Inflammation is closely related to the progression of cancer as well as tumorigenesis. Here, we investigated the effect of prostaglandin E2 (PGE2) and interleukin-1beta (IL-1beta) on E-cadherin expression in SNU719 gastric cancer cells. E-cadherin expression decreased as the dose or exposure time of PGE2 and IL-1beta increased, whereas Snail expression increased with dose or time of PGE2 and IL-1beta. E-cadherin expression reduced by PGE2 treatment increased after the transfection of Snail siRNA. Neutralization of IL-1beta using anti-IL-1beta antibody blocked the expression pattern of E-cadherin and Snail occurred by IL-1beta treatment. However, there was no synergic effect of IL-1beta and PGE2 on the expression pattern of E-cadherin and Snail. In conclusion, inflammatory mediators reduced E-cadherin expression by enhancing Snail expression in gastric cancer cells. Inflammation-induced transcriptional regulation of E-cadherin in gastric cancer has implications for targeted chemoprevention and therapy.
Antibodies/immunology ; Antineoplastic Agents/pharmacology ; Cadherins/*metabolism ; Cell Line, Tumor ; Dinoprostone/*pharmacology ; Gene Expression Regulation/*drug effects ; Humans ; Interleukin-1beta/immunology/*pharmacology ; RNA Interference ; RNA, Small Interfering/metabolism ; Stomach Neoplasms/metabolism/pathology ; Transcription Factors/antagonists & inhibitors/genetics/*metabolism

OBJECTIVETo investigate if granulocyte-macrophage colony stimulating factor (GM-CSF) gene-modified dendritic cells (DC) enhance antitumor immunity in vitro.

METHODSMice were injected with chemokine ligand 3 (CCL3) via the tail vein. Fresh B220(-)CD11c(+) cells were sorted from the peripheral blood mononuclear cells (PBMCs) and cultured into DCs by cytokines.DCs were transfected with AdGM-CSF gene at different ratios of multiplicity of infection (MOI) to determine the optimal gene transfection conditions, and the expression of GM-CSF was detected after transfection. The variation of GM-CSF gene-modifiedDCs were analyzed by morphological examination, phenotype analysis, and mixed lymphocyte reaction (MLR).DCs were loaded with gastric cancer antigen obtained by freezing and thawing method. The killing effect of DCs vaccine-stimulated T lymphocytes on gastric cancer cells was assessed by MTT assay. INF-gamma production was determined with the INF-gamma ELISA kit.

RESULTSB220(-)CD11c(+) cells increased obviously after CCL3 injection. The ELISA results showed that after GM-CSF gene modification, DCs could produce high level of GM-CSF. When DCs were transfected with AdGM-CSF gene at MOI equal to 100, the GM-CSF level in culture supernatants reached saturation [(130.00 +/- 12.61) pg/ml]. After GM-CSF gene-modification, DCs tend to be more maturated as detected by morphological observation and phenotype analysis. At the same time, the capacity of activating the proliferation of allogeneic T lymphocytes was enhanced greatly. T lymphocytes stimulated by DCs transfected with GM-CSF gene showed a specific killing effect on gastric carcinoma cells and produced high level of INF-gamma [(1245.00 +/- 13.75) pg/ml].

CONCLUSIONAfter GM-CSF gene modification, DCs can produce high level of GM-CSF, which tend to be more maturated, and the capacity of activating the proliferation of allogeneic T lymphocytes is enhanced greatly. GM-CSF gene modified DCs can induce specific CTL to target tumor cells in vitro.

Adenoviridae ; genetics ; Animals ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; CD40 Antigens ; metabolism ; Cancer Vaccines ; immunology ; Cell Line, Tumor ; Cell Proliferation ; Cytotoxicity, Immunologic ; Dendritic Cells ; cytology ; immunology ; metabolism ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; metabolism ; Histocompatibility Antigens Class II ; metabolism ; Interferon-gamma ; secretion ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; Stomach Neoplasms ; immunology ; metabolism ; pathology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology ; Transfection

OBJECTIVETo construct the murine CCL21 eukaryotic expression plasmid, and to investigate the chemotactic function of its products.

