Human epidermal growth factor receptor 2 (HER2) proteins are overexpressed in a high proportion of gastric cancer (GC) cases and affect the maintenance of cancer stem cell (CSC) subpopulations, which are used as targets for the clinical treatment of patients with HER2-positive GC. Despite improvements in survival, numerous HER2-positive patients fail treatment with trastuzumab, highlighting the need for more effective therapies. In this study, we generated a novel type of genetically modified human T cells, expressing a chimeric antigen receptor (CAR), and targeting the GC cell antigen HER2, which harbors the CD137 and CD3ζ moieties. Our findings show that the expanded CAR-T cells, expressing an increased central memory phenotype, were activated by the specific recognition of HER2 antigens in an MHC-independent manner, and effectively killed patient-derived HER2-positive GC cells. In HER2-positive xenograft tumors, CAR-T cells exhibited considerably enhanced tumor inhibition ability, long-term survival, and homing to targets, compared with those of non-transduced T cells. The sphere-forming ability and in vivo tumorigenicity of patient-derived gastric cancer stem-like cells, expressing HER2 and the CD44 protein, were also inhibited. Our results support the future development and clinical application of this adoptive immunotherapy in patients with HER2-positive advanced GC.
Animals ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasms, Experimental ; immunology ; pathology ; therapy ; Receptor, ErbB-2 ; immunology ; Receptors, Antigen, T-Cell ; immunology ; Stomach Neoplasms ; immunology ; pathology ; therapy ; Tumor Cells, Cultured

No abstract available.
Aged ; Antigens, CD38/analysis ; Biomarkers, Tumor/analysis ; Biopsy ; Gastrointestinal Hemorrhage/diagnosis/*etiology/therapy ; Gastroscopy ; Hematemesis/etiology ; Humans ; Immunohistochemistry ; Male ; Melena/etiology ; Membrane Glycoproteins/analysis ; Multiple Myeloma/*complications/immunology/pathology/therapy ; Recurrence ; Stomach Neoplasms/*complications/immunology/pathology/therapy

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

Actins ; immunology ; metabolism ; Antibodies, Monoclonal ; metabolism ; Child ; Diagnosis, Differential ; Fibroma ; metabolism ; pathology ; surgery ; Follow-Up Studies ; Gastrointestinal Neoplasms ; metabolism ; pathology ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Humans ; Leiomyoma ; metabolism ; pathology ; Male ; Pyloric Antrum ; pathology ; Stomach Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

BACKGROUND AND OBJECTIVEAs a prospective vaccine carrier, nanoparticles can protect antigens from degradation and enhance immune response. This study prepared nanovaccines with MAGE-3-derived CD4+-CD8+T cell epitope peptides, and investigated its character and antitumor effects on transplanted gastric cancer in mice.

METHODSWe adopted the self-assembly method to prepare peptide/chitosan conjugated with deoxycholic acid (chitosan-deoxycholic acid) nanoparticles. We observed the appearance of the chitosan-deoxycholic acidnanoparticles through a transmission electron microscope (TEM) and analyzed the peptide content and its release pattern by fluorescence spectrophotometry. We observed tumor-suppression efficacy in vivo through animal experiments.

RESULTSWe successfully prepared nanoparticles with MAGE-3 peptide antigen, and its encapsulation efficiency and loading level were about 37% and 17.0%, respectively. These nanoparticles presented a delayed release pattern in phosphate buffered saline (PBS) at pH 7.4, and the full release time was about 48 h. In 2 mg/mL lysozyme, the nanoparticles showed a sudden release, and the full release time was about 24 h. ELISPOT and cytotoxic experiments showed that the MAGE-3 peptide loaded nanoparticles could stimulate immune response in vivo and could generate MAGE-3-targeted cytotoxic T lymphocytes (CTLs), and kill MAGE-3-specific tumor cells. Tumor suppression experiments showed that the regression ratio of the peptide-loaded nanoparticles group was 37.81%.

CONCLUSIONSMAGE-3 peptide/chitosan-deoxycholic acidvaccine-loaded nanoparticles can stimulate antitumor immune response in vivo and can regress the growth of mouse forestomach carcinoma cell line MFC.

