Objective     To investigate the possibility of inhibiting the malignant proliferation of tumor cells in vitro through down-regulating the expression of MMP-7 by antisense gene technology.      Methods     A Phosphorothioate antisense oligodeoxynucleotide (ASODN) and scrambled oligodeoxynucleotide (SCODN) against MMP-7 were respectively transfected into A549 cells mediated by liposome. The expression of MMP-7 and cell proliferation in the cells were respectively examined by immunohistochemical assay and MTT. Flow cytometry was used to detect the cell cycles.   

   Results     After A549 cells were transfected with MMP-7 ASODN

the cell number was decreased. MTT method indicated that the proliferation of A549 cells was inhibited by MMP-7 ASODN at different concentrations

with the inhibition reaching the peak at 48 h. ASODN transfection downregulated the expression levels of MMP-7 protein

and inhibited the transition period of G

0

/G

1

phase to S phase.      Conclusion     The artificial MMP-7 ASODN can specifically inhibit the expression of MMP-7 protein and regulate cell cycle and cell proliferation in A549 cells.