Human Gastric Cancer Cell AGS Research Articles

Celastrol impairs tumor growth by modulating the CIP2A-GSK3β-MCL-1 axis in gastric cancer cells.

High Cancerous Inhibitor of PP2A (CIP2A) expression has been reported in solid and hematologic malignancies and is inversely associated with prognosis in Gastric Cancer, the non-small cell lung cancer, et al. CIP2A can be a drug target for the development of novel anti-gastric cancer agent. Our study was designed to explore the anti-cancer effect of celastrol, a small natural compound, and whether it has an anti-proliferative effect through inducing CIP2A degradation against gastric cancer cells. Employing human gastric cancer cells AGS and BCG-823 cells, the effects of celastrol on cell proliferation, apoptosis and cell cycle was specifically investigated via Annexin V-FITC/PI staining and CCK8 assay. The functional association between celastrol and CIP2A was evaluated by using CIP2A knockdown and overexpression technique. The mechanism of underlying celastrol-triggering anti-gastric cancer effect was detected by real-time PCR and western blot analysis. Celastrol concentration- and time-dependently induced CIP2A degradation and led to gastric cancer cell apoptosis. More in depth studies revealed specific activation of Protein phosphatase 2A (PP2A)-GSK3β-MCL-1 signaling pathway was involved in pro-apoptosis effect of celastrol, due to celastrol-triggering degradation of CIP2A, which mainly suppressed PP2A activity. Our findings highlight that celastrol has therapeutic potential via inducing apoptosis of gastric cancer cells.

Ginsenoside Rh1 regulates gastric cancer cell biological behaviours and transplanted tumour growth in nude mice via the TGF-β/Smad pathway.

Gastric cancer (GC) is one of the most prevalent malignancies of the digestive tract. Ginsenoside Rh1 was reported to exert effects on GC. The current study set out to explore the mechanism underlying Ginsenoside Rh1 effects on GC. With oxaliplatin (OXA) serving as the positive control, human GC cells AGS were treated with 0, 10, 25, 50, 74, or 100 μM of ginsenoside Rh1 for 48 h. Proliferation, migration, invasion, and apoptosis were subsequently assessed by means of MTT, scratch test, Transwell, and TUNEL, respectively. AGS cells were further jointly treated with Rh1 and the TGF-β/Smad pathway activator Kartogenin, followed by detection of TGF-β/Smad pathway effects on AGS biological behaviours. Moreover, TGF-β/Smad pathway activation was detected with a Western blot assay. Furthermore, xenograft tumour models were established and tumour growth was recorded. Ki-67 expression patterns and apoptosis were detected with immunohistochemistry and TUNEL, respectively. In vitro, Ginsenoside Rh1 repressed AGS cell proliferation, migration, and invasion, and further promoted apoptosis, with a concentration of 50 μM Rh1 exerting the equivalent effects as OXA. In vivo, Ginsenoside Rh1 inhibited GC proliferation and induced tumour cell apoptosis. Mechanistically, Ginsenoside Rh1 reduced TGF-β1 and TGF-β2 levels and Smad2 and Smad3 phosphorylation levels. Collectively, our findings highlighted that ginsenoside Rh1 inhibited GC cell growth and tumour growth in xenograft tumour models via inhibition of the TGF-β/Smad pathway.

Circ_0110940 Exerts an Antiapoptotic and Pro-Proliferative Effect in Gastric Cancer Cells via the miR-1178-3p/SLC38A6 Axis.

Circular RNAs (circRNAs) are essential regulators in human cancers, including gastric cancer, by the miRNA/mRNA axis. A previous study identified the upregulation of circ_0110940 in human gastric cancer tissues. The present study performed in vitro assays to reveal the functions of circ_0110940 and its downstream miRNA/mRNA axis in gastric cancer cells. Traditional proliferation and apoptosis assays including colony formation, EdU staining, and Annexin V-PI staining assays were conducted. A luciferase reporter assay was performed to assess the binding between miR-1178-3p and circ_0110940 or SLC38A. We found the significant upregulation of circ_0110940 in human gastric cancer cells AGS and MKN45. Circ_0110940 was a stable circRNA and exerted an antiproliferative and proapoptotic effect in AGS and MKN45. Circ_0110940 binded with miR-1178-3p, which further targeted SLC38A6 3′UTR. Circ_0110940 degraded miR-1178-3p, and miR-1178-3p degraded SLC38A6. Thus, circ_0110940 has a positive effect on SLC38A6 expression. Furthermore, SLC38A6 rescued the effects of circ_0110940 knockdown on gastric cancer cell proliferation and apoptosis. In conclusion, circ_0110940 exerted an antiapoptotic and pro-proliferative effect in gastric cancer cells via the miR-1178-3p/SLC38A6 axis, which may provide basis for the targeted therapy of gastric cancer.

