Human Gastric Cancer Cell MGC-803 Research Articles

Two new sesterterpenoids from Atractylodes japonica Koidz. ex Kitam.

Two new sesterterpenoids, atractylodes japonica terpenoid acid I (1) and atractylodes japonica terpenoid aldehyde I (2), were isolated from the rhizomes of Atractylodes japonica Koidz. ex Kitam together with ten known compounds (3-12). Their structures were elucidated on the basis of comprehensive spectroscopic analysis (1D/2D NMR, HRESIMS and IR). In addition, all of these isolated compounds were evaluated for their cytotoxic activities against human gastric cancer cell MGC-803 and human hepatocellular cancer cell HepG-2. Most of them exhibited moderate to weak inhibitory effects with IC50 values in the range of 25.15-88.85μM except for 9-12.

Construction of gigantic highly-porous microcarriers as a three-dimensional cell culture platform

3D cell carriers with porous structures have the potential to promote cellular interactions and extracellular matrix remolding, making it a promising strategy to investigate the complex mechanisms behind drug treatments for tumors. Nevertheless, the applicability of currently reported porous microcarriers is still limited by the relatively small size and poor pore interconnectivity. Herein, a well-defined gigantic highly-porous poly(lactic-co-glycolic acid) (PLGA) microsphere (named LPMs) fabrication platform is reported. Utilizing this “LPMs” platform, arrays of well-uniform particles with sizes up to approximately 1000 µm are prepared in an orderly and controlled manner. The preparation matrix and crucial parameters affecting the particle size and pore size were established through extensive single-factor screening. It was also found that the loading of human gastric cancer cells MGC-803 to the LPMs cell carriers was facilitated not only by the increased pore size, but the particle size should also be enlarged along with the increased pore size. Through surface modification of gelatin on LPMs, cell loading could be dramatically enhanced, and microtissue-like structures were formed through cross-linking LPMs under extended 3D culture time. Under the guidance of these findings, we successfully constructed massive tumor cell carriers with 1000 µm LPMs, a preliminary prototype of a massive tumor tissue mimic. Together, the fabrication of these gigantic highly-porous microcarriers possibly allows for the high-efficiency 3D cell culture and represents the attractive potential of the construction of artificial tumor tissue models with massive and multiple-type cells.

Silencing Rac1 and Prex1 Inhibit Epithelial-Mesenchymal Transition in Human Gastric Cancer Cells Induced by Transforming Growth Factor-β1.

Transforming growth factor-beta can influence tumor cells, causing epithelial-mesenchymal transition and enhancing their invasion and metastasis ability. Rac1 protein could be used as an independent tumor diagnostic marker and survival predictor. Prex1 is closely related to cell metastasis. In this study, the impact of silencing Rac1 and Prex1 on transforming growth factor-beta 1-induced epithelial-mesenchymal transition and apoptosis of human gastric cancer cells MGC-803 and MKN45 was investigated. MGC-803 and MKN45 cells received recombinant transforming growth factor-beta 1 (rTGF-β1) treatments at various concentrations. Cell Counting Kit-8 kit was used to determine cell viability. Rac1 and Prex1 interference vectors were transfected into the rTGF-β1-treated MGC-803 and MKN45 cells. Cell apoptosis and migration were detected by flow cytometry and scratch test, respectively. Western blot was used to detect the epithelial-mesenchymal transition-related markers E-cadherin, N-cadherin, vimentin, and PDLIM2 expression levels. The rTGF-β1 (10 ng/mL) could promote MGC-803 and MKN45 cell viability. Silencing Rac1 and Prex1 could increase E-cadherin and PDLIM2 expression, decrease N-cadherin and vimentin expression, inhibit cell viability and migration, and promote apoptosis in rTGF-β1-treated MGC-803 and MKN45 cells. Silencing Rac1 and Prex1 could inhibit epithelial-mesenchymal transition, reduce cell viability and migration, and promote apoptosis in human gastric cancer cells.

