Human Gastric Cancer AGS Cells Research Articles

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.

Melittin suppresses epithelial-mesenchymal transition and metastasis in human gastric cancer AGS cells via regulating Wnt/BMP associated pathway.

Gastric cancer has a poor prognosis; once cancer has metastasized, it can easily lead to patient death. Melittin is one of the major components extracted from the bee venom. It has been shown that melittin emerges antitumor activities against many human cancer cell lines. Our results indicated that melittin at 0.2-0.5 µm significantly reduced total cell viability in human gastric cancer AGS cells. At low concentrations (0.05-0.15 µm), melittin displayed antimetastasis effects and inhibited cell adhesion and colony formation. Besides, it inhibited cell motility and suppressed cell migration and invasion. Melittin inhibited the activities of MMP-2 and MMP-9 and the integrity of cell membrane in AGS cells. Furthermore, Western blotting results showed that melittin decreased the protein expressions of Wnt/BMP and MMP-2 signaling pathways. Based on these observations, melittin inhibited cell migration and invasion of AGS cells through multiple signaling pathways. It may be used to treat metastasized gastric cancers in the future.

Induction of Apoptosis in AGS Human Gastric Cancer Cells by Platycarya strobilacea Leaf Extract

Induction of Apoptosis in AGS Human Gastric Cancer Cells by <i>Platycarya strobilacea</i> Leaf Extract

The Endocannabinoid, Anandamide, Acts as a Novel Inhibitor of LPS-Induced Inflammasome Activation in Human Gastric Cancer AGS Cell Line: Involvement of CB1 and TRPV1 Receptors

Inflammasome activation is a pivotal step for the maturation of IL-1β, which is involved in the development and progression of gastric cancer (GC). Endocannabinoids, such as anandamide (AEA), are emerging as new anticancer therapeutic agents; however, their effects on inflammasome components and underlying mechanisms have not been well elucidated. This study was designed to investigate the effects of AEA on the expression of inflammasome components in lipopolysaccharide- (LPS-) stimulated AGS cells. Moreover, we explored the involvement of cannabinoid receptors (CRs), including CB1R and TRPV1R, in the observed effects of AEA. Our results showed that inflammation was induced by LPS (10 μg/ml) in AGS cells, and inflammasome components (NLRP3, MLRC4, ASC, IL-18, and IL-1β) were overexpressed. Exposure to AEA (10 μM, 24 h) before or after inflammation induction downregulated the expression of inflammasome components and attenuated inflammasome activation as demonstrated by cleavage of caspase 1 and matured IL-1β secretion, although AEA pretreatment showed more reducing effects on the inflammasome activation. In addition, blocking of CB1R and TRPV1R by application of AM-251 and AMG-9810 antagonists remarkably reversed the observed effects of AEA and revealed that NLRP3, NLRC4, and IL-1β genes were mainly regulated via CB1R, while TRPV1R could only regulate the expression of IL-1β and IL-18 genes. In conclusion, our results would indicate a novel anticancer effect of anandamide by attenuation of inflammasome activation and consequently reducing IL-1β production in human AGS cancer cell line via CB1R and TRPV1R.

D-Carvone inhibits the JAK/STAT3 signaling pathway and inducedthe apoptotic cell death in the human gastric cancer AGS cells.

Globally, gastric cancer is one of the leading causeof death. Surgical and chemotherapy constitute an important treatment regimen. Unfortunately, less than 20 persons out of 100 patients are live on almost 5 years. Hence, anontoxic, effective and significantly enhancing novel therapeutic agent is required. d-Carvone is a natural terpenoid present in the essential oils and abundant in the seeds of caraway, as well asknownfolk medicationfor diarrhea, acidity, and other gastric disorders. Nevertheless, the role of d-carvone on gastric cancer and its underlying molecular mechanism resides enigmatic. Cells were treated with d-carvone to find out the IC50 by MTT assay. This study showsthat 20 and 25 μM d-carvone has induced the reactive oxygen speciesproduction and mitochondrial membrane potential in gastric cancer AGS cells, which were evaluated by 2,7-dichlorofluoresceindiacetateand Rh123 staining methods, respectively. The effect of d-carvone against the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3)pathway was studied through immunoblotting. Then, we found that iteffectively inhibited the proliferation of cell, and the induction of cell apoptosis was scrutinized by dual, 4',6-diamidino-2-phenylindole, and also propidiumiodide staining methods. We also explored the fundamental molecular signaling mechanism of the d-carvone and our data depicts that d-carvone induced apoptosis cell death by mitochondrial reactive oxygen species production and downregulation of the and JAK and STAT3 signaling molecules. These overall findings supportthat the d-carvone inhibits the JAK/STAT3 signaling pathway and induces cell death in the gastric cancer AGS cells.

