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Objective:To investigate the differentially expressed microRNAs (miRNAs) in human gastric carcinoma SGC-7901 cell-derived exosomes induced by Helicobacter pylori ( H. pylori), providing new clues for further elucidating the carcinogenic mechanism of H. pylori. Methods:Ultracentrifugation and exosome extraction kit were used to extract the exosomes released by the H. pylori-stimulated and negative control group, and transmission electron microscope(TEM), nanoparticle tracking analysis(NTA) and Western blot experiments were employed to identify exosomes. Then, exosomes were labeled with the fluorescent dye PKH67 and co-cultured with THP-1-derived macrophages. The internalization of exosomes by macrophages was observed by laser confocal fluorescent microscopy. Additionally, miRNA microarray chips were performed to detect the differentially expressed miRNAs of exosomes from the two groups of cells. Real-time fluorescence quantitative PCR (qRT-PCR) was used to verify the expression of four differentially expressed miRNAs. Furthermore, the target genes and their functions as well as the possible signal pathways involved of partial differentially expressed miRNAs were predicted and analyzed by bioinformatics software. Differentially expressed miR-382-5p was labeled by Cy3 to observe whether it could be transferred to macrophages through exosomes. The expression of phenotype molecule CD206 and the cytokines TNF-α, IL-6 and IL-10 in miR-382-5p mimic-transfected macrophages were analyzed by qRT-PCR and ELISA, and the proportion of cells expressing CD206 and HLA-DR was analyzed by flow cytometry. Results:The extracted exosomes were consistent with exosome morphology and highly expressed the surface marker proteins CD9, CD63 and TSG101. After co-culturing with THP-1 derived macrophages for 12 h, the exosomes could be internalized by macrophages. Compared with the control group, there were 130 up-regulated miRNAs and 111 down-regulated miRNAs in the H. pylori-stimulated group. Bioinformatic analysis showed that the potential target genes of partial differentially expressed miRNAs were mainly involved in the regulation of PI3K-AKT, NF-κB, JAK-STAT, stem cell pluripotency and other inflammation and tumor-related pathways. miR-382-5p could be transferred to macrophages through exosomes, and induced the expression of M2-type phenotype molecule CD206 and cytokines IL-10 in macrophages, while inhibited the expression of TNF-α and IL-6 and increased the proportion of CD206 high HLA-DR low cells. Conclusions:H. pylori treatment caused a significant change in the expression level of exosome miRNAs in SGC-7901 cells. Bioinformatics analysis demonstrated that the prospective targets of these differentially expressed miRNAs might play an important role in the regulation of inflammation and tumor-related signaling pathways. miR-382-5p might induce the M2-type polarization of macrophages.
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Objective: To investigate the cytotoxic effects and the potential mechanisms of crebanine N-oxide in SGC-7901 gastric adenocarcinoma cells. Methods: The cytotoxicity of crebanine N-oxide was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and cellular morphology was observed under a microscope. Cell apoptosis was determined by flow cytometry using propidium iodide staining. The expression levels of apoptotic-related proteins, cleaved caspase-3, cytochrome C, p53 and Bax, and autophagy-related proteins p62, beclin1 and LC3 were detected by Western blotting assays. Results: Crebanine N-oxide treatment significantly inhibited the proliferation of SGC-7901 cells in a dose-dependent and time-dependent manner via induction of G
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Objective To investigate the effect of gambogic acid (GA) on invasion in human gastric carcinoma SGC-7901 cells and its possible mechanism. Methods Cell counting kit-8(CCK-8) assay was performed to detect the effects of GA, inhibitor of nuclear factor kappa-B kinase( IKK) 16 and 5-fluorouracil (5-FU) on cell activity of GES-1 and SGC-7901 cells. Cell invasion was assessed with Transwell invasion assay. Western blotting was used to analyze the protein levels of vimentin, matrix metalloproteinase 2 ( MMP-2) and MMP-9 and protein phosphorylation of IKKα and p65. Results The cell activity was significantly decreased in SGC-7901 cells treated with GA in a dose-dependent manner with a half inhibiton concentration(IC50) value of 1. 89 μmol/L. But GA had no significant influence on cell viability of GES-1 cells. Meanwhile, 5-FU reduced the cell activity of GES-1 and SGC-7901 cells with IC50values of 7.36 μmol/L and 199.57 μmol/L respectively. Low-dose GA and IKK 16 impaired separately the ability of invasion in SGC-7901 cells, and down-regulated the protein levels of MMP-2, MMP-9 and vimentin, and inhibited phosphorylation of IKKot and p65, while a stronger inhibition was showed when the combination of GA and IKK16 was used. Conclusion Low-dose GA might inhibit invasion of SGC-7901 cells via IKKot/p65 signaling pathway.
