[Effects of metalloproteinases-1 (TIMP-1) cDNA transfection on biological behaviors of PG cells].

A recombinant plasmid, which contains a full length cDNA of human tissue inhibitor of metalloproteinases-1 (TIMP-1), was constructed by using gene recombinant technique, and introduced into a highly metastatic human giant cell carcinoma (PG) by lipofectin technique. Two of the transfectants, PG-T2 and PG-T4, were studied thoroughly. Northern blot showed an increased level of TIMP-1 mRNA in PG-T2 and PG-T4, compared with PG and PG-MV1 (vector-transfected control). The two transfectants also exhibited higher TIMP-1 protein activities. Moreover, they showed significant reduction in their proliferation rate and invasive abilities. The abilities of forming colonies in soft agar and tumorigenecity in athymic nude mice were abrogated in PG-T2 and PG-T4. The preliminary results suggest that a specific upregulation of TIMP-1 expression in metastatic cells could not only suppress their invasive and metastatic phenotype, but also inhibit their proliferation and tumorigenecity.