Growth Of MGC-803 Cells Research Articles

Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer.

ObjectiveHuman induced pluripotent stem (iPS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human iPS cells labeled with fluorescent magnetic nanoparticles (FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo.MethodsHuman iPS cells were prepared and cultured for 72 h. The culture medium was collected, and then was co-incubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human iPS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly.ResultsiPS cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iPS cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field.ConclusionFMNP-labeled human iPS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.

Variant RONΔ160 of the RON receptor tyrosine kinase promotes the growth and invasion in vitro and in vivo in gastric cancer cell lines.

BackgroundRecepteur d’origine nantais (RON) is a receptor tyrosine kinase whose overexpression has been observed in human gastric cancers. This study aimed to determine whether overexpression of the variant RONΔ160 could induce tumorigenicity of gastric cancer cells in vitro or in vivo, and whether its specific small molecule inhibitor (Compound I) could inhibit the effect of RONΔ160.MethodsWe constructed human gastric cancer cell line MGC-803 that was stably transfected with a recombinant plasmid expressing RONΔ160, and the effect of RONΔ160 overexpression and macrophage-stimulating protein (MSP) activation on proliferation, migration and invasion abilities of MGC-803 cells were evaluated. Tumor-bearing mice with gastric cancer cells were used to analyze the effects of RONΔ160 overexpression and Compound I on implanted tumor growth.ResultsIn vitro, overexpression of RONΔ160 in MGC-803 cells resulted changes to their cell morphology, and promoted cell proliferation, migration and invasion. In addition, overexpression of RONΔ160 increased the proportion of cells in the S phase. The effect of RONΔ160 was significantly enhanced by induction of MSP inducing (p < 0.05). In vivo, RONΔ160 promoted the growth of MGC-803 cells in nude mice, including increased tumor size and weight, and lower tumor incubation period. The Compound I inhibited the tumorigenic abilities of RONΔ160 (p <0.05).ConclusionsThe results indicate that overexpression of the variant RONΔ160 altered the phenotype and tumorigenicity of MGC-803 cells. Its specific small molecule inhibitor could inhibit the effect of RONΔ160. Therefore, the variant RONΔ160 may become a potential therapeutic target for gastric cancer.

Synthesis of novel amino acid derivatives containing chrysin as anti-tumor agents against human gastric carcinoma MGC-803 cells

Two series of amino acid derivatives containing chrysin were prepared from 7-O-carboxymethyl chrysin (4a) and 7-O-carboxypropyl chrysin (4b) and amino acid methyl esters by treatment with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxybenzotriazole as coupling reagents. The anti-proliferative activities of these derivatives in vitro against human gastric carcinoma MGC-803 cells were evaluated by the standard MTT method. The results showed that among these derivatives tested, compound N-[4-(5-hydroxy-4-oxo-2-phenyl-4H-chromen-7-yloxy)butyryl]-l-isoleucine methyl ester (7c) exhibited the most potent inhibitory activity against the growth of MGC-803 cells with IC50 value of 3.78 μmol/L, comparable to the positive control cisplatin. The preliminary apoptotic mechanism of compound 7c was also investigated by flow cytometry (FCM) and Western blot analysis. Results form the FCM assay demonstrated that compound 7c could induce the apoptosis of MGC-803 cells in a dose-dependent manner. And further Western blot assay indicated that 7c could induce the apoptosis through increasing protein expression of Bax and decreasing protein expression of Bcl-xl. In summary, these results suggest that compound 7c may serve as an effective chemotherapeutic candidate.

Silibinin inhibits proliferation, induces apoptosis and causes cell cycle arrest in human gastric cancer MGC803 cells via STAT3 pathway inhibition.

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

A multifunctional ribonuclease A-conjugated carbon dot cluster nanosystem for synchronous cancer imaging and therapy.

