Human Gastric Cancer SGC-7901 Cells Research Articles

Identification of anti-tumor constituents from toad skin and toad venom by UPLC-QTOF/MS in-depth chemical profiling combined with bioactivity-based molecular networking

Toad skin (TS) and toad venom (TV) are two different traditional Chinese medicine (TCM) prepared from Bufo bufo gargarizans Cantor and Bufo melanostictus Schneider. Both of them were used in the treatment of ulcers, and now they are regarded as animal drugs with anti-tumor activity. However, the comparison analysis between their compositions and anti-tumor active ingredients has not been elucidated clearly. In this study, technology of ultra-performance liquid chromatography coupled with tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) and bioactivity-based molecular networking were applied to investigate the anti-tumor active ingredients of TS and TV. A method of collision energies-relied mass spectrometry combined with molecular networking was initially developed for identifying their chemical components. A combination of Cytoscape and molecular networking was then employed to analyze the prototype constitutes of TS absorbed in rat serum. In addition, cytotoxicity test was applied to evaluate their anti-proliferative activities against human gastric cancer (GC) cells. As a result, a total of 162 compounds were tentatively characterized, and four structural types existed in both TS and TV, including bufogenins, bufotoxins, indolealkylamines (IAAs), and acyl-arginine. Cyclic dipeptides could only be detected in TS, and the total number of bufogenins and bufotoxins in TV was higher than that of TS. Both of them significantly inhibited the viability of SGC7901 cells, and 70% methanol eluate of TS was the most potential active fraction. 44 prototype compounds in TS were identified, from which three types of potential tumor cytotoxic components, including bufogenins, IAAs, and cyclic dipeptides, were predicted. In human GC cells SGC7901, a mixture of nine bufogenins, including bufotalin, cinobufotalin, gamabufotalin, telocinobufagin, cinobufagin, bufarenogin, arenobufagin, hellebrigenin, and desacetylcinobufotalin, was conducted as bioactive components, which exerted a significant inhibitory effect on the cell viability of SGC7901 cells with a half maximal inhibitory concentration (IC50) value of 0.23 (0.19–0.27, 95%CI) μg/mL. Comparison of their chemical composition and anti-tumor activity reveals that TS might be able to partially replace TV, whilst bufogenins are the potential active ingredients.

Semisynthesis and anti-cancer properties of novel honokiol derivatives in human nasopharyngeal carcinoma CNE-2Z cells

In this study, 21 new honokiol derivatives were synthesised, and their anti-cancer properties were investigated. Among these, compound 1g exhibited the most potent cytotoxic activity against human nasopharyngeal carcinoma CNE-2Z cells, human gastric cancer SGC7901 cells, human breast cancer MCF-7 cells, and mouse leydig testicular cancer I-10 lines with IC50 values of 6.04, 7.17, 6.83, and 5.30 μM, respectively. Compared to the parental compound, 1g displayed up to 5.18-fold enhancement of the cytotoxic effect on CNE-2Z cells. We further demonstrated that 1g inhibited cell growth, suppressed migration and invasion, and induced apoptosis of CNE-2Z cells by down-regulating HIF-1α, MMP-2, MMP-9, Bcl-2, Akt and up-regulating Bax protein levels. Transfection of CNE-2Z cells with HIF-1α siRNA reduced cell migration and invasion. In addition, in vivo experiments confirmed that 1g inhibited tumour growth in CNE-2Z cell-xenografted nude mice with low toxicity. Thus, our data suggested that 1g was a potent and safe lead compound for nasopharyngeal carcinoma therapy.