MiRNA-195: The New Target of Inhibiting the Proliferation, Migration and Invasion of Gastric Cancer Cells via Propofol

Objective: To explore the effect of propofol (Prof) on the proliferation, migration and invasion of human gastric cancer cell MGC-803 and its molecular mechanism. Methods: The MTT method was used to study the effects of Prof with different doses and durations on the viability of MGC-803 cells. Hoechst 33258 staining and electron microscopy were used to detect the effects of Prof on MGC-803 cell apoptosis. Transwell experiments were used to detect the effects of Prof on the migration and invasion of MGC-803 cells. RT-PCR detects the effect of Prof on the expression of miR-195 in MGC-803 cells, and Western Blot detects the effect of Prof on the protein expression of JAK/STAT signaling pathway. Results: Compared with 0mg/ml Prof, 5mg/ml, 10mg/ml and 20mg/ml Prof treatment with 24h, 48h and 72h can significantly reduce cell viability (P <0.05). Compared with the Control group, the percentage of Hoechst 33258 staining positive cells in the Prof group and the apoptosis rate under the electron microscope were significantly increased (P <0.05). Compared with the Control group, the cell migration rate and invasion rate of the Prof group were significantly reduced (P <0.05). Compared with the Control group, the expression of miRNA-195 in the Prof group cells was increased significantly (P <0.05). Compared with the Control group, the activity of p-Jak1 and p-STAT3 proteins in the Prof group were significantly reduced (P <0.05). Conclusion: Prof can reduce the cell viability, migration and invasion of gastric cancer cell MGC-803, and promote its apoptosis. Its mechanism may be related to the promotion of miR-195 expression and inhibition of JAK/STAT signal pathway activity.

New Alkaloids and Polyketides from the Marine Sponge-Derived Fungus Penicillium sp. SCSIO41015

The sponge-derived fungus Penicillium sp. SCSIO41015 cultured on solid rice medium yielded twenty-one compounds (1–21), including two new alkaloids (1 and 2) and one new pyrone derivative (3). Their structures were elucidated by analysis of 1D/2D NMR data and HR–ESI–MS. Their absolute configurations were established by single-crystal X-ray diffraction analysis and comparison of the experimental with reported specific rotation values. Compound 16 exhibited selective cytotoxic activity against the human gastric cancer cells MGC803, with IC50 value of 5.19 μM. Compounds 9 and 18 showed weak antibacterial activity against Staphylococcus aureus and Acinetobacter baumannii, respectively, both with MIC values of 57 μg/mL. Furthermore, compound 16 displayed potent antibacterial activity against S. aureus with an MIC value of 3.75 μg/mL.

Effect of Ferula ferulaeoides on growth and apoptosis of human gastric cancer MGC-803 transplantation tumor in nude mice

In this paper,the effects of active fractions of Ferula ferulaeoides on the growth and apoptosis of human gastric cancer cell MGC-803 transplantation tumor were systematically studied. The subcutaneous ectopic transplantation tumor model was established in human gastric cancer MGC-803 nude mice by cell suspension implantation method. The anti-tumor rate and organ index were used to evaluate the anti-tumor effect of the active fractions of F. ferulaeoides on the tumor-bearing nude mice. HE staining,TUNEL staining,RT-PCR,Western-blot and ELISA were used for pathological examination,apoptosis observation,and detection of apoptosis-related genes,proteins and cytokines expression. The results showed that as compared with the model group,the low,medium and high doses of the active fraction of F. ferulaeoides had inhibitory effects on xenografts in nude mice,respectively,in a dose-dependent manner; the apoptotic ratio was increased with the increase of drug concentration. As compared with the model group,F. ferulaeoides could down-regulate the expression of survivin mRNA in nude mice,and the protein expression levels of Bax,Bcl-2,caspase-3 and caspase-9 in tumor tissues of nude mice could be increased to different degrees in F. ferulaeoides groups. The contents of IL-10 and TGF-β1 in plasma of nude mice were decreased in high dose group of F. ferulaeoides active fractions. The results indicated that F. ferulaeoides can significantly inhibit the growth of human gastric cancer MGC-803 subcutaneously transplanted tumor,and its mechanism may be related with down-regulating the expression of survivin mRNA,and up-regulating the expression of apoptosis-related proteins Bax,caspase-3 and caspase-9.