Carbon dots exhibit great potential in applications such as molecular imaging and in vivo molecular tracking. However, how to enhance fluorescence intensity of carbon dots has become a great challenge. Herein, we report for the first time a new strategy to synthesize fluorescent carbon dots (C-dots) with high quantum yields by using ribonuclease A (RNase A) as a biomolecular templating agent under microwave irradiation. The synthesized RNase A-conjugated carbon dots (RNase A@C-dots) exhibited quantum yields of 24.20%. The fluorescent color of the RNase A@C-dots can easily be adjusted by varying the microwave reaction time and microwave power. Moreover, the emission wavelength and intensity of RNase A@C-dots displayed a marked excitation wavelength-dependent character. As the excitation wavelength alters from 300 to 500 nm, the photoluminescence (PL) peak exhibits gradually redshifts from 450 to 550 nm, and the intensity reaches its maximum at an excitation wavelength of 380 nm. Its Stokes shift is about 80 nm. Notably, the PL intensity is gradually decreasing as the pH increases, almost linearly dependent, and it reaches the maximum at a pH = 2 condition; the emission peaks also show clearly a redshift, which may be caused by the high activity and perfective dispersion of RNase A in a lower pH solution. In high pH solution, RNase A tends to form RNase A warped carbon dot nanoclusters. Cell imaging confirmed that the RNase A@C-dots could enter into the cytoplasm through cell endocytosis. 3D confocal imaging and transmission electron microscopy observation confirmed partial RNase A@C-dots located inside the nucleus. MTT and real-time cell electronic sensing (RT-CES) analysis showed that the RNase A@C-dots could effectively inhibit the growth of MGC-803 cells. Intra-tumor injection test of RNase A@C-dots showed that RNase A@C-dots could be used for imaging in vivo gastric cancer cells. In conclusion, the as-prepared RNase A@C-dots are suitable for simultaneous therapy and in vivo fluorescence imaging of nude mice loaded with gastric cancer or other tumors.

Synergistic inhibitory effect of berberine and d-limonene on human gastric carcinoma cell line MGC803.

This study aims at evaluating the anticancer effects of berberine hydrochloride (berberine) and d-limonene, alone and in combination, on human gastric carcinoma cell line MGC803 to determine whether berberine and d-limonene work synergistically and elucidate their mechanisms. MGC803 cells were treated with berberine and d-limonene, alone and in combination, for 24-48 h. The inhibitory effects of these drugs on growth were determined by MTT assay. The combination index and drug reduction index were calculated with the Chou-Talalay method based on the median-effect principle. Flow cytometry and laser scanning confocal microscopy were employed to evaluate the effects of both drugs on cell-cycle perturbation and apoptosis, generation of reactive oxygen species (ROS), mitochondrial membrane potential, and expression of Bcl-2 and caspase-3 in MGC803 cells. Berberine or d-limonene alone can inhibit the growth of MGC803 cells in a dose- and time-dependent manner. Berberine and d-limonene at a combination ratio of 1:4 exhibited a synergistic effect on anti-MGC803 cells. The two drugs distinctly induced intracellular ROS generation, reduced the mitochondrial transmembrane potential (ΔΨm), enhanced the expression of caspase-3, and decreased the expression of Bcl-2. The combination of berberine and d-limonene showed more remarkable effects compared with drugs used singly in MGC803 cells. The combination of berberine and d-limonene exerted synergistic anticancer effects on MGC803 cells by cell-cycle arrest, ROS production, and apoptosis induction through the mitochondria-mediated intrinsic pathway.

