| PTPRU belongs to the R2B subfamily of receptor type tyrosine phosphatase family. Full-length PTPRU is composed of a MAM domain, an Ig-like domain, three consecutive FNIII domains and two phosphatase domains. Full-length PTPRU has been shown to be a tumor suppressor in colon cancer by dephosphorylating β-catenin and reducing the activation of β-catenin signaling.However, the protein expression and feature of endogenous PTPRU in many cancers, including gastric cancer, remains unknown. In the present study, we find that the expression of a 130kDa nuclear-localizedPTPRU isoform in gastric cancer cell lines and gastric cancer samples is relatively high when compared with full-length PTPRU. Knockdown of endogenous PTPRU in gastric cancer cells using lentivirus-delivered specific shRNA results in the attenuation of cell growth, migration, invasion and adhesion.correspondingly, the level of proteins associated with cell cycle and cell motility regulation also is downregulated following PTPRU knockdown. Knockdown of PTPRU also inhibits tyrosine phosphorylation and transcriptional activity of β-catenin-TCF4/LEF complex as well as levels of several target genes, focal adhesion proteins and lysine methylation of histone H3.Taken together, our findings indicate that endogeneous PTPRU has high expression in gastric cancer tissues. It is required for the growth and motility of gastric cancer cell, functioning as an important role in the progression of gastric cancer. It indicates that PTPRU may serve as a potential therapeutic target. |
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