Gastric Adenocarcinoma Cell Line SGC-7901 Research Articles

Transcriptome sequencing identifies prognostic genes involved in gastric adenocarcinoma.

Gastric adenocarcinoma (GAC) is one of the world's most lethal malignant tumors. It has been established that the occurrence and progression of GAC are linked to molecular changes. However, the pathogenesis mechanism of GAC remains unclear. In this study, we sequenced 6 pairs of GAC tumor tissues and adjacent normal tissues and collected GAC gene expression profile data from the TCGA database. Analysis of this data revealed 465 differentially expressed genes (DEGs), of which 246 were upregulated and 219 were downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that DEGs were observably enriched in ECM-receptor interaction, protein digestion and absorption, and gastric acid secretion pathways. Six key genes (MATN3, COL1A1, COL5A2, P4HA3, SERPINE1 and VCAN) associated with poor GAC prognosis were screened from the protein‒protein interaction (PPI) network by survival analysis, and P4HA3 and MATN3 have rarely been reported to be associated with GAC. We further analyzed the function of P4HA3 in the GAC cell line SGC-7901 by RT‒qPCR, MTT, flow cytometry, colony formation, wound healing, Transwell and western blot assays. We found that P4HA3 was upregulated in the SGC-7901 cell line versus normal control cells. The outcomes of the loss-of-function assay illustrated that P4HA3 significantly enhanced the ability of GAC cells to proliferate and migrate. This study provides a new basis for the selection of prognostic markers and therapeutic targets for GAC.

Expression of miR-124 in gastric adenocarcinoma and the effect on proliferation and invasion of gastric adenocarcinoma SCG-7901 cells.

Expression of miR-124 in gastric adenocarcinoma cell line SGC-7901 and its effect on biological functions was investigated. Expression of miR-124 in cancer tissues and paracancerous tissues of gastric adenocarcinoma patients was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR was used to detect the expression of miR-124 in human normal gastric epithelial cells GES-1 and gastric adenocarcinoma SGC-7901 cells. Cells in miR-124 group were transfected with miR-124 agomir, cells in NC group were transfected with agomir-negative control sequence and cells in the control group were not transfected. MTT assay was used to detect cell proliferation, and Transwell invasion assay to detect cell invasion ability, and the effect of transfected miR-124 agonist on the proliferation and invasive ability of gastric adenocarcinoma cells was evaluated. RT-qPCR results showed that miR-124 expression was significantly downregulated in gastric adenocarcinoma tumor tissues compared with paracancerous tissues. Compared with cells of normal human gastric epithelial cell line GES-1, the expression of miR-124 human gastric adenocarcinoma SGC-7901 cells was significantly downregulated. At 12 h, there was no significant difference in OD at 490 nm in the three groups (P>0.05). OD (490) in the three groups showed a gradual upward trend. After transfection, proliferation curves of the three groups showed an upward trend, proliferation rate of miR-124 group was significantly lower than that of NC and control groups (P<0.05). The number of invading cells in miR-124 group was significantly lower than that in NC group and control group, but there was no significant difference in the number of cell invasion between the NC and control groups. miR-124 can inhibit the proliferation and invasion of gastric adenocarcinoma cells. Downregulation of miR-124 expression in gastric adenocarcinoma may be closely related to the development of gastric adenocarcinoma.

The role of propranolol as a radiosensitizer in gastric cancer treatment.