RGD peptide-modified phase-change nanoparticles combining with low-intensity focused ultrasound for targeting and imaging experiments of gastric cancer in vivo and vitro

Objective To prepare RGD peptide modified perfluorohexane (PFH) polymer nanoparticles RGD-PFH-NPs and investigate its basic characteristics, targeting ability and combine with low-intensity focused ultrasound (LIFU) for ultrasonic imaging in vivo and vitro. Methods Targeted nanoparticles RGD-PFH-NPs were prepared by double emulsifying method and carbodiimide method. Their morphology and distribution were observed. The particle size, zeta potential and connection probability were measured. The phase-changed properties and the LIFU-induced imaging ability in contrast-enhanced ultrasound mode of RGD-PFH-NPs were investigated in vivo and vitro. The tagetability of nanoparticles to human gastric cancer cell line MGC803 and tumor-bearing nude mouse were observed through targeting group and non-targeting group. Results The prepared sample was milky white suspension liquid. The RGD-PFH-NPs were spherical uniform size, good dispersion when observed through the optical microscope and transmission electron microscopy. The particle size was (259.3±42.6)nm and the Zeta potential was (-17.6+ 5.4)mV. The connection probability of RGD peptide was 89.13%. With 70℃ water bath and LIFU stimulation RGD-PFH-NPs can remarkably change phase and show good imaging performance in both conventional ultrasound and contrast-enhanced ultrasound mode in vivo and vitro. The connection probability to MGC803 cells in targeting group (RGD-PFH-NPs ) and the non-targeting group(PFH-NPs) were 82.59% and 2.96%. The accumulation of nanoparticles in the RGD-PFH-NPs group in tumor tissues was significantly higher than that in the non-targeted PFH-NPs group(P). Conclusions The constructed nanoparticles RGD-PFH-NPs, providing contrast-enhanced ultrasonic imaging and excellent targeting ability to human gastric cancer cells MGC803 and gastric cancer tissue, is expected to become a new type of gastric cancer targeted ultrasound contrast agent. Key words: Contrast-enhanced ultrasound; Gastric cancer; Nnanoparticle; Phase change; Poly(lactic-co-glycolic acid)

Over-expression of human Notch ligand Delta-like 3 promotes proliferation of human gastric cancer cells in vitro

To construct a eukaryotic expression plasmid carrying human full-length Notch ligand Delta-like 3 (DLL3) gene and study the effect of DLL3 knockdown and overexpression on the proliferation of gastric cancer cells in vitro. Human full-length DLL3 gene was amplified by PCR and cloned into the eukaryotic expression vector pCMV-Tag4. After verification by restriction enzymes and sequencing, the recombinant DLL3/pCMV-Tag4 vector was transiently transfected into HEK293T cells, in which the expressions of human DLL3 mRNA and protein were detected using real-time quantitative PCR and Western blotting, respectively. The expression of DLL3 in normal gastric epithelial cells and gastric cancer cell lines was detected by qRT-PCR and Western blotting. DLL3/pCMV-Tag4 was transfected into 3 gastric cancer cell lines, and their proliferation was assessed with MTT assay. Human gastric cancer cells MGC803 and MKN45 were also transfected with a specific human DLL3-siRNA to assess the effect of DLL3 down-expression on the cell proliferation. The recombinant eukaryotic expression vector DLL3/pCMV-Tag4 was successfully constructed and human full-length DLL3 was expressed in HEK293T cells. MTT assay showed that DLL3 over-expression obviously promoted the proliferation and down-regulation of DLL3 inhibited the proliferation of the gastric cancer cells. DLL3 overexpression can promote the proliferation of gastric cancer cells in vitro, and down-regulation of DLL3 inhibits the proliferation of gastrc cancer cells, which provides a novel strategy for targeted thrapy of gastric cancer.

RETRACTED ARTICLE: siRNA-participated chemotherapy: an efficient and specific therapeutic against gastric cancer

