• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.16
• /
• pp.6791-6798
• /
• 2014

Background: To investigate the effect of silibinin on proliferation and apoptosis in human gastric cancer cell line MGC803 and its possible mechanisms. Materials and Methods: Human gastric cancer cell line MGC803 cells were treated with various concentration of silibinin. Cellular viability was assessed by CCK-8 assay andapoptosis and cell cycle distribution by flow cytometry. Protein expression and mRNA of STAT3, and cell cycle and apoptosis regulated genes were detected by Western blotting and real-time polymerase chain reaction, respectively. Results: Silibinin inhibits growth of MGC803 cells in a dose- and time-dependent manner. Silibinin effectively induces apoptosis of MGC803 cells and arrests MGC803 cells in the G2/M phase of the cell cycle, while decreasing the protein expression of p-STAT3, and of STAT3 downstream target genes including Mcl-1, Bcl-xL, survivin at both protein and mRNA levels. In addition, silibinin caused an increase in caspase 3 and caspase 9 protein as well as mRNA levels. Silibinin caused G2/M phage arrest accompanied by a decrease in CDK1 and Cyclin B1 at protein and mRNA levels.. Conclusions: These results suggest that silibinin inhibits the proliferation of MGC803 cells, and it induces apoptosis and causes cell cycle arrest by down-regulating CDK1, cyclinB1, survivin, Bcl-xl, Mcl-1 and activating caspase 3 and caspase 9, potentially via the STAT3 pathway.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.4
• /
• pp.2343-2347
• /
• 2013

Objective: This investigation aimed to determine effects of celecoxib on the cell cycle kinetics of the gastric cancer cell line MGC803 and the mechanisms involved by assessing expression of cytochrome C and caspase-9 at the protein level. Methods: Cell proliferation of MGC803 was determined by MTT assay after treatment with celecoxib. Apoptosis was assessed using fluorescence staining and cell cycle kinetics by flow cytometry. Western blotting was used to detect the expression of caspase-9 protein and of cytochrome C protein in cell cytosol and mitochondria. Results: Celecoxib was able to restrain proliferation and induce apoptosis in a dose- and time-dependent manner, inducing G0/G1 cell cycle arrest, release of cytochrome C into the cytosol, and cleavage of pro-caspase-9 into its active form. Conclusion: Celecoxib can induce apoptosis in MGC803 cells through a mechanism involving cell cycle arrest, mitochondrial cytochrome C release and caspase activation.

• Molecules and Cells
• /
• v.39 no.10
• /
• pp.742-749
• /
• 2016

The cancer chemo-preventive effects of equol have been demonstrated for a wide variety of experimental tumours. In a previous study, we found that equol inhibited proliferation and induced apoptotic death of human gastric cancer MGC-803 cells. However, the mechanisms underlying equol-mediated apoptosis have not been well understood. In the present study, the dual AO (acridine orange)/EB (ethidium bromide) fluorescent assay, the comet assay, MTS, western blotting and flow cytometric assays were performed to further investigate the pro-apoptotic effect of equol and its associated mechanisms in MGC-803 cells. The results demonstrated that equol induced an apoptotic nuclear morphology revealed by AO/EB staining, the presence of a comet tail, the cleavage of caspase-3 and PARP and the depletion of cIAP1, indicating its pro-apoptotic effect. In addition, equol-induced apoptosis involves the mitochondria-dependent cell-death pathway, evidenced by the depolarization of the mitochondrial membrane potential, the cleavage of caspase-9 and the depletion of Bcl-xL and full-length Bid. Moreover, treating MGC-803 cells with equol induced the sustained activation of extracellular signal-regulated kinase (ERK), and inhibiting ERK by U0126, a MEK/ERK pathway inhibitor, significantly attenuated the equol-induced cell apoptosis. These results suggest that equol induces mitochondria-dependent apoptosis in human gastric cancer MGC-803 cells via the sustained activation of the ERK1/2 pathway. Therefore, equol may be a novel candidate for the chemoprevention and therapy of gastric cancer.

• Food Science and Biotechnology
• /
• v.18 no.1
• /
• pp.103-107
• /
• 2009

Three traditional Chinese medicines, Agrimonia pilosa Ledeb, Grifola umbellata (pers.) Pilat, and Gambogia, are combined to form a compound extract, AGC. In this study, the in vitro and in vivo inhibitory effects of AGC on human gastric carcinoma MGC-803 cells were demonstrated, and the molecular mechanisms underlying these effects are investigated. Our results indicate that AGC inhibited MGC-803 cell growth in a dose-dependent manner as measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, with an $IC_{50}$ of about $6.045{\pm}0.69{\mu}g/mL$. In vivo, AGC inhibited growth of human gastric carcinoma in xenograft tumors in nude mice, and the inhibitory rate reached 55.2% at 300 mg/kg. The pro-apoptotic activity of AGC was attributed to its ability to decrease the expression of Bcl-2 and Pro-caspase3 and increase the expression of Bax. These results demonstrate that AGC can effectively induce programmed cell death and may be a promising anti-tumor drug in human gastric carcinoma.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.4
• /
• pp.1377-1382
• /
• 2012

