Proteolytic enzymes play fundamental roles in many biological processes. Members of the
matrix metalloproteinase (
MMP) family have been shown to take part in processes crucial in
disease progression. The current study used the ExcelArray Human
MMP/TIMP Array to quantify
MMP and
tissue inhibitor of metalloproteinase (TIMP) production in the lysates and media of 14
cancer cell lines and 1 normal cell line. The overall patterns were very similar in terms of which
MMPs and TIMPs were secreted in the media versus associated with the cells in the individual samples. However, more
MMP was found in the media (in both amount and variety).
TIMP-1 was produced in all cell lines.
MMP activity assays with three different fluorescence resonance energy transfer (FRET) substrates were then used to determine whether
protein production correlated with function for the WM-266-4 and BJ cell lines.
Metalloproteinase activity was observed for both cell lines with a general
MMP substrate (Knight SSP), consistent with
protein production data. However, although both cell lines promoted the hydrolysis of a more selective
MMP substrate (NFF-3),
metalloproteinase activity was confirmed only in the BJ cell line. The use of inhibitors to confirm
metalloproteinase activities pointed to the strengths and weaknesses of in situ FRET substrate assays.