PurposeThe National Comprehensive Cancer Network guidelines indicate that radiotherapy in gastric cancer shows limited effectiveness at reducing the growth of gastric cancer. Therefore, enhancing the sensitivity and effect of radiotherapy with propranolol, a β-adrenoceptor antagonist, could reduce tumor growth. The role of propranolol as a radiosensitizer has not been adequately studied; therefore, the purpose of the present study is to evaluate the effect of propranolol as a radiosensitizer against gastric cancer in vivo.MethodsSixty-four male nude mice bearing tumor xenografts were randomly divided into four groups. Cell culture was performed using the human gastric adenocarcinoma cell line SGC-7901. Mice with tumor xenografts were treated with propranolol, isoproterenol, and radiation. The data for tumor weight and volume were obtained for statistical analyses. Furthermore, the expression levels of COX-2, NF-κB, VEGF, and EGFR were examined using immunohistochemical techniques and Western blotting.ResultsThe growth in the volume and weight of the tumor was lower in mouse models treated with propranolol and radiation therapy compared to the other groups. Decreased expression of NF-κB was also observed in treatment groups where both propranolol and radiation were used, leading to the reduction of COX-2, EGFR, and VEGF expression compared to that in the other groups.ConclusionThe present study indicated that propranolol potentiates the antitumor effects of radiotherapy in gastric cancer by inhibiting NF-κB expression and its downstream genes: VEGF, EGFR, and COX-2.

Endocan reduces the malign grade of gastric cancer cells by regulating associated protein expression.

Endocan, which has been identified to be low expressed in gastric cancer, was found to be positively related to the differentiation level of gastric cancer in vivo and in vitro. In the present study, we aimed to investigate the role of endocan in gastric adenocarcinoma cell line SGC7901 by artificially upregualting or downregulating endocan expression using endocan recombinant vector or specific small interfering RNA (siRNA)-targeting endocan gene, respectively. The effects of endocan recombinant vector-mediated over-expressing and siRNA-mediated endocan silencing on the differentiation, migration, and apoptosis of SGC7901 cells were assessed. Furthermore, the primary molecular mechanisms of endocan were explored by testing the expression alterations of associated protein in SGC7901 along endocan over-expression or knockdown. We found that over-expression of endocan reduced the migration but promoted the differentiation and apoptosis of SGC7901 cells. While, knockdown of endocan did just the opposite. Some molecules were found to participate in endocan-mediated anti-tumor effects, such as p53, caspase 3, and MMP-9. In conclusion, our findings suggest that endocan plays an anti-carcinogenic role in gastric cancer development and progression and might serve as a prognostic biomarker as well as a potential therapeutic target for gastric cancer.

Genetically engineered Newcastle disease virus expressing human interferon-λ1 induces apoptosis in gastric adenocarcinoma cells and modulates the Th1/Th2 immune response.

Interferon-λ1 (IFN-λ1), a recently discovered cytokine of the typeIII IFN family, was found to be a therapeutic alternative to typeI IFN in terms of tumors. Using reverse genetics technique, we generated a recombinant Newcastle disease virus (NDV) LaSota strains named as human IFN‑λ1 recombinant adenovirus (rL-hIFN-λ1) containing human IFN-λ1 gene and further evaluated the expressing of IFN-λ1 in human gastric adenocarcinoma cell line SGC-7901 after infected with rL-hIFN-λ1 by using western blot analysis, RT-PCR and immunofluorescence analyses. IFN-λl specific receptor IFNLR1 was detected on several gastric tumor cell lines including SGC-7901 and AGS and on PBMCs.The expression of the IFN-λ1 proteins reached a high level detected in the supernatant harvested 24h after the infection of tumor cells. The proliferation changes of SGC infected with rL-hIFN-λ1 was significantly inhibited compared with NDV-infected group. Apoptosis was significantly induced by rL-hIFN-λ1 in gastric cancer cells compared with NDV virus tested by TUNEL assay, western blot analysis and AnnexinV flow cytometry. Due to the high dose of IFN-λ1 expressed by the rL-hIFN-λ1-infected tumor cells, the immune study showed that rL-hIFN-λ1 increased IFN-γ production [the Thelper cell subtype1 (Th1) response] and inhibited interleukin(IL)-13 production [the Thelper cell subtype2 (Th2) response] to change the Th1/Th2 response of tumor microenvironment which inhibited tumor growth. This study aims at building recombinant NDV rL-hIFN-λ1 as an efficient antitumor agent.

