Abstract: Objective: to investigate the expression of PTPN13 in human gastric cancer and gastric cancer SGC-7901 cell line and its association with proliferation and invasion. Methods: 106 cases gastric cancer tissue samples and matched normal peritumorial tissues were collected. SGC-7901 cells were cultured and divided into two groups including pcDNA3.1-PTPN13 transfection group and without transfection group. Immunohistochemical technique were used to detected protein expression of PTPN13. The association of PTPN13 expression with tumor location, tumor size, depth of invasion and tumor metastasis was analyzed. The survival rate of patients with different PTPN13 expression was calculated by Kaplan-Meier curves. CCK-8 assay was used to estimate the proliferation changes. Using Trans-well assay analyzed the invasion of SGC-7901 cells. Moreover, Western blot was performed to detect the markers of EMT including E-cadherin, Snail and MMP9.Results: Immunohistochemistry showed the expression rate of PTPN13 in gastric cancer tissues was lower than normal tissue (31 % vs.83%, P<0.05). The expression of PTPN13 in patients was related to with different tumor size, depth of invasion and tumor metastasis (P<0.05). The 2-years survival rate of patients with negative PTPN13 expression were lower. Overexpression reduced both proliferation and invasion in SGC-7901 cells. Western blot showed that up-regulated PTPN13 could increase E-cadherin level but decreased the level of Snail and MMP9.Conclusions: PTPN13 play a role in gastric cancer tissue and cells as a tumor suppressor. Lower PTPN13 may indicate a poor prognosis. PTPN13 could be used as therapy target in gastric cancer.

Key words: Gastric Cancer, Protein Tyrosine Phosphatases Non-Receptor Type 13, Proliferation, Invasion