Non-coexpression of collagenase and transin in malignant epithelial cells

Increased synthesis and secretion of the matrix metalloproteinase has been associated with the acquisition of the invasive properties of malignant cells. In a rat malignant anaplastic cell line (T952/F7) sporadic expression of mRNA for collagenase-3 against a background of high transin-1 mRNA has been shown. Sporadic induction of either metalloproteinase was not found in the benign precursor cells (A5P/B10) of T952/F7 cells, but a coordinate mRNA induction profile for these two genes could be induced by the addition of 12-O-tetradecanoylphorbol-13-acetate. In a different uncloned neoplastic epithelial cell line (BC1) fluctuations in the levels of collagenase and transin appeared coordinately, but coordinate expression was not a feature in cloned lines derived from BC1. The loss of coordinate regulation of the two matrix metalloproteinases may relate to the variability in metastatic potential seen in clonal cell lines.