Oleanolic acid induces apoptosis and autophagy via the PI3K/AKT/mTOR pathway in AGS human gastric cancer cells

• Oleanolic acid inhibited AGS human gastric cancer cells by inducing apoptosis. • Oleanolic acid induced protective-autophagy in AGS cancer cell. • Oleanolic acid induced apoptosis and autophagy through PI3K/AKT/mTOR pathway. • Oleanolic acid suppress tumor growth by downregulating AKT pathway. Oleanolic acid (OA) is widely distributed in food and medicinal plants, it reportedly exerts anti-inflammatory and anti-cancer effects. In this study, we investigated the effect of OA on human gastric cancer cells AGS in vitro and in vivo. The OA treatment significantly inhibited the AGS cell viability. Apoptosis was confirmed via annexin V/PI staining and 4′,6-diamidino-2-phenylindole (DAPI) staining. The results from western blotting revealed that treatment with OA affected apoptosis-related protein. Meanwhile, OA induced autophagy, characterized by the formation of autophagic vacuoles and acidic vesicular organelles, also increased autophagy-related protein. Inhibition of autophagy further reduced cell proliferation. Moreover, OA treatment decreased phosphorylation of PI3K/AKT/mTOR pathway proteins. Finally, we found that OA reduced tumor volume and weight in xenograft mice via apoptosis without side effects. Overall, our study provides experimental evidence for the anti-cancer action of OA and suggests the possibility of its use as an adjuvant in gastric cancer therapy.

Two New Cu(II) and Zn(II)-Coordination Polymers Induce Gastric Cancer Cells Apoptosis via Upregulating ROS Related Genes

Two new coordination polymers, namely {[Cu(oba)(bpb)0.5](DMF)2}n [1, H2oba = 4,4′-oxybis(benzoic acid), bpb = 1,4-di(pyridin-4-yl)benzene] and {[Zn7(TPA)6(F)4(H2O)6](NO3)4(DMF)3}n (2, Htpa = 4-(1,2,4-triazol-4-yl)phenylacetic acid, DMF = N,N′-dimethylformamide) have been successfully constructed under solvothermal conditions. The in vitro anti-cancer activities of compounds 1 and 2 were evaluated on cancer cells in this study. The CCK-8 assay indicated both compounds 1 and 2 have excellent anti-cancer ability, but the activity of compound 1 is much stronger than compound 2. And the Annexin V-FITC/PI assay revealed that compounds exert anti-cancer effect via inducing cells apoptosis. Then, the further ROS assay revealed that the compound could induce human gastric cancer cells AGS apoptosis by up-regulating the ROS related genes and increasing the generation of ROS.

Anticancer activity of two novel ruthenium compounds in gastric cancer cells

AimsRuthenium (II) complexes are promising anticancer molecules due its pharmacological properties and selectivity to cells tumor. The aim of this work was to study the cytotoxic activity, and apoptosis induction of two new ruthenium complexes on a human gastric cancer cell line. Main methodsTwo ruthenium(II) complexes were synthesized: [(H2pbbzim)Ru(tpy-Ph-COOCH3)](Cl)2 (Ru-UCN1), and [(tpy)Ru(tpy-Ph-bzH)](Cl)2 (Ru-UCN3), and their anticancer capacity determined by cytotoxic assays, gene expression analysis, caspase activation and confocal microscopy. Key findingsRu-UCN3 is more notably cytotoxic than cisplatin in human gastric cancer cells AGS at 24 h, while Ru-UCN1 is more active against gastric cancer cells than cisplatin at 48 h. The complexes induce apoptosis as shown by RT-qPCR, protease activity, and confocal microscopy. Ru-UCN1 induces the overexpression of pro-apoptotic genes at 3 and 6 h, whereas Ru-UCN3 induces overexpression of these genes at 12 and 24 h. Ru-UCN1 treatment shows a strong activation of caspases 3/7 at 24 h, which was not observed for Ru-UCN3 treatment in the same timeframe. SignificanceTaken together, this data suggests that Ru-UCN1 and to a lesser extent, Ru-UCN3, may be interesting anticancer agents for gastric cancer.

Helicobacter pylori Might Induce TGF-β1-Mediated EMT by Means of cagE.