Recombinant adenovirus expressing hIFN-λ1 inhibits gastric adenocarcinoma cell line SGC-7901 proliferation.

The aim of the present study is to investigate the effect of a recombinant plasmid adenovirus (pAd) expressing human interferon-λ1 (hIFN-λ1) on the proliferation of the gastric adenocarcinoma cell line SGC-7901. For this purpose, human gastric adenocarcinoma SGC-7901 cells were infected with recombinant pAd-hIFN-λ1, pAd-LacZ and phosphate-buffered saline (PBS), respectively, and the subsequent effects on the proliferation of the infected cells were compared. Cell proliferation was evaluated by MTT assay, while mRNA and protein expression of hIFN-λ1 were detected by reverse transcription-polymerase chain reaction analysis and immunofluorescence assay, respectively. In addition, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay and flow cytometry were conducted to analyze the rate of cell apoptosis. The results indicated that the proliferation of gastric adenocarcinoma SGC-7901 cells was significantly inhibited by pAd-hIFN-λ1. Furthermore, the apoptosis rate and the mRNA and protein expression levels of hIFN-λ1 were higher in pAd-hIFN-λ1-transfected cells, compared with the pAd-LacZ and PBS control groups. In conclusion, recombinant pAd-hIFN-λ1 induced the expression of hIFN-λ1 in gastric adenocarcinoma SGC-7901 cells, and significantly inhibited cell proliferation by promoting apoptosis in these cancer cells.

Expressions of putative cancer stem cell markers ABCB1, ABCG2, and CD133 are correlated with the degree of differentiation of gastric cancer

The present study was carried out to determine whether a quantitative relationship exists between the expressions of 3 cancer stem cell (CSC) markers and the degree of differentiation of gastric cancer. The expressions of 3 putative CSC markers, ABCB1, ABCG2, and CD133, were detected in 90 human gastric adenocarcinoma cases by immunofluorescence assay. The differentiation statuses of 3 gastric cancer cell lines (the undifferentiated gastric cancer cell line HGC-27, the poorly differentiated gastric cancer cell line BGC-823, and the moderately-poorly differentiated gastric adenocarcinoma cell line SGC-7901) were observed and compared by performing the 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. Gastric xenotransplant cancers in nude mice were constructed to compare the malignancy of the 3 variously differentiated gastric cancer cell lines. The expressions of the 3 putative CSC markers were also detected in the 3 gastric cancer cell lines in vitro by flow cytometric analysis and in the 3 gastric xenotransplant cancers in vivo by immunofluorescence staining. The expressions of ABCB1, ABCG2, and CD133 were generally correlated with the degree of differentiation of the gastric cancers. In the human gastric adenocarcinomas and in the cancer cell lines, the expressions of ABCB1, ABCG2, and CD133 increased with the increases in the malignancy grades of the gastric cancers. In the human gastric adenocarcinomas, poorly differentiated adenocarcinoma expressed more ABCB1, ABCG2, and CD133 than well-differentiated adenocarcinoma. In addition, the expressions of ABCB1 and CD133 were higher in the diffuse type than in the intestinal type of human gastric cancers. The undifferentiated cell line HGC-27 expressed more putative CSC markers than the moderately-poorly differentiated cell line SGC-7901. Similar results were observed in the xenotransplant tumors that arose from the 3 gastric cancer cell lines. The expressions of the CSC markers ABCB1, ABCG2, and CD133 differed in the gastric cancers with various degrees of differentiation, with poorly differentiated gastric cancer expressing relatively more CSC markers.

