Gastric Carcinoma Cell Line BGC-823 Research Articles

Role of triosephosphate isomerase and downstream functional genes on gastric cancer.

Triosephosphate isomerase (TPI) is highly expressed in many types of human tumors and is involved in migration and invasion of cancer cells. However, TPI clinicopathological significance and malignant function in gastric cancer(GC) have not been well defined. The present study aimed to examine TPI expression in GC tissue and its biological functions. Furthermore, we investigated its downstream genes by gene chip technology. Our results showed that TPI expression was higher in gastric cancer tissues than adjacent tissues, although no statistical differences were found between TPI expression and clinicopathological factors. TPI overexpression in human gastric carcinoma cell line BGC-823 enhanced cell proliferation, invasion and migration, but did not change cell cycle distribution, while TPI knockdown suppressed proliferation, invasion and migration, induced apoptosis and increased G2/M arrest of human gastric carcinoma cell line MGC-803. Since the cell division cycle associated 5 (CDCA5) was identified as the one with the most decreased expression after TPI knockdown, we investigated its role in MGC-803 cells. The results showed that CDCA5 knockdown also inhibited proliferation, migration, induced apoptosis and increased G2/M arrest similarly to TPI knockdown. CDCA5 overexpression promoted MGC-803 cell proliferation, clone formation and migration abilities. These results indicated that TPI expression level might affect GC cell behavior, suggesting that both TPI and CDCA5 might be considered as potential tumor markers related with GC development and might be potential new targets in GC treatment.

PBX1 attributes as a determinant of connexin 32 downregulation in Helicobacter pylori-related gastric carcinogenesis.

AIMTo clarify the mechanisms of connexin 32 (Cx32) downregulation by potential transcriptional factors (TFs) in Helicobacter pylori (H. pylori)-associated gastric carcinogenesis.METHODSApproximately 25 specimens at each developmental stage of gastric carcinogenesis [non-atrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia and gastric carcinoma (GC)] with H. pylori infection [H. pylori (+)] and 25 normal gastric mucosa (NGM) without H. pylori infection [H. pylori (-)] were collected. After transcriptional factor array analysis, the Cx32 and PBX1 expression levels of H. pylori-infected tissues from the developmental stages of GC and NGM with no H. pylori infection were measured by real-time polymerase chain reaction (RT-PCR) and Western blot analysis. Regarding H. pylori-infected animal models, the Cx32 and PBX1 mRNA expression levels and correlation between the gastric mucosa from 10 Mongolian gerbils with long-term H. pylori colonization and 10 controls were analyzed. PBX1 and Cx32 mRNA and protein levels were further studied under the H. pylori-infected condition as well as PBX1 overexpression and knockdown conditions in vitro.RESULTSIncremental PBX1 was first detected by TF microarray in H. pylori-related gastric carcinogenesis. The identical trend of PBX1 and Cx32 expression was confirmed in the developmental stages of H. pylori-related clinical specimens. The negative correlation of PBX1 and Cx32 was confirmed in H. pylori-infected Mongolian gerbils. Furthermore, decreased PBX1 expression was detected in the normal gastric epithelial cell line GES-1 with H. pylori infection. Enforced overexpression or RNAi-mediated knockdown of PBX1 contributed to the diminished or restored Cx32 expression in GES-1 and the gastric carcinoma cell line BGC823, respectively. Finally, dual-luciferase reporter assay in HEK293T cells showed that Cx32 promoter activity decreased by 30% after PBX1 vector co-transfection, indicating PBX1 as a transcriptional downregulator of Cx32 by directly binding to its promoters.CONCLUSIONPBX1 is one of the determinants in the Cx32 promoter targeting site, preventing further damage of gap junction protein in H. pylori-associated gastric carcinogenesis.

Lobaplatin induces BGC-823 human gastric carcinoma cell apoptosis via ROS- mitochondrial apoptotic pathway and impairs cell migration and invasion.

