Abstract: Background and purpose: Gastric cancer is the most common malignant tumor of digestive tract, and the possibility of postoperative recurrence and metastasis is higher. Our previous studies showed that protein tyrosine phosphatase1B (PTP1B) gene is closely correlated with tumor size, lymph node metastasis and TNM stage of gastric cancer. The purpose of the present study was to explore the effect of PTP1B gene on cell proliferation and migration of gastric cancer cell lines. Methods: Short hairpin RNA (shRNA) sequence targeting PTP1B gene and PTP1B cDNA were transfected into MKN28 and MKN45 cells, respectively. The expression of PTP1B mRNA and its protein in MKN28 and MKN45 cells were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. The effect of PTP1B on cell proliferation and migration was respectively assessed by cell counting kit-8 (CCK-8) assay, Transwell migration assay and wound healing assay. Results: Compared with blank and negative controls, the expressions of PTP1B mRNA and protein in MKN28 cells were successfully suppressed after the cells were transfected with shRNA (P<0.05). As CCK-8 test showed, the proliferation of MKN28 cells was successfully restrained at 48, 72 and 96 h after transfected with shRNA compared with blank control and negative control (P<0.05). Transwell and wound healing test were performed after PTP1B expression was interfered by shRNA. The result demonstrated that migration of MKN28 cells was significantly inhibited (P<0.05). On the contrary, the expressions of PTP1B mRNA and protein in MKN45 cells were obviously enhanced after the cells were transfected with PTP1B cDNA. And the proliferation and migration of cells were significantly increased. Conclusion: PTP1B gene is an important enchancer for the proliferation and migration of gastric cancer.

Key words: Gastric cancer, Protein tyrosine phosphatase 1B, Short hairpin RNA, Cell proliferation, Cell migration