Discovery and antitumor activities of constituents from Cyrtomium fortumei(J.) Smith rhizomes

BackgroundCyrtomium fortumei (J.) Smith is an important Chinese herbal medicine because of its biological functions. However, systematic and comprehensive studies on the phytochemicals from Cyrtomium fortumei (J.) Smith and their bioactivity are limited.ResultsUsing the bioassay-guided technique, the ethyl acetate and n-BuOH extracts of the rhizomes of Cyrtomium fortumei (J.) Smith were shown to exhibit good antitumor activities, consequently leading to the isolation of 23 compounds. All compounds were isolated from the plant for the first time. The inhibitory activities of these compounds were investigated on tumor cells MGC-803, PC3, and A375 in vitro by MTT (thiazolyl blue tetrazolium bromide) assay, and the results showed that pimpinellin (3) had potent cytotoxic activities against the three cell lines, with the IC50 values of 14.4 ± 0.3 μM, 20.4 ± 0.5 μM, and 29.2 ± 0.6 μM, respectively. The mechanism of the antitumor action indicated that pimpinellin inhibited the growth of MGC-803 cells via the induction of tumor cell apoptosis, with apoptosis ratio of 27.44% after 72 h of treatment at 20 μM.ConclusionsThis study suggests that most of the compounds from the roots of Cyrtomium fortumei (J.) Smith could inhibit the growth of human carcinoma cells. Moreover, pimpinellin inhibited the growth of tumor cells via the induction of tumor cell apoptosis.

Antiproliferative and cell apoptosis-inducing activities of compounds from Buddleja davidii in Mgc-803 cells

BackgroundBuddleja davidii is widely distributed in the southwestern region of China. We have undertaken a systematic analysis of B. davidii as a Chinese traditional medicine with anticancer activity by isolating natural products for their activity against the human gastric cancer cell line Mgc-803 and the human breast cancer cell line Bcap-37.ResultsTen compounds were extracted and isolated from B. davidii, among which colchicine was identified in B. davidii for the first time. The inhibitory activities of these compounds were investigated in Mgc-803, Bcap-37 cells in vitro by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, and the results showed that luteolin and colchicine had potent inhibitory activities against the growth of Mgc-803 cells. Subsequent fluorescence staining and flow cytometry analysis indicated that these two compounds could induce apoptosis in Mgc-803 cells. The results also showed that the percentages of early apoptotic cells (Annexin V+/PI-, where PI is propidium iodide) and late apoptotic cells (Annexin V+/PI+) increased in a dose- and time-dependent manner. After 36 h of incubation with luteolin at 20 μM, the percentages of cells were approximately 15.4% in early apoptosis and 43.7% in late apoptosis; after 36 h of incubation with colchicine at 20 μM, the corresponding values were 7.7% and 35.2%, respectively.ConclusionsColchicine and luteolin from B. davidii have potential applications as adjuvant therapies for treating human carcinoma cells. These compounds could also induce apoptosis in tumor cells.

Exogenous Morphine Inhibits Human Gastric Cancer MGC-803 Cell Growth by Cell Cycle Arrest and Apoptosis Induction

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

SiRNA targeting of Cdx2 inhibits growth of human gastric cancer MGC-803 cells

To investigate the effects of small interference RNA (siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo. The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro. The stable transfectants were selected. The effects of Cdx2 siRNA on growth, proliferation, cell cycle, apoptosis, migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog (PTEN), caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting analysis. We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo. Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis. Cdx2 siRNA significantly inhibited cell growth and proliferation, blocked entry into the S-phase of the cell cycle, induced cell apoptosis, and reduced the motility and invasion of MGC-803 cells. Cdx2 siRNA also increased PTEN expression, and activated caspase-9 and caspase-3 in MGC-803 cells in vitro . In addition, siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models. Cdx2 was involved in regulating pro-gression of human gastric cancer cells MGC-803. Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.