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Objective: To investigate the cytotoxic effects and the potential mechanisms of crebanine N-oxide in SGC-7901 gastric adenocarcinoma cells. Methods: The cytotoxicity of crebanine N-oxide was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and cellular morphology was observed under a microscope. Cell apoptosis was determined by flow cytometry using propidium iodide staining. The expression levels of apoptotic-related proteins, cleaved caspase-3, cytochrome C, p53 and Bax, and autophagyrelated proteins p62, beclin1 and LC3 were detected by Western blotting assays. Results: Crebanine N-oxide treatment significantly inhibited the proliferation of SGC-7901 cells in a dose-dependent and timedependent manner via induction of G2-phase cell cycle arrest, apoptosis, and autophagy in SGC-7901 cells. Conclusions: Crebanine N-oxide could inhibit the growth of gastric cancer cells by promoting apoptosis and autophagy and could be used as a potential agent for treating gastric cancer.
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Objective: To investigate the regulatory effect of lumbrukinase CI.RK) on the gastric cancer SGC7901 Cells, and to clarify its mechanism Methods: The SGC7901 cells in the logarithmic growth phase were selected and divided into control group and 2, 4 , 8 U • ml. I.RK groups. MTT assay was used to detect the inhibitory rates of proliferation of SGC7901 cells in various groups in vitro at different time (24, 48 and 72 h). Cell scratch assay was used to detect the migration abilities of the SGC7901 cells in vitro in various groups. Flow cytometry was used to determine the apoptotic rates of SGC7901 cells and the pencentages of cells at different cell cycles in various groups. The expression levels of Bcl-2, Rax, and caspase-3 in the SGC790I cells in various groups were detected by Western blotting method. Results: The results of MTT assay showed that compared with control group, the inhibitory rates of SGC7901 cells in different doses of I.RK groups after treated for 24, 48 and 72 h were increased ( P<0.01). The cell scratch assay results showed that compared with control group, the migration distances of SGC790I cells in 4 and 8 U • mL"1 I.RK groups were increased significantly ( P
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To explore the mechanism of β-carboline alkaloids inhibiting the migration and invasion of SGC-7901 cells and its correlation with FAK gene expression,CCK-8 method was used to determine the inhibitory rate of β-carboline alkaloids on the proliferation of gastric cancer SGC-7901 cells under different concentrations.The effect of β-carboline alkaloids on the migration and invasion of SGC-7901 cells was used by Transwell compartment.Detection of mRNA and protein expression of FAK genes were used by qRT-PCR and Western blot.Then si-FAK-1051 recombinant plasmid was transfected into SGC-7901 cells.FAK gene silencing effect was identified by qRT-PCR and Western blot technique again.Finally,the effects of FAK gene silencing on proliferation and migration of gastric cancer SGC-7901 cells were detected by CCK-8 kit and Transwell chamber assay respectively.With the increase of the concentration ofβ-carboline alkaloids,the inhibitory rate of SGC-7901 cells in human gastric cancer cells increased gradually,with IC5013.364 mg·L-1.The number of SGC-7901 cells of Transwell compartment in the positive experimental group(5-FU,5 mg·L-1) and the β-carboline alkaloids group decreased significantly(P<0.01) and the number of SGC-7901 cells in the β-carboline alkaloids group was significantly lower than that in the positive experimental group(P<0.01).Compared with the blank control group,the mRNA and protein expression level of FAK genes in the positive experimental group was significantly lower than that in the experimental group of β-carboline alkaloids(P<0.05).After transfection of si-FAK-1051 into gastric cancer SGC-7901 cells,the expression of mRNA and protein of FAK gene was significantly down regulated(P<0.05).SGC-7901 cell proliferation and cell migration ability also decreased significantly(P<0.05).β-carboline alkaloids are more effective than 5-FU in inhibiting migration and invasion of gastric cancer SGC-7901 cells,and the mechanism may be related to the inhibition of mRNA and protein expression of FAK gene by β-carboline alkaloids.