CO/chemosensitization/antiangiogenesis synergistic therapy with H2O2-responsive diselenide-containing polymer

Carbon monoxide (CO) therapy and antiangiogenesis therapy (AAT) are regarded as promising approaches for cancer treatment. However, the poor tumor targeting ability and inevitable side effects prevent their clinical application. In this study, we developed H2O2-responsive diselenide-containing micelles that combined CO therapy with chemosensitization therapy and AAT in a single system. Under the interaction of intratumoral H2O2, CO and gemcitabine (GEM) were released in situ from the micelles to reduce side effects, and CO significantly sensitized the chemotherapeutic effect of GEM by elevating the level of reactive oxygen species (ROS) in human gastric cancer AGS cells. Furthermore, diselenide bonds in the micelles were oxidized to seleninic acid in organic form, which suppressed the expressions of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) to realize AAT. This study provides an integrated solution to combine CO therapy with chemosensitization therapy and AAT together with good biocompatibility.

Carthami flos induces apoptosis by activating caspases and regulating mitogen-activated protein kinase and reactive oxygen species signaling pathways in AGS human gastric cancer cells

Background: Carthami flos (CF) is a traditional medicine used to treat various diseases, especially cancer therapy. Objectives: The mechanisms of cell death induction by CF were investigated in AGS human gastric adenocarcinoma cells. Materials and Methods: Cell viability assay, cell cycle analysis, caspase activity assay, western blotting, and reactive oxygen species (ROS) assay were used to check the anti-cancer effects of CF on AGS cells. Results: Treatment with CF (100500 μg/mL) inhibited AGS cell proliferation and increased the ratio of the subG1 phase of the cell cycle. CF induced cell death was associated with a reduction in Bcl-2 and an increase in Bax levels. Moreover, expression of the apoptosismediating surface antigen (FAS) was increased. CF activated caspase-3 and -9. In addition, it regulated the activation of mitogen-activated protein kinases and increased intracellular ROS generation. Conclusion: These findings suggest that CF induced apoptosis in AGS cells and could thus, serve as a novel anticancer agent to promote apoptosis of gastric cancer cells.

Knockdown of m6A methyltransferase METTL3 in gastric cancer cells results in suppression of cell proliferation.

N6-methyladenosine (m6A) RNA modification regulates multiple biological functions. Methyltransferase like 3 (METTL3), one of the major N6-methyltransferases, is highly expressed in gastric cancer, but its potential role in disease is unclear. The current study knocked out METTL3 (METTL3-KO) in human gastric cancer AGS cells using CRISPR/Cas9. METTL3-KO AGS cells exhibited decreased m6A methylation levels. A significant inhibition of cell proliferation was observed in METTL3-KO AGS cells. Silencing METTL3 in AGS cells altered the expression profile of many effector molecules that were previously demonstrated to serve key roles in AGS cell proliferation, including the suppressor of cytokine signaling (SOCS) family of proteins. The results further demonstrated that SOCS2 upregulation in METTL3-KO AGS cells was associated with a decreased RNA decay rate. Furthermore, SOCS2 KO or SOCS2 overexpression caused a significant increase and decrease in AGS cell proliferation, respectively. The current data suggested that METTL3-KO in gastric cancer cells resulted in the suppression of cell proliferation by inducing SOCS2, suggesting a potential role of elevated METTL3 expression in gastric cancer progression.

Calprotectin (S100A8/S100A9)-induced cytotoxicity and apoptosis in human gastric cancer AGS cells: Alteration in expression levels of Bax, Bcl-2, and ERK2.