METHODSMurine CCL21 cDNA was amplified by RT-PCR from murine total RNA, and was inserted into eukaryotic expression plasmid pcDNA3.1 after confirmation of sequencing. The recombinant CCL21 plasmid was transferred into mouse forestomach carcinoma (MFC) cells and the chemotactic function of expressed products was detected by chemotaxis assay.

RESULTGene sequencing, gel electrophoresis of PCR products and restrictive digestion proved the successful construction of CCL21, and its expression was confirmed by Western Blot. The transfected tumor cells had a significant chemotactic function to DC.

CONCLUSIONThe recombinant murine CCL21 eukaryotic expression plasmid has been successfully constructed, and its expression products in tumor cells have a marked chemotactic function to DC.

Animals ; Base Sequence ; Chemokine CCL21 ; biosynthesis ; genetics ; Chemotaxis, Leukocyte ; Cloning, Molecular ; DNA, Complementary ; genetics ; Dendritic Cells ; drug effects ; immunology ; Genetic Vectors ; genetics ; Mice ; Mice, Inbred C57BL ; Molecular Sequence Data ; Plasmids ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Stomach Neoplasms ; metabolism ; pathology ; Transfection ; Tumor Cells, Cultured

OBJECTIVEThe B7-H1/PD-1 co-signaling pathway has recently been found to play a pivotal role in the immune evasion of tumor cells from host immune system. The aim of this study was to examine the B7-H1 and PD-1 expression and TILs status in gastric cancer and to elucidate the clinical relevance of B7-H1 and PD-1 to the pathogenesis of gastric carcinoma.

METHODSImmunohistochemistry and ANAE histochemical staining were used to investigate the in situ expression of B7-H1 and PD-1 and TILs status in the gastric tissues. RT-PCR was used to explore B7-H1 and PD-1 expression at the transcriptional level. The B7-H1 expression at protein level was detected by Western blot.

RESULTSExpression of B7-H1 and PD-1 was found to be increased in gastric carcinoma, but absent in normal gastric tissue. B7-H1 expression in gastric carcinoma was inversely correlated with TILs infiltration. B7-H1 but not PD-1 expression in tumor tissue was significantly correlated with some clinicopathhological variables including depth of invasion, lymph node metastasis and distant metastasis.

CONCLUSIONB7-H1 and PD-1 expressions are increased in gastric carcinoma. This signaling pathway may inhibit antitumor immune responses in gastric carcinoma. B7-H1 expression plays a critical role in the pathogenesis of human gastric carcinoma,and might be a promising prognostic marker and therapeutic target in the treatment of this disease.

Adult ; Aged ; Antigens, CD ; genetics ; metabolism ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; B7-H1 Antigen ; CD4-Positive T-Lymphocytes ; immunology ; Female ; Humans ; Lymphatic Metastasis ; Lymphocyte Subsets ; immunology ; Lymphocytes, Tumor-Infiltrating ; immunology ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Staging ; Programmed Cell Death 1 Receptor ; RNA, Messenger ; metabolism ; Stomach Neoplasms ; genetics ; immunology ; pathology

Although N-myc downstream regulated gene 2 (NDRG2) has been known to be a tumor suppressor gene, the function of this gene has not been elucidated. In the present study, we investigated the expression and function of NDRG2 in human gastric cancer. Among seven gastric cancer and two non-cancer cell lines, only two gastric cancer cell lines, SNU-16 and SNU-620, expressed NDRG2, which was detected in the cytoplasm. Interestingly, NDRG2 was highly expressed in normal gastric tissues, but gastric cancer patients were divided into NDRG2-positive and -negative groups. The survival rate of NDRG2-negative patients was lower than that of NDRG2-positive patients. We confirmed that the loss of NDRG2 expression was a significant and independent prognostic indicator in gastric carcinomas by multivariate analysis. To investigate the role of NDRG2 in gastric cancer cells, we generated a NDRG2-silenced gastric cancer cell line, which stably expresses NDRG2 siRNA. NDRG2-silenced SNU-620 cells exhibited slightly increased proliferation and cisplatin resistance. In addition, inhibition of NDRG2 decreased Fas expression and Fas-mediated cell death. Taken together, these data suggest that inactivation of NDRG2 may elicit resistance against anticancer drug and Fas-mediated cell death. Furthermore, case studies of gastric cancer patients indicate that NDRG2 expression may be involved in tumor progression and overall survival of the patients.
Apoptosis/*physiology ; Cell Line, Tumor ; Down-Regulation ; Fas Ligand Protein/*physiology ; Gene Expression Regulation, Neoplastic ; Humans ; Stomach Neoplasms/metabolism/*mortality/pathology ; Tumor Markers, Biological/*metabolism ; Tumor Suppressor Proteins/biosynthesis/genetics/immunology/*metabolism

