Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the inhibitory effect of the Bcl-XL small interfering RNA (siRNA) on Bcl-XL gene expression in the human gastric cancer cell line MGC-803, green fluorescent protein (GFP) siRNA was constructed and transfected into MGC-803 cells, together with GFP expression vector pTrace SV40. GFP expression levels were observed using fluorescence microscopy. Bcl-XL siRNA and negative siRNA were then constructed and stably transfected into MGC-803 cells. RT-PCR and immunofluorescence were used to detect the expression of Bcl-XL. Spontaneous apoptosis was detected by acridine orange (AO) and flow cytometry. Results were as follows: (1) 48 h after GFP expression vector and GFP siRNA co-transfection, the expression level of GFP in the GFP siRNA group was much lower than the negative siRNA group, according to fluorescence microscopy results. The mRNA and protein levels of Bcl-XL in Bcl-XL siRNA stable transfectants were reduced to almost background level compared with negative siRNA transfectants or untreated cells. (2) Changes in nucleus morphology was observed by AO staining nucleic and flow cytometry analysis, which showed that stable Bcl-XL siRNA transfectants have an increased spontaneous apoptosis (21.17%+/-1.26% vs. 1.19%+/-0.18% and 1.56%+/-0.15% respectively, P < 0.05 vs. negative siRNA or untreated control). siRNA targeting GFP or Bcl-XL genes can specifically suppress GFP or Bcl-XL expression in MGC-803 cells, and Bcl-XL siRNA can increase spontaneous apoptosis. Bcl-XL siRNA may be a beneficial agent against human gastric adenocarcinoma.
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PMID:Silencing of Bcl-XL expression in human MGC-803 gastric cancer cells by siRNA. 1607 3

Natural products derived from plants provide a rich source for development of new anticancer drugs. Recent studies suggest that modulation of subcellular localization of retinoid X receptor-alpha (RXRalpha) represents a potential approach for inducing cancer cell apoptosis. In this study, we screened a herbal library for inducing translocation of RXRalpha from the nucleus to the cytoplasm. Our results revealed that the extract of Hypericum sampsonii, a member of the genus Hypericum, had remarkable effect on RXRalpha subcellular localization in various cancer cells. Treatment of NIH-H460 human lung cancer cells with H. sampsonii extract resulted in relocalization of RXRalpha from the nucleus to the cytoplasm. Cytoplasmic RXRalpha induced by H. sampsonii was associated with mitochondria, accompanied with cytochrome c release and apoptosis. H. sampsonii extract effectively inhibited the growth of various cancer cell lines, including NIH-H460 lung cancer, MGC-803 stomach cancer and SMMC7721 liver cancer cells. The growth inhibitory effect of H. sampsonii extract depended on levels of RXRalpha, as it failed to inhibit the growth of CV-1 cells lacking detectable RXRalpha, whereas transfection of RXRalpha into CV-1 cells restored its apoptotic response to H. sampsonii. Furthermore, the apoptotic effect of H. sampsonii was significantly enhanced when RXRalpha was overexpressed in NIH-H460 cells. Together, our results demonstrate that H. sampsonii contains ingredient(s) that induce apoptosis of cancer cells by modulating subcellular localization of RXRalpha.
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PMID:Hypericum sampsonii induces apoptosis and nuclear export of retinoid X receptor-alpha. 1662 85

5-Fluorouracil is the first choice chemotherapeutic drug for patients with gastric cancer, but the mechanism that 5-fluorouracil plays the anti-tumor role remains unclear. The aim of this study was to clarify correlated [corrected] proteins induced by 5-fluorouracil in the apoptosis-initiation of human gastric cancer (MGC-803) cells. The time point of apoptosis-initiation induced by 5-fluorouracil in MGC-803 cells was determinated using 5-fluorouracil-withdrawal. Two-dimensional electrophoreses (2-DE) were employed to compare the differentials of protein expressions of the MGC-803 cells at the apoptosis-initiation phase and those of the MGC-803 cells untreated with 5-fluorouracil. The differential proteins included 14 upregulated proteins and 8 downregulated proteins. They indicated a more-than-doubled alteration. These proteins were digested in gels by trypsin and the mass of generated peptides were measured by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). The data obtained from peptide mass fingerprinting (PMF) were searched out using the internet available database mascot (http://www.matrixscience.com). The results showed that proteomics analyses have evidenced that many kinds of proteins are involved in the apoptosis initiation of human gastric cancer MGC-803 cells. These proteins are related to metabolism, oxidation, cytoskeleton and signal transduction and other aspects of cells. In conclusion, the experiment model of apoptosis-initiation of human gastric cancer MGC-803 cells induced by 5-fluorouracil based on proteomic analysis has been established, giving an impetus to researches of the mechanism of apoptosis in human gastric cancer, and laying a foundation for the selection of potential drug precursors specific for inducing apoptosis-initiation in human gastric cancer.
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PMID:Comparative proteomics of apoptosis initiation induced by 5-fluorouracil in human gastric cancer. 1690 Jul 3