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Humans , Alkaloids , Pharmacology , Carbolines , Pharmacology , Cell Line, Tumor , Cell Movement , Cell Proliferation , Focal Adhesion Kinase 1 , Genetics , Gene Expression Regulation, Neoplastic , Gene Silencing , Neoplasm Invasiveness , Stomach Neoplasms , Drug Therapy , PathologyABSTRACT
Objective:To investigate the regulatory effect of lumbrukinase (LBK) on the gastric cancer SGC7901cells, and to clarify its mechanism.Methods:The SGC7901cells in the logarithmic growth phase were selected and divided into control group and 2, 4, 8U·mL-1 LBK groups.MTT assay was used to detect the inhibitory rates of proliferation of SGC7901cells in various groups in vitro at different time (24, 48and 72h) .Cell scratch assay was used to detect the migration abilities of the SGC7901cells in vitro in various groups.Flow cytometry was used to determine the apoptotic rates of SGC7901cells and the pencentages of cells at different cell cycles in various groups.The expression levels of Bcl-2, Bax, and caspase-3in the SGC7901cells in various groups were detected by Western blotting method.Results:The results of MTT assay showed that compared with control group, the inhibitory rates of SGC7901cells in different doses of LBK groups after treated for 24, 48and 72hwere increased (P＜0.01) .The cell scratch assay results showed that compared with control group, the migration distances of SGC7901cells in4and 8U·mL-1 LBK groups were increased significantly (P＜0.01) .The flow cytometry results showed that compared with control group, the apoptotic rates of SGC7901cells in 4and 8U·mL-1 LBK groups were increased significantly (P＜0.01) ;the percentages of cells in G1and S phases were decreased (P＜0.01) ;the percentages of cells in G2phase were increased (P＜0.01) .The results of Western blotting method showed that compared with control group, the Bcl-2protein expression level in the SGC7901cells in 8U·mL-1 LBK group was decreased (P＜0.05) ;the Bax and caspase-3protein expression levels were increased (P＜0.05) .Conclusion:LBK can inhibit the proliferation and migration abilities of SGC7901cells in vitro and induce the apoptosis;its mechanism is achieved through the regulation of expression levels of Bcl-2, Bax, and caspase-3proteins.
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The purpose of this study was to investigate the inhibitory effect of the main 9,10-dihydrophenanthrene orchinol isolated from Spiranthes sinensis Radix et Herba on the invasion and migration of human gastric cancer SGC-7901 cells and its preliminary molecular mechanism. SGC-7901 cells were cultured in vitro, after the cells were treated with different final concentrations(5, 10, 20, 40, 80 μmol·L⁻¹) of orchinol for 24, 48 or 72 hours, the effect of orchinol on cell viability was measured by MTT assay. Wound healing and Transwell assays were performed to determine the effects of different final concentrations(5, 10, 20, 40 μmol·L⁻¹) of orchinol for 48 hour on invasion and migration abilities of SGC-7901 cells, respectively. The protein expression levels of β-catenin, Wnt-3α, DvL2, cyclinD1 and GSK-3β were detected by Western blot. The results showed that 5-80 μmol·L⁻¹ orchinol inhibited the viability of SGC-7901 cells in a dose-dependent and time-dependent manner, and the IC₅₈ values of 24, 48 and 72 hours were 77.79, 42.96 and 7.85 μmol·L⁻¹, respectively. Compared with the control group, the ability of invasion and migration of SGC-7901 cells was significantly inhibited after treated with 5, 10 and 20 μmol·L⁻¹ orchinol for 48 hours (<0.05, <0.01), and the dose-effect relationship was observed. The results of Western blot showed that orchinol could significantly down-regulate the protein expression levels of β-catenin, Wnt3a, DvL2 and cyclinD1, and up-regulate the protein expression level of GSK-3β(<0.05, <0.01, <0.001). The above results suggest that orchinol can obviously inhibit the invasion and migration of SGC-7901 cells, which may be related to its inhibition of Wnt3a/β-catenin signaling pathway and the proteins expression of downstream genes.
