NEOPLASIA Interleukin-6 Regulation of Matrix Metalloproteinase (MMP-2 and MMP-9) and Tissue Inhibitor of Metalloproteinase (TIMP-1) Expression in Malignant Non-Hodgkin’s Lymphomas

We showed previously that human malignant non-Hodgkin’s lymphomas (NHL) degrade extracellular matrix (ECM) components through the action of metalloproteinases and that elevated expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) correlated with a poor clinical outcome in patients with NHL. In the present study we sought to investigate whether there is any correlation between the expression of gelatinases (MMP-2 and MMP-9), TIMP-1, and the expression of cytokines and growth factors such as interleukin-1b (IL-1b), IL-6, IL-10, tumor necrosis factor a (TNF-a), transforming growth factor b (TGFb), and basic fibroblast growth factor (bFGF) in human NHL. In lymphoma tissues obtained from 32 patients, elevated expression of IL-6 correlated significantly with elevated messenger RNA (mRNA) levels of MMP-9, MMP-2, and TIMP-1. Moreover, in human lymphoid cell lines of Band T-cell origin (Raji, Jurkat, and NC-37), IL-6 stimulated production of MMP-9 and MMP-2 but not TIMP-1. In the Matrigel invasion assay IL-6 significantly upregulated transmigration of Raji and Jurkat cells, which in turn was inhibited by recombinant human TIMP-1 and anti-MMP-9 and MMP-2 antibodies. We postulate that IL-6 may play a role in the clinical aggressiveness of human NHL by stimulating MMP production. r 1999 by The American Society of Hematology.