Human gastric cancer cell MKN45: MKN45-GFP control vs. highly metastatic sublines
ABSTRACT: Gene expression profiles of in vitro selected highly metastatic MKN45-GFP sublines. The results were compared with MKN45-GFP control cell line to determine the metastasis associated genes. Four pairs compared experiment. Each pair was used MKN45-GFP cells as correlated control. Determining on the gene expression trends were by various metastatic ability of each subline.
Project description:Gene expression profiles of in vitro selected highly metastatic MKN45-GFP sublines. The results were compared with MKN45-GFP control cell line to determine the metastasis associated genes. Overall design: Four pairs compared experiment. Each pair was used MKN45-GFP cells as correlated control. Determining on the gene expression trends were by various metastatic ability of each subline.
Project description:Cancer relapse after curative treatment is thought to originate from drug-tolerant and invisible cancer cell subpopulations. Using cancer cell colonies emerging in the presence of drugs (drug-tolerant colonies, DTCs), we found that the drug-tolerant properties of DTCs are lost through a reversible mechanism. To examine whether epigenetic regulation is responsible for the phenotypic changes in DTCs, we performed a genome-wide analysis for relative CpG methylation between the DTCs and untreated colonies derived from MKN45 by NimbleGen Human Meth 385K Prom Plus CpG Arrays. Global changes in the methylation levels were evident in a chromosomal location-dependent manner. The methylation status of the upstream regions of the transcription start sites of the pluripotency-inducing genes showed good agreement with the qRT-PCR data. These results suggest that reversible drug-tolerant properties in DTCs are epigenetically regulated and associated with transcriptional regulation, including pluripotency-inducing factors. Comparison of untreated colonies v.s. DTCs derived from MKN45 cells.
Project description:Expression of SET7/9, a histone methyltransferase, was frequently reduced in cultured and primary gastric cancers. To identify the SET7/9 target genes in gastric cancer, we performed siRNA-based knockdown of SET7/9 in MKN74 and MKN45 cells and then examined significant expression changes of genes by microarray. Transfection of SET7/9 siRNA into MKN74 and MKN45 cells were performed by electroporation. After 48hrs, cells were harvested. Total RNA was used for cDNA microarray.
Project description:This study set out to identify global changes in gene expression in MKN45 gastric epithelial cells following 8 hours stimulation with 10 μg/ml lipopolysaccharide (LPS) from the gastric pathogen H. pylori. Microarray analysis was used to compare changes in gene expression between cells treated with 10 μg/ml H. pylori LPS and untreated cells at the same time point. Total RNA was harvested from MKN45 cells following treatment with LPS for 8h or untreated cells at the same time-point. 2 independent experiments were carried out. RNA was labeled and hybridized to GeneChips to analyse changes in gene expression.
Project description:MET amplification is present in 20% of gastric cancers and has been confirmed as a therapeutic target in clinical trials. The molecular mechanisms of response and resistance to MET inhibitors are not well understood. We investigated the determinants of MET dependency in human gastric cancer. MET inhibition inhibited proliferation and induced cell death only in MET-amplified gastric cancer cell lines. The effects on growth arrest were stronger than the effects on cell death. To identify possible resistance mechanisms, we performed whole-genome mRNA expression profiling. Molecular changes related to autophagy were among the top alterations observed. Consistent with these findings, autophagy levels increased in a concentration-dependent manner when MET-amplified cells were exposed to crizotinib. Autophagy inhibition caused a dramatic decrease in apoptosis in one of the MET-amplified cell lines (MKN45) but not in the other (SNU-5). Because autophagy may provide energy in cells subjected to growth factor deprivation, we explored the effects of MET or autophagy inhibition on cellular ATP levels. This revealed that autophagy-dependent ATP production was selectively required for apoptosis in the MKN45 cells and that chemical ATP depletion mimicked the effects of autophagy inhibition to block cell death. Overall, the data reveal a novel relationship between ATP depletion and resistance to MET inhibitor-induced cell death. Our observations suggest that autophagy inhibitors could have unintended consequences when they are combined with growth factor receptor inhibitors in tumors that require autophagy-dependent ATP production for apoptosis. 12 samples triplicate samples of SNU-5 and MKN45 +/- criztonib for 24 hours
Project description:Transcripts upregulated or downregulated by knockdown of MUC1 were identified through expression profiling of a total of 12,135 genes in comparison with MKN45- MUC1 RNAi clones and control clones. We endeavored to identify genes which expression is affected by MUC1 by performing cDNA microarray analysis on two MKN45 MUC1 RNAi clones and one control clone.
Project description:Analysis to find splicing variants that are differentially expressed in a highly metastatic stomach cancer cell line, MKN45P, versus its parental cell line, MKN45 Comparison between highly metastatic gastric cancer cell line MKN45P and its parental cell line MKN45
Project description:Analysis to find splicing variants that are differentially expressed in a highly metastatic stomach cancer cell line, MKN45P, versus its parental cell line, MKN45 Overall design: Comparison between highly metastatic gastric cancer cell line MKN45P and its parental cell line MKN45
Project description:Persistent colonization of the gastric mucosa by Helicobacter pylori (Hp) elicits chronic inflammation and aberrant epithelial cell proliferation, which increases the risk of gastric cancer. We examined the ability of microRNAs to modulate gastric cell proliferation in response to persistent Hp infection and found that epigenetic silencing of miR-210 plays a key role in gastric disease progression. Importantly, DNA methylation of the miR-210 gene was increased in Hp-positive human gastric biopsies as compared to Hp-negative controls. Moreover silencing of miR-210 in gastric epithelial cells promoted proliferation. We identified STMN1 and DIMT1 as miR-210 target genes and demonstrated that inhibition of miR-210 expression augmented cell proliferation by activating STMN1 and DIMT1. Together, our results highlight inflammation-induced epigenetic silencing of miR-210 as a mechanism of induction of chronic gastric diseases, including cancer, during Hp infection. To identify miR-210 targets in gastric cells, whole transcriptome analysis of AGS and MKN45 cells transfected with pre-miR-210 was conducted using Affymetrix GeneChip Human Genome U133 Plus 2.0 Array.