Subject(s)
Humans , Cell Line, Tumor , Cell Movement , Cell Proliferation , Phenanthrenes , Stomach Neoplasms , Wnt Signaling Pathway , Wnt3A Protein , beta CateninABSTRACT
@#Objective: To detect the expression of miR-133a-3p in gastric cancer (GC) tissues and plasma of GC patients, and to investigate its effect on the proliferation of GC cells as well as its correlation toprognosis of GC patients. Methods: 52 cases of cancertissues (non-necrosis part) and corresponding adjacent tissues as well as the pre-operative peripheral blood samples from GC patients, who underwent surgery at Department of General Surgery, the Forth Hospital of Hebei Medical University(Shijiazhuang, China) between May 2012 and May 2013, were collected for this study. The plasma sample (n=35) from healthy donors were obtained during their physical examination. RT-qPCR was adopted to detect the expression of miR-133a-3p in gastric cancer tissues, adjacent tissuesand plasma samples of GC patients and healthy volunteers. The relationships between miR-133a-3p expression and the median DFS as well as clinicopathological parameters were also analyzed. CCK-8 assay was adopted to detect the effect of miR-133a-3p silence or over-expression on proliferation of gastric cancer SGC7901 cells. Results: miR-133a-3p was dramatically decreased in gastric cancer tissues (P<0.01), and its expression was associated with TNM stage, tumor infiltration (T), lynphonode metastasis (N), and vascular tumor thrombus (all P<0.01); miR-133a-3p was significantly increased in the plasma of GC patients (P<0.01), and its expression was associated with TNM stage, lynphonode metastasis (N), and vascular tumor thrombus (all P<0.05). miR-133a-3p expression was positively correlated with serum CA199 level of GC patients (P<0.01). The median DFS of patients with high miR-133a-3pexpression in cancer tissues was significantly longer than that of the patients with low expression(20.8 vs 14.8 months, P<0.05); The median DFS of patients with high plasma miR-133a-3p expression was significantly shorter than that of the patients with low expression (14.4 vs 20.3 months, P<0.05). Over-expression of miR-133a-3p could significantly inhibit the proliferation of gastric cancer SGC7901 cells, while miR-133a-3p silence could significantly promote the proliferation (all P<0.05). Conclusion: miR-133a-3p could significantlyinhibit the proliferation of SGC7901 cells; miR-133a-3p aberrantlyexpressed in gastric cancer tissues and plasma, and obviously correlated with prognosis of gastric cancer patients, which may be used as a potential clinical bio-maker for early diagnosis and treatment as well as the prognosis prediction of gastric cancer.
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Objective: To investigate the effects of xanthotoxin from Apiaceae medicinal plants on cell proliferation and apoptosis, and explore its mechanism of action against human gastric carcinoma SGC-7901 cells in vitro. Methods: SGC-7901, HepG-2, MCF-7, and A549 cells were treated with different concentrations of xanthotoxin (10, 20, 60, 80, 100, 120, 140, and 160 µg/mL) for 48 h, and the cell viability (IC50) was determined by MTT assay; Xanthotoxin-induced apoptosis in cells was observed by using Hoechst 33258 Staining Kit and Annexin V-FITC Apoptosis Detection Kit; Flow cytometry was used to detect apoptosis related proteins of Fas/FasL, Bid, and DR5/TRAIL proteins in human gastric carcinoma SGC-7901 cells after being treated by xanthotoxin; The influence of xanthotoxin on Caspase-8 protein expression in the cells was determined by Flouormetric Assay Kit. Results: Xanthotoxin obviously inhibited SGC-7901, HepG-2, MCF-7, and A549 cells proliferation, and its inhibition was in a concentration-dependent manner; flow cytometry results showed that in a certain concentration range, xanthotoxin can increase the expression levels of Fas/FasL and DR5/TRAIL proteins in a concentration-dependence manner. The content of Bid protein in cells was increased, and it showed concentration-dependence. Conclusion: Xanthotoxin may induce SGC-7901 cells apoptosis in a certain concentration range through the Fas/FasL protein mediated death receptor pathway, or by DR5/TRAIL mediated death receptor pathway, and increase the expression level of death receptor protein, activation Caspase-8, activating downstream effect factor, inducing cell apoptosis, or activate Caspase-8 cutting activate protein Bid, and then enter the mitochondrial pathway, induction of apoptosis.