Antitumor activity of Xiaoaiping injection on human gastric cancer SGC-7901 cells

Antitumor activity of Xiaoaiping injection on human gastric cancer SGC-7901 cells

Synthesis and anti-tumor activity of asiatic acid derivatives targeting VEGFR

To discovery novel VEGFR inhibitors, 12 novel asiatic acid derivatives were designed by computer-aided drug design (CADD) technology. Then, these novel asiatic acid derivatives were synthesized by introducing active groups at ring A and C-28 positions of asiatic acid. The structures of these novel analogues were confirmed by NMR and MS. Moreover, the anti-tumor activities of these novel asiatic acid derivatives on human hepatoma cells HepG2 and human gastric cancer cells SGC7901 were evaluated by MTT assay. As a result, compounds I2 and II4 showed stronger cytotoxicity on tumor cells than asiatic acid and positive control drugs such as gefitinib and paclitaxel. In conclusion, our study synthesized twelve novel asiatic acid derivatives and determined compounds I2 and II4 had better anti-tumor effect which may be potential candidate compounds for tumor therapy.

Fabrication of Doxorubicin Nanoparticles Mediated by Folic Acid and Its Effect on the Wnt/β-Catenin Signaling to Improve Precancerous Lesions in Gastric Cancer

Doxorubicin hydrochloride (DOX) is an anthracycline broad-spectrum antitumor drug, but it can produce a wide range of cytotoxicities in the body. Intravenous injection of a high dose of DOX causes serious toxicity and side effects in the heart and spinal cord. These shortcomings limit the clinical adoption of DOX. In this work, folic acid was coupled to DOX albumin nanoparticles (NPs) by chemical modification so that the preparation could actively target tumor site accumulation and release DOX to inhibit tumor cells. Albumin NPs were prepared by the desolvation method, and the formulation and preparation process were optimized. The particle size and granularity were taken as evaluation indexes. The in vitro antitumor activity of folic acid-mediated DOX albumin NPs against human hepatoma cell HepG2 and human gastric cancer cell SGC7901 was evaluated by using the methyl tetrazolium (MTT) assay with commercial DOX as a reference. Twenty SD rats were utilized to participate in the efficacy analysis of folic acid-mediated DOX albumin NPs for gastric precancerous lesions (GPLs). The results showed that the average particle size of folate-mediated doxorubicin albumin NPs was 267.28±0.38 nm, and 90% of them were less than 280.00 nm, showing a uniform particle size distribution. The drug release rate of the NPs within 24 h was 27.3%, and the NPs had sustained release properties. The IC50 values of the NPs and DOX aqueous solution on the highly expressed HepG2 cells were 4.78 μmol/L and 5.26 μmol/L, respectively, and those on the SGC7901 cells were 4.62 μmol/L and 5.06 μmol/L, respectively. After the establishment of the GPL model, the gene levels in the Wnt/β-catenin signaling were markedly upregulated (P <0.05). Folic acid-mediated doxorubicin albumin NPs greatly inhibited the abnormal expression of the above genes (P <0.01), i.e., they could effectively prevent further precancerous lesions of gastric cancer.

Role of IRE1 in autophagy induced by vitamin E succinate in human gastric cancer cell