Induction of cell differentiation and promotion of endocan gene expression in stomach cancer by melatonin

The pineal hormone melatonin has been shown to have anticancer therapeutic properties in patients with gastric cancer, the mechanisms, however, remain largely unknown. The present study examined the effects of melatonin on cell differentiation related factors, namely, endocan, alkaline phosphatase, and lactate dehydrogenase, in gastric adenocarcinoma cell line SGC7901. Expression of endocan was significantly decreased in tissue of gastric cancer as compared to normal stomach tissue, as determined by immunohistochemical staining, and there is correlation between the degree of the decrease of endocan expression and the degree of differentiation of the cancer. Treatment of cultured gastric adenocarcinoma cells with 10(-4) mol/l melatonin significantly increased the gene expression of endocan and down-regulated the activity of alkaline phosphatase and lactate dehydrogenase, two enzymes that promote de-differentiation in gastric tissue; and there was a negative correlation between the level of endocan expression and the activities of differentiation marker enzymes in the melatonin treated cancer cells. Gastric cancer cells treated with melatonin show more differentiated morphologic phenotype as compared the untreated cells. The findings indicate that melatonin may play its anticancer role in gastric adenocarcinoma by acting as a differentiation inducer.

Effect of RNA interference targeting HIF-1α gene on biological behavior of human esophageal squamous cell carcinoma and gastric adenocarcinoma cells in vitro

To investigate the effect of hypoxia inducible factor-1α (HIF-1α) on the proliferation, migration and vasculogenic mimicry(VM) in human esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 in vitro. The recombinant plasmid pGCsi-shHIF-1α was transfected into Eca-109 and SGC-7901 cells by Lipofectamine(TM) 2000. The inhibitory effect of HIF-1α was measured at protein level by Western blot under normoxia and hypoxia. The cell proliferation was detected by colony formation and MTT assays. The migration of transfected cells was assayed using Transwell chambers. Whether Eca-109 and SGC-7901 cells could form the capillary tube-like structures (TLSs) was observed by 3-dimensional culture, and the tube formation of transfected cells was detected by tube-like structure formation assay. The expression of HIF-1α protein in each group of transfected cells was significantly suppressed under normoxia and hypoxia (Eca-109: 0.00, 0.74 ± 0.05; 0.00, 1.11 ± 0.06; SGC-7901: 0.00, 0.60 ± 0.05; 0.00, 0.96 ± 0.07, P < 0.01). Colony formation and MTT assays showed that the cell proliferation of the pGCsi-shHIF-1α transfected cells was slower than that of the control groups (104.7 ± 9.6, 151.7 ± 4.5; 88.3 ± 5.1, 128.3 ± 6.7, P < 0.05). The migration of the recombinant plasmid-transfected cells was significantly suppressed compared with that of cells transfected with empty vector (55.5 ± 11.2, 121.9 ± 17.3; 64.7 ± 10.8, 132.3 ± 16.0, P < 0.01). Both the Eca-109 and SGC-7901 cells could form TLSs when cultured on matrigel, and the number of tubules was significantly increased under hypoxia (30.8 ± 3.9, 34.3 ± 3.4; 26.2 ± 3.4, 30.1 ± 4.1, P < 0.05), the tubule-forming ability of transfected groups was significantly inhibited under normoxia and hypoxia (Eca-109: 3.7 ± 2.8, 30.8 ± 3.9; 3.9 ± 2.7, 34.3 ± 3.4; SGC-7901: 4.9 ± 3.5, 26.2 ± 3.4; 5.3 ± 3.6, 30.1 ± 4.1, P < 0.01). Both the esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 are capable of forming vasculogenic mimicry structures in vitro. The recombinant plasmid pGCsi-shHIF-1α can efficiently suppress their proliferation, migration and vasculogenic mimicry formation.

A study of the single SGC7901 and GES1 cell using synchrotron infrared microspectroscopy and imaging

In order to obtain unique information of the single gastric cancer cell and investigate gastric cancer further at the cellular and subcellular level, synchrotron infrared (SR-IR) microspectroscopy and imaging was used to study human gastric adenocarcinoma cell line SGC7901 and normal gastric mucosal epithelial cell line GES1. When we compared the infrared micro-spectra of the SGC7901 cells with those of the GES1 cells, the peak height ratios of 1121 cm −1/1020 cm −1 (RNA/DNA) of the SGC7901 cells were significantly higher than those of the GES1 cells, which might be useful for distinguishing malignant cells from normal cells. Furthermore, chemical imaging reveals that the amide II/the amide I ratio of the SGC7901 cell is lower than that of the GES1 cell in the most intense absorption region of v as PO 2 - . The result indicates the study of the single gastric cancer cell at subcellular level by synchrotron infrared microspectroscopy and imaging can provide more detailed information which is very helpful for the research and diagnosis of gastric cancer.