Human gastric cancer is the fifth common cancer with considerable metastasis potential, and its high incidence and mortality rate threaten public health. In this study, we examined the anticancer effects of lobaplatin on the human gastric carcinoma cell line BGC-823 in vitro, and explored its relative mechanisms. The results of MTT assay showed dose- and time-dependent cytotoxicity in BGC-823 cells with lobaplatin. Flow cytometry (FCM) assay indicated that lobaplatin affected BGC-823 cells' survival by inducing apoptosis. Western blot analysis also demonstrated that the occurrence of its apoptosis was associated with activation of Cleaved caspase-3 and Bax, downregulation of Bcl-2. Moreover, lobaplatin could also increase the reactive oxygen species (ROS) slightly and decrease the mitochondrial membrane potential (ΔYm) obviously, elucidating that lobaplatin may induce apoptosis via mitochondria-dependent apoptotic pathway. Furthermore, lobaplatin markedly blocked BGC-823 cells migration and invasion, and the reduction of matrix metalloproteinase (MMP) MMP-2 and MMP-9 expression were also observed in vitro. Our findings demonstrated the chemotherapeutic potential of lobaplatin for treatment of human gastric carcinoma cell line BGC-823 by inhibiting proliferation, inducing apoptosis and attenuating cell migration and invasion.

4-Amino-2-trifluoromethyl-phenyl retinate inhibits the migration of BGC-823 human gastric cancer cells by downregulating the phosphorylation level of MLC II.

4-Amino-2-trifluoromethyl-phenyl retinate (ATPR) is a novel all-trans retinoic acid (ATRA) derivative which was reported to have a superior antitumor effect in breast cancer cells. However, little is known about its antitumor effects on human gastric cancer cells and the mechanisms have not been fully elucidated. The results of the present study suggest that in the human gastric carcinoma cell line BGC-823, ATPR plays a more effective role than ATRA at the same dose in inhibiting proliferation, migration and inducing differentiation after the same treatment time. Furthermore, we investigated the preliminary mechanism of ATPR's anti‑migration effect. Immunofluorescence assay demonstrated that claudin-18 positioned from cytoplasm to cell surface following ATPR stimuli. Real-time quantitative RT-PCR and western blot analyses showed that ATPR had significant effects on downregulation of the phosphorylation level of myosin light chainII (MLCII) by suppressing myosin light chain kinase (MLCK) and Rho-associated coiled-coil containing kinase (ROCK), as well as its regulation in the protein expression of RARα and RARβ. Moreover, ATPR increased the activity of myosin phosphatase by inhibiting ROCK. Consequently, ATPR showed more promising antitumor effects than ATRA in BGC-823 invitro, and it may conduct its anti-migration effects by decreasing the phosphorylation level of MLCII, as well as by regulating MLCK and ROCK as downstream target genes.

Matrine inhibits the adhesion and migration of BCG823 gastric cancer cells by affecting the structure and function of the vasodilator-stimulated phosphoprotein (VASP)

Vasodilator-stimulated phosphoprotein (VASP) expression is upregulated in human cancers and correlates with more invasive advanced tumor stages. The aim of this study was to elucidate the mechanisms by which matrine, an alkaloid derived from Sophora species plants, acted on the VASP protein in human gastric cancer cells in vitro. VASP was expressed and purified. Intrinsic fluorescence spectroscopy was used to study the binding of matrine to VASP. CD spectroscopy was used to examine the changes in the VASP protein secondary structure. Human gastric carcinoma cell line BGC823 was tested. Scratch wound and cell adhesion assays were used to detect the cell migration and adhesion, respectively. Real-time PCR and Western blotting assays were used to measure mRNA and protein expression of VASP. In the fluorescence assay, the dissociation constant for binding of matrine to VASP protein was 0.86 mmol/L, thus the direct binding between the two molecules was weak. However, matrine (50 μg/mL) caused obvious change in the secondary structure of VASP protein shown in CD spectrum. Treatments of BGC823 cells with matrine (50 μg/mL) significantly inhibited the cell migration and adhesion. The alkaloid changed the subcellular distribution of VASP and formation of actin stress fibers in BGC823 cells. The alkaloid caused small but statistically significant decreases in VASP protein expression and phosphorylation, but had no significant effect on VASP mRNA expression. Matrine modulates the structure, subcellular distribution, expression and phosphorylation of VASP in human gastric cancer cells, thus inhibiting the cancer cell adhesion and migration.

Isolation and characterization of side population cells in human gastric cancer cell line BGC-823

Isolate and characterize the side population (SP) cells with potency of stem cells from human gastric carcinoma cell line BGC-823. SP and non-SP cells were sorted from BGC-823 cells by fluorescence-activated cell sorting (FACS) using Hoechst33342 staining. The tumorigenic ability of the SP cells was assessed by in vivo transplantation into non-obese diabetic/severe combined immunodeficiency mice. SP cells were isolated from BGC-823 cells in a proportion of 0.9% to 2.1% with respect to the whole cell population. The colony formation assay showed that the colony formation rate of the SP cells was significantly higher than that of the non-SP cells (72.56% vs. 49.00%, P < 0.01). The drug sensitivity test showed that the SP cells showed stronger drug resistance to 5-Fu than the non-SP cells. The in vivo transplantation of SP cells in mice showed that the tumor weight was (0.176 ± 0.034) g, significantly higher than that of non-SP cells (0.045 ± 0.046) g (P < 0.01). The results of this study indicate the existence of cancer stem-like SP cells in the human gastric cancer line BGC-823 cells. Further characterization of this SP cell population may provide new insights for diagnosis and treatment of gastric cancer.