To investigate the role of inositol-requiring enzyme 1(IRE1) in autophagy of human gastric cancer cells induced by vitamin E succinate(VES). Human gastric cancer SGC-7901 cells were cultured in vitro and divided into solvent control group(0.1% ethanol absolute), different doses(5, 10, 15 and 20 μg/mL) VES group, 4μ8C group, and VES + 4μ8C group. The endoplasmic reticulum stress-related molecules glucose regulated protein 78(GRP78) and C/EBP homologous protein(CHOP), autophagy marker microtubule associated Protein1 light chain 3(LC3), Beclin-1, unfolded protein response branching pathway Inositol-requiring enzyme 1(IRE1), X box-binding protein 1(XBP1), c-Jun n-terminal kinase(JNK) and p-JNK were detected by Western blot in the solvent control group and different doses of VES group. IRE1 was inhibited by 4μ8C. The expressions of IRE1, XBP1, JNK, p-JNK, GRP78 and CHOP were detected by Western blot, and the expressions of LC3 and Beclin-1 were detected. The expression of GRP78(1.16±0.06) and CHOP(1.36±0.11) in 20 μg/mL VES group were significantly higher than those in solvent control group GRP78(0.36±0.10) and CHOP(0.48±0.05)(P<0.001). The expression of Beclin-1(1.09±0.20) and LC3-Ⅱ/LC3-Ⅰ(1.29±0.03) in 20 μg/mL VES group were significantly higher than those in solvent control group(0.27±0.07) and LC3-Ⅱ/LC3-Ⅰ(0.43±0.06)(P<0.001). The expression levels of IRE1(1.07±0.20), XBP1(1.33±0.07) and p-JNK/JNK(1.19±0.31) in 20 μg/mL VES group were significantly higher than those in the solvent control group(P<0.01). After IRE1 is inhibited: The expression level of IRE1(0.63±0.27), XBP1(0.74±0.09), p-JNK/JNK(0.35±0.04), GRP78(0.66±0.02), CHOP(0.51±0.02), LC3-Ⅱ/LC3-Ⅰ(0.72±0.01), Beclin-1(0.70±0.15) was significantly lower than that of VES group(P<0.05). VES may participate in the regulation of autophagy in gastric cancer cells by upregulating IRE1 pathway.

Retracted: Inhibition of Proliferation of SGC7901 and BGC823 Human Gastric Cancer Cells by Ursolic Acid Occurs Through a Caspase-Dependent Apoptotic Pathway.

This publication has been retracted by the Editor due to concerns regarding the originality of the figure images. Reference: Jing Zhang, Fengjun Liu, Xin Zhang. Inhibition of Proliferation of SGC7901 and BGC823 Human Gastric Cancer Cells by Ursolic Acid Occurs Through a Caspase-Dependent Apoptotic Pathway. Med Sci Monit, 2019; 25: 6846-6854. DOI: 10.12659/MSM.916740.

Isolation of Peptide Inhibiting SGC-7901 Cell Proliferation from Aspongopus chinensis Dallas.

Aspongopus chinensis Dallas is used as a traditional Chinese medicine as well as an edible insect. Although its anti-tumor effects have been observed, the anti-tumor active component(s) in the hemolymph of A. chinensis remains unknown. In this study, a combination usage of ultrafiltration, gel filtration chromatography, FPLC and RP-HPLC to separate and purify active peptides was performed based on the proliferation of the human gastric cancer SGC-7901 cell line treated with candidates. One peptide (MW = 2853.3 Da) was isolated from the hemolymph of A. chinensis. A total of 24 amino acid residues were continuously determined for the active peptide: N′-ECGYCAEKGIRCDDIHCCTGLKKK-C′. In conclusion, a peptide that can inhibit the proliferation of gastric cancer SGC-7901 cells in the hemolymph of A. chinensis was purified in this study, which is homologous to members of the spider toxin protein family. These results should facilitate further works for this peptide, such as the cloning of genes, expression in vitro by prokaryotic or eukaryotic systems, more specific tests of anti-tumor activity, and so on.

Mechanism of Linderae Radix against gastric cancer based on network pharmacology and in vitro experimental validation

The present study explored the main active ingredients and the underlying mechanism of Linderae Radix the treatment of gastric cancer by network pharmacology, molecular docking, and in vitro cell experiments. TCMSP, OMIM and GeneCards database were used to obtain the active ingredients of Linderae Radix to predict the related targets of both Linderae Radix and gastric cancer. After screening the common potential action targets, the STRING database was used to construct the PPI network for protein interaction of the two common targets. Enrichment analysis of GO and KEGG by DAVID database. Based on STRING and DAVID platform data, Cytoscape software was used to construct an "active ingredient-target" network and an "active ingredient-target-pathway" network. Molecular docking was performed using the AutoDock Vina to predict the binding of the active components to the key action targets, and finally the key targets and pathways were verified in vitro. According to the prediction results, there were 9 active components, 179 related targets of Radix Linderae, 107 common targets of Linderae Radix and gastric cancer, 693 biological processes, 57 cell compositions, and 129 molecular functions involved in the targets, and 161 signaling pathways involved in tumor antigen p53, hypoxia-indu-cible factor 1, etc. Molecular docking results showed that the core component, jimadone, had high binding activity with TP53. Finally, in an in vitro experiment, the screened radix linderae active ingredient gemmadone is used for preliminarily verifying the core targets and pathways of the human gastric cancer cell SGC-7901, The results showed that germacrone could significantly inhibit the proliferation of gastric cancer cells and induce the apoptosis of SGC-7901 by regulating the expression of p53, Bax, Bcl-2 and other key proteins. In summary, Radix Linderae can control the occurrence and development of gastric cancer through multi-components, multi-targets and multi-pathways, which will provide theoretical basis for further clinical discussion on the mechanism of Radix Linderae in treating gastric cancer.