Epithelial-mesenchymal transition (EMT), in which polarized epithelial cells have mesenchymal cell phenotypes, is thought to be a key process of invasion and metastasis of cancer. Transforming growth factor beta-1 (TGF-β1) is known to be carcinogenic and Helicobacter pylori is a predominant carcinogen of gastric cancer. Our study aimed to determine whether TGF-β1 or H. pylori infection enhances EMT process and cytotoxin-associated gene E (CagE) is associated with EMT. Human gastric cancer cell AGS and MKN45 were treated with recombinant TGF-β1 or H. pylori including cagE-negative (ΔcagE) mutant. Besides the assessment of EMT-related markers expression levels by means of RT-qPCR, Western blot, and immunofluorescence assay, the induction of in vitro EMT on gastric cancer cells (AGS and MKN cell lines) was confirmed by wound-healing assay and invasion assay. When gastric cancer cells were treated with TGF-β1 or various strains of cagE-positive H. pylori, EMT-related marker altered significantly. However, the ΔcagE mutant did not. Wound-healing assay and invasion assay showed enhanced migration ability of the cells treated with cagE-positive H. pylori but not in ΔcagE mutant. EMT induction in gastric cancer cells by TGF-β1 was confirmed. Only infection with cagE-positive H. pylori upregulated the TGF-β1-mediated EMT pathway and consequently promotes EMT. Therefore, H. pylori might induce TGF-β1-mediated EMT associated with the cagE.

An increase in integrin-linked kinase non-canonically confers NF-κB-mediated growth advantages to gastric cancer cells by activating ERK1/2.

BackgroundIncreased activity or expression of integrin-linked kinase (ILK), which regulates cell adhesion, migration, and proliferation, leads to oncogenesis. We identified the molecular basis for the regulation of ILK and its alternative role in conferring ERK1/2/NF-κB-mediated growth advantages to gastric cancer cells.ResultsInhibiting ILK with short hairpin RNA or T315, a putative ILK inhibitor, abolished NF-κB-mediated the growth in the human gastric cancer cells AGS, SNU-1, MKN45, and GES-1. ILK stimulated Ras activity to activate the c-Raf/MEK1/2/ERK1/2/ribosomal S6 kinase/inhibitor of κBα/NF-κB signaling by facilitating the formation of the IQ motif-containing GTPase-activating protein 1 (IQGAP1)–Ras complex. Forced enzymatic ILK expression promoted cell growth by facilitating ERK1/2/NF-κB signaling. PI3K activation or decreased PTEN expression prolonged ERK1/2 activation by protecting ILK from proteasome-mediated degradation. C-terminus of heat shock cognate 70 interacting protein, an HSP90-associated E3 ubiquitin ligase, mediated ILK ubiquitination to control PI3K- and HSP90-regulated ILK stabilization and signaling. In addition to cell growth, the identified pathway promoted cell migration and reduced the sensitivity of gastric cancer cells to the anticancer agents 5-fluorouracil and cisplatin. Additionally, exogenous administration of EGF as well as overexpression of EGFR triggered ILK- and IQGAP1-regulated ERK1/2/NF-κB activation, cell growth, and migration.ConclusionAn increase in ILK non-canonically promotes ERK1/2/NF-κB activation and leads to the growth of gastric cancer cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12964-014-0069-3) contains supplementary material, which is available to authorized users.

An increase in integrin-linked kinase non-canonically confers NF-¿B-mediated growth advantages to gastric cancer cells by activating ERK1/2

BackgroundIncreased activity or expression of integrin-linked kinase (ILK), which regulates cell adhesion, migration, and proliferation, leads to oncogenesis. We identified the molecular basis for the regulation of ILK and its alternative role in conferring ERK1/2/NF-κB-mediated growth advantages to gastric cancer cells.ResultsInhibiting ILK with short hairpin RNA or T315, a putative ILK inhibitor, abolished NF-κB-mediated the growth in the human gastric cancer cells AGS, SNU-1, MKN45, and GES-1. ILK stimulated Ras activity to activate the c-Raf/MEK1/2/ERK1/2/ribosomal S6 kinase/inhibitor of κBα/NF-κB signaling by facilitating the formation of the IQ motif-containing GTPase-activating protein 1 (IQGAP1)-Ras complex. Forced enzymatic ILK expression promoted cell growth by facilitating ERK1/2/NF-κB signaling. PI3K activation or decreased PTEN expression prolonged ERK1/2 activation by protecting ILK from proteasome-mediated degradation. C-terminus of heat shock cognate 70 interacting protein, an HSP90-associated E3 ubiquitin ligase, mediated ILK ubiquitination to control PI3K- and HSP90-regulated ILK stabilization and signaling. In addition to cell growth, the identified pathway promoted cell migration and reduced the sensitivity of gastric cancer cells to the anticancer agents 5-fluorouracil and cisplatin. Additionally, exogenous administration of EGF as well as overexpression of EGFR triggered ILK- and IQGAP1-regulated ERK1/2/NF-κB activation, cell growth, and migration.ConclusionAn increase in ILK non-canonically promotes ERK1/2/NF-κB activation and leads to the growth of gastric cancer cells.