This study aims to investigate the role of siRNA silencing fibroblast growth factor receptor (FGFR) expression in promoting chemotherapy effect of gastric cancer and to explore its mechanism. Human gastric cancer cells MGC80-3 were divided into four groups: control group, cisplatin group (2 μg/L), cisplatin (2 μg/L) + siRNA group and siRNA group. The expressions of FGFR in four groups were detected by immunofluorescence. The cell proliferation and apoptosis were detected by MTT assay and flow cytometry. The protein expression levels of vascular endothelial growth factor receptor (VEGFR), caspase-3 and Bax were detected by Western blot. Further, animal model of gastric cancer was established and divided into four groups as in vitro experiment. The expression of FGFR mRNA in tumor tissue was detected by the real-time fluorescence quantitative polymerase chain reaction. The size of tumor was measured to analyze the effects of treatment. Histopathological detections were performed by hematoxylin and eosin staining and immunohistochemistry. For in vitro experiment, significant decrease inFGFR expression, inhibition of proliferation and promotion of apoptosis were observed in siRNA-treated cells, so as cisplatin group. siRNA also resulted in the reduction of VEGFR and rise in apoptosis-related protein (caspase-3). As for the experiment in vivo, siRNA also suppressed the expression of FGFR and enhanced tumor shrink. Furthermore, the co-administration of siRNA and cisplatin revealed a more excellent antitumor effect than other therapies. siRNA can effectively suppress FGFR expression and cell proliferation, but promote apoptosis in vitro and also inhibit tumor growth and FGFR production in vivo. siRNA-participated chemotherapy may provide an efficient therapeutic approach to treat gastric cancer.

Perifosine inhibits the proliferation of human gastric cancer cell MGC803 via downregulating M2 isoform of pyruvate kinase in vitro

Objective To observe the effects of perifosine on the proliferation of human gastric cancer cell MGC803 and the action mechanism.Methods MGC803 cells were treated with various concentrations of perifosine (0,2.5,5.0,7.5,10.0,12.5,15.0 μmol/L),and sulforhodamine B (SRB) assay was used to detect the effects of different concentrations of perifosine on the proliferation of MGC803 cells.The expression of M2 isoform of pyruvate kinase (PKM2) protein in MGC803 cells was detected by using Western blotting.Results The expression of PKM2 protein in gastric cancer cells was significantly higher than that of normal gastric epithelial cells (GES-1),indicating that PKM2 may play an important role in gastric cancer development and progression.The proliferation ability of MGC803 cells transfected with PKM2 small interfering RNA (siRNA),on the fffth day in vitro,was significantly lower than negative controls (P ＜0.01).After MGC803 cells were transfected with PKM2 siRNA (100 nmol/L) for 5 days,the cell colony formation rate (21.00 ± 1.34) was statistically decreased (P ＜ 0.05) as compared with that in the blank control group (75.00 ±2.13) and the negative control group (63.00 ± 1.47).Treatment with perifosine significantly repressed the viability of MGC803 cells in a dose-dependent manner.Perifosine significantly decreased the protein expression of PKM2 in a time-and dose-dependent manner (P ＜ 0.05).Conclusion Perifosine could inhibit the proliferation of MGC803 cells probably by decreasing the PKM2 expression. Key words: Perifosine; Stomach carcinoma; Proliferation; Pyruvate kinase

SiRNA targeting of Cdx2 inhibits growth of human gastric cancer MGC-803 cells

To investigate the effects of small interference RNA (siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo. The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro. The stable transfectants were selected. The effects of Cdx2 siRNA on growth, proliferation, cell cycle, apoptosis, migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog (PTEN), caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting analysis. We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo. Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis. Cdx2 siRNA significantly inhibited cell growth and proliferation, blocked entry into the S-phase of the cell cycle, induced cell apoptosis, and reduced the motility and invasion of MGC-803 cells. Cdx2 siRNA also increased PTEN expression, and activated caspase-9 and caspase-3 in MGC-803 cells in vitro . In addition, siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models. Cdx2 was involved in regulating pro-gression of human gastric cancer cells MGC-803. Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.

Latexin expression is downregulated in human gastric carcinomas and exhibits tumor suppressor potential

