Gene Expression in Adult T Cell Leukemia/Lymphoma

Up-Regulation of Matrix Metalloproteinase 2 in Skin Lesions

Abstract

The neoplastic cells of adult T-cell leukemia/lymphoma (ATLL) invade various body organs, typically the lymