cells. Moreover, DS intervention enhanced the inhibitory effect of miR-34c-5p over-expression on the proliferation, invasion, and migration of gastric cancer cells, and partially reversed the promotive effect of miR-34c-5p on the proliferation, invasion, and migration of gastric cancer cells. In addition, DS could affect the activation of the MAP2K1/ERK signaling pathway through the up-regulation of miR-34c-5p, thereby inhibiting the malignant biological behavior of gastric cancer. Finally, it was demonstrated that DS could also inhibit the expression of MAP2K1 in vivo, which in turn inhibits the activation of the ERK signaling pathway to exert anti-cancer effects. Conclusion: DS may inhibit the proliferation and metastasis of gastric cancer cells by regulating miR-34c-5p, which may be a new option for clinical treatment.
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Adenosine receptors play a key role in cancer progression. This study investigated the effect of the adenosine A2B receptor (ADORA2B) on epithelial-mesenchymal transition (EMT) markers and cell metastasis of gastric cancer (GC) cells. Public databases were used to investigate the specificity of ADORA2B expression in GC tissue. We used immunohistochemistry and immunofluorescence to detect ADORA2B expression in GC tissue, paracancerous tissue, and metastatic greater omental tissue. AGS and HGC-27 GC cells were selected. The effect of ADORA2B on the invasion and migration of GC cells was examined using cell scratch and transwell assays. The effect of ADORA2B on the expression of EMT marker proteins (ß-catenin, N-cadherin, and vimentin) in GC cells was measured by cellular immunohistochemistry, immunofluorescence, and Western blot. The effects of an ADORA2B inhibitor combined with cisplatin on EMT markers in GC cells were further explored. The expression levels of ADORA2B in GC tissue, metastatic greater omental tissue, and lymphatic metastasis tissue were significantly higher than those in paracancerous tissue, and ADORA2B was associated with lymph node metastasis and invasion. ADORA2B significantly regulated the invasion and migration ability of GC cells and the expression levels of EMT marker proteins. The combination of an ADORA2B antagonist (PSB-603) and cisplatin had a more significant effect on reversing the expression of EMT marker proteins. ADORA2B was overexpressed in GC tissue, metastatic greater omental tissue, and metastatic lymph node tissue. ADORA2B regulated the expression of EMT marker proteins in GC cells and affected GC cell metastasis. Antagonizing ADORA2B expression increased the efficacy of cisplatin treatment.
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Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Cisplatino/farmacologia , Antagonistas de Receptores Purinérgicos P1/farmacologia , Receptor A2B de Adenosina/genética , Receptor A2B de Adenosina/metabolismo , Caderinas , Metástase Linfática , Transição Epitelial-Mesenquimal/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Invasividade NeoplásicaRESUMO
Obesity is occurring due to continue taken high fat diet; this is the fast-growing problem reaching epidemic proportion globally. Ursolic acid altered the abnormal glucose metabolism in diabetic rats. In this experimental protocol, we examine ursolic acid (UA) anti-obesity effect against streptozotocin (STZ) and high-fat diet-induced obesity in rats. Orally administered the ursolic acid (2.5, 5 and 10 mg/kg) dose to the hyperglycemic rats for 8 weeks and estimated the blood glucose level at different time intervals. Biochemical, hepatic, lipid, renal and antioxidant parameters were estimated. Traf-4, Mapk-8, Traf-6 and genes such as Ins-1, ngn-3 and Pdx-1 mRNA expression were estimated using qRT-PCR to scrutinize the molecular mechanism in MAPK downstream JNK cascade and insulin pathway signalling pathways. Ursolic acid significantly (p<0.001) down-regulated the blood glucose level at dose dependent manner. Its also reduced the plasma insulin level, non-essential fatty acid and increased the level of adiponectin as compared to obese control group rats. Ursolic acid treated group rats reduced the level of total cholesterol and triglycerides. Ursolic-acid-treated rats have been shown to decrease oxidative stress in pancreatic tissue by restoring the free radical effect of scavenging, suppress the Traf-6, Mapk-8 and Traf-4 mRNA expression, enhance the expression of Pdx-1, Ins-1 and Ngn-3 and ensure the regeneration of pancreas ß cells and therefore pancreas insulin. The current result suggested the anti-obese effect of ursolic acid against high fat diet (HFD) induced obese rats via alteration of insulin and JNK signaling pathway.
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Fármacos Antiobesidade , Diabetes Mellitus Experimental/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Hipoglicemiantes , Insulina/metabolismo , Obesidade/tratamento farmacológico , Triterpenos/administração & dosagem , Triterpenos/farmacologia , Administração Oral , Animais , Antioxidantes , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/metabolismo , Relação Dose-Resposta a Droga , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Estreptozocina/efeitos adversos , Ácido UrsólicoRESUMO
Purpose: Gastric cancer(GC)is one of the deadliest digestive tract tumors worldwideï¼existing studies suggest that dysregulated expression of microRNAs (miRNAs) plays an important role in the pathogenesis and progression of GC. This study aimed to investigate the expression, biological function, and downstream mechanism of miR-34c-5p in GC, provide new targets for gastric cancer diagnosis and treatment. Methods: The expression of miR-34c-5p in GC tissues and cell lines was examined by RT-qPCR. Cell wound healing, transwell and cell cloning assays were used to detect the effect of miR-34c-5p on the migration and invasion abilities, respectively, of GC cells. Western blot was performed to detect the expression of related proteins. Bioinformatics analysis was used to predict the binding of MAP2K1 to miR-34c-5p and the targeting relationship was confirmed by dual luciferase reporter assay. Results: The expression level of miR-34c-5p was significantly decreased in GC tissues and cell lines. miR-34c-5p overexpression inhibited migration, invasion, and colony formation of gastric cancer cells, the related protein E-cadherin expression was significantly increased and N-cadherin, vimentin, and PCNA expression were significantly decreased, while miR-34c-5p knockdown exerted the opposite effects. In addition, the targeting relationship between miR-34c-5p and MAP2K1 was predicted and confirmed, and further confirmed by rescue experiments that MAP2K1 alleviated the inhibitory effect of miR-34c-5p in GC. Conclusion: MiR-34c-5p is lowly expressed in GC, and it can target MAP2K1 to exert inhibitory effects on GC proliferation, invasion, and migration. These findings provide a promising biomarker and a potential therapeutic target for gastric cancer.
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MicroRNAs , Neoplasias Gástricas , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Luciferases/metabolismo , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 1/farmacologia , MAP Quinase Quinase 1/uso terapêutico , MicroRNAs/metabolismo , Processos Neoplásicos , Antígeno Nuclear de Célula em Proliferação/metabolismo , Neoplasias Gástricas/patologia , Vimentina/metabolismoRESUMO
Affordably tracking the transmission of respiratory infectious diseases in urban transport infrastructures can inform individuals about potential exposure to diseases and guide public policymakers to prepare timely responses based on geographical transmission in different areas in the city. Towards that end, we designed and tested a method to detect SARS-CoV-2 RNA in the air filters of public buses, revealing that air filters could be used as passive fabric sensors for the detection of viral presence. We placed and retrieved filters in the existing HVAC systems of public buses to test for the presence of trapped SARS-CoV-2 RNA using phenol-chloroform extraction and RT-qPCR. SARS-CoV-2 RNA was detected in 14% (5/37) of public bus filters tested in Seattle, Washington, from August 2020 to March 2021. These results indicate that this sensing system is feasible and that, if scaled, this method could provide a unique lens into the geographically relevant transmission of SARS-CoV-2 through public transit rider vectors, pooling samples of riders over time in a passive manner without installing any additional systems on transit vehicles.
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Veículos Automotores , RNA Viral/isolamento & purificação , SARS-CoV-2 , Meios de Transporte , COVID-19 , Monitoramento Ambiental , Humanos , SARS-CoV-2/isolamento & purificação , WashingtonRESUMO
PURPOSE: To explore the effect of dextran sulfate (DS) on the angiogenesis, invasion, and migration of gastric cancer cells by interfering with the polarization of M2-type macrophages. METHODS: The infiltration of M2-type macrophages and microvascular density in gastric cancer and paracancerous tissues were analyzed using immunohistochemistry and immunofluorescence. The effects of DS on M2-type macrophages and the angiogenesis in metastatic tumors were investigated in the nude mice intraperitoneal metastasis model using immunohistochemistry and western blot. The differentiation and polarization of macrophages, immunocytochemistry, western blot, ELISA, and transwell migration assay were used to evaluate the effect of DS on the polarization of macrophages, immunocytochemistry, western blot, ELISA, and transwell migration assay were used to evaluate the effect of DS on the polarization and recruitment capacity of macrophages. Immunocytofluorescence, tube formation assay, transwell invasion assay, wound healing assay, and western blot were used to investigate the effect of DS on the angiogenesis, invasion, and migration-promoting phenotype of M2- type macrophage in a co-culture system of macrophages and gastric cancer cells. RESULTS: The infiltration of M2-type macrophages and the microvascular density were highly expressed and positively correlated in the human gastric cancer tissue. DS can significantly inhibit the intraperitoneal metastases of gastric cancer in nude mice, and reduce the infiltration of M2-type macrophages and the angiogenesis in intraperitoneal metastatic tumors. Moreover, DS can prevent the polarization of M0-type macrophages to M2 type, reduce the expression of M2-type macrophage markers (CD206, CD163, IL-10, and Arg-1), down-regulate the IL-6-STAT3 pathway, and inhibit the recruitment capability of M2-type macrophages. Finally, the co-culture experiment showed that DS significantly reduced the enhancing effects of M2-type macrophages on the angiogenesis, invasion, and migration of gastric cancer cells, as well as down-regulated the related expressions of proteins (VEGF, N-cadherin, MMP-2 and Vimentin) in gastric cancer cells. CONCLUSION: DS can reduce the infiltration of M2-type macrophages and the microvascular density in intraperitoneal metastases of gastric cancer in nude mice, and inhibit the angiogenesis, invasion, and migration of gastric cancer cells by interfering with the polarization of M2-type macrophages through repression of the IL-6/STAT3 signaling pathway.
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Neoplasias Gástricas , Humanos , Camundongos , Animais , Neoplasias Gástricas/metabolismo , Camundongos Nus , Vimentina/metabolismo , Vimentina/farmacologia , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/farmacologia , Sulfato de Dextrana , Interleucina-6 , Fator A de Crescimento do Endotélio Vascular/metabolismo , Macrófagos , Neovascularização Patológica/patologia , Caderinas/metabolismoRESUMO
Nitroaromatic compounds (NACs) can lead to various environmental pollution healh problems. In order to effectively recognize and sense NACs, a novel coordination polymers (CPs) with fluorescent characteristic [Zn3(btc)2(tpt)(H2O)2]·4H2O (1) (tpt = tris(4-pyridyl)triazine, H3btc = 1,3,5-benzenetricarboxylic acid) has been triumphantly prepared as an fluorescence probe by solvothermal method. 1 possesses remarkable PH stability ranging from 2.0 to 12.0 and is also stable in different pure organic solvents. It should be noted that 1 manifests a fluorescence quenching response against the detection of selectivity and sensitivity towards 2,4,6-trinitrophenol (TNP) in aqueous solution. It also makes analysis on the limit of detection towards TNP, which is as low as 0.94 µM compared with most reported CPs sensors for TNP. Therefore, 1 can become a satisfactory sensor for TNP detection with remarkable selectivity, strong anti-interference and favorable recyclability. In addition, the quenching mechanisms were also discussed. It was supposed that the mechanisms of photoinduced electron transfer (PET) as well as resonance energy transfer (RET) might be the main influencing factors.
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Luminescência , Polímeros , Picratos , ZincoRESUMO
Introduction: Low physical activity (LPA) is associated with several major non-communicable diseases (NCDs) and premature mortality. In this study, we aimed to assess the global burden and trends in disease attributable to LPA (DALPA) from 1990 to 2019. Methods: Annual age-standardized disability-adjusted life years (DALYs) and death rates of DALPA [all-cause and five specific causes (ischaemic heart disease, diabetes mellitus, stroke, colon and rectal cancer, and breast cancer)] by sex, age, geographical region and social deprivation index (SDI) score from 1990 to 2019 were available from the Global Burden of Disease (GBD) study 2019. The estimated annual percentage changes (EAPCs) were calculated to quantify the changing trend. A generalized linear model (GLM) was used to explore the relationship between DALYs/death rates of DALPA and sociodemographic factors. Results: Globally, in 2019, the age-standardized DALYs and death rates of DALPA were 198.42/100,000 (95% UI: 108.16/100,000-360.32/100,000) and 11.10/100,000 (95% UI: 5.66/100,000-19.51/100,000), respectively. There were 15.74 million (8.51-28.61) DALYs and 0.83 million (0.43-1.47) deaths attributable to LPA. Overall, age-standardized DALYs and death rates presented significant downward trends with EAPCs [-0.68% (95% CI: -0.85- -0.50%) for DALYs and -1.00% (95% CI: -1.13- -0.86%) for deaths] from 1990 to 2019. However, age-standardized DALYs and death rates of diabetes mellitus attributable to LPA were substantially increased [EAPC: 0.76% (95% CI: 0.70-0.82%) for DALYs and 0.33% (95% CI: 0.21-0.51%) for deaths]. In the 15-49 age group, DALPA presented significant upward trends [EAPC: 0.74% (95% CI: 0.58-0.91%) for DALYs and 0.31% (95% CI: 0.1-0.51%) for deaths]. The GLM revealed that higher gross domestic product and current health expenditure (% of GDP) were negatively associated with DALYs and death rates of DALPA. Conclusion: Although global age-standardized DALYs and death rates of DALPA presented downward trends, they still cause a heavy burden worldwide. These rates showed upward trends in the diabetic and 15-49 age groups, which need more attention and health interventions.
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Doença da Artéria Coronariana , Carga Global da Doença , Humanos , Expectativa de Vida , Anos de Vida Ajustados por Qualidade de Vida , Saúde GlobalRESUMO
PURPOSE: Gastric cancer (GC) is one of the most fatal digestive tumors worldwide. Abnormal activation or accumulation of the nuclear factor-erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) axis is a malignant event in numerous solid tumors. However, its involvement in angiogenesis of GC remains unknown. This study investigated the role of the Nrf2/HO-1 axis in angiogenesis of GC. METHODS: The expression of Nrf2, HO-1, and vascular endothelial growth factor (VEGF) in BGC-823 cells under hypoxia was analyzed using immunocytochemistry, immunofluorescence, Western blotting, and quantitative polymerase chain reaction. The effects of brusatol (Nrf2 inhibitor) and tert-butylhydroquinone (Nrf2 inducer) on these factors and angiogenesis were examined using immunofluorescence, Western blotting, quantitative polymerase chain reaction, and tube formation assay. Moreover, immunohistochemistry and Western blotting were used to determine these factors and microvessel density in tumor and normal tissues of tumor-bearing and tumor-free mice, respectively. Immunohistochemistry and Western blotting were employed to examine these factors and microvessel density in human paracancerous tissues, well-differentiated GC, and poorly differentiated GC. The correlations between Nrf2, HO-1, and VEGF gene expression in 375 patients with GC from The Cancer Genome Atlas cohort were analyzed. RESULTS: The expression of Nrf2, HO-1, and VEGF was increased in hypoxic BGC-823 cells (P<0.05). Although brusatol decreased their expression and angiogenesis (P<0.05), tert-butylhydroquinone had the opposite effect (P<0.05). Moreover, the expression of Nrf2, HO-1, and VEGF, and microvessel density in tumor tissues was higher than that recorded in normal tissues of nude mice (P<0.05). Similarly, these parameters were low in paracancerous tissues, but high in GC tissues (P<0.05). Also, they were weak in well-differentiated GC, but strong in poorly differentiated GC (P<0.05). In addition, there was a significant correlation between Nrf2, HO-1, and VEGF (P<0.05). CONCLUSION: The Nrf2/HO-1 axis may regulate the angiogenesis of GC via targeting VEGF. These findings provide a promising biomarker and potential treatment target for GC.
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BACKGROUND: Gastric cancer (GC) is one of the most common gastrointestinal malignancies. According to reports, the enhancer of zeste homolog 2 (EZH2) exhibits carcinogenic function in a variety of cancers. Therefore, EZH2 may be a potential therapeutic target for the treatment of human cancer. Macromolecular Dextran Sulfate (DS) has been displayed to play a critical role in tumor inhibition. However, the molecular mechanism by which DS mediates this effect is unclear. OBJECTIVES: In this study, we explored the effects of DS on the proliferation and apoptosis of gastric cancer and the related mechanisms. Cell proliferation and counting assays, as well as cell colony formation assays, revealed that DS inhibited the proliferation and tumorigenesis of GC cells. Additionally, flow cytometry analysis displayed that DS blocked the cell cycle of GC cells in the G1/S phase and promoted their apoptosis. METHODS: Bioinformatics analyses, enzyme-linked immunosorbent assays, immunohistochemistry, and other methods were applied to measure the expression of EZH2 in human GC cells and tissues. RESULTS AND DISCUSSION: Further studies have shown that DS treatment can reduce the expression of proliferating cell nuclear antigen (PCNA) and increase the level of the ratio of Bax: Bcl-2 protein in GC cells. In addition, DS reduced EZH2 levels and increased CXXC finger protein 4 levels both in vitro and in vivo. In addition, down-regulation of EZH2 with EZH2 inhibitors reversed the inhibitory effect of DS on gastric cancer cells. CONCLUSION: Collectively, our work demonstrates that DS suppresses proliferation and promotes apoptosis of GC cells by regulating EZH2. Our study suggests that DS is a promising therapeutic compound for the treatment of GC.
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Carcinoma , Neoplasias Gástricas , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Sulfato de Dextrana , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genéticaRESUMO
Objective: Peritoneal metastasis frequently occurs in advanced gastric cancer, which is typically not eligible for radical surgery. Here, this study observed the function and regulatory mechanism of ADAR1 in peritoneal metastasis of gastric cancer. Methods: ADAR1, CALR and ß-catenin proteins were detected in normal mucosa, primary gastric cancer, metastatic lymph node and metastatic omentum tissues by immunohistochemistry, western blot, and immunofluorescence. After silencing ADAR1 by siADAR1, the effect and mechanism of ADAR1 on gastric cancer metastasis were observed in nude mouse models of gastric cancer with peritoneal metastasis as well as HGC-27 and AGS gastric cancer cells. Result: Our results showed that ADAR1 was significantly up-regulated in gastric cancer, metastatic lymph node and metastatic omentum tissues. Its up-regulation was significantly correlated to lymph node metastasis and peritoneal metastasis. Silencing ADAR1 significantly reduced the volume of peritoneal metastatic tumors and weakened oncogene CALR expression, Wnt / ß-catenin pathway and epithelial-mesenchymal transition (EMT) process in vivo. Furthermore, ADAR1 knockdown distinctly suppressed cell viability, colony formation and migration of HGC-27 and AGS cells and ameliorated the effects of Wnt pathway activator on tumor progression. The similar findings were investigated when treated with ADAR1 inhibitor 8-Azaadenosine. Conclusion: Collectively, this study identified a novel oncogenic function of ADAR1 in peritoneal metastasis of gastric cancer via Wnt / ß-catenin pathway. Hence, ADAR1 could be a novel marker and therapeutic target against gastric cancer metastasis.
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Purpose: To investigate the role of Nrf2/HO-1 signaling pathway in angiogenesis and whether dextran sulfate (DS) could suppress angiogenesis by inhibiting Nrf2/HO-1 signaling pathway in gastric cancer. Methods: In vitro; Western blot analyzed the expression of Nrf2 in gastric cell lines. Tube formation assay observed the effect of gradient concentration DS on the angiogenic potential of HGC-27 cells. Immunofluorescence,western blot and qPCR analyzed the effects of DS on the expression of Nrf2, HO-1 and VEGF under gradient hypoxia time. Immunofluorescence,western blot,qPCR and tube formation assay analyzed the effects of up-regulating or down-regulating Nrf2/HO-1 signaling pathway on VEGF expression and angiogenic potential in HGC-27 cells. In vivo: Construct nude mouse intraperitoneal implantation metastasis model. Immunohistochemistry and western blot analyzed the effects of DS on the expression of Nrf2, HO-1, VEGF and MVD in nude mice. Immunohistochemistry detected the expression of Nrf2, HO-1, VEGF and MVD in human paracancerous tissue and gastric cancer tissues with different degrees of differentiation. Results: The expression of Nrf2 increased most significantly in HGC-27 cell line. DS reduced the angiogenic potential and the expression of Nrf2, HO-1 and VEGF in HGC-27 cells. Down-regulation of Nrf2/HO-1 signaling pathway decreased VEGF expression and angiogenic potential in HGC-27 cells. Up-regulation of Nrf2/HO-1 signaling pathway increased VEGF expression and angiogenic potential in HGC-27 cells. DS reduced the expression of Nrf2, HO-1, VEGF and MVD in nude mice. Nrf2, HO-1, VEGF and MVD showed low expression in paracancerous tissue but high expression in gastric cancer tissues. They were weak, moderate and strong in well, moderately and poorly differentiated gastric cancer tissues, respectively. Conclusion: Nrf2/HO-1 signaling pathway may positively regulate gastric cancer angiogenesis and DS may suppress the angiogenesis by inhibiting Nrf2/HO-1 signaling pathway in gastric cancer.
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The peritoneal implant metastasis is one of the main pathway and main cause for high mortality for gastric cancer metastasis. Researchs show that epithelial-mesenchymal transition (EMT) playing essential role in modulating gastric cancer metastasis, and the expression of hypoxia inducible factor-1α (HIF-1α) can promote EMT in tumor cells. This research aims to explore the influence and mechanism of Dextran Sulfate (DS) affecting EMT of human gastric cancer. In the present study, we found that DS can enter into the cytoplasm and function in it. Inhibition of HIF-1α or DS significantly inhibit the migration and invasion of human gastric cancer cells, and decrease the mRNA and protein expressions of HIF-1α, matrix metalloproteinase-2 (MMP-2), transforming growth factor-ß (TGF-ß), Twist and N-cadherin (N-cad), rise E-cadherin (E-cad) expression, DS with HIF-1α knockdown has a stronger effect. In vivo studies indicated that compared with using DS or HIF-1α knockdown alone, DS with HIF-1α knockdown can better suppress the volume and number of metastatic tumors, and reduce the mRNA and protein expressions of HIF-1α, MMP-2, TGF-ß, Twist and N-cad in metastatic tumor tissues of nude mice. We further demonstrated that the expression of HIF-1α, MMP-2, TGF-ß , Twist and N-cad were higher in well and poorly differentiated gastric cancer than paracancerous tissue, and poorly differentiated gastric cancer were even higher, while E-cad expression was opposite. Taken together, this study shows that DS can interfere the expression of HIF-1α, thereby inhibiting TGF-ß-mediated EMT of gastric cancer cells, and demonstrated a promising application of DS in gastric cancer therapy.