Aloe-emodin is a novel active compound found in the root and rhizome of Rheum palmatum. To investigate the effects and mechanisms of aloe-emodin on human gastric cancer, MGC-803 cells were treated with 2.5, 5, 10, 20 and 40 microM aloe-emodin for 1-5 d. The results showed that aloe-emodin inhibited the growth of cancer cells in a dose-dependent manner with an increase in S phase and in the proportion of cells cycling at a higher ploidy level (>G2/M). Moreover, the alkaline phosphatase (ALP) activity, an indicator of cell differentiation, was found decreased. This is one of the first to focus on the effect of ALP activity in human gastric carcinomas cells treated by aloe-emodin. These results indicate that aloe-emodin has a potential value for the treatment of gastric cancer and its mechanisms are by means of cell cycle interruption and induce differentiation.
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PMID:Growth inhibitory effects of gastric cancer cells with an increase in S phase and alkaline phosphatase activity repression by aloe-emodin. 1729 1

In this study, we analyzed the mechanisms of the apoptotic effects of celecoxib on COX-2 deficient gastric cancer cell line, MGC-803. We found celecoxib treatment induced caspase-dependent apoptosis in MGC-803 cells. Celecoxib inhibited Ser473 Akt and Ser9 GSK3beta phosphorylation and induced upregulation of nonsteroidal anti-inflammatory drugs-activated gene-1 (NAG-1) expression. The effects of celecoxib on NAG-1 expression were abolished by pretreatment with GSK3beta inhibitor, SB216763. Furthermore, GSK3beta gene silencing by siRNA inhibited the celecoxib-induced NAG-1 expression. Our study demonstrated that Akt/GSK3beta/NAG-1 signal pathway may represent as the major mechanism of the COX-2-independent effects of celecoxib on gastric cancer cells.
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PMID:Celecoxib induces apoptosis in COX-2 deficient human gastric cancer cells through Akt/GSK3beta/NAG-1 pathway. 1725 45

To investigate the association between endothelin-converting enzyme-1b (ECE-1b) C-338A polymorphism and gastric cancer risk, we conducted a hospital-based case-control study of 256 gastric cancer cases and 256 controls matched on age and gender. The genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. We found that the genotype frequencies were significantly different (P=0.005) between cases and controls. Compared with the wild genotype CC, the variant genotypes (CA+AA) were associated with a 64% increased risk of gastric cancer [adjusted odds ratio (OR)=1.64, 95% confidence interval (CI) 1.15-2.33]. Further stratification analyses indicated that the increased risk was especially noteworthy in older subjects (age 58) (adjusted OR=1.91, 95% CI 1.18-3.09), women (adjusted OR=2.30, 95% CI 1.11-4.79) and non-smokers (adjusted OR=1.79, 95% CI 1.19-2.67). Our results suggest that the ECE-1b C-338A polymorphism may be associated with increased risk of gastric cancer.
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PMID:Association of endothelin-converting enzyme-1b C-338A polymorphism with gastric cancer risk: a case-control study. 1797 16

Aloe-emodin is a hydroxyanthraquinone found in Aloe vera, as well as in leaves and roots of other plants. The mechanisms of its anticancer effect are largely unknown. The present study investigated its molecular mechanisms. Crystal violet assay showed that aloe-emodin had a long-term anti-proliferation effect on human gastric cancer MGC-803 and SGC-7901 cells. Scratch wound-healing motility assays indicated its anti-migration effect. Aloe-emodin arrested SGC-7901 cells at G2/M phase. More importantly, aloe-emodin inhibited the expressions of protein kinase C and c-myc. In conclusion, the anticancer effect of aloe-emodin on gastric cancer cells involves suppression of c-myc expression.
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PMID:Suppression of C-myc expression associates with anti-proliferation of aloe-emodin on gastric cancer cells. 1844 57