Effect of insulin on the differential expression of VLDL receptor isoforms of SGC7901 cell and its biological implication

This study examined the effect of insulin on the expression of very low density lipoprotein receptor (VLDLR) subtypes of SGC7901 cells and discussed its biological implication. In vitro, moderately or poorly-differentiated human gastric adenocarcinoma cell line SGC7901 was incubated with insulin for different lengths of time, and then the expression of protein and RNA level in VLDLR subtypes were detected by Western blotting and real-time PCR, respectively. The results showed that, at certain time interval, insulin could down-regulate expression of type I VLDLR and up-regulate the expression of type II VLDLR in SGC7901 cells, at both protein and RNA level. We are led to conclude that insulin serves as a regulator in maintaining the balance between glucose and lipid metabolism in vivo, possibly through its effect on the differential expression of VLDLR subtypes.

Pretreatment with proton pump inhibitor increases sensitivity of human gastric adenocarcinoma cell line to antitumor drugs

Objective To investigate whether pantoprazole (PPZ), a proton pump inhibitor,could reverse the transmember pH gradient by inhibiting vacuolar H+-ATPase so as to increase the sensitivity of human gastric adenocarcinoma cell line SGC7901 to antitumor drugs and to evaluate the optimal time of drug administration, dosage of PPZ and the possible mechanism. Methods Western blotting and immunofluorescent staining were used to determine the expression and intracellular distribution of vacuolar H+-ATPase in human gastric adenocarcinoma cell line SGC7901 with or without PPZ pretreatment. 2', 7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM) fluorescent probe was used to measure the intracellular pH value of human gastric adenocarcinoma cell line SGC7901 which pretreated with different dose and time of PPI. Methyl thiazolyl tetrazolium (MTT) assay and annexin V-fluorescent isothiocyanate-propidium iodide double staining were performed to evaluate the cytotoxic effects and apoptosis of cells treated with antitumor drugs combined with PPZ. Adriamycin (ADR) was used as probe to estimate drug accumulation and retention with PPZ pretreatment. Results After 24 hours, the expression of vacuolar H+-ATPase in cells pretreated with PPZ of 10 μg/ml (1.19±0.03) or 100 μg/ml (0. 70±0.03) was significantly lower than that in blank control (1.53±0. 05), but this expression was increased by pretreatment with PPZ of 1 μg/ml (2.29 +0.06, P<0.05). The inhibitory effects of PPZ (10 μg/ml) on vacuolar H+-ATPase was observed at 6 hours (0.32±0.02)and 12 hours (0. 13±0.02). And it could alter the intracellular distribution of vacuolar H+-ATPase at 24-hours. The intracellular pH value in cells pretreated with PPZ of 10 μg/ml (7.44±0. 09 ) or 100 μg/ml (7.31 ± 0. 06) was significantly decreased in comparison with untreated cells (7.51±0.05, P< 0. 01). After administration of anti-tumor drugs, the viability in SGC7901 cells pretreated with PPZ for 24 hours (58.71%±1.18 %) was significantly lower than that in cells untreated with PPZ (74. 33% ± 1.77%, P<0.05), while thetotal and early apoptotic rates in former cells(80.81% ±1. 16% and 77.52 %±1.13 %, respectively) were significantly higher than those in later cells (26. 42%±1.19% and 23. 18% ±0.92%,respectively,P < 0. 01). And the ADR releasing index in cells treated with PPZ (20, 50 and 100 μg/ml) for 24 hours was obviously lower than that in the blank control (0. 164±0. 013, 0. 162±0.015, 0. 152±0. 012 vs 0. 277±0. 011, respectively, P<0. 01). Conclusion The sensitivity of human gastric adenocarcinoma cell line to antitumor drugs may be increased by pretreatment with PPZ. Key words: Vacuolar proton-translocationg ATPases; Pantoprazole; Antineoplastic agents