Abstract 5475: DNA methylation regulator cordycepin suppresses gastric and colorectal cancer in combination with chemotherapy

Abstract Gastric cancer and colorectal cancer are the fifth and third most frequent malignant tumors, respectively. One of the most prevalent epigenetic characteristics in gastric and colorectal cancer is aberrant hypermethylation in the promoter of numerous tumor suppressor genes. Hypermethylation of the promoter inactivates tumor suppressor expression and contributes to tumor progression. DNA methyltransferases (DNMTs), which mediate DNA hypermethylation, are putative drug targets of cancer therapy. Several DNMTs inhibitors are under development. 5’-azacytidine and decitabine have been approved for the treatment of AML, myelodysplastic syndrome, and CMML. Clinical trials investigating DNMTs inhibitors in combination with other drugs are ongoing. However, clinical use of 5’-azacytidine and decitabine has been limited due to their toxicity. We have ever demonstrated that cordycepin, a major ingredient of Chinese traditional medicine Cordyceps, has activity of DNMTs inhibition. Treating cancer cells reversed hypermethylation of some tumor suppressor genes promoter, reactivated gene expression, and inhibited cancer cell proliferation. Here, we report the preclinical anti-cancer efficacy of Cordycepin in colorectal and gastric cancers in combination with chemotherapy drugs. In SGC-7901 human gastric cancer cells derived nude mice xenograft tumor model, mice were dosed 20mg/kg Cordycepin alone, 400mg/kg Capecitabine alone, or in combination orally, once daily, for 14 days. Tumor Growth Inhibition rate (TGI) of 89.2% was achieved in the combination therapy group comparing to 57.8% in the 400mg/kg Capecitabine mono-therapy group, and less than 10% in the Cordycepin alone group. Additionally, 20mg/kg Cordycepin plus 3mg/kg fluorouracil achieved TGI of 81.3% after 28 days of treatment in this model, comparing to 67.5% in the 6mg/kg fluorouracil monotherapy group. In HT-29 human colorectal cancer cells derived xenograft model, 20mg/kg Cordycepin plus 250mg/kg Capecitabine orally dosed once daily for 14 days showed TGI of 72.6%, similar to that treated by 400mg/kg Capecitabine alone (80.1%). 20mg/kg Cordycepin plus 2.5mg/kg Tegafur/Gimeracil/Oteracil once daily for 14 days had TGI of 76.7%, while 5mg/kg Tegafur/Gimeracil/Oteracil alone treatment group had TGI of 66.1%. 20mg/kg Cordycepin alone treatment showed only weak inhibition of tumor growth. Synergistic effects of Cordycepin and chemotherapy drugs were observed in treating both tested tumor models. Better tolerance was also shown in the combination therapy groups, as indicated by the mice body weight change. It is demonstrated that the DNMTs regulator Cordycepin has improved the anti-cancer activity and tolerance of chemotherapy drugs, such as Capecitabine, 5-FU, Tegafur/Gimeracil/Oteracil. Clinical development of Cordycepin and chemotherapy combination for cancer patients is strongly supported. Citation Format: Qing Dong, Yangze Cao, Jianyu Liu, Yang Qin. DNA methylation regulator cordycepin suppresses gastric and colorectal cancer in combination with chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5475.

