mRNA expression from wild type and gp130F/F mice antrum at 4 weeks of age in specific pathogen free (SPF) and germ free (GF) conditions

The role of microbe in promoting the initiation of gastric cancer (GC), the third most lethal cancer worldwide, are ill-defined. Here, we found that tumor size and weight in gp130F/F mouse stomach at condition were significantly reduced compared to those of at SPF condition. To investigate the underlying mechanism and how host genes were regulated in the presence/absence of microbe, arrays were performed in stomach tissue from gp130F/F and WT at 4 week old at SPF and GF conditions. The onset of gastric inflammation-associated adenomatous hyperplasia in gp130F/F mice occurs at ~6 weeks of age, with established intestinal-type tumors (3 months of age) progressively growing until a maximum size is reached at 6 months of age, with some evidence of carcinoma in situ. Since this phenotype histologically mimics early stage human GC, we therefore utilized gp130F/F mice as a model to identify miRNAs involved in the initiating molecular events leading to early stage GC. For this purpose, we performed miRNA microarrays on mouse gastric antrum tissue from gp130F/F and sex-matched littermate wild-type (gp130+/+) control mice aged 4 weeks; this age was chosen since antrum tissue from 4 week old (wo) gp130F/F mice is devoid of any histological signs of inflammation or hyperplasia, and is thus comparable to wild-type gastric antrum tissue. Total RNA from 4 week old mouse antrum samples was subjected to an illumina array platform. The raw data was normalized using neqc. We included BL6 samples for data normalization, but not for comparisons between sample groups.