Etoposide Induces Mitochondria-Associated Apoptotic Cell Death in Human Gastric Carcinoma Cells

Recent observations indicate that the resistance of apoptosis is an important process of tumor metastasis and metastases are the cause of 90% of human cancer death. Etoposide, a semisynthetic derivative of the podophyllotoxins, is a clinically used anti-cancer reagent, but the effects of it on metastatic gastric carcinoma cells are totally unknown. In this study, etoposide induced apoptotic cell death in human gastric adenocarcinoma cell line SGC-7901, derived from metastatic lymph nodes, as evidenced by the analysis of DNA fragmentation, apoptotic body formation, caspase activation, and apoptosis specific changes in cell morphology is demonstrated. The depolarization of mitochondrial membrane and the release of cytochrome c were most early events in etoposide treated SGC-7901 cells, and were followed by caspase-3 activation and PARP cleavage. Caspase-8 activation was not detected under the same condition. Thus, it was proposed that etoposide induces caspase-associated apoptotic cell death in human metastatic gastric carcinoma, which is initiated by mitochondrial cytochrome c release.

Effects of Wei Chang An on expression of multiple genes in human gastric cancer grafted onto nude mice

To investigate the expression of multiple genes in Chinese jianpi herbal recipe Wei Chang An (WCA) in human gastric cancer cell line SGC-7901. A human gastric adenocarcinoma cell line SGC-7901 grafted onto nude mice was used as the animal model. The mice were randomly divided into 3 groups, one control and the two representing experimental conditions. Animals in the two experimental groups received either WCA over a 34-d period or 5-fluorouracil (5-FU) over 6-d period starting at 8th d after grafting. Control animals received saline on an identical schedule. Animals were killed 41 d after being grafted. The expression profiles in paired WCA treated gastric cancer samples and the N.S. control samples were studied by using a cDNA array representing 14181 cDNA clusters. The alterations in gene expression levels were confirmed by Real-time Quantitative polymerase chain reaction (qPCR). When compared with controls, the average tumor inhibitory rate in WCA group was 44.32% +/- 5.67% and 5-FU 47.04% +/- 11.33% (P < 0.01, respectively). The average labeling index (LI) for PCNA in WCA group and 5-FU group was significantly decreased compared with the control group. Apoptotic index (AI) was significantly increased to 9.72% +/- 4.51% using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method in WCA group compared with the controls 2.45% +/- 1.37%. 5-FU group was also found to have a significantly increased AI compared with the controls. The expression of cleaved Caspase-3 in WCA group and 5-FU group was significantly increased compared with the control group respectively. There were 45 different expressed sequence tags (ESTs) among the control sample pool and WCA sample pool. There were 24 ESTs up-regulated in WCA samples and 21 ESTs down-regulated. By using qPCR, the expression level of Stat3, rap2 interacting protein x (RIPX), regulator of differentiation 1 (ROD1) and Bcl-2 was lower in WCA group than that in control group respectively. By using SP immunohistochemical method the expression of Phospho-Stat3 (Tyr705) and Bcl-2 in WCA group and 5-FU group was significantly decreased compared with the control group respectively. WCA could inhibit gastric cancer cell SGC-7901 growth in vivo. WCA could induce gastric cancer cell apoptosis and suppress proliferation. Its mechanisms might be involved in the down-regulation of Stat3, RIPX, ROD1 and Bcl-2 gene.

