Quantitative Transcriptome Analysis of the Stomach Neck Mucosa from Control vs Claudin (CLDN)-18 knockout mice.

Purpose: To determine early changes in gene expression that drive gastric cancer development in the landscape of CLDN18 loss using RNAseq. Results: Although claudin-18 is a tight junction protein and should regulate paracellular permeabiity and/or ion flux across the mucosa, we showed this protein is rather a potent tumor suppressor that regulates cellular signaling and differentiation pathways in gastric epithelial cells. Methods: Stomach neck region mRNA profiles of 7-day-old wild-type (WT) and claudin-18 knockout (CLDN18−/−) mice were generated by deep sequencing, in triplicate, using the Illumina HiSeq2000 sequencing system. The resulting sequences were mapped to the Mouse genome (mm10) using STAR aliger and P-values were adjusted using the Benjamini-Hochberg procedure (J R Statist Soc B 1995;57:289-300). Conclusions: Loss of claudin-18 promotes gastric cancer development by modulating the expression program of gastric epithelial cells, including cellular signaling and differentiation pathways that are required for mucosal homeostasis. Stomach (neck region only) mRNA profiles of 7-day old wild-type (WT) and CLDN18-/- mice were generated by deep sequencing, in triplicate, using an Illumina HiSeq2000 sequencing system.