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Objective: To investigate the effects of silymarin on the proliferation, migration and invasion of human gastric cancer cell line SGC 7901 and its role in promoting apoptosis, and to clarify their possible mechanisms. Methods: The human gastric cancer SGC 7901 cells in logarithmic growth phase were selected and divided into control group (without silymarin) and different concentrations (15, 30, and 60 mg · L-1) of silymarin groups. Inverted microscope was used to observe the morphology of cells. MTT method was used to detect the cell cycle and the apoptotic rates of cells in various groups. The inhibitory rates of proliferation of cells in various groups were detected by flow cytametry. Scratch test and Trans well chamber assay were used to detect the cell migration and invasion abilities. Results: After the SGC 7901 cells were treated with silymarin for 24 h, compared with control group, the adherent densities of the cells in 30 and 60 mg · L-1 silymarin groups were smaller, the cell shape was irregular and the volume was smaller, resulting in a large number of cell debris. Compared with control group, the inhibitory rates of cells in different concentrations of silymarin groups were increased significantly (P<0. 05); the percentages of cells in Gi phase and the apoptosis rates of SGC 7901 cells were increased significantly (P<0. 05); the migration distances were decreased (P<0. 05) and the number of transmembrane cells was decreased significantly (P<0. 05). Conclusion: Silymarin can inhibit the proliferation of human gastric cancer SGC 7901 cells by inducing the G1 phase cell arrest and early apoptosis.
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Objective: To investigate the regulatory effect of genipin (GP) on the gastric cancer SGC 7901 cells, and to clarify its mechanism. Methods: The SGC 7901 cells in logarithmic growth phase were selected and divided into control group and different concentrations (5. 0, 10. 0, and 20. 0 mg · L-1) of GP groups. MTT was used to detect the inhibitory rates of proliferation of SGC 7901 cells at different time points (24, 48, and 72 h). Transwell chamber cell invasion assay was used to detect the invasion ability of SGC 7901 cells in vitro. The expression levels of Bcl-2, Bax and caspase-3 proteins in the SGC 7901 cells were detected by Western blotting method. Results: The results of MTT assay showed that the inhibitory rates of proliferation of the cells in different concentrations of GP groups after treated with GP for different time were increased significantly compared with control group (P< 0. 01). The Transwell cell invasion assay results showed that compared with control group, the number of transmembrane cells in 10. 0 and 20. 0 mg · L-1 GP groups was decreased significantly after treated for 72 h (P< 0. 01). The results of Western blotting method showed that compared with control group, the expression level of Bcl-2 protein in 20. 0 mg · L-1 GP group was decreased after treated for 72 h (P<0. 01), and the expression levels of caspase-3 and Bax proteins were increased (P<0. 05). Conclusion; GP can inhibit the abilities of proliferation and invasion in vitro of SGC 7901 cells, and induce the apoptosis; its mechanism may be related to the regulation of Bcl-2, caspase-3, and Bax protein expressions.
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Objective To study the molecular mechanism of interleukin-17A(IL-17A)induced the secretion of CXCL13 in gas-tric cancer cell line SGC-7901.Methods SGC-7901 cells were stimulated by recombination cytokine IL-17A,or SGC-7901 were pre-incubated with signal pathway inhibitor for 1 hour and then stimulated by IL-17A,the level of CXCL13 were detected by using en-zyme-linked immunosorbent assay.Results After IL-17A stimulation,the secretion of CXCL13 by SGC-7901 cells was significant-ly increased(P<0.05),which was with dose and time dependence.IL-17A-induced secretion of CXCL13 could be inhibited when SGC-7901 were pre-incubated with STAT3 inhibitor(P<0.05).However,such effect was not observed while SGC-7901 were pre-incubated with NK-κB,MEK1/2,p38/MAPK and JNK inhibitors.Conclusion IL-17A could induce the secretion of CXCL13 in gastric cancer cell line SGC-7901 by activating STAT3 signal pathway,which might play regulation role in gastric cancer.
