摘要Background MMPs and TIMPs play important roles in tumor angiogenesis and invasion.Studies have shown that TIMP-2 has two roles in tumor invasion.However,its role in leukemic infiltration has not been well investigated.This study explored the roles of TIMP-2 in extramedullary infiltration of acute monocytic leukemic SHI-1 cells both in vitro and in vitro.Methods A retroviral vector carrying the human TIMP-2 cDNA was constructed and transfected into the monocytic leukemic cell line SHI-1.The expression of TIMP-2 in the positive clones was determined.The proliferation of SHI-1 cells was examined by MTT assay.Trans-Matrigel invasion assays were used to investigate the infiltration ability in vitro.SHI-1 cells were intravenously injected into pre-treated nu/nu mice to investigate the infiltration ability feature in vitro.Results The expression of TIMP-2 on the cell membrane was significantly elevated in SHI-1/TIMP-2 cells.Over-expression of TIMP-2 promoted the cells proliferation and the invasions in vitro.The SHI-1/TIMP-2 cells demonstrated higher infiltration ability when intravenously injected into nu/nu mice.Conclusion Over-expression of TIMP-2,especially on the cell membrane,may play important roles in promoting the proliferation and infiltration of SHI-1 leukemic cells.