Three New Phenolic Glucosides from the Roots of Rheum palmatum

A novel naphthalene glucoside, rheumone A (1), with an unprecedented skeleton containing a seven-membered lactone, and two new compounds, 1-O-phloroglucinyl-2-O-galloyl-6-O-cinnamoyl-β-D-glucoside (2) and chrysophanol 1-O-β-D-(6'-O-malonyl)glucoside (3), together with three known compounds (4-6) were isolated from the roots of Rheum palmatum. Their structures were elucidated mainly by spectroscopic analysis. These compounds were evaluated in vitro for their cytotoxicities towards human hepatocellular cancer cell lines Bel-7402 and Bel-7402/5Fu, and human gastric carcinoma cell line BGC-823. None of them showed cytotoxicity with IC(50) far beyond 50 μM.

Synthesis of PEGylated fullerene–5-fluorouracil conjugates to enhance the antitumor effect of 5-fluorouracil

Many drugs have been delivered by different types of nanoscale vehicles to enhance their therapeutic efficacy. 5-Fluorouracil (5FU) is a widely used antitumor drug, however its bioavailability still needs to be improved. Herein we synthesized a polyethylene glycol monomethylether-C(60)-5FU conjugate (mPEG-C(60)-5FU) and evaluated its antitumor efficacy in vitro. The results show that the inhibition abilities of mPEG-C(60)-5FU to the human breast cancer cell line MCF-7 and the human gastric carcinoma cell line BGC-823 are significantly higher than that of 5FU. The conjugate has good stability in murine serum for at least 24 h. Moreover, the PEGylated fullerene (mPEG-C(60)) vehicle is non-toxic to MCF-7 cells. These results demonstrate that mPEG-C(60) is an efficient vehicle for the delivery of 5FU.

The studies on regulating the expression of PTEN and Livin genes in gastric carcinoma cell line BGC823 and characterization of their bioactivity

Objective To study the effect of simultaneously increasing PTEN gene expression and inhibiting Livin expression on the proliferation, apoptosis, invasion and metastasis of gastric carcinoma cell line (BGC823) in vitro. Methods To construct the eukaryotic expression vector pCL-neo-PTEN and siRNA vector pRNAT-U6, 1-Livin. The siRNA expression unit against Livin gene (siLivin) was cut from pRNAT-U6, 1-Livin vctor, and then inserted into pCL-neo-PTE to construct the recombinant vector pCL-neo-PTEN-siLivin. Then, pCL-neo-PTEN-siLivinp, pCL-neo-PTEN, pRNAT-U6, 1-Livin, pCL-neo,pRNAT-U6. 1 were respectively transfected into the gastric carcinoma cell hne (BGC823) with LipofectAMINE 2000TM. The mRNA and protein expression level of PTEN and Livin genes in each group cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, Cell proliferation curve, the activity of Caspase-3 and 9, cell apoptosis, ability of invasion and metastasis were detected in vitro. Results Recombants vector of pCL-neo-PTEN, pRNAT-U6, l-Livin and pCL-neo-PTEN-siLivin were constructed successfully. After transfected with pCL-neo-PTEN-siLivin, the mRNA (0. 897±0. 112) and protein expression level of PTEN in BGC823 cells were rised,meanwhile, Livin genes were silenced (0. 071 ±0. 009). And characterization of the regulated cells bioactivity has improved, such as the reduced proliferation ,higher apoptosis ( 16. 72±1.84) ,more effective activity of Caspase-3 and 9 ( 1.88 ±O. 21,1.07 ± 0. 18 ), fewer cells penetrating the Matrigel (23. 1 ± 3. 5 ). There were significant differences between transfected groups and control groups ( P < 0. 05 ). And the inhibiting effect on the BGC823 cells' proliferation and metastasis by increasing PTEN expression and silencing Livin simultaneously was better than that only by regulating PTEN genes or Livin genes alternatively. Conclusion The PTEN gene upregulated and the Livin gene silenced at same time could contribute to reduce the proliferation and metastasis in gastric carcinoma cell line BGC823. Key words: PTEN; Livin; Gastric carcinoma cell line BGC823; Regulating; Growth inhibition