Gastric cancer is the fourth most common cancer in the world and the leading cause of cancer death in China. It is necessary to find a safe and effective way to treat this disease. A sustained overexpression of survivin is a characteristic feature of gastric cancer as it gives cancer cells a survival and growth advantage. RNA interference (RNAi), which has been proven to be a powerful tool for suppressing gene expression, may provide a promising way forward in gastric cancer therapy. Few studies have been conducted on the inhibitory effects of small interfering RNA (siRNA) against survivin in gastric cancer. In this study, we constructed the recombinant Psilencer 2.1-survivin siRNA plasmids and transfected them into gastric cancer MGC-803 cells in vitro, and also injected MGC-803/Silence (+) cells into nude mice to observe the inhibitory effects in vivo. The transfection of Psilencer 2.1-survivin (+) plasmid led to remarkable inhibition of survivin mRNA expression, the intensity of survivin mRNA was lower (P<0.05), the expression of survivin protein was strongly suppressed, the amount of survivin protein was also lower (P<0.05) and the percentage of apoptotic cells was much higher (P<0.05). The tumor size and growth ratio were lower in nude mice injected with MGC-803/Silence (+) cells and the inhibition ratio of survivin expression was higher (P<0.05). In summary, siRNA targeting of survivin can effectively inhibit the growth of gastric cancer cells and may be used as a potent therapy.
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PMID:Inhibitory effect of siRNA targeting survivin in gastric cancer MGC-803 cells. 1848 12

The herb medicine formula "Yang Wei Kang Liu" (YWKLF) has been used to inhibit the metastasis of human gastric cancer to prolong patient survival. In this study, we evaluated the effect of combination of chemotherapy with YWKLF on the survival of stage IV gastric cancer patients and the potential mechanisms of YWKLF by focusing on its capacity to activate apoptotic pathways in human gastric cancer cell line MGC-803. We found that combination of chemotherapy with oral administration of YWKLF significantly increased the survival of stage IV gastric cancer patients. In an approach of "serum pharmacology" in which sera were collected from rabbits orally administered with YWKLF and examined for their anti-tumor cell activity in vitro, we observed that sera from rabbits administered with YWKLF induced the apoptosis of MGC-803 cells by causing the loss of mitochondrial membrane potential, increasing the expression of Fas protein and Bax mRNA, as well as down-regulating Fas-L mRNA. Our results suggest that activation of major pro-apoptotic pathways may account for the anti-gastric cancer activity of YWKLF, which may provide a basis for isolation and identification of more highly effective anti-cancer components.
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PMID:The herb medicine formula "Yang Wei Kang Liu" improves the survival of late stage gastric cancer patients and induces the apoptosis of human gastric cancer cell line through Fas/Fas ligand and Bax/Bcl-2 pathways. 1860 65

A fluorescent silica nanoparticles (FSiNPs) mediated double immunofluorescence staining technique has been proposed for MGC-803 gastric cancer cells imaging by confocal laser scanning microscopy. Anti-CEA antibody and anti-CK19 antibody which can be both bonded to MGC-803 gastric cancer cells were first conjugated to fluorescein isothiocyanate (FITC) doped fluorescent silica nanoparticles (FFSiNPs) and RuBPY doped fluorescent silica nanoparticles (RFSiNPs), respectively. The MGC-803 gastric cancer cells were incubated with the mixture of anti-CEA antibody-conjugated FFSiNPs and anti-CK19 antibody-conjugated RFSiNPs, and subsequently imaged using confocal laser scanning microscopy. With this method, the in vitro cultured MGC-803 gastric cancer cells lines were successfully doubled labeled and distinguished through antigen-antibody recognition, together with the green and red signal of FFSiNPs and RFSiNPs simultaneously obtained without crossreactivity by confocal laser scanning microscopy imaging. By comparison with the conventional double immunofluorescence staining using green-emitting and red-emitting dyes, the photostability of this proposed method for confocal laser scanning microscopy imaging has been greatly improved. Furthermore, the ex vivo imaging of primary MGC-803 gastric cancer cells samples came from the tumor tissues of mice bearing the MGC gastric cancer tumor xenografts by this method have also been explored. The results demonstrate that the method offers potential advantage of photostability for the confocal laser scanning microscopy imaging of MGC-803 gastric cancer cells, and is applicable to the imaging of primary MGC-803 gastric cancer cells from the tumor tissues.
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PMID:FSiNPs mediated improved double immunofluorescence staining for gastric cancer cells imaging. 1876 Nov 78


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