Calprotectin is a heterodimeric EF-hand Ca2+ binding protein that is typically released by infiltrating polymorphonuclear leukocytes and macrophages. This protein is a key player linking inflammation and cancer. Due to the increased levels of calprotectin in different inflammatory diseases and cancer, it is considered as a marker for diagnostic purposes. In this study, we evaluated the mechanism of cell viability and apoptotic-inducing effects of recombinant human calprotectin (rhS100A8/S100A9) on the gastric adenocarcinoma (AGS), the most common type of gastric cancer cell line. AGS cells were exposed to the different concentrations (5-100 μg/ml) of calprotectin for 24, 48, and 72 h, and cell viability was assessed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic-inducing effects of calprotectin were evaluated by sub-G1 cell cycle assay and Annexin V/propidium iodide double staining. Furthermore, real-time polymerase chain reaction and Western blot analysis were performed to evaluate the mechanism of action of calprotectin. Our findings indicated that calprotectin inhibits growth and viability of AGS cells in a time- and dose-dependent manner. The half-maximal inhibitory concentration values were measured as 85.77, 79.14, and 65.39 μg/ml for 24, 48, and 72 h, respectively. Additionally, we found that calprotectin downregulated the expression of antiapoptotic protein Bcl-2 and upregulated proapoptotic protein Bax in a time- and concentration-dependent fashion. Calprotectin also slightly upregulated the expression of extracellular signal-regulated protein kinase 2 (ERK2), while it significantly decreased the levels of phospho-ERK in a time-dependent manner. Overall, these findings indicated that calprotectin has cytotoxicity and apoptosis-inducing effects on AGS cell lines in high concentration by modulating Bax/Bcl-2 expression ratio accompanied by inhibition of ERK activation.

A fluorescent "ON-OFF-ON" switch for the selective and sequential detection of Hg2+ and I- with applications in imaging using human AGS gastric cancer cells.

A new fluorescent "on-off-on" probe (BIPQ) is designed and developed which selectively binds with Hg2+; its emission intensity is quenched almost 40-fold at 455 nm without interference from other metal cations. On gradual addition of I- to the solution of BIPQ-Hg2+, the emission reverts to its original intensity. The limits of detection of BIPQ for Hg2+ and I- are found to be on the order of 3.12 × 10-9 and 5.48 × 10-8 M, respectively, which shows clearly that BIPQ can sense Hg2+ at a very minute level. DFT and TDDFT studies are conducted with the probe to establish similarity between theoretical and experimental outcomes. Finally, to demonstrate its practical benefit in biological fields, live cell imaging experiments with BIPQ are carried out to detect Hg2+ in human AGS gastric cancer cell lines.

Salidroside induces apoptosis and protective autophagy in human gastric cancer AGS cells through the PI3K/Akt/mTOR pathway

Salidroside, a natural active ingredient extracted from Rhodiola rosea, has been shown to exert antitumor activity against breast cancer Dong Young et al. [1], colon cancer Sun et al. [2] and bladder cancer Tian et al. [3]. However, the effect of salidroside on apoptosis and autophagy in gastric cancer remains unclear. In our research, we observed the biological effect of salidroside on human gastric cancer AGS cells. Our results demonstrated that salidroside inhibited the growth of AGS cells both in vivo and in vitro and exerted a proapoptotic effect on AGS cells as confirmed by flow cytometry, Hoechst staining and western blot analysis. Additionally, we found that salidroside decreased the phosphorylation of PI3K and Akt and that pretreatment with the PI3K/Akt agonist IGF-1 could weaken the proapoptotic effect of salidroside. Interestingly, the exposure of AGS cells to salidroside induced autophagy as indicated by transmission electron microscopy, mRFP-GFP-LC3 transfection and western blot analysis, suggesting that salidroside promoted autophagy in gastric cancer AGS cells. Furthermore, treatment with the autophagy inhibitor chloroquine enhanced salidroside-induced cell apoptosis, indicating that the autophagy mediated by salidroside may protect AGS cells from death. Additionally, we found that salidroside decreased the level of p-mTOR protein in a concentration-dependent manner and that pretreatment with IGF-1 decreased the expression of autophagy proteins, suggesting that salidroside induced autophagy through the PI3K/Akt/mTOR pathway. The above findings indicate that salidroside inhibited the growth of gastric cancer and induced apoptosis and protective autophagy through the PI3K/Akt/mTOR pathway. In summary, our study provides novel insights regarding the activity of salidroside against gastric cancer and contributes to the clinical application of salidroside combined with autophagy inhibitors as a chemotherapeutic strategy for human gastric cancer.

