Low Expression of SP1 has a Different Effect on Intestinal-type compared to Diffuse-type Gastric Adenocarcinoma
ABSTRACT: 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:To identify the specific genes for intestinal-type and diffuse-type gastric cancers. We selected 18 intestinal-type gastric cancers and 12 diffuse-type gastric cancers showing typical characteristics on the form of cell growth (clustered or scattered) and the degree of differentiation (well/moderate or poor), and performed microarray analysis for obtaining genome-wide mRNA expression profiles.
Project description:Gene expression profiling of gastric cancer cells MKN28 infected with Sox2 lentivirus comparing with MKN28 infected with control lentivirus Transfected cell lines, MKN28-Sox2 vs. MKN28-NC
Project description:To investigate the effect of STAT3 activation on the expression of gastric cancer cells, expression profile was compared in MKN28 cells overexpressed with control vector vs mouse constitutively activated STAT3 mutant (STAT3c). MKN28 gastric cancer cells were transfected with pcDNA3.1 (vector control) or plasmid overexpressing STAT3c (treatment). Stable clones were selected for RNA extraction and expression microarray analysis (Agilent). Experiments were repeated twice.
Project description:To identify the transcriptional targets of CDX1 underlying the metaplastic change, we explored genes affected by ectopic expression of CDX1 in gastric epithelial cells by combining expression microarray and ChIP-chip analyses. Overall design: CDX1-inducible MKN28 cells, which inducibly express Flag-tagged CDX1 with the use of a tetracycline-regulated Tet-Off System (Clontech), were established from MKN28 human gastric epithelial cells. CDX1-inducible MKN28 cells were cultured for 24 h in the absence or presence of doxycycline (Clontech), a tetracycline analog. We then performed expression microarray and ChIP-chip analyses.
Project description:To access target binding sites of TEAD4 in gastric cancer, TEAD4 binding was investigated using MKN28 and SNU216 cell lines by ChIP-seq. MKN28 and SNU216 cell lines were cross-linked with formaldehyde, fractionated by sonication and immunoprecipitated by TEAD4 antibody. Immunoprecipitated DNA was prepared by generating libraries and sequenced by massive parallel sequencing.
Project description:This series studied the patterns of gene expression among different types of gastric tumors. Gastric tumors and adjacent non-tumor normal tissues were obtained from 50 gastric cancer patients of diverse stages (IA, IB, II, IIIA, IIIB, and IV), tumor types (intestinal, diffuse, or mixed), and degree of tumor differentiation (moderately or poorly differentiated). Keywords: Cancer patient samples Overall design: We obtained both tumor and normal tissue samples from the same patient and hybridized them together to remove any individual biological variations unrelated to gatric cancer progression. We hybridized each patient's sample twice with dye swapping.
Project description:The study was undertaken to identify microRNAs differently expressed by intestinal type of gastric cancer using miRNA microarray. The miRNA expression in the intestinal type of gastric cancer depending on H. pylori infection suggest that different gastric cancer pathogenesis could be exist between H. pylori-positive and -negative gastric cancer. Total RNA was extracted from cancerous region and non-cancerous regions in formalin fixed paraffin embedded tissues of intestinal type gastric cancer patients who were H. pylori-positive (n=8) or -negative (n=8). Corresponding author: Nayoung Kim, M.D., Department of Internal Medicine, Seoul National University Bundang Hospital (Tel., +82-31-787-7008; e-mail, email@example.com).