Solasonine induces apoptosis of the SGC-7901 human gastric cancer cell line in vitro via the mitochondria-mediated pathway.

Solasonine, a steroidal glycoalkaloid isolated from the herbal plant Solanum nigrum Linn., has shown active against multiple human cancers; however, there is little knowledge on the activity of solasonine against gastric cancer until now. This study aimed to examine the effect of solasonine on the biological behaviours of human gastric cancer SGC‐7901 cells. The results showed that solasonine suppressed SGC‐7901 cell proliferation in a dose‐dependent manner. Solasonine treatment mainly induced the cell cycle arrest at G2 phase in SGC‐7901 cells. Treatment with solasonine resulted in significant down‐regulation of Bcl‐2 and Caspase‐3 protein expression and reduced Bax and Bcl‐xL protein expression in SGC‐7901 cells. Solasonine shows a comparable inhibitory effect on the proliferation of human gastric cancer SGC‐7901 cells with cisplatin, and solasonine induces of SGC‐7901 cell apoptosis through triggering the endoplasmic reticulum stress pathway and the mitochondrial pathway. Our data indicate that solasonine may be a promising agent for the treatment of gastric cancer.

Targeting Inhibition of Notch1 Signaling Pathway on the Study of Human Gastric Cancer Stem Cells with Chemosensitization.

Background Gastric cancer is the second most frequent cause of cancer death worldwide, although much geographical variation in incidence exists. Prevention and personalized treatment are regarded as the best options to reduce gastric cancer mortality rates (Hartgrink et al., 2009). Numerous studies have suggested that Notch1 and its ligands are overexpressed in gastric cancer, and its knockdown can inhibit the proliferation and survival of gastric cancer cells. Objective To investigate the effect of Notch1 on the stemness and drug sensitivity of human gastric cancer SGC-7901 cells. Methods Highly expressed Notch1 intracellular domain (NICD1) and Notch1-shRNA lentiviral expression vector were used to infect human gastric cancer SGC-7901 cells cultured in vitro, and western blot and immunofluorescence staining were used to identify highly expressed NICD and Notch1 silenced cells. The percentage of CD133+ cells was analyzed by flow cytometry, the expression of nestin and CFAP by immunofluorescence staining, the formation rate of tumor cell spheres and the tumorigenicity of SCID mice in vivo, and the regulation of cell stemness by Notch1. The sensitivity of each group of cells to the chemotherapeutic drugs teniposide (VM-26) and carmustine (BCNU) was also detected by the MTT method. Results The stemness phenotype of tumor cells with the increased NICD expression was enhanced, such as an increased proportion of CD133+ cells, enhanced nestin expression, decreased GFAP expression, increased tumor cell sphere formation rate and tumorigenic rate of SCID mice implantation, and decreased sensitivity to VM-26 and BCNU. In contrast, the stemness phenotype of tumor cells with downregulated Notch1 gene expression was significantly suppressed, while the sensitivity to VM-26 and BCNU was increased. Conclusion High Notch1 expression increased the stemness of SGC-7901 cells and decreased the sensitivity of SGC-7901 cells to chemotherapeutic drugs.

The Inhibitory Effect and Mechanism of Ferula akitschkensis Volatile Oil on Gastric Cancer.

Ferula akitschkensis volatile oil (FAVO) has a good inhibitory activity on gastric cancer cell proliferation, but the mechanism of action is not yet clear. In this study, we tested the antigastric cancer efficacy and mechanism of FAVO using both in vivo and in vitro models. The results showed that FAVO effectively inhibited the proliferation, migration, and invasion of human gastric cancer SGC-7901 cells, the formation of small tubules of human umbilical vein endothelial cells as well as zebrafish intersegmental vessel and intestinal vein angiogenesis. In vivo experiments showed that FAVO significantly delayed the growth of SGC-7901 tumor-bearing nude mice and induced higher serum IL-2 and IFN-γ and reduced serum IL-6. Western blot results showed that FAVO reduced the expression of HIF-2α, VEGF, VEGFR2, P-VEGFR2, Akt, and P-Akt in SGC-7901 cells with CoCl2 induced hypoxia. We further clarified the main chemical components of FAVO through GC-MS analysis. In summary, FAVO may inhibit tumor growth and angiogenesis via inhibiting the HIF-2α/VEGF signaling pathway.