OBJECTIVETo investigate the relationship between the expression of host human leukocyte antigen-B mRNA (HLA-B mRNA) and HLA-B antigen in peripheral blood leukocytes (PBLs) and the differentiation and metastasis of gastric carcinoma (GC).

METHODSTo design and screen specific primers of HLA-B gene independently, detect the expression of HLA-B mRNA from 30 GC patients by reverse transcription-PCR and compare with the HLA-B antigen expression measured by flow cytometry.

RESULTSThe expression rate of PBL HLA-B mRNA from GC patients (23. 3% ) was very significantly lower than that of normals (87. 5% ) (P <0. 01) , especially concerning the poorly differentiated GC patients with lymph node metastasis (16. 0% ). Measured by flow cytometry, the expression percentage of HLA-B antigen of well-differentiated GC patients without lymph node metastasis was 88. 2% , an obviously decreasing tendency was showed in comparison with that in the normal group (98. 8% ) , although the difference was not significant (P = 0. 056) , and the expression percentage in poorly differentiated GC patients with lymph node metastasis(73. 3% )was declined significantly (P <0. 05).

CONCLUSIONThe expression of PBL HLA-B mRNA and HLA-B antigen in GC patients is decreased or lost, and correlated with differentiation and metastasis of the cancer. The expression of PBL HLA-B mRNA may more directly reflect its relationship with the tumor differentiation and metastasis than that of HLA-B antigen.

Adult ; Aged ; Cell Differentiation ; Female ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; HLA-B Antigens ; analysis ; genetics ; Humans ; Leukocytes ; immunology ; metabolism ; Lymphatic Metastasis ; Male ; Middle Aged ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Stomach Neoplasms ; genetics ; immunology ; pathology

Animals ; Antigens, Neoplasm ; biosynthesis ; genetics ; immunology ; Apoptosis ; physiology ; Breast Neoplasms ; immunology ; metabolism ; CD3 Complex ; immunology ; Female ; Humans ; Killer Cells, Natural ; pathology ; Neoplasms ; immunology ; metabolism ; Receptors, Antigen, T-Cell ; immunology ; Stomach Neoplasms ; immunology ; metabolism ; Uterine Cervical Neoplasms ; immunology ; metabolism

OBJECTIVESTo explore the mechanism of development and aggressiveness in gastric carcinomas by investigating the expression and role of CD97 and its cellular ligand CD55 in gastric carcinomas.

METHODSTumor and corresponding normal mucosal tissue, collected from 39 gastric carcinoma patients, were examined by immunohistochemistry and RT-PCR for the expression of CD97 and CD55.

RESULTSCD97(stalk) was strongly stained on scattered tumor cells or small tumor cell clusters at the invasion front of gastric carcinomas. The expression of CD97(stalk) was frequently observed in tumors of stage I and T1 gastric carcinoma patients. The expression of CD97(stalk) between Stage I and Stage II, III, IV specimens showed significant difference (P<0.05), between T1 and T2, T3, T4 specimens also showed significant difference (P<0.05). Specimens with tumor invasion depth limited in mucosa of T1 specimens showed higher positive CD55 expression than specimens with the same tumor invasion depth in T2, T3, T4 specimens, the expression of CD55 between T1 and T2, T3, T4 specimens was significantly different (P<0.05). There was strong correlation between the distribution patterns of CD97(stalk) and CD55 on tumor tissues (r=0.73, P<0.05). Signet ring cell carcinomas frequently contained strong CD97(stalk) and CD55-staining.

