Abstract
Protein tyrosine phosphatase receptor U (PTPRU) has been shown to be a tumor suppressor in colon cancer by dephosphorylating β-catenin and reducing the activation of β-catenin signaling. Here, we investigate the expression of PTPRU protein in gastric cancer cell lines, gastric cancer tissues and respective adjacent non-cancer tissues and find that the 130 kDa nuclear-localized PTPRU fragment is the main PTPRU isoform in gastric cancer cells, whereas the full-length PTPRU is relatively lowly expressed. The level of the 130 kDa PTPRU is higher in gastric cancer tissues than in adjacent non-cancer tissues. Knockdown of endogenous PTPRU in gastric cancer cells using lentivirus-delivered specific shRNA results in the attenuation of cell growth, migration, invasion and adhesion. Knockdown of PTPRU also inhibits tyrosine phosphorylation and transcriptional activity of β-catenin as well as levels of focal adhesion proteins and lysine methylation of histone H3. These results indicate that PTPRU is required for gastric cancer progression and may serve as a potential therapeutic target.