EXPRESSION OF MATRIX METALLOPROTEINASES AND TISSUE INHIBITORS OF METALLOPROTEINASES IN REACTIVE AND NEOPLASTIC LYMPHOID-CELLS

We have studied the expression of gelatinase A, gelatinase B, intersti tial collagenase, tissue inhibitor of metalloproteinase (TIMP)-1 and T IMP-2 in reactive lymphoid cells, as well as in a series of cell lines derived from neoplasms of B- and T-cell lineage. Using both Northern blot analysis and zymography, gelatinase B activity was detected by zy mography in two Burkitt cell lines and in a tonsillar cell suspension, while gelatinase A and interstitial collagenase activities were not d etected by either method. TMP-1 expression was demonstrated by Norther n blot analysis in the multipotential neoplastic K-562 cell line, the high grade Burkitt's B-cell lymphoma lines, isolated tonsillar B cells and at low levels in peripheral blood T cells, but was not expressed in any of the neoplastic T-cell lines or isolated peripheral blood B c ells. In contrast, TIMP-2 expression was restricted to tissues contain ing cells of T-cell lineage with high levels being observed in the neo plastic T-cell lines and lower levels in normal peripheral blood T cel ls and hyperplastic tonsil. Expression of TIMP-1 and TIMP-2 was confir med at the protein level by reverse zymography and immunofluorescence assays using antihuman TIMP polyclonal antibodies. Expression of gelat inase B by the high grade B-cell Burkitt's lymphoma cell lines is cons istent with previous findings in large cell immunoblastic lymphomas an d indicates that this enzyme may play an important role in high grade non-Hodgkin's lymphomas. TIMP expression correlated with cell lineage in that TIMP-1 was primarily observed in B cells and TIMP-2 was restri cted to T cells.