Lemon Peel Polyphenol Extract Reduces Interleukin-6-Induced Cell Migration, Invasiveness, and Matrix Metalloproteinase-9/2 Expression in Human Gastric Adenocarcinoma MKN-28 and AGS Cell Lines.

Among plant polyphenols, lemon peels extract (LPE) from the residues of the industrial processing of lemon (Citrus limon) shows anti-proliferative properties in cancer cells and anticholinesterase activity. In this study, we analyze the anti-cancer properties of LPE on migration and invasiveness in MKN-28 and AGS human gastric cancer cell lines either in the absence or presence of the pro-inflammatory cytokine IL-6. We find that the pretreatment with non-cytotoxic concentrations (0.5–1 μg/ml of gallic acid equivalent) of LPE inhibits interleukin-6 (IL-6)-induced cell migration and invasiveness in MKN-28 and AGS cells, as analyzed by wound and matrigel assays. Pretreatment with LPE is able to prevent either IL-6-induced matrix metalloproteinases (MMP)-9/2 activity, as assessed by gel zymography, or mRNA and protein MMP-9/2 expression, as evaluated by qPCR and Western blotting analysis, respectively. These LPE effects are associated with an IL-6-dependent STAT3 signaling pathway in MKN-28 and AGS cells. Furthermore, LPE shows acetylcholinesterase inhibitory activity when assayed by the Ellman method. In conclusion, our results demonstrate that LPE reduces the invasiveness of gastric MKN-28 and AGS cancer cells through the reduction of IL-6-induced MMP-9/2 up-regulation. Therefore, these data suggest that LPE exerts a protective role against the metastatic process in gastric cancer.

Lycopene induces apoptosis by inhibiting nuclear translocation of β-catenin in gastric cancer cells.

Reactive oxygen species (ROS) promote the development and progression of cancer by their effects on several signaling pathways. Lycopene, a major carotenoid natural product, is known to display antioxidant activity and to induce apoptosis of cancer cells. The aim of the present study was to investigate the mechanism by which lycopene induces apoptosis of the human gastric cancer AGS cells. In the present study, we showed that lycopene reduces the viability of AGS cells by inducing DNA fragmentation and increasing the Bax/Bcl-2 ratio. To determine the mechanistic basis for these effects, studies were conducted to assess the effects of this carotenoid on activation and nuclear translocation of β-catenin, and the expression of β-catenin target genes in AGS cells. The results showed that lycopene reduces the levels of ROS. It also inhibits activation of β-catenin signaling by changing the Wnt/β-catenin multi-protein complex such as a reduction in phosphorylation of glycogen synthase kinase 3β [GSK3β] and an increase in adenomatous polyposis coli [APC] and β-transducin repeats-containing proteins [β-TrCP]). It suppresses nuclear translocation of β-catenin and the expression of the β-catenin target survival genes c-myc and cyclin D1. Lycopene induces apoptosis by reducing ROS levels and suppressing β-catenin-c-myc/cyclin D1 axis. Thus, lycopene induces apoptosis of gastric cancer cells by disrupting nuclear translocation of β-catenin and expression of key cell survival genes.

Silymarin induces inhibition of growth and apoptosis through modulation of the MAPK signaling pathway in AGS human gastric cancer cells.

Apoptosis is regarded as a therapeutic target because it is typically disturbed in human cancer. Silymarin from milk thistle (Silybum marianum) has been reported to exhibit anticancer properties via regulation of apoptosis as well as anti-inflammatory, antioxidant and hepatoprotective effects. In the present study, the effects of silymarin on the inhibition of proliferation and apoptosis were examined in human gastric cancer cells. The viability of AGS human gastric cancer cells was assessed by MTT assay. The migration of AGS cells was investigated by wound healing assay. Silymarin was revealed to significantly decrease viability and migration of AGS cells in a concentration-dependent manner. In addition, the number of apoptotic bodies and the rate of apoptosis were increased in a dose-dependent manner as determined by DAPI staining and Annexin V/propidium iodide double staining. The changes in the expression of silymarin-induced apoptosis proteins were investigated in human gastric cancer cells by western blotting analysis. Silymarin increased the expression of Bax, phosphorylated (p)-JNK and p-p38, and cleaved poly-ADP ribose polymerase, and decreased the levels of Bcl-2 and p-ERK1/2 in a concentration-dependent manner. The in vivo tumor growth inhibitory effect of silymarin was investigated. Silymarin (100 mg/kg) significantly decreased the AGS tumor volume and increased apoptosis, as assessed by the TUNEL assay, confirming its tumor-inhibitory effect. Immunohistochemical staining revealed elevated expression of p-JNK and p-p38 as well as reduced expression of p-ERK1/2 associated with silymarin-treatment. Silymarin was revealed to reduce tumor growth through inhibition of p-ERK and activation of p-p38 and p-JNK in human gastric cancer cells. These results indicated that silymarin has potential for development as a cancer therapeutic due to its growth inhibitory effects and induction of apoptosis in human gastric cancer cells.