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BACKGROUND AND OBJECTIVE: Sapylin is one of the biological response modifiers. It has been used in the comprehensive treatment for advanced cancer, and its clinical efficacy has been proved. This study was to evaluate the effect of preoperative intraperitoneal injection of Sapylin in treatment of advanced gastric cancer. METHODS: Seventy-nine patients eligible for radical gastrectomy were randomly divided into the treatment group (Sapylin + mitomycin C, 40 patients) and the control group (mitomycin C alone, 39 patients). In the treatment group, 5 KE Sapylin was injected intraperitoneally 48 h before operation and 4 mg of mitomycin C was injected into peritoneal cavity before the closure of the peritoneum. In the control group, only 4 mg mitomycin C was injected into peritoneal cavity before the closure of the peritonium. RESULTS: There was no operative mortality or duodenal stump leakage in the two groups. Postoperative complications were anastomotic leakage (2.5%, 1/40) and incision rupture (2.5%, 1/40) in the treatment group, and incision rupture (2.6%, 1/39) in the control group, with no significant difference between the two groups (P > 0.05). The 3-year survival rate was significantly higher in the treatment group than in the control group (76.5% vs. 49.4%, P < 0.05). CONCLUSIONS: Preoperative intraperitoneal injection of Sapylin can raise the 3-year survival rate after radical gastrectomy , without increasing the incidence rate of operative complications. Preoperative intraperitoneal injection of Sapylin is therefore a valuable therapy for advanced gastric cancer in clinic.
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Adenocarcinoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Fístula Anastomótica/etiologia , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/uso terapêutico , Antineoplásicos/administração & dosagem , Produtos Biológicos/administração & dosagem , Produtos Biológicos/isolamento & purificação , Feminino , Seguimentos , Gastrectomia/efeitos adversos , Gastrectomia/métodos , Humanos , Injeções Intraperitoneais , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Mitomicina/uso terapêutico , Estadiamento de Neoplasias , Período Pré-Operatório , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Ruptura Gástrica/etiologia , Streptococcus pyogenes/química , Taxa de SobrevidaRESUMO
The objective of the present study was to observe the influence of dextran sulfate (DS) on the proliferation, invasion and migration of AGS, BGC-23, GES-1, MGC-803 and SGC-7901 cells. Additionally, the possible inhibition mechanism of DS on BGC-823 cells epithelial-mesenchymal transition (EMT) was explored. The cells in the control and experimental group were treated with PBS and DS respectively. The effect of DS on the invasion and migration of these five types of cells were investigated using Transwell invasion and migration assays. Immunocytochemistry, western blotting and reverse transcription-polymerase chain reaction (RT-PCR) assays were used to measure gene and protein expression of hypoxia-inducible factor 1α (HIF1-a) and EMT associated factors [Twist, E-cadherin, N-cadherin and ß-catenin] of BGC-823 cells. According to the results of CCK-8, DS significantly decreased the proliferation of AGS, SGC-7901 and BGC-823 cells to different extents, but there were no notable differences for MGC-803 cells. Transwell migration and invasion results demonstrated that, compared with the control group, DS reduced the migration and invasion of every types of cells to different extents, and the inhibition to BGC-823 cells invasion is the most notably. Immunofluorescence, RT-PCR and western blot analysis results indicated that HIF-1α, Twist and N-cad expressions levels had different degrees of reduction in the experimental group following DS treatment; however, the expression level of E-cad had increased. In conclusion, DS inhibited the proliferation of AGS, BGC-823, SGC-7901 and GES-1 cells, the inhibition degree may be associated with the differentiation degree of every cancer cell, the higher the differentiation degree, the stronger the inhibition. DS inhibited migration and invasion of the five types of gastric cancer cells in different degree. DS may inhibit EMT of BGC-823 by inhibiting Wnt signaling.