Lentivirus-mediated RNA interference targeting E2F-1 inhibits human gastric cancer MGC-803 cell growthin vivo

The E2F-1 transcription factor is post-translationally modified and stabilized in response to various forms of DNA damage to regulate the expression of cell-cycle and pro-apoptotic genes. The sustained overexpression of E2F-1 is a characteristic feature of gastric cancer. In this study, we investigated the role of short hairpin RNA (shRNA) targeting E2F-1 gene on human gastric cancer MGC-803 cell growth in vivo, and preliminarily revealed the mechanism. Thus, we constructed recombinant pGCSIL-GFP-shRNA-E2F-1 lentiviral vector to knock down E2F-1 expression in human gastric cancer MGC-803 cells in vivo, and studied the effect of E2F-1 shRNA on growth of MGC-803 tumor and evaluated its treatment efficacy. Our data demonstrated that in a mouse model of established gastric cancer, intratumor injection of lentiviral shRNA targeting E2F-1 definitely decreased the endogenous E2F-1 mRNA and protein expression in MGC-803 tumor, and inhibited tumor growth and promoted tumor cells apoptosis. Moreover, we found that E2F-1 shRNA increased the expression of phosphatase and tensin homolog (PTEN), activated caspase-3 and caspase-9, and suppressed nuclear factor (NF)-κB expression in tumor tissue as determined by reverse transcription (RT)-PCR and western blotting. In summary, shRNA targeting of E2F-1 can effectively inhibits human gastric cancer MGC-803 cell growth in vivo and may be a potential therapeutic strategy for gastric cancer.

Regulation of the transcription factor NF-κB1 by microRNA-9 in human gastric adenocarcinoma

BackgroundMicroRNAs (miRNAs) are a new class of naturally occurring, small, non-coding RNAs that regulate protein-coding mRNAs by causing mRNA degradation or repressing translation. The roles of miRNAs in lineage determination and proliferation, as well as the localization of several miRNA genes at sites of translocation breakpoints or deletions, have led to speculation that miRNAs could be important factors in the development or maintenance of the neoplastic state.ResultsWe showed that miR-9 was downregulated in human gastric adenocarcinoma. Overexpression of miR-9 suppressed the growth of human gastric adenocarcinoma cell line MGC803 cell as well as xenograft tumors derived from them in SCID mice. Bioinformatics analysis indicated a putative miR-9 binding site in the 3'-untranslated region (3'UTR) of the tumor-related gene NF-κB1 mRNA. In an EGFP reporter system, overexpression of miR-9 downregulated EGFP intensity, and mutation of the miR-9 binding site abolished the effect of miR-9 on EGFP intensity. Furthermore, both the NF-κB1 mRNA and protein levels were affected by miR-9. Finally, knockdown of NF-κB1 inhibited MGC803 cell growth in a time-dependent manner, while ectopic expression of NF-κB1 could rescue MGC803 cell from growth inhibition caused by miR-9.ConclusionThese findings indicate that miR-9 targets NF-κB1 and regulates gastric cancer cell growth, suggesting that miR-9 shows tumor suppressive activity in human gastric cancer pathogenesis.

Preliminary studies on anti-tumor activity of 2′,4′-dihydroxychalcone isolated from Herba Oxytropis in human gastric cancer MGC-803 cells

2′,4′-Dihydroxychalcone (TFC), one of the main components in Herba Oxytropis, belongs to the flavonoid group, which is known to have anti-tumor activity in vitro. In this study, the authors examined the effects of TFC on cell proliferation and apoptosis in human gastric cancer MGC-803 cells. The MTT assay results showed that TFC was able to induce cytotoxicity in MGC-803 cells in a concentration- and time-dependent manner. Acridine orange/ethidium bromide (AO/EB) staining analysis indicated that the cytotoxicity induced by TFC was mediated by apoptosis, and flow cytometry analysis indicated an increase in apoptotic cells after treatment with TFC. Furthermore, typical apoptotic morphology such as condensed chromatin, irregular nuclei, vacuoles, and dispersed granular material in the nuclear compartment were also observed using a transmission electron microscope. These results suggested that TFC can inhibit the growth of MGC-803 cells and induce apoptosis. However, further studies are necessary to investigate the possible mechanism.