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AIM: To explore the effect of microRNA-146a (miR-146a) on apoptosis of human gastric cancer SGC-7901 cells and the underluing mechanism.METHODS: miR-146a mimic (up-regulated miR-146a expression) and miR-146a inhibitor (down-regulated miR-146a expression) were transfected into the SGC-7901 cells by liposome method.At the same time, miRNA nonsense sequence transfection group as the negative control group (NC group) was set up.RT-qPCR was used to evaluate the levels of miR-146a in the SGC-7901 cells after transfection.The effects of miR-146a on the cell apoptosis and growth were assessed by flow cytometry analysis and CCK-8 assay, respectively.The effect of over-expression or knockdown of miR-146a on transforming growth factor-β-activated kinase 1 (TAK1)/ nuclear factor-kappa B (NF-κB) signaling was evaluated by RT-qPCR and Western blot.RESULTS: miR-146a modulated apoptosis of SGC-7901 cells.Over-expression of miR-146a significantly increased apoptosis, whereas knockdown of miR-146a inhibited the apoptosis of SGC-7901 cells.The expression of TAK1 at mRNA and protein levels was significantly decreased when miR-146a mimic was transfected into the SGC-7901 cells (P<0.05).On the contrast, the expression of TAK1 at mRNA and protein were significantly higher in miR-146a inhibitor transfection group than that in NC group (P<0.05), suggesting that miR-146a negatively regulated TAK1 expression.Moreover, knockdown of TAK1 enhanced the apoptosis of SGC-7901 cells (P<0.01), while over-expression of TAK1 inhibited the apoptosis of SGC-7901 cells(P<0.01).Additionally, both over-expression of miR-146a and knockdown of TAK1 led to a prominent increase in the expression of NF-κB inhibitor protein alpha (IκBα) and a significat decrease in B cell lymphoma-2 (Bcl-2) level in the SGC-7901 cells.CONCLUSION: miR-146a significantly promotes apoptosis of SGC-7901 cells by inhibition of NF-κB pathway via targeting TAK1.
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Objective: To study the influence of gallic acid (GA) on the migration of human gastric carcinoma SGC-7901 cells, and to explore its mechanism.Methods: The human gastric carcinoma SGC-7901 cells were cultured and divided into control group and 3.125, 6.250, 12.500, 25.000, 50.000,100.000 mg·L-1 GA groups. The inhibitory rates of proliferation of SGC-7901 cells in various groups were examined by MTT assay;the migration abilities of SGC-7901 cells in various groups were measured with scratch assay;the expression levels of vascular of endothelial growth factor (VEGF) in various groups were detected by immunocytochemistry.Results: Compared with control group, the inhibitory rates of proliferation of SGC-7901 cells in different doses of GA groups were significantly increased in a dose-dependent manner(F=59.451,P<0.01).Compared with control group, the wound healing rates in different doses of GA groups were significantly decreased (P<0.01).Compared with control group, the expression levels of VEGF protein in 12.500 and 25.000 mg· L-1 GA groups were decreased (P<0.05).Conclusion: GA could inhibit the proliferation and migration of SGC-7901 cells through down-regulating the expression levels of VEGF protein.
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Objective To study the effect of annonaceous acetogenins (ACGs) on human gastric cancer cells in vitro. Methods After ACGs were administered to gastric cancer cells in vitro, the cell viability, cell adhesion ability and cell migration ability were assessed by MTT assay, adhesion assay and wound-healing assay, respectively. Results ACGs inhibited the cell viability, adhesion ability and migration ability in a dose-dependent manner in gastric cancer cells. Conclusion ACGs could inhibit cell activities of human gastric cancer cells in viro, and will be developed as a promising anticancer candidate and used in gastric cancer.
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AIM: To investigate the effect of digoxin on apoptosis and growth in human gastric carcinoma SGC7901 cells and its possible mechanism.METHODS: SGC7901 cells were incubated in the medium containing digoxin at different concentrations for 24 h.CCK-8 assay was employed to detect the anti-tumor effect of digoxin on SGC7901 cells, and IC50 value of digoxin was calculated.Flow cytometry was used to determine the apoptosis and the cell cycle.Western blot was used to analyze the protein levels of c-Src, p-c-Src(Tyr416), Akt, p-Akt(Ser473), ERK1/2 and p-ERK1/2 (Tyr204).The mRNA expression of c-Src was by RT-PCR.RESULTS: As the concentration of digoxin increased, the cell viability was reduced gradually starting at 50 nmol/L digoxin treatment (P<0.05).The cell viability was reduced to the lowest extent by exposure to 500 nmol/L digoxin (P<0.05).The IC50 value of digoxin was 191.45 nmol/L for 24 h.After treatment with 200 nmol/L digoxin for 24 h, the apoptotic rate and the proportion of G0/G1 phase were significantly increased (P<0.05), the phosphorylated levels of c-Src, ERK1/2 and Akt declined (P<0.05), the mRNA and protein levels of c-Src were down-regulated (P<0.05) and the ability of migration was weaker (P<0.05) than that in control group.CONCLUSION: Digoxin may suppress the growth and induce the apoptosis of human gastric carcinoma SGC7901 cells by inhibiting the expression of c-Src gene and down-regulating the phosphorylated levels of ERK1/2 and Akt.
