OBJECTIVETo explore the effect of serum restriction on the invasiveness and expressions of insulin-like growth factor-1 (IGF-1) and matrix metalloproteinase-2 (MMP-2) in human trophoblast HTR-8/SVneo cells in vitro.

METHODSHTR-8/SVneo cells were cultured in the presence of 1%, 5%, or 10% fetal bovine serum (FBS) for 48 h. Fluorescence quantitative PCR and immunofluorescence staining were employed to examine the changes in IGF-1 and MMP-2 expressions at both the mRNA and protein levels in HTR-8/SVneo cells; MTT assay and Transwell invasion assay were used to assess the changes of the cell proliferation and the cell invasion ability, respectively. MMP-2 expression, cell proliferation and invasiveness were also assessed in the cells treated with recombinant human IGF-1.

RESULTSHTR-8/SVneo cells exhibited significantly lowered cell proliferation in cultures containing low concentrations of FBS (P<0.05). The expressions of IGF-1 and MMP-2 at both mRNA and protein levels were significantly down-regulated and the invasiveness was significantly lowered in cells cultured in the medium containing 1% FBS as compared with those of cells cultured in the presence of 5% and 10% FBS (P<0.05). Treatment of the cells with recombinant human IGF-1 significantly up-regulated MMP-2 expression (P<0.05) and increased the cell invasiveness (P<0.05).

CONCLUSIONSFBS restriction down-regulates IGF-1 expression in human trophoblast HTR-8/SVneo cells and suppress the cell invasiveness possibly by suppressing MMP-2 expression. Treatment with recombinant human IGF-1 can up-regulate MMP-2 expression and promote the invasiveness of HTR-8/SVneo cells.