The synthesis and biological evaluation of some caffeic acid amide derivatives: E-2-Cyano-(3-substituted phenyl)acrylamides

A series of caffeic acid amide derivatives 2-cyano-(3-substituted phenyl)acrylamides were synthesized via Knoevenogal condensation of substituted benzaldehydes with cyanoacetamides. The structure of compound 1f was determined as E-isomer by X-ray diffractive analysis. The biological screening tests in vitro showed that compound 1b has obvious inhibitory activities against human gastric carcinoma cell line BGC-823, human nasopharyngeal carcinoma cell line KB and human hepatoma cell line BEL-7402 with IC 50 values of 5.6 μg/mL, 13.1 μg/mL and 12.5 μg/mL, respectively. Some preliminary structure–activity relationships (SAR) were also proposed which may provide a direction for further study.

Apoptosis of BGC823 cell line induced by p‐hydroxymethoxybenzobijuglone, a novel compound from Juglans mandshurica

p-Hydroxymethoxybenzobijuglone (HMBBJ), a new quinone compound isolated from Juglans mandshurica (by bioassay-guided fractionation), showed cytotoxic activity in the gastric carcinoma cell line BGC823. The growth of BGC823 cells was inhibited as demonstrated by MTT assay and several cellular characteristic changes, such as cell shrinkage, chromatin condensation and apoptotic body formation with programmed cell death. Flow cytometry analysis revealed that the BGC823 cell cycle was arrested at G2/M phase by HMBBJ, and the apoptotic rate of BGC823 cells increased with respect to HMBBJ in a dose-dependent manner. HMBBJ also activated caspase-3, decreased the expression of Bcl-2 and caused a decrease in the mitochondrial membrane potential (Delta Psi(m)). These findings suggest that HMBBJ could significantly induce apoptosis in BGC823 cells and should be considered as a potential candidate for a chemotherapeutic drug against cancer.

Sinulaflexiolides A−K, Cembrane-Type Diterpenoids from the Chinese Soft Coral Sinularia flexibilis

A bioassay-guided fractionation and chemical examination of the soft coral Sinularia flexibilis resulted in the isolation and characterization of sinulaflexiolides A-K (1-11), along with sinulariolone (12), 5-dehydrosinularolide (13), capillolide (14), sinulariolide (15), 5,8-epoxy-9-acetoxysinulariolide (16), flexibilide (17), dihydroflexibilide (18), and the enantiomer of 14-deoxycrassin (19). Their structures were determined on the basis of extensive spectroscopic (IR, MS, 2D NMR) data analysis and by comparison with spectroscopic data reported in the literature. Sinulaflexiolides D and E showed selective inhibitory activity against the gastric gland carcinoma cell line BGC-823 at 8.5 and 0.12 microM, respectively.

PI3K/Akt/p27kip1 pathway mediates chemoresistance to Etoposide and Doxorubicin in gastric carcinoma cell line BGC-823 and its mechanism

PI3K/Akt/p27kip1 pathway mediates chemoresistance to Etoposide and Doxorubicin in gastric carcinoma cell line BGC-823 and its mechanism

Studies on the chemical constituents and anticancer activity of Saxifraga stolonifera (L) Meeb

Saxifraga stolonifera, an evergreen dicotyledon, has been identified as an important resource in Chinese medicine due to its anticancer activity. In the present report, chemical components of S. stolonifera (L) Meeb which is found in Guizhou province were investigated. Ten compounds were isolated from ethanol extracts of S. stolonifera plant and were identified as n-C 31H 64 ( 1), ( n-C 17H 35) 2CO ( 2), β-sitosterol ( 3), n-C 29H 60 ( 4), Bergenin ( 5), Protocatechuic acid ( 6), Gallic acid ( 7), Quercitrin 3- O-α- l-rhamnoside ( 8), Quercetin ( 9), and Quercetin 3- O-β- d-glucopyranoside ( 10). Among them, n-C 31H 64 ( 1), ( n-C 17H 35) 2CO ( 2), β-sitosterol ( 3), and n-C 29H 60 ( 4) were isolated from this plant for the first time. The anticancer activities of S. stolonifera constituents on human gastric carcinoma cell line BGC-823 were evaluated by MTT assay and microscopic observation, DNA fragmentation, and flow cytometry analysis assay. It was found that quercetin could inhibit cell viability after 72 h of exposure. Furthermore, DNA ladder assay revealed that quercetin could induce DNA strand break in a concentration- and time-dependent fashion. Flow cytometric analysis shows that quercetin can induce 11.82% BGC-823 cell apoptosis in 48 h. These data reveal that quercetin is a potential agent capable of inducing apoptosis in BGC-823 cells.