Screening and identification of vascular-endothelial-cell-specific binding peptide in gastric cancer

Antiangiogenesis therapy has become a hot field in cancer research. Blood vessels of tumor carry specific markers that are usually related to angiogenesis. Study of these heterogeneous molecules in different tumor vessels may be beneficial for promoting antiangiogenic therapy. In this study, we established an in vitro co-culture model of human umbilical vein endothelial cells (HUVECs) and gastric adenocarcinoma cell line SGC7901, screened the peptides binding specifically to the HUVECs co-cultured with gastric cancer cells (Co-HUVECs) using phage display peptides library, and studied the affinity of these peptides to gastric cancer vascular endothelial cells. After four rounds of panning, there was an obvious enrichment for the phages specifically binding to the Co-HUVECs, and the output/input ratio of Co-HUVECs increased about 590-fold (from 0.95x10(-7) to 561.25x10(-7)). Five phage clones (M6, M3, M9, IN12, IN11), which could strongly bind to Co-HUVECs instead of wild-type HUVECs, were characterized by ELISA. In vitro cellular binding assay showed that phage IN11 preferably bound to Co-HUVECs rather than control HUVECs, and the number of the phage IN11 recovered from Co-HUVECs was 5.7- and 16.9-folds, respectively, as much as those from control HUVECs and GES cells. Immunocytochemical and immunohistochemical staining confirmed that phage IN11 could specifically bind to Co-HUVECs as well as vascular endothelial cells in gastric cancer tissue sections. Competitive and inhibitory assay revealed the synthetic peptide GEBP11 (CTKNSYLMC) displayed on phage IN11 could competitively inhibit binding of the phage IN11 to Co-HUVECs. Immunofluorescence microscopy showed that the fluorescence-labeled peptide GEBP11 was located at the membrane and perinuclear cytoplasm of Co-HUVECs. Meanwhile, GEBP11 was found to be able to target the gastric cancer vascular endothelial cells. Therefore, GEBP11 may be a potential candidate for targeted drug delivery in antivascular therapy and diagnosis of gastric cancer.

Synergistic effects of matrine and 5‐fluorouracil on tumor growth of the implanted gastric cancer in nude mice

To investigate the inhibitive effects of matrine and 5-fluorouracil (5-FU) on the growth of human gastric adenocarcinoma cell line SGC-7901 when transplanted into nude mice and to investigate the bone marrow toxicity of these compounds. 50 mg/kg and 100 mg/kg matrine with 50 mg/kg 5-FU, and 50 mg/kg matrine only, 50 mg/kg 5-FU only were intraperitoneally injected to observe their inhibitive effects by calculating the relative tumor volume (RTV) and tumor inhibition rates (IR%) as shown by the number of nucleated cells and bone marrow cell colony culture. The tumor inhibitive effect of the combined 100 mg/kg matrine and 50 mg/kg 5-FU group was stronger than that of the combined 50 mg/kg matrine and 50 mg/kg 5-FU groups (P < 0.05), and were also much stronger than that of the control group (50 mg/kg matrine only, 50 mg/kg 5-FU only, P < 0.01). As for the bone marrow inhibition effect, there was no significant statistical difference between the combination group and 5-FU alone group. In the cultured bone marrow cell colony, exuberant growth was seen in the combination group, but not in the control group. The inhibitive effect of combined matrine and 5-FU on the growth of transplanted human gastric cancer in nude mice is superior to that of matrine or 5-FU alone. Combined matrine and 5-FU can increase the inhibitive effect on proliferative hemopoietic bone marrow cells in nude mice and does not affect the resting bone marrow stem cells.

Effects of mifepristone on proliferation of human gastric adenocarcinoma cell line SGC-7901 in vitro.

