Project description:Sequencing of 16S ribosomal RNA (rRNA) gene, which has improved the characterization of microbial community, has made it possible to detect a low level Helicobacter pylori (HP) sequences even in HP-negative subjects which were determined by a combination of conventional methods. This study was conducted to obtain a cutoff value for HP colonization in gastric mucosa biopsies and gastric juices by the pyrosequencing method. Corresponding author: Nayoung Kim, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoungnam, Gyeonggi-do, Korea; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea (Tel., +82-31-787-7008; e-mail, nayoungkim49@empas.com).
Project description:Sequencing of 16S ribosomal RNA (rRNA) gene, which has improved the characterization of microbial community, has made it possible to detect a low level Helicobacter pylori (HP) sequences even in HP-negative subjects which were determined by a combination of conventional methods. This study was conducted to obtain a cutoff value for HP colonization in gastric mucosa biopsies and gastric juices by the pyrosequencing method. Corresponding author: Department of Internal Medicine, Seoul National University Bundang Hospital, Seoungnam, Gyeonggi-do, Korea; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea (Tel., +82-31-787-7008; e-mail, nayoungkim49@empas.com). Microbial DNA from gastric mucosal samples [gastric antrum (n=63, mucosal biopsy), follow-up sample on gastric antrum (n=16, mucosal biopsy), and gastric body (n=18, mucosal biopsy)] and gastric juices (n=4, not mucosal biopsy) was amplified by nested PCR using universal bacterial primers, and the 16S rRNA genes were pyrosequenced.
Project description:Epithelial-mesenchymal transition (EMT) is in the highlights as a significant role in tumor progression and invasion. Snail was known as the one of regulators of EMT in various malignant tumors. The aim of this study was to investigate the effect of Snail on invasiveness/migratory ability of gastric cancer cell lines and clinicopathological and prognostic significance of Snail over-expression using immunohistochemistry in tissue microarray of 314 gastric adenocarcinomas (GC). Differential gene expression in Snail over-expressed GC was investigated using cDNA microarray analysis. Silencing of Snail by ShRNA induced decreased of invasion, migration of gastric cancer cell lines. In contrast, over-expression of Snail induced increased invasiveness and migratory ability of gastric cancer cell lines in accordance increase of VEGF and MMP11. Furthermore, the over-expression of Snail (?75% nuclear staining of Snail) was significantly associated with tumor progression (p<0.0001), lymph node metastases (p=0.002), lymphovascular invasion (p=0.002), and perineural invasion (p=0.002) in 314 GC patient. Snail over-expression was also associated with poor prognosis (shorter survival) in GC patients (p=0.023). cDNA microarray revealed 213 differential expressed genes in Snail over-expressed GC tissues, including genes related to metastasis, invasion. Based on above results, it was suggested that Snail plays a significant role in invasiveness/migratory ability of GCs. In addition, Snail might be used to predictive biomarker for evaluation of prognosis or aggressiveness in GCs. 48 primary gastric adenocarcinoma fresh frozen tissues were used for microarray. All the tissues were obtained after curative resection after pathologic confirm at Pusan National University Hospital (PNUH, Busan, Korea) and Cheonnam University Hospital (CNUH, Cheonnam, Korea). Microarray experiment and data analysis were done at Cancer research institute, PNUH, Busan, Korea.