Abstract 391: Short hairpin RNA targeting autotaxin reduces the human gastric carcinoma AGS cell proliferation, migratory and invasive capability in vitro and causes tumor regression in vivo.

Abstract To investigate the effect of short hairpin RNA(shRNA) targeting autotaxin on the migratory and invasive capability of human gastric cancer cell AGS and the growth xenografts in nude mice. The pSUPER-ATX and pSUPER-mock (non-specific), which were constructed in corresponding to the ATX-shRNA and negative control mock-shRNA synthesized on basis of gene sequence, were transfected with blank plasmid pSUPER-control into human gastric cancer cell AGS by Lipofectamine. At 24 h, 48 h and 72 h post-transfection, the cells were harvested and analyzed. The endogenous ATX mRNA and protein of different group AGS cells were detected by RT-PCR and western blot assays. The cell proliferation was measured by MTT assay. In vitro Transwell and Matrigel assay were used to detect the cell migratory and invasive capability. Tumor xenograft model was generated by subcutaneous injection of AGS cells into the dorsum of nude mice. The growth of xenograft tumor was monitored and measured; change of the tumor morphology and mice organs were observed by HE staining. The expressions of autotaxin, MMP-2 and MMP-9 protein in xenograft tumor tissue were detected by immunohistochemistry and western blot. in vitro, both the mRNA and protein level of ATX in pSUPER-ATX group were significantly down-regulated (P<0.01), and the cell proliferation, migration and invasive capability were significantly decreased as well. In vivo, no obvious damage of the organs was found. The pSUPER-ATX significantly suppressed the tumor volume and weight since 7th week after cell transplantation, when compared to the pSUPER-mock, pSUPER-control and WT groups, the inhibition rates were about 50%(P<0.05). However, no significant differences of these parameters were found among the WT, pSUPER-mock and pSUPER-control group. Furthermore, autotaxin, MMP-2/MMP-9 were expressed at significantly lower level in pSUPER-ATX group than in other three groups (P<0.05), and a significant correlation between ATX and MMP-2 expression was displayed (r=0.869, P<0.01). The specific shRNA targeting ATX down-regulated the endogenous ATX of human gastric cancer AGS cells, and could inhibite the AGS cell proliferation, migratory and invasive capability. Moreover, the shRNA targeting autotaxin inhibited the growth of human gastric cancer xenograft in nude mice. Citation Format: Zhouxun Chen, Yingpeng Huang, Xian Shen, Henning Dralle, Cuong Hoang-Vu, Oliver Gimm. Short hairpin RNA targeting autotaxin reduces the human gastric carcinoma AGS cell proliferation, migratory and invasive capability in vitro and causes tumor regression in vivo. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 391. doi:10.1158/1538-7445.AM2013-391 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Effect of Abl-interacting protein 1 overexpression upon human gastric cancer cell proliferation in vitro

To investigate the expression of Abl-interacting protein 1 (ABI1) in normal gastric mucosal cell line GES-1 and gastric cancer cell line AGS, and the effects of ABI1 gene overexpression upon the proliferation of human gastric cancer cell AGS in vitro. Firstly the ABI1 expression in GES-1 and AGS cells were identified by immunohistochemistry, immunofluorescence, RT-PCR, real-time PCR and Western blot. Secondly human gastric cancer cell line AGS was cultured and transfected with recombinant MSCV-GFP-ABI1 plasmid or blank plasmid MSCV-GPF. Real-time PCR and Western blot were used to detect the mRNA and protein expression of ABI1. And lastly the cell proliferation was detected by CCK-8 assay. ABI1 was expressed both in normal gastric mucosal cell line GES-1 and in gastric cancer cell line AGS. Compared to GES-1 cells, the ABI1 expression in AGS cells was lowered significantly. There were no significant differences in the ABI1 mRNA and protein expression between the AGS and AGS-MSCV-GFP groups. Compared to those of the AGS group, the ABI1 mRNA expression levels of the AGS-MSCV-GFP-ABI1 group increased by 1.87 times (P = 0.002). The protein expression levels of the AGS-MSCV-GFP-ABI1 group were remarkably higher than those of the AGS and AGS-MSCV-GFP groups (P = 0.002). CCK-8 assay showed that there were no significant differences in the proliferation rates at different time points between the AGS and AGS-MSCV-GFP groups. However, the proliferation rates at the time points of 24, 48, 72 and 96 hours of the AGS-MSCV-GFP-ABI1 were 1.46 +/- 0.31, 4.75 +/- 0.12, 6.62 +/- 0.32 and 8.96 +/- 0.27 respectively. And they were significantly lower than the proliferation rates of the AGS and AGS-MSCV-GFP groups (P < 0.01). ABI1 gene is down-regulated in gastric cancer cells. The ABI1 overexpression effectively inhibits the proliferation in human gastric cancer cell lines. It suggests that ABI1 may be involved in gastric cancer pathogenesis by regulating the proliferation of gastric carcinomas cells.

Evaluation of Multi-Target and Single-Target Liposomal Drugs for the Treatment of Gastric Cancer

We studied the effects of multi- and single-target liposomal drugs on human gastric cancer cell AGS both in vitro and in vivo. The cytotoxic effect of dihydrotanshinone I was significantly enhanced by treatment with octreotide-polyethylene glycol(PEG)-liposome, Arg-Gly-Asp(RGD)-PEG-liposome, and RGD/octreotide-PEG-liposome encapsulated with 0.5 mug/ml of dihydrotanshinone I to AGS cell for 24 h, compared to control. Furthermore, the AGS cell survival rate for multi-target versus single target liposomal drugs was significantly suppressed. Microscopic examination revealed that significant cell death occurred in the multi- and single-target liposomal encapsulated drug groups. Significant suppression of tumor growth in AGS cell xenograft nude mice given octreotide-PEG-liposome, RGD/octreotide-PEG-liposome encapsulated drug, versus those given a free drug was noted after 13 d of experimentation with the multi-targeted liposome: up to 60.75% and 41.2% reduction of tumor volume as compared to dimethylsulfoxide (DMSO) control and the free drug groups respectively. The treated animals showed no gross signs of toxicity. The results have potential clinical application.

P37 from Mycoplasma hyorhinis promotes cancer cell invasiveness and metastasis through activation of MMP-2 and followed by phosphorylation of EGFR

High Mycoplasma infection in gastric cancer tissues suggests a possible association between Mycoplasma infection and tumorigenesis. By using human gastric cancer cells AGS and mouse melanoma cells B16F10 stably expressing p37, the major immunogen of Mycoplasma hyorhinis, we found that p37 enhanced cell motility, migration, and invasion in vitro. With experimental metastasis model in C57BL/6 mice, p37 adenovirus-infected B16F10 cells formed more metastasis lesions in the lung. Furthermore, p37 promoted the phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase and the activity of matrix metalloproteinase-2 (MMP-2). Inhibitor of MMPs significantly blocked p37-induced EGFR but has little effect on extracellular signal-regulated kinase phosphorylation, whereas the p37-induced MMP-2 activation was only partially suppressed by inhibitor of MEK1/2 or by inhibitor of EGFR. However, all these inhibitors significantly reduced the p37-induced invasiveness of AGS cells. These results suggest that p37 may stimulate invasion by increasing the activity of MMP-2, thereby inducing EGFR phosphorylation and contributing to tumor metastasis on M. hyorhinis infection. p37 and its regulated molecules could be the potential targets for cancer therapy.

Lipoprotein p37 from Mycoplasma hyorhinis inhibiting mammalian cell adhesion

p37 protein is a membrane lipoprotein of Mycoplasma hyorhinis, and our previous work showed that there was high ratio of M. hyorhinis infection in human gastric carcinoma. To investigate the possible functions of p37 in cancer development, the nucleotide sequence of p37 gene was modified and expressed well in transfected cells. We found that p37 localized at the Golgi apparatus and could be secreted out of the cell. Human gastric cancer cells AGS, after being transfected with the p37 gene, were smaller, more spherical and easy to detach from each other. Their adhesion to matrix was also diminished and cytoskeleton in these stable p37 AGS cell was rearranged and transcription co-factor beta-actin was transferred to nucleolus with down-regulation of ICAM-1 and integrin beta1. These findings will be helpful for us to elucidate the effects of p37 on eukaryotic cells as well as to better understand the potential relationship between cancer and mycoplasma infection.