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OBJECTIVE: To investigate the effect and mechanism of juglone on the apoptosis of human gastric cancer SGC-7901 cells. METHODS: The antiproliferative effect of juglone on SGC-7901 cells was tested by the MTT assay. The apoptosis rate and in-tracellular reactive oxygen species(ROS) level were detected by flow cytometry (FCM). The expression of JNK, p-JNK, p38, and p-p38 proteins were examined by Western blot. In order to clarify the role of ROS in the apoptosis induced by juglone on SGC-7901 cells, the combination of the juglone and ROS inhibitor NAC groups were set up in each experiment above. RESULTS Juglone could effectively inhibit the proliferation of SGC-7901 cells (IC50 for 72 h was 24.16 μmol·L-1). When combination juglone with NAC, the IC50 raised to 36.91 μmol·L-1. After 72 h of exposure to 5-20 μmol·L-1 of juglone, the cell apoptosis rate increased gradually with the increase of juglone concentration. After adding NAC, the apoptosis rates declined and the apoptosis rate of 20 μmol·L-1 group decreased from 32.06% to 11.56%. After SGC-7901 cells were treated with juglone for 24 h, the ROS level increased and mitochondrial transmembrane potential decreased which were inhibited by the pretreatment of NAC. After 48 h of exposure to different con-centration of juglone, the expressions of p-p38 and p-JNK proteins were up-regulated which could also be inhibited by the adding of NAC. Meanwhile, there were no significant changes in p38 and JNK protein expression in all groups. CONCLUSION: Juglone can induce apoptosis of human gastric cancer SGC-7901 cells by JNK and P38 pathway mediated by reactive oxygen species.
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@#The study aims to establish a human gastric cancer orthotopic transplantation model in nude mice and to use 7T MRI for detection. After poorly differentiated human gastric adenocarcinoma SGC-7901 cells were injected subcutaneosly into the right flanks of nude mice, the model of in nude mice was established with orthotopic transplanted cancer of gastric tumor by the Compont® gel pasted method. 7T MRI scan was conducted on the mice after operating model about 20 days later. Histopathological examinations were carried out on the stomach. Two of three mice on which 7T MRI scan were performed showed visible suspected stomach tumor and their presence was verified again by histopathological examinations; tumor formation rate in the nude mice gastric orthotopic transplantation model was 66. 7%. This study suggested that 7T MRI could be used in the live detection of in situ tumor and that MRI could be used for pre-clinical gastric cancer drug development and clinical gastric carcinoma diagnosis.
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AIM:To explore the expression level of microRNA-140 ( miR-140 ) in human gastric cancer and normal gastric tissues, and the regulatory effect of miR-140 expression on the function of SGC-7901 cells.METHODS:The expression levels of miR-140 in human gastric cancer and normal gastric tissues were detected by real-time PCR.miR-140 mimics ( miR-140 up-regulated expression) and miR-140 inhibitors ( miR-140 down-regulated expression) were trans-fected into human gastric cancer SGC-7901 cells by liposome method.At the same time, the untransfected control group ( control group) and miRNA nonsense sequence transfection group ( NC group) were set up .The expression of miR-140 in the cells after transfection was detected by real-time PCR.The cell viability and growth inhibition rate with DDP were meas-ured by MTT assay.The cell cycle and apoptotic rate of SGC-7901 cells were analyzed by flow cytometry.The invasion a-bility of SGC-7901 cells was measured by Transwell assay.The protein expression of histone deacetylase 4(HDAC4) in the cells was determined by Western blot.RESULTS:The expression level of miR-140 in human gastric cancer tissues was significantly lower than that in normal gastric tissues (P<0.05).Compared with control group and NC group, the viability and invasion ability of the SGC-7901 cells were decreased, the cell cycle was arrested, the cell growth inhibition rate and apoptotic rate with DDP treatment were increased, and the protein expression of HDAC4 was down-regulated ( P<0.05) in miR-140 mimics group.However, in miR-140 inhibitors group, the viability and invasion ability of the SGC-7901 cells were increased, the cell cycle was promoted, the cell growth inhibition rate and apoptotic rate with DDP treatment were de-creased, and the protein expression of HDAC4 was up-regulated ( P<0.05 ) .CONCLUSION:The expression level of miR-140 in the gastric cancer tissues is low.miR-140 serves as a tumor suppressor to regulate the viability, apoptosis and invasion ability of gastric cancer cells, and to play a role by down-regulating HDAC4 protein.miR-140 may serve as a new target for diagnosis and treatment of gastric cancer.