Down-regulation of miR-141 in gastric cancer and its involvement in cell growth

Human microRNA-141 (miR-141), a member of the miR-200 family, has been reported to be associated with various human malignancies. However, it remains unknown whether miR-141 is involved in the pathogenesis of gastric cancer. Therefore, we examined the expression of miR-141 in gastric cancer tissues and the effect of miR-141 overexpression on cancer cell proliferation. The expression level of miR-141 in 35 pair-matched gastric neoplastic and adjacent non-neoplastic tissues, and in 5 gastric cancer cell lines were examined by quantitative real-time PCR. The growth of MGC-803 cells transfected with miRNA precursor was examined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazoliumbromide) assay. MiR-141 was significantly down-regulated in 80% (28/35) of primary gastric cancer tissues compared with pair-matched adjacent non-tumor tissues (P < 0.01). The expression of miR-141 was also found to be substantially reduced in several human gastric cancer cell lines such as MGC-803, HGC-27, SGC-7901 and BGC-823 cells. Overexpression of miR-141 with its precursors significantly inhibited the proliferation of gastric cancer cells. These results suggest that miR-141 may be involved in the development of gastric cancer through its inhibitory effect on cell proliferation.

Caudal-related homeobox 2 gene expression and its effects on human gastric carcinoma cell line

To investigate the effect of human caudal-related homeobox 2 (Cdx2) gene expression on human gastric carcinoma cell line MGC-803. pCMV-Cdx2-HA eukaryotic expression plasmid was constructed by using DNA recombinant method. The MGC-803 cells were divided into 4 groups: non-transfected, transfected with pCMV-HA, transfected with pCMV-GAPDH-HA, transfected with pCMV-Cdx2-HA. Cdx2 gene and its protein expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot techniques respectively. The effects of Cdx2 overexpression on the growth of MGC-803 cells in vitro was assessed by measuring MTT, flow cytometry and transmission electron microscopy analysis. In MGC-803 cells transfected with pCMV-Cdx2-HA, cell proliferation was significantly suppressed, the cells was ultrastructurally destroyed, cell cycle progression was blocked in G0/G1 and apoptosis rate was higher (P<0.05) in comparison with non-transfected cells or cells transfected with empty vector. It indicated that Cdx2 gene can suppress the growth of gastric carcinoma and may save as a novel therapeutic target.

Erk is involved in the differentiation induced by diallyl disulfide in the human gastric cancer cell line MGC803

Diallyl disulfide (DADS) is a major constituent of garlic. Previously, we found that DADS both inhibited proliferation in human gastric cancer cells in vitro and in vivo, and induced G2/M arrest. In this study, we investigated whether this differentiation effect was induced by DADS in human gastric cancer MGC803 cells, and whether it was related to an alteration in ERK activity. The results showed that the growth of MGC803 cells was inhibited by DADS. Cells treated with DADS displayed a lower nucleocytoplasmic ratio and tended to form gland and intercellular conjunction structures. The ConA-mediated cell agglutination ratio and cells' ALP specific activity decreased. In MGC803 cells, dye transfer was limited to a few cells neighbouring the dye-injected cell and to a depth of 1-2 layers beneath the scrape site. However, after treatment with DADS, the LY (Lucifer Yellow) was transferred to several cells immediately neighbouring the microinjected cell and to a depth of 2-4 cell layers from the scrape site. This indicated that DADS induced differentiation in MGC803 cells. Western blot analysis revealed that although DADS did not influence the quantity of ERK1/2 protein expressed, it did decrease its phosphorylation in a concentration-dependent manner, compared with the controls. At 30 mg x L(-1), DADS inhibited the activation of ERK1/2 in 15-30 min. These results suggested that the DADS-induced differentiation of MGC803 cells involved an alteration of the ERK1/2 signaling pathway.