FIP-nha, a fungal immunomodulatory protein from Nectria haematococca, induces apoptosis and autophagy in human gastric cancer cells via blocking the EGFR-mediated STAT3/Akt signaling pathway

FIP-nha, a fungal immunomodulatory protein from Nectria haematococca, has been demonstrated a broad spectrum of antitumor activity and cell selectivity against human cancers in our previous study. However, the effect and mechanism of FIP-nha on gastric cancer remains unclear. In this study, we systematically observed the cytotoxicity, biological effect, regulatory mechanism and interaction target of FIP-nha on human gastric cancer cell lines, AGS and SGC7901. Our results demonstrated that FIP-nha inhibited the growth of AGS and SGC7901 cells in a dose-dependent manner and exerted proapoptotic effects on both cells as confirmed by flow cytometry, DAPI staining and western blot analysis. Additionally, the exposure of AGS and SGC7901 to FIP-nha induced autophagy as indicated by western blot analysis, GFP-LC3 and mCherry-GFP-LC3 transfection and acridine orange staining. Furthermore, we found that FIP-nha decreased the phosphorylation of EGFR, STAT3 and Akt and inhibited activation effect of ligand factor EGF to EGFR and its downstream signal molecule STAT3 and Akt. Finally, we proved that FIP-nha located on the surface of gastric cancer cells and bound directly to the transmembrane protein of EGFR by immunoprecipitation, cellular localization, molecular docking, microscale thermophoresis assay. The above findings indicated that FIP-nha inhibited the growth of gastric cancer and induced apoptosis and autophagy through competitively binding to EGFR with EGF to blocking the EGFR-mediated STAT3/Akt pathway. In summary, our study provided novel insights regarding the activity of FIP-nha against gastric cancer and contributed to the clinical application of FIP-nha as a potential chemotherapy drugs that targeted EGFR for human gastric cancer.

PlexinA1 activation induced by β2-AR promotes epithelial-mesenchymal transition through JAK-STAT3 signaling in human gastric cancer cells.

With the medical model shifting from a single biomedical model to a biopsychological-social model, the impact of psychosocial factors on cancer patients has attracted attention. Studies have shown that chronic stress caused by long-term psychological stress, such as anxiety and depression, can promote the malignant progression of tumors by acting on β2-adrenergic receptor (β2-AR). β2-AR can promote tumor migration by activating epithelial-mesenchymal transition (EMT). However, the underlying mechanisms in the regulation of EMT by β2-AR are still unclear. In this study, we established a chronic stress model by treating MGC-803 and SGC-7901 human gastric cancer cells with isoproterenol (ISO), a β2-AR agonist. EMT in the two gastric cancer cell lines was enhanced after ISO treatment. Thereafter, we found that the interaction between β2-AR and PlexinA1 was involved in the process by which chronic stress affects EMT in both MGC-803 and SGC-7901 cells. Moreover, the activation of β2-AR by ISO increased the expression of PlexinA1, activated JAK-STAT3 signaling and further promoted EMT in human gastric cancer cells. Importantly, the knockdown of PlexinA1 by small hairpin RNAs inhibited JAK-STAT3 signaling and abolished the EMT induced by β2-AR. In conclusion, PlexinA1 was an important downstream target of β2-AR, through which β2-AR promoted EMT in human gastric cancer cells by activating JAK-STAT3 signaling.

Salidroside Induces Apoptosis in Human Gastric Cancer Cells via the Downregulation of ENO1/PKM2/GLUT1 Expression.

