Abstract:      Background and purpose: Progranulin (PGRN) is a novel growth factor that plays an important role in the tumorigenicity, tumor cell migration and cell cycle. Its expression in many malignant tumor cells is high. It is not only involved in tumor cell growth, but also closely related with the occurrence and evolution of tumor. This study was to investigate the expression of PGRN in gastric cancer and the effects on proliferation and senescence in gastric cancer cell line BGC823. Methods: Immunohistochemical method was used to detect the expression of PGRN in gastric cancer tissues and adjacent normal tissues; Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of PGRN in PGRN-siRNA BGC823 cells; MTT method, cell colony formation and cell senescence experiments were used to explore the effects of PGRN on proliferation and senescence in BGC823 cell. Results: PGRN protein levels were high in gastric cancer tissues; Knocking down the PGRN gene in BGC823 decreased the proliferation and clonogenic capacity, cloning efficiency in PGRN-siRNA group was (25.3±3.1)%, in the control group was (72.1±5.7)%, and in the normal cells was (80.3±4.0)%, there was no significant difference between normal group and control group, but there were significant differences among PGRN-siRNA group and the other two groups (P<0.05); Knocking down the PGRN gene in BGC823 cells could promote cell senescence. The positive rate of aging in PGRN-siRNA group was (27.6±2.1)%, in the control group was (3.2±1.3)%, and in the normal group was (1.9±1.2)%, there was no significant difference between normal group and control group. But there were significant differences among PGRN-siRNA group and the other two groups (P<0.05). Conclusion: PGRN can be used as a new marker for gastric cancer, and provide new ideas to the treatment of gastric cancer.

Key words: Gastric neoplasms, Progranulin, siRNA, Cell senescence