Inhibitory and apoptosis-inducing effects of CD44 antisense oligodeoxyribonucleotides on human gastric cancer cell line MGC80-3

AIM: To study the role and mechanism of antisense oligodeoxyribonucleotides (ASODN) on proliferation and apoptosis of MGC80-3 cells. METHODS: Flow cytometry was used to detect CD44, Fas expression and apoptosis of MGC80-3 cells. Reverse transcription polymerase chain reaction (RT-PCR) assay was used to examine CD44 mRNA level; MTT assay was used to detect cell proliferation. RESULTS: CD44 mRNA and CD44 protein expression in MGC80-3 cells was blocked and down-regulated after transfected with CD44ASODN (1.6 μmol/L). CD44ASODN inhibited the growth of MGC80-3 cells with depression ratios of 31.0%, 46.3% (P0.01), and 49.6% (P0.01) at 48 h, 72 h, and 96 h respectively in a time-dependant manner. With the existence of hyaluronic acid, CD44ASODN improved Fas expression in MGC80-3 cells from 6.7% to 16.8% (P0.01). At the same time, it enhanced the susceptibility of MGC80-3 cells to Fas mAb and the apoptotic rate of the cells increased from 0% to 26.5% (P0.01). CONCLUSION: CD44ASODN can down-regulate the expression of CD44 mRNA and protein, inhibit MGC80-3 cell pro liferation and promote apoptosis induced by Fas mAb.

Coexpression of vascular endothelial growth factor and its receptor KDR on gastric adenocarcinoma MGC803 cell line and stimulation of exogenous VEGF165 to MGC803 cells

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is an angiogenic factor playing an important role in tumor growth. VEGF/VPF interacts with endothelial cells by way of two high-affinity receptor tyrosine kinases: flt-1 and KDR. The vast majority of published studies have described expression of the VPF/VEGF receptors specifically in endothelial cells. To elucidate the further function of VEGF in solid tumor development, the coexpression of VEGF and KDR in gastric adenocarcinoma MGC803 cell lines was shown by reverse transcription polymerase chain reaction (RT-PCR). The MGC803 tumor cells could also be strongly immunostained for KDR by immunocytochemistry. It was further demonstrated that exogenous VEGF(165) can stimulate the MGC803 cell growth in both dose-dependent and time-dependent manners by(3)H-thymidine incorporation. Furthermore, anti-VEGF(165) monoclonal antibody and anti-KDR monoclonal antibody could dose-dependently block the VEGF(165)-induced cell growth. These results provided new evidence that VEGF could cause autocrine stimulation to the proliferation of gastric adenocarcinoma cells.

Induction of apoptosis and inhibition of human gastric cancer MGC-803 cell growth by arsenic trioxide

Arsenic trioxide (As2O3), used to treat human diseases for centuries in traditional Chinese medicine, has been identified as a very effective antileukaemic agent, but its effect on solid tumours which could be more suitable for clinical treatment with arsenic compounds is still unknown. In this study, we investigated the in vitro effect of As2O3 at concentrations of 0.01–1μM against six human malignant cell lines, MGC-803, HIC, MCF-7, HeLa, BEL-7402 and A549 cells. As2O3 inhibited growth and induced apoptosis in these malignant cells at varying degrees, in a time dose-dependent manner. The most marked effects were seen in the gastric cancer cell line, MGC-803. In contrast, minimal growth inhibition and induction of apoptosis occurred in human embryonic pulmonary cells following treatment with As2O3 found at the same concentrations. Changes in intracellular Ca2+, following As2O3 treatment were measured by Ca2+ sensitive fluorescent probe Indo-1/AM in flow cytometric assays. The increase in intracellular Ca2+ correlated with the sensitivity of these cells to As2O3, possibly indicating that a critical intracellular Ca2+ signal transduction pathway could be involved in As2O3-mediated cell-death and its selectivity. The marked sensitivity of MGC-803 cells in vitro suggests that As2O3 may be a potential antigastric cancer agent.