Animals ; Antigens, Neoplasm ; chemistry ; immunology ; Cancer Vaccines ; administration & dosage ; Cell Line, Tumor ; Chitosan ; chemistry ; Dendritic Cells ; immunology ; Deoxycholic Acid ; chemistry ; Drug Carriers ; chemistry ; Epitopes, T-Lymphocyte ; immunology ; Male ; Mice ; Nanoparticles ; Neoplasm Proteins ; chemistry ; immunology ; Neoplasm Transplantation ; Stomach Neoplasms ; pathology ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Burden

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

OBJECTIVEEGFR-mediated tumor proliferation plays an important role in the development of cancer, and is a key candidate for targeted therapy. The aim of this study is to evaluate the impact of EGFR monoclonal antibody Cetuximab (C225) on the growth, proliferation and apoptsis of gastric cancer xenograft in nude mice, and its possible mechanisms.

METHODSA gastric cancer cell line SGC-7901 with high EGFR expression level was screened from 7 gastric cancer cell lines. Gastric cancer xenografts in nude mice were established, and randomly divided into C225 treatment group and PBS control group. Tumor growth curves were calculated, the impact of C225 on the tumor growth, proliferation and angiogenesis was evaluated by immunohistochemical (IHC) staining Ki67 and CD34, respectively. The effect of C225 on apoptosis in the gastric cancer cells was evaluated by TUNEL assay. The expression levels of EGFR and its transcription factor Sp1 were detected by IHC staining and Western blot.

RESULTSAfter C225 treatment, the proliferation and growth of gastric cancer xenograft in nude mice were significantly decreased. In the contrast, the apopotic indexes in C225 treatment group and PBS control group were (16.4% +/- 0.3%) and (3.1% +/- 0.9%), respectively, with a significant difference (P < 0.001). There was no significant difference of the densities of CD34-positive microvessels between C225 treatment group and control group. Elevated expression of EGFR and Sp1 after C225 treatment was observed by IHC staining and Western blot assay.

CONCLUSIONEGFR monoclonal antibody cetuximab (C225) can effectively inhibit the growth of gastric cancer xenografts in nude mice, and trigger its apoptosis. Yet, C225 treatment may upregulate the expression of EGFR and its transcription factor Sp1. A "block-transcription activation-compensation" mechanism may exist to explain the molecular mechanism of acquired resistance of a single target blockade treatment.

Animals ; Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cetuximab ; Humans ; Ki-67 Antigen ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microvessels ; pathology ; Neovascularization, Pathologic ; prevention & control ; Random Allocation ; Receptor, Epidermal Growth Factor ; immunology ; metabolism ; Sp1 Transcription Factor ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Tumor Burden ; drug effects ; Xenograft Model Antitumor Assays

This study sought to shed light on the killing effect of peripheral blood mononuclear cells (PBMCs) irradiated by gamma ray at a dose of 1 Gy on cultured human gastric tumor cell line MKN-28. The radiation dose rate of 17 Gy/min was used. The groups in the experiment were MKN-28 cell control group, PBMCs control group, MKN-28 tumor cells with irradiated or non-irradiated PBMCs co-cultured groups. Radiation dosage was one Gray, acridine orange/ethidium bromide (AO/EB) staining was used for observation of the killing effects of PBMCs on tumor cells in different period. Cells were harvested 240 h later and observed by transmission electron microscopy. The result showed the living period of irradiated PBMCs was shorter than that of non-irradiated PBMCs. In the irradiated and non-irradiated groups,a few PBMCs were still alive after being cultured for 240 h, but the cell volume was larger than that of lymphocytes. These cells were identified as monocytes (95%) or DCs (5%) by transmission electron microscopy. The co-culture of irradiated PBMCs and MKN-28 cells showed that tumor cells were eliminated after 96 h. As compared with the non-irradiated goup, the irradiated PBMCs had more potent ability for killing tumor. The results demonstrate that 1 Gy gamma irridiation can improve the killing effect of PBMCs on the tumor cells, and that 1 Gy gamma irritation can also induce shorter living period of lymphocytes in PBMCs cultured in vitro, but such irritation has little effect on the living period of monocytes and DCs in PBMCs.
Cell Survival ; Coculture Techniques ; Gamma Rays ; Humans ; Leukocytes, Mononuclear ; cytology ; immunology ; radiation effects ; Stomach Neoplasms ; immunology ; pathology ; Tumor Cells, Cultured

Breast Neoplasms ; metabolism ; pathology ; Cytokines ; metabolism ; Female ; Fluorescent Antibody Technique ; Humans ; Microscopy, Fluorescence ; Paraffin Embedding ; Proliferating Cell Nuclear Antigen ; metabolism ; Quantum Dots ; Receptor, ErbB-2 ; metabolism ; Receptors, Estrogen ; metabolism ; Stomach Neoplasms ; immunology ; pathology