BackgroundLatexin, also known as endogenous carboxypeptidase inhibitor (CPI), has been found to inhibit mouse stem cell populations and lymphoma cell proliferation, demonstrating its potential role as a tumor suppressor. Our previous study also suggested a correlation between latexin expression and malignant transformation of immortalized human gastric epithelial cells. Here, we examined latexin expression in human gastric carcinomas and investigated the effect of differential latexin expression on proliferation of gastric cancer cells in vitro and in vivo.MethodsMonoclonal antibody against human latexin was prepared and immunohistochemical analysis was performed to detect latexin expression in 41 paired gastric carcinomas and adjacent normal control tissues. Human gastric cancer cells MGC803 (latexin negative) stably transfected with LXN gene and BGC823 cells (latexin positive) stably transfected with antisense LXN gene were established for anchorage-dependent colony formation assay and tumorigenesis assay in nude mice. Differentially expressed genes in response to exogeneous latexin expression were screened using microarray analysis and identified by RT-PCR. Bisulfite sequencing was performed to analyze the correlation of the methylation status of LXN promoter with latexin expression in cell lines.ResultsImmunohistochemical analysis showed significantly reduced latexin expression in gastric carcinomas (6/41, 14.6%) compared to control tissues (31/41, 75.6%) (P < 0.05). Overexpression of LXN gene in MGC803 cells inhibited colony formation and tumor growth in nude mice. Conversely, BGC823 cells transfected with antisense LXN gene exhibited enhanced tumor growth and colony formation. Additionally, several tumor related genes, including Maspin, WFDC1, SLPI, S100P, and PDGFRB, were shown to be differentially expressed in MGC803 cells in response to latexin expression. Differential expression of Maspin and S100P was also identified in BGC823 cells while latexin expression was downregulated. Further bisulfite sequencing of the LXN gene promoter indicated CpG hypermethylation was correlated with silencing of latexin expression in human cells.ConclusionsLatexin expression was reduced in human gastric cancers compared with their normal control tissues. The cellular and molecular evidences demonstrated the inhibitory effect of latexin in human gastric cancer cell growth and tumorigenicity. These results strongly suggest the possible involvement of latexin expression in tumor suppression.

Effect of angiopoietin-1 on expression of Bcl-2 and Bax in human gastric cancer cells

AIM: To explore the possible mechanism underlying the inhibitory effect of angiopoietin-1 (Ang1) on apoptosis of human gastric cancer cells MGC-803. METHODS: The human gastric cancer cells (MGC-803) were cultured with Ad-Ang1 and Ad-GFP at proper multiplicity of infection (MOI=20) and the expression levels of bcl-2 mRNA, bax mRNA and Bcl-2 protein, Bax protein were determined us-ing RT-PCR and Western blot, respectively. RESULTS: The expression levels of Bcl-2 mRNA and its protein were higher in Ad-Ang1 trans-fected group than in Ad-GFP transfected group and control group (0.609±0.01 vs 0.462±0.02, 0.609±0.01 vs 0.475±0.02, both P＜0.05). There was no significant difference between Ad-GFP group and control group. However, compared with the other groups, the expression level of Bax mRNA and its protein in the MGC-803 cells treated with Ad-Ang1 were significantly down-regulated (0.313±0.04 vs 0.413±0.02, 0.313±0.04 vs 0.407±0.03, both P＜0.05). Meanwhile, the ratio of Bcl-2 to Bax increased markedly in Ad-Ang-1 transfected group. CONCLUSION: Ang1 gene can significantly up-regulate Bcl-2 expression and down-regulate Bax expression at both transcriptional and translational levels in vitro, which may be one of mechanisms underlying protection against se-rum starvation-induced apoptosis.

The effect of thermal double distilled water on gastric cancer cell line and its effect in peritoneal lavage during radical gastrectomy

To evaluate the effect and indications of radical gastrectomy combined with peritoneal lavage with thermal double distilled water (DDW) or DDW plus chlorhexidine acetate. On the bases of the study on the killing effect of 43°C DDW on human gastric cancer cell line MGC-803 and its inhibiting effect on ascitic tumor of SY86B mouse, 500 cases of gastric cancer who underwent radical gastrectomy from January 1986 to December 1995 were divided into three groups: group A (n=198) subject to radical gastrectomy and peritoneal lavage for 10 min with 4000 ml DDW at 43°C; group B (n=89) subject to radical gastrectomy and peritoneal lavage for 4 min with 400 ml DDW plus 0.6g chlorhexidine acetate, and group C (n=213) subject to radical gastrectomy and peritoneal lavage for 4 min with 4000 ml normal saline at room temperature as control. Human gastric cancer cells MGC-803 could be completely killed by treatment of either 43°C DDW for 10 min or DDW plus 0.015 ml/L chlorhexidine acetate for 4 min. Clinical trials proved that group A and group B (called lavage group as a whole) had almost the same curative effects. The 1-year survival rate and 3-year survival rate were similar in different stages among the groups. The 5-year survival rate was 63.8% in the lavage group and 51.2% in the control group respectively. Most of the cases with good effect were at the mid-stage (II and III A stage). Radical gastrectomy combined with peritoneal lavage before closing the abdomen has satisfying effect on patients with gastric cancer at stage II and stage III A.