RESUMO
In the present study, the effect of dextran sulfate (DS) on the metastasis and invasion of human gastric cancer cells and its key underlying mechanism were investigated. The levels of hypoxiainducible factor 1α (HIF1α), transforming growth factor ß (TGFß) and lysyl oxidase (LOX) expression were evaluated in human gastric cancer and peritumoral tissues by immunohistochemical analysis. Cell proliferation and apoptosis were also examined using the Cell Counting Kit8 assay and flow cytometry. The effect of DS on the invasion and migration of BGC823 cells was assessed using a Transwell assay. BGC823 cells were divided into the control (phosphatebuffered salinetreated) and experimental (DStreated) groups, and cultured for different times under hypoxic conditions. Subsequently, LOX and TGFß expression levels in the cells were measured by immunocytochemistry, immunofluorescence, reverse transcriptionquantitative polymerase chain reaction and western blot analysis. HIF1α, TGFß and LOX expression levels were significantly higher in human gastric cancer tissues as compared with that in adjacent tissues. DS influenced cell proliferation and apoptosis in a dosedependent manner. Furthermore, DS reduced the number of invaded and migrated cells. Under hypoxic conditions, DS reduced HIF1α, TGFß and LOX expression levels in BGC823 cells. After 12 h, the effect of combination of DS and ßaminopropionitrile (BAPN) on LOX and TGFß protein levels was more significant compared with that of DS or BAPN alone. Therefore, DS may inhibit the invasion and migration of human gastric cancer cells under hypoxic conditions by influencing LOX.
Assuntos
Antineoplásicos/farmacologia , Sulfato de Dextrana/farmacologia , Regulação para Baixo/efeitos dos fármacos , Invasividade Neoplásica/prevenção & controle , Proteína-Lisina 6-Oxidase/genética , Neoplasias Gástricas/tratamento farmacológico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Invasividade Neoplásica/patologia , Proteína-Lisina 6-Oxidase/análise , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Fator de Crescimento Transformador beta/análise , Fator de Crescimento Transformador beta/genéticaRESUMO
The present study investigated the inhibitory effects of dextran sulphate (DS) on the peritoneal metastasis of gastric cancer by observing the adhesion and implantation of human gastric cancer cells in the omenta of nude mice. DS or PBS was added to the culture medium of gastric cancer MKN1 cells. The adhesion of the cancer cells to the culture dishes, and the morphological changes of fixed and living cancer cells were observed using fluorescence staining and confocal microscopy. In addition, the expression of integrin ß1 was measured using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Gastric cancer BGC-823 cells were peritoneally injected into nude mice to develop an animal model. DS and PBS were peritoneally injected into the experimental and control groups, respectively, concurrently with the tumour cells. Haematoxylin and eosin staining was performed, and the number of carcinoma nodules with celiac implantation was counted. Integrin expression was determined by immunohistochemistry and RT-PCR. The results showed that MKN1 cells strongly expressed integrin ß1 in the cell membrane and clustered in vitro. DS inhibited the expression of integrin ß1 and reduced cluster formation. In addition, the number of pseudopodia formed by the cells decreased, and the cells maintained a rounded shape. The expression of integrin ß1 in the adherent and free cells in the experimental group was reduced to 74 and 38% of the levels in the control group, respectively. In the in vivo study, significantly fewer tumour nodules were observed in the experimental group than in the control group (P<0.01). Integrin ß1 expression in the experimental group was decreased significantly compared with that in the control group (P<0.01). The present study indicates that DS inhibits the adhesion of human gastric cancer cells, accompanied by a decrease in the expression of integrin ß1. DS may inhibit the metastatic celiac implantation of human gastric cancer cells by downregulating integrin ß1.