Salidroside is reported to have a wide range of pharmacological properties and has been proven to play a key anti-cancer effect. This study investigated the effects of purified salidroside, an ingredient of Rhodiola rosea, on the proliferation of two human gastric cancer cell lines and further investigating its possible molecular mechanisms. We verified that salidroside exerts a dose-dependent inhibitory effect on the proliferation of SGC-7901 and MKN-45 human gastric cancer cells. Moreover, salidroside can induce cell apoptosis, which was accompanied by an increase in nuclear fragmentation. In addition, salidroside inhibited glycolysis, as evidenced by the reduced expression levels of the glycolysis-related enzymes pyruvate kinase isoenzyme M2 (PKM2), enolase 1 (ENO1) and glucose transporter 1 (GLUT1), which could play important roles in the metabolism of gastric cancer cells. Further investigation showed that salidroside exerted potent anti-proliferative effects by inhibiting glycolysis in human gastric cancer cells in vitro. In vivo, xenograft tumors treated with salidroside were significantly smaller than those in the control animals. Therefore, salidroside could be a promising therapeutic prospect in the treatment of gastric cancer.

A Cyclic Peptide Epitope of an Under-Explored VEGF-B Loop 1 Demonstrated In Vivo Anti-Angiogenic and Anti-Tumor Activities

Pathological angiogenesis is mainly initiated by the binding of abnormal expressed vascular endothelial growth factors (VEGFs) to their receptors (VEGFRs). Blocking the VEGF/VEGFR interaction is a clinically proven treatment in cancer. Our previous work by epitope scan had identified cyclic peptides, mimicking the loop 1 of VEGF-A, VEGF-B and placental growth factor (PlGF), inhibited effectively the VEGF/VEGFR interaction in ELISA. We described here the docking study of these peptides on VEGFR1 to identify their binding sites. The cellular anti-angiogenic activities were examined by inhibition of VEGF-A induced cell proliferation, migration and tube formation in human umbilical vein endothelial cells (HUVECs). The ability of these peptides to inhibit MAPK/ERK1/2 signaling pathway was examined as well. On chick embryo chorioallantoic membrane (CAM) model, a cyclic peptide named B-cL1 with most potent in vitro activity showed important in vivo anti-angiogenic effect. Finally, B-cL1 inhibited VEGF induced human gastric cancer SGC-7901 cells proliferation. It showed anti-tumoral effect on SGC-7901 xenografted BALB/c nude mouse model. The cyclic peptides B-cL1 constitutes an anti-angiogenic peptide drug lead for the design of new and more potent VEGFR antagonists in the treatment of angiogenesis related diseases.

Effects of Betulinic acid on apoptosis in human gastric cancer SGC-7901 cells

Objective: To investigate the effects of betulinic acid on apoptosis of human gastric cancer SGC-7901 cells. Methods: The human gastric cancer SGC-7901cells were divided in to 4 groups, and each group was set with 3 replicates. The SGC-7901cells in control group were not treated with betulinic acid; the other 3 experimental groups were treated with betulinic acid at the concentrations of 10, 20 and 30 mg/L, respectively; each group was incubated in a 5% carbon dioxide incubator for 48 h. Laser confocal microscope was used to observe morphological changes of SGC-7901 cells; Flow cytometry was applied to determine apoptosis rate and mitochondrial membrane potential. The mRNA and protein levels of Bcl-2, Bax and Caspase-3 were also detected by qRT-PCR and western blot respectively. Results: Compared with the control group, SGC-7901 cells in the treated group at final concentrations of 10, 20 and 30 mg/L shrinked, appeared apoptosis body along with nuclear splitting. The percentage of cells in early and advanced period of apoptosis were markedly increased (P＜0.05 or P＜0.01), mitochondrial membrane potential was obviously reduced (P＜0.05 or P＜0.01). qRT-PCR and western blot analysis showed that the mRNA and protein expressions of Bax and Caspase-3 were increased significantly (P＜0.01), while the expressions of Bcl-2 were decreased significantly (P＜0.01). Conclusion: Within a certain range of concentrations, betulinic acid induces cell apoptosis by regulating the expression of Bcl-2, Bax and Caspase-3 in human gastric cancer.

