Project description:Gastric cancer is a highly immunogenic malignancy. Immune tolerance facilitated by myeloid-derived suppressor cells (MDSCs) has been implicated in gastric cancer resistance mechanisms. The potential role of APE1 in regulating gastric cancer metastasis by targeting MDSCs remains uncertain. In this study, the plasmid Plxpsp-mGM-CSF was used to induce high expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in GES-1 cells. For tumor transplantation experiments, AGS, AGS+GM-CSF and AGS+GM-CSF-siAPE1 cell lines were established by transfection, followed by subcutaneous implantation of tumor cells. MDSCs, Treg cells, IgG, CD3 and CD8 levels were assessed. Transfection with siAPE1 significantly inhibited tumor growth compared to the AGS+GM-CSF group. APE1 gene knockdown modulated the immune system in gastric cancer mice, characterized by a decrease in MDSCs and an increase in Treg cells, IgG, CD3 and CD8. In addition, APE1 gene knockdown resulted in decreased levels of pro-MDSC cytokines (HGF, CCL5, IL-6, CCL12). Furthermore, APE1 gene knockdown inhibited proliferation, migration and invasion of AGS and MKN45 cells. AGS-GM-CSF cell transplantation increased MDSC levels and accelerated tumor growth, whereas APE1 knockdown reduced MDSC levels, inhibited tumor growth and attenuated inflammatory infiltration in gastric cancer tissues.
Project description:Expression analysis of gene expression changes in Homo sapiens SGC-7901 cells after knock down of MTA2 (Metastasis-associated protein) or overexpression SNHG5 (snoRNA host gene 5) Investigation of whole genome gene expression level changes in a Homo sapiens gastric carcinoma cells SGC-7901 after knock down MTA2 expression and upregulation of SNHG5 A four chip study using total RNA extracted from SGC-7901 cells transfected with siRNA negative control and SGC-7901 cells knock down of MTA2 with siRNA. Each chip measures the expression level of 45033 genes collected from the authoritative data source including NCBI
Project description:In order to better understand the relationship between NOTCH1 gene and immunity in gastric adenocarcinoma cells, we performed the silent interference of NOTCH1 gene on three gastric adenocarcinoma cell lines AGS, MKN-45 and MGC-803. We extracted the total RNA from the interfered and untreated blank control cells, and performed lncRNA library construction and sequencing. The results of bioinformatics analysis showed that the silencing of NOTCH1 gene in gastric adenocarcinoma cells activated several immune-related signal transduction pathways, including T cell receptors, chemokines, JAK-STAT, Toll-like receptors, ECM receptors and other signals. Conduction pathway. These results confirm that NOTCH1 may down-regulate the immune response of gastric adenocarcinoma.
Project description:Specificity protein 1 (SP1) is an essential transcription factor regulating multiple cancer-related genes. Since aberrant expression of SP1 was known to be related to cancer development and progression, we focused on SP1 expression in gastric carcinoma and its correlation with disease outcomes. We discovered a different relationship between SP1 expression and patient survival in intestinal- and diffuse-type gastric cancer. In diffuse-type gastric cancer, patient survival decreased as SP1 expression increased (P < 0.05) in accordance with previously published papers, whereas the lack of SP1 expression in intestinal-type gastric cancer was correlated significantly with poor survival (P < 0.05). When SP1 downregulation was forced in high SP1 expressor intestinal-type gastric cell line MKN28 with siRNA, both migration and invasion were increased but cell proliferation was decreased. In accordance with these results, microarray data in siRNA-transfected MKN28 showed that genes inhibiting migration were downregulated and the expression of genes negatively facilitating proliferation was increased. Both migration and invasion, however, in low SP1 expressor intestinal-type gastric cell line AGS were decreased by forced SP1 expression. In contrast to intestinal-type, in diffuse-type gastric cell line SNU484, high SP1 expressor, both migration and invasion were decreased by siRNA. Contrary to previous studies, which did not reflect differences between the 2 histological types, our results showed that low expression of SP1 is involved in cancer progression and metastasis, and has a different effect on intestinal-type compared to diffuse-type gastric adenocarcinoma. 2 samples for MKN28 cells: si-SP1 against si-control and dyeswap of it upon 72 hour
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Stable knockdown of NET1, a RhoGEF, was achieved in AGS Gastric Cancer cells. This gene is known to be overexpressed in the disease. Knockdown was achieved using lentiviral shRNA particles. Gene expression was compared between knockdown and scrambled shRNA treated control cells. Cells were treated with and without LPA, a known activator of RhoA.
Project description:To investigate the knockdown effect of STAT3 on DNA methylation on gastric cancer cells, genome wide DNA methylation profiling of AGS transfected with pLKO.1-puro-shGFP or shSTAT3 generated from Illumina Infinium MethylationEPIC.