Invasiveness corresponds to differentiation rather than to proteinase secretion in endometrial cancer cell lines

Local invasiveness is an important prognostic factor in endometrial carcinoma. To study the role of two groups of secreted proteinases (serine proteinases and matrix metalloproteinases) in this process, we examined three endometrial cancer cell lines (Ishikawa HEC 1A, AN3CA) for their invasiveness in vitro. Additionally, we considered the secretion of urokinase type plasminogen activator (uPA), plasminogen activator inhibitor 1 and 2 (PAI-1 and PAI-2), as well as matrix metalloproteinases (MMP) 1, 2, 3, and 9, and their inhibitors TIMP-1 and TIMP-2. Compared to the highly invasive fibrosarcoma cell line HT 1080, Ishikawa displayed low and AN3CA moderate invasiveness, while HEC 1A cells were almost as invasive as HT 1080 cells. Ishikawa cells secreted the highest amounts of proteinases. Cytokine and steroid treatments upregulated MMP-1 in all cell lines while the effects were heterogeneous regarding other proteinases and inhibitors. No effect of these treatments on invasiveness could be detected. Both basal secretion and regulation of the proteinases tested in this set of experiments seem to be markers of differentiation rather than of invasiveness.