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-${\kappa}B$ using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-${\kappa}B$ were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-${\kappa}B$.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.2
• /
• pp.633-636
• /
• 2012

Purpose: PRIL (proliferation-inducing ligand) is a newly identified member of the tumor necrosis factor (TNF) family and modulates death ligand-induced apoptosis. Here, we investigated the effect of PRIL on cellular characteristics relating to tumor progression in human gastric cancer. Method: Recombinant lentivirus containing PRIL siRNA was constructed and then infected MGC803 and SGC7901 gastric cancer cells. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colony formation and cell cycle analysis were used to study the effect of PRIL knockdown on gastric cancer cell proliferation. Results: PRIL expression in lentivirus infected cells was significantly reduced as evidenced by quantitative real-time PCR. Cell viability and colony formation of MGC803 and SGC7901 cells were significantly hampered in PRIL knock-down cells. Moreover, the cell cycle was arrested at G2/M phase, elucidating the mechanism underlying the inhibitory effect of siRNA on cell proliferation. Conclusions: Our study indicated that PRIL functions in promoting cell growth, and lentivirus-mediated PRIL gene knockdown might be a promising strategy in the treatment of gastric cancer.

• Journal of Gastric Cancer
• /
• v.18 no.4
• /
• pp.356-367
• /
• 2018

Purpose: Kallikrein (KLK) proteases are hormone-like signaling molecules with critical functions in different cancers. This study investigated the expression of KLK6 in gastric cancer and its potential role in the growth, migration, and invasion of gastric cancer cells. Materials and Methods: In this study, we compared protein levels of KLK6, vascular endothelial growth factor (VEGF), and matrix metallopeptidase (MMP) 9 in normal gastric epithelial and gastric cancer cell lines by western blot. Fluorescence-activated cell sorting was employed to sort 2 clones of SGC-7901 cells with distinct KLK6 expression, namely, KLK6-high ($KLK6^{high}$) and KLK6-low ($KLK6^{low}$), which were then expanded. Lastly, immunohistochemical analysis was performed to investigate KLK6 expression in gastric cancer patients. Results: The expression levels of KLK6, VEGF, and MMP 9, were significantly higher in the gastric cancer cell lines SGC-7901, BGC-823, MKN-28, and MGC-803 than in the normal gastric epithelial cell line GES-1. Compared to $KLK6^{low}$ cells, $KLK6^{high}$ cells showed enhanced viability, colony-forming ability, migration, and invasion potential in vitro. Importantly, immunohistochemical analysis of a human gastric cancer tissue cohort revealed that the staining for KLK6, VEGF, and MMP9 was markedly stronger in the cancerous tissues than in the adjacent normal tissues. KLK6 expression also correlated with that of VEGF and MMP9 expression, as well as several key clinicopathological parameters. Conclusions: Together, these results suggest an important role for KLK6 in human gastric cancer progression.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.5
• /
• pp.1781-1787
• /
• 2015

Background: miRNAs are relatively recently discovered cancer biomarkers which have important implications for cancer early diagnosis, treatment and estimation of prognosis. Here we focussed on expression of mir-196a-5p in gastric cancer tissues and cell lines so as to analyse its significance for clinicopathologic characteristics and generate enriched KEGG pathways clustered by target genes for exploring its potential roles as a biomarker in gastric cancer. Materials and Methods: The expression of mir-196a-5p in poorly, moderate and well differentiated gastric cancer cell lines compared with GES-1 was detected by RT-qPCR, and the expression of mir-196a-5p in gastric cancer tissues comparing with adjacent non cancer tissues of 58 cases were also assessed by RT-qPCR. Subsequently, an analysis of clinical significance of mir-196a-5p in gastric cancer and enriched KEGG pathways was executed based on the miRWalk prediction database combined with bioinformatics tools DAVID 6.7 and Mirfocus 3.0. Results: RT-qPCR showed that mir-196a-5p was up-regulated in 6 poorly and moderate differentiated gastric cancer cell lines SGC-7901, MKN-45, MKN-28, MGC-803, BGC-823, HGC-27 compared with GES-1, but down-regulated in the highly differentiated gastric cancer cell line AGS. Clinical data indicated mir-196a-5p to beup-regulated in gastric cancer tissues (47/58). Overexpression of mir-196a-5p was associated with more extensive degree of lymph node metastasis and clinical stage (P < 0.05; x2 test). Enriched KEGG pathway analyses of predicted and validated targets in miRWalk combined with DAVID 6.7 and Mirfocus 3.0 showed that the targeted genes regulated by mir-196a-5p were involved in malignancy associated biology. Conclusions: Overexpression of mir-196a-5p is associated with lymph node metastasis and clinical stage, and enriched KEGG pathway analyses showed that targeted genes regulated by mir-196a-5p may contribute to tumorgenesis, suggesting roles as an oncogenic miRNA biomarker in gastric cancer.