High-Throughput Sequencing Reveals the Differential MicroRNA Expression Profiles of Human Gastric Cancer SGC7901 Cell Xenograft Nude Mouse Models Treated with Traditional Chinese Medicine Si Jun Zi Tang Decoction.

Objective. The present study aimed to investigate the potential mechanism underlying the antitumor effect of Si Jun Zi Tang (SJZT) decoction on gastric cancer. Methods. Twelve human gastric cancer SGC7901 cell xenograft nude mouse models were established. The mice were randomly divided into the Model group and SJZT group. SJZT exerted significant antitumor effects after 21 days of decoction administration. High-throughput sequencing was used to analyze the microRNA (miRNA) expression profiles of tumor tissues. Bioinformatics analysis was performed to provide further information regarding the differentially expressed miRNAs. Five representative differentially expressed miRNAs and four predicted target genes were further validated using quantitative real-time reverse transcription PCR (qRT-PCR). Results. We identified 33 miRNAs that were differentially expressed in the SJZT group compared with the Model group. Among them, 32 miRNAs were upregulated and 1 miRNA was downregulated. Bioinformatic analysis showed that most of miRNAs acted as tumor suppressors and their target genes participated in multiple signaling pathways, including the PI3K/Akt signaling pathway, microRNAs in cancer, and Wnt signaling pathway. The qRT-PCR result confirmed that miR-223-3p, miR-205-5p, miR-147b-3p, and miR-223-5p were overexpressed and their respective paired target genes FUT9, POU2F1, MUC4, and RAB14 mRNA were obviously downregulated in the SJZT group compared with those in the Model group. Network analysis revealed that miR-223-3p and miR-205-5p shared two targets POU2F1 (encoding POU class 2 homeobox 1) and FUT9 (encoding fucosyltransferase 9), suggesting they have a common role in certain pathways. Conclusion. This study provided novel insights into the anticancer mechanism of SJZT against gastric cancer, which might be partly related to the modulation of miRNA expression and their target pathways in tumors.

Autophagy induced by H. pylori VacA regulated the survival mechanism of the SGC7901 human gastric cancer cell line

BackgroundVacuolating cytotoxin (VacA) is an important virulence factor of Helicobacter pylori (H. pylori). It was previously believed that VacA can trigger the cascade of apoptosis on mitochondria to lead to cell apoptosis. Recently, it was found that VacA can induce autophagy. However, the molecular mechanism by which VacA induces autophagy is largely unknown.ObjectiveWe aimed to explore the molecular mechanism of autophagy induced by H. pylori in gastric cancer cells and the effect of autophagy on the survival of gastric cancer cells.MethodsThe autophagy of human gastric cancer cell line SGC7901 was detected by Western blot and RT-PCR in the treatment of VacA protein of H. pylori. The relationship between autophagy and reactive oxygen species (ROS) in the proliferation of gastric cancer cells were studied by gene expression silences (siRNA) and CM-H2DCFDA (DCF) staining.ResultsThe results showed that VacA protein secreted by H. pylori in the supernatant stimulated autophagy in SGC7901 cells. After VacA protein treatment, the mRNA expressions of BECN1, ATG7 and PIK3C3, were up-regulated. ATG7 silencing by siRNA inhibited VacA-induced autophagy. Furthermore, our data demonstrated that VacA protein increased ROS levels. Addition of the antioxidant N-acetyl-l-cysteine (NAC) suppressed the levels of ROS, leading to inhibition of autophagy.ConclusionsH. pylori VacA is a key toxin that induces autophagy by increased ROS levels. And our findings demonstrated that VacA significantly inhibited proliferation in SGC7901 cells.