Inhibitory effect of antisense RNA on the gene expression of membrane-type 1 matrix metalloproteinase and invasiveness of human gastric carcinoma cells

AIM:To investigate the influence on the gene expression of membrane-type 1 matrix metalloproteinase(MT1-MMP)and invasiveness of human gastric carcinoma cell line BGC823 by antisense RNA. METHODS:The eukaryotic expression vector carrying MT1-MMP antisense RNA was con- structed with recombinant technology and then transfected into human gastric cancer cell line BGC823.The changes of MT1-MMP mRNA ex- pression,cell proliferation,activation of gelatin- ase A and cell invasion ability were examined by reverse transcription-polymerase chain reaction (RT-PCR),MTT assay,zymography and Tran- swell invasion assay,respectively. RESULTS:The eukaryotic expression vector (named pasMMP14)containing MT1-MMP an- tisense RNA was successfully constructed and transfected into BGC823 cells.The expression of MT1-MMP mRNA was down-regulated with an inhibitory rate of 36%,in comparison with that in negative control group.At the 48th hour after transfection with pasMMP14,the activity of gelatinase A was dramatically inhibited.Af- ter 72 hours,cell proliferation was significantly decreased as compared with that in pcDNA3.0 group and normal control group(t=2.358,P0.01;t=2.727,P0.01).Transwell invasion assay showed that the invasive property was greatly suppressed in pasMMP14-transfected group as compared with that in pcDNA3.0 group and normal control group(t=5.744,P0.01;t=5.695,P0.01). CONCLUSION:Antisense RNA can evidently inhibit the gene expression of MT1-MMP and invasiveness of gastric cancer cells,suggesting that MT1-MMP gene may be a molecular target of anti-invasion therapy for gastric cancer.

Co-expression of heat shock protein 70 and glucose-regulated protein 94 in human gastric carcinoma cell line BGC-823

To investigate the co-expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human gastric carcinoma cell line BGC-823. The expression and localization of HSP70 and grp94 in human gastric carcinoma cell line BGC-823 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. Flow cytometry was used to analyze the correlation between expression of HSP70, grp94 and cell cycle in BGC-823 cell line. Gastric cancer cell line BGC-823 expressed high level of HSP70 and grp94. The positive rate of HSP70 and grp94 was 84.9+/-4.94% and 79.6+/-5.16%, respectively. Both of them were stained in cell plasma. There was a significant difference compared with control group (1.9+/-0.94%, P<0.01). During the cell cycle, HSP70 and grp94 were continuously expressed in BGC-823. HSP70 and grp94 are highly expressed in human gastric carcinoma BGC-823 cells through the whole cell cycle. There is no relationship between expression of HSP70, grp94 and cell cycle.

Effects of tachyplesin on the morphology and ultrastructure of human gastric carcinoma cell line BGC-823.

AIM:To investigate the morphological and ultrastructural changes in the human gastric carcinoma cell line BGC-823 after being treated with tachyplesin.METHODS:Tachyplesin was isolated from acid extracts of Chinese horseshoe crab (Tachypleus tridentatus) hemocytes. BGC-823 cells and the cells treated with 2.0mg/L tachyplesin were examined respectively under light microscope, scanning and transmission electron microscope.RESULTS: BGC-823 cells had undergone the restorational alteration in morphology and ultrastructure after tachyplesin treatment. The changes were as follows: the shape of cells was unanimous, the volume enlarged and cells turned to be flat and spread, the nucleo-cytoplasmic ratio lessened and nuclear shape became rather regular, the number of nucleolus reduced and its volume lessened,heter-chromatin decreased while euchromatin increased in nucleus. In the cytoplasm, mitochondria grew in number with consistent structure relatively, Golgi complex turned to be typical and well-developed,rough endoplasmic reticulum increased and polyribosome decreased. The microvilli at cellular surface were rare and the filopodia reduced while lamellipodia increased at the cell edge.CONCLUSION:Tachyplesin could alter the malignant morphological and ultrastructural charact-eristics of human gastric carcinoma cells effectively and have a certain inducing differen-tiation effect on human gastric carcinoma cells.