CONCLUSIONSOur results suggest that CD97(stalk) is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55. CD97(stalk) and CD55 could be useful as molecular markers for prognosis and therapy of gastric carcinoma patients.

Antigens, CD ; genetics ; metabolism ; Base Sequence ; Biomarkers, Tumor ; genetics ; metabolism ; CD55 Antigens ; genetics ; metabolism ; Female ; Gene Expression ; Humans ; Male ; Membrane Glycoproteins ; genetics ; metabolism ; Middle Aged ; Neoplasm Staging ; Prognosis ; RNA, Messenger ; genetics ; metabolism ; RNA, Neoplasm ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; immunology ; pathology ; therapy ; Tissue Distribution

BACKGROUND: It is well known that both gastric and intestinal phenotypic cell markers are expressed in gastric cancers. This study was aimed at investigating the correlation between gastric and intestinal phenotypic marker expression patterns of tumors and the clinicopathologic characteristics of gastric carcinomas. METHODS: We evaluated phenotypic marker expression by immunohistochemical staining with monoclonal antibodies. All tumors were classified as gastric (G), gastric and intestinal mixed (GI), intestinal (I), or null (N) phenotype. RESULTS: The tumors were phenotypically divided into G-phenotype tumors (33.2%), GI-phenotype tumors (25.7%), I-phenotype tumors (26.8%), and N-phenotype tumors (14.3%). N-phenotype tumors were associated with more corporeal location than GI- and I-phenotype tumors (p=0.009 and p=0.007, respectively), a larger size than I-phenotype tumors (p=0.007), a higher proportion of advanced gastric cancers than G-, GI-, and I-phenotype tumors (p=0.003, p< 0.001, and p< 0.001, respectively), more perineural invasion than G-, GI-, and I-phenotype tumors (p=0.076, p=0.003, and p=0.003, respectively), and more lymph node metastasis than GI-phenotype tumors (p=0.017). I-phenotype tumors were associated with a higher proportion of intestinal-type tumors than G-, GI-, and N-phenotype tumors (p< 0.001, p=0.011, and p< 0.001, respectively). CONCLUSION: Our results indicate that the gastric and intestinal phenotypic marker expression pattern of tumors is prognostically useful for patients with gastric carcinoma.
Tumor Markers, Biological/genetics ; Stomach Neoplasms/genetics/immunology/*pathology ; Prognosis ; *Phenotype ; Middle Aged ; Male ; Intestinal Neoplasms/genetics/immunology/*pathology ; Immunohistochemistry ; Humans ; Female ; Carcinoma/genetics/immunology/*pathology ; Antibodies, Neoplasm ; Antibodies, Monoclonal

OBJECTIVETo investigate the expression of gastrin in human gastric cancer cell line SGC-7901 and the effects of gastrin-17 and anti-gastrin mAb on its growth.

METHODSThe expression of gastrin was determined by immunohistochemistry with anti-gastrin mAb prepared by our group. In a series of experiments, the growth of SGC-7901 cells was evaluated by MTT assay on cells grown in serum-free medium and treated with gastrin-17 and/or anti-gastrin mAb.

RESULTSImmunohistochemical examination of SGC-7901 cells revealed a specific gastrin immunoreactivity. Gastrin-17 significantly stimulated cell growth at the concentrations of 1 x 10(-9) mol/L approximately 1 x 10(-5) mol/L in a dose-dependent manner. The growth of SGC-7901 cells treated with anti-gastrin mAb, either alone or in combination with gastrin-17 (1 x 10(-7) mol/L), was significantly inhibited.

CONCLUSIONGrowth of human gastric cancer cells SGC-7901 can be stimulated in an autocrine fashion. The gastrin-stimulated growth of gastric cancer cells can be blocked by anti-gastrin mAb bound specifically with gastrin. Further study on the significance of anti-gastrin mAb in designing immunotherapy targeting to gastrin or gastrin receptor is warranted.

Antibodies, Monoclonal ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; Gastrins ; biosynthesis ; genetics ; immunology ; Humans ; Receptor, Cholecystokinin B ; biosynthesis ; genetics ; Stomach Neoplasms ; metabolism ; pathology