To explore the effects of mifepristone, a progesterone receptor (PR) antagonist, on the proliferation of human gastric adenocarcinoma cell line SGC-7 901 in vitro and the possible mechanisms involved. In situ hybridization was used to detect the expression of PR mRNA in SGC-7901 cells. After treatment with various concentrations of mifepristone (2.5, 5, 10, 20 micromol/L) at various time intervals, the ultrastructural changes, cell proliferation, cell-cycle phase distribution, and the expression of caspase-3 and Bcl-XL were analyzed using transmission electron microscopy (TEM), tetrazolium blue(MTT) assay, 3H-TdR incorporation, flow cytometry, and reverse transcription-polymerase chain reaction (RT-PCR). Mifepristone markedly induced apoptosis and inhibited cell proliferation of PR- positive SGC-7901 cells revealed by TEM, MTT assay and 3H-TdR incorporation, in a dose- and time-dependent manner. The inhibitory rate was increased from 8.98% to 51.29%. Flow cytometric analysis showed mifepristone dose-dependently decreased cells in S and G2/M phases, increased cells in G0/G1 phase, reduced the proliferative index from 57.75% to 22.83%. In addition, mifepristone up-regulated the expression of caspase-3, and down- regulated the Bcl-XL expression, dose-dependently. Mifepristone effectively inhibited the proliferation of PR-positive human gastric adenocarcinoma cell line SGC-7901 in vitro through multiple mechanisms, and may be a beneficial agent against human adenocarcinoma.

Apoptosis of human gastric adenocarcinoma cells induced by beta-ionone.

To investigate the effect of beta-ionone on the growth and apoptosis of gastric adenocarcinoma cell line SGC-7901. Using MTT, fluorescence dye (Hoechst-33258), transmission electron microscopy and the TUNEL assay, we examined growth and apoptosis of SGC-7901 cells treated with beta-ionone at various concentrations (i.e. 25, 50, 100 and 200 micromol/L) for 24 h, 48 h. The growth of SGC-7901 cells was inhibited by beta-ionone. Seven days after treatment with beta-ionone at four concentrations, the inhibition rates were 12.04%, 30.59%, 78.25% and 94.15%, respectively. The IC(50) value of beta-ionone for SGC-7901 cells was estimated to be 89 micromol/L. The apoptotic morphology was demonstrated in SGC-7901 cells treated with beta-ionone by Hoechst-33258 staining and electron microscopy. Apoptosis was also shown in beta-ionone-treated SGC-7901 cells by the TUNEL assay. beta-ionone can inhibit cell proliferation and induce apoptosis of SGC-7901 cells. However, the mechanism needs to be further investigated.

Inhibition of beta-ionone on SGC-7901 cell proliferation and upregulation of metalloproteinases-1 and -2 expression.

To observe the effect of beta-ionone on the proliferation of human gastric adenocarcinoma cell line SGC-7901 and the inhibition of metalloproteinase. Using growth inhibition, Zymograms assays and reverse transcription-polymerase-chain reaction (RT-PCR), we examined cell growth rates, activities of matrix metalloproteinases-2 (MMP-2) and -9 (MMP-9), and expression of metalloproteinases-1 (TIMP-1) and -2 (TIMP-2) in SGC-7901 cells after the treatment with beta-ionone for 24 h and 48 h, respectively. beta-ionone had an inhibitory effect on the growth of SGC-7901 cells. Eight days after the treatment with beta-ionone at concentrations of 25, 50, 100 and 200 micromol/L, the inhibition rates were 25.9%, 28.2%, 74.4% and 90.1%, respectively. The IC50 value of beta-ionone for SGC-7901 cells was estimated to be 89 micromol/L. The effects of beta-ionone on MMP-2 and MMP-9 activities in SGC-7901 cells were not observed. However, the levels of TIMP-1 and TIMP-2 transcripts were elevated in cells treated with beta-ionone in a dose-dependent manner. beta-ionone can inhibit the proliferation of SGC-7901 cells, upregulate the expression of TIMP-1 and TIMP-2 expression, and may influence metastasis of cancer.

Effect of heparanase antisense oligodeoxynucleotide on expressions of Fas and FasL in human gastricadenocarcinoma cell line SGC7901

Effect of heparanase antisense oligodeoxynucleotide on expressions of Fas and FasL in human gastricadenocarcinoma cell line SGC7901