Application value of CyTOF 2 mass cytometer technology at single-cell level in human gastric cancer cells

Chemotherapy and radiotherapy are main adjuvant therapies for the treatment of gastric cancer, the treatment effects are individual difference, but the specific mechanism is unknown. CyTOF 2 mass cytometer (CyTOF) enables the detecting up to 135 parameters on single cell, the emergence of which is an opportunity for proteomics research. We first tried to apply CyTOF technique to gastric cancer cells. We verified applicability of CyTOF in gastric cancer cells, and analyzed the responses of seventeen proteins to chemoradiotherapy in human gastric cancer AGS cells. To analyze the high dimensional CyTOF data, we used two statistical and visualization tools including viSNE and Citrus. Two specific clusters were found which had differences in protein expression profiles. CyTOF technology is proved feasibility and value at single cell level of gastric cancer.

Sesquiterpenes from Curcuma zedoaria rhizomes and their cytotoxicity against human gastric cancer AGS cells

Curcuma zedoaria rhizome (Zingiberaceae) is a well-known traditional medicinal plant used in Ayurvedic and traditional Chinese medicine to treat various cancers. This study aimed to identify the cytotoxic components from C. zedoaria rhizomes that act against gastric cancer, which is the third leading cause of death from cancer worldwide because the MeOH extract of C. zedoaria rhizome was found to show a cytotoxic effect against gastric cancer AGS cells. Repeated column chromatography and semi-preparative HPLC purification were used to separate the components from the C. zedoaria MeOH extract. Two new sesquiterpenes, curcumenol-9,10-epoxide (1) and curcuzedoalide B (2), and 12 known related sesquiterpenes (3–14) were isolated from the C. zedoaria MeOH extract. The structures of new compounds were determined by 1D and 2D NMR spectroscopic experiments and HR-ESIMS, and quantum chemical ECD calculations. The cytotoxic effects of the isolated compounds were measured in human gastric cancer AGS cells using an MTT cell viability assay. Compounds 9, 10, and 12 exhibited cytotoxic effects against gastric cancer AGS cells, with IC50 values in the range of 212–392 μM. These findings provide further experimental scientific evidence to support the traditional use of C. zedoaria rhizomes for the treatment of cancer. Curcumenol (9), 4,8-dioxo-6β-methoxy-7α,11-epoxycarabrane (10), and zedoarofuran (12) were identified as the main cytotoxic components in C. zedoaria rhizomes.

BP‑1‑102 exerts an antitumor effect on the AGS human gastric cancer cell line through modulating the STAT3 and MAPK signaling pathways.

BP-1-102, a novel inhibitor of signal transducer and activator of transcription 3 (STAT3), exhibits significant antitumor effects in several malignancies in vitro and in vivo. However, its role in gastric cancer (GC) remains to be elucidated. In the present study, the effect and potential molecular mechanisms of BP-102 in human GC cell lines were investigated. The results showed that BP-1-02 dose-dependently inhibited the proliferation of AGS cells, whereas it had little effect on HGC-27 cells. Flow cytometric analysis indicated that BP-1-102 induced apoptosis, but had minimal effect on cell cycle distribution. In addition, cells treated with BP-1-102 demonstrated markedly suppressed migration and invasion capacities. Western blot analysis revealed that BP-1-102 inhibited the phosphorylation of STAT3 and its target genes, including c-Myc, cyclin D1 and survivin, in a time- and dose-dependent manner. Furthermore, it was found that BP-1-102 induced the phosphorylation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase (MAPK) and inhibited the activation of extracellular signal-related kinases. Taken together, these results demonstrated that BP-1-102 may be a potent antitumor agent that acts through modulating the STAT3 and MAPK signaling pathways in GC cells.

Effects of siRNA-mediated silencing of Bmi-1 gene expression on proliferation of gastric cancer cells

This study was designed to investigate the effects of siRNA-mediated silencing of Bmi-1 gene expression on proliferation of AGS gastric cancer cell. siRNA Bmi-1 was transfected into human AGS gastric cancer cells by liposome (as siRNA Bmi-1 group) with negative control (as control group); the expressions of Bmi-1 and apoptosis-related genes like P21, Bax, and Bcl-2 in AGS cells were determined by Western blot method; the apoptosis of AGS cells was detected by flow cytometry double staining and Hoechst staining; and cell cycle was measured by flow cytometry. Compared with the control group, the expression of Bmi-1 in the siRNA Bmi-1 group was significantly decreased ( P &lt; 0.05), the apoptosis rate was increased ( P &lt; 0.05), and cell cycles were arrested at G1 phase (P &lt; 0.05); the expression level of P21 and Bax in cells was significantly up-regulated while that of Bcl-2 down-regulated ( P &lt; 0.05). The down regulation of Bmi-1 can inhibit the proliferation of AGS gastric cancer cell and promote its apoptosis, which takes such effects mainly by up-regulating P21 as well as Bax and down-regulating Bcl-2.

MHY440, a Novel Topoisomerase Ι Inhibitor, Induces Cell Cycle Arrest and Apoptosis via a ROS-Dependent DNA Damage Signaling Pathway in AGS Human Gastric Cancer Cells.

We investigated the antitumor activity and action mechanism of MHY440 in AGS human gastric cancer cells. MHY440 inhibited topoisomerase (Topo) Ι activity and was associated with a DNA damage response signaling pathway. It exhibited a stronger anti-proliferative effect on AGS cells relative to Hs27 human foreskin fibroblast cells, and this effect was both time- and concentration-dependent. MHY440 also increased cell arrest in the G2/M phase by decreasing cyclin B1, Cdc2, and Cdc25c, and upregulating p53 and p73. MHY440 induced AGS cell apoptosis through the upregulation of Fas-L, Fas, and Bax as well as the proteolysis of BH3 interacting-domain death agonist and poly(ADP-ribose) polymerase. It also contributed to the loss of mitochondrial membrane potential. The apoptotic cell death induced by MHY440 was inhibited by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, indicating that apoptosis was caspase-dependent. Moreover, the apoptotic effect of MHY440 was reactive oxygen species (ROS)-dependent, as evidenced by the inhibition of MHY440-induced PARP cleavage and ROS generation via N-acetylcysteine-induced ROS scavenging. Taken together, MHY440 showed anticancer effects by inhibiting Topo I, regulating the cell cycle, inducing apoptosis through caspase activation, and generating ROS, suggesting that MHY440 has considerable potential as a therapeutic agent for human gastric cancer.

CRISPR/Cas9-mediated knockout of the PDEF gene inhibits migration and invasion of human gastric cancer AGS cells

Gastric cancer is one of the most common malignant tumors worldwide and has the second highest incidence and mortality rate among malignant tumors in China. Prostate-derived Ets factor (PDEF) is a member of the Ets family of transcription factors. Although PDEF plays an important role in tumorigenesis, its biological function in gastric cancer is still unclear. Here, we evaluated PDEF expression in 30 cases of human gastric carcinoma and the corresponding peritumoral tissues, using immunohistochemistry and immunofluorescence. Significantly higher levels of PDEF were detected in tumors compared to peritumoral tissues. We then investigated PDEF expression in the gastric cancer cell lines SGC and AGS and the normal gastric epithelial cell line GES; The CRISPR/Cas9 genome-editing system was used to knockout PDEF in AGS cells as a model for gastric cancer. Cell proliferation, apoptosis, migration, and invasion of PDEF-knockout AGS cells were evaluated using CCK-8, flow cytometry, scratch wound, and transwell assays, respectively. The results illustrated that PDEF-knockout inhibited AGS cell proliferation, migration, and invasion. Taken together, the results imply that PDEF plays important roles in the proliferation, migration, and invasion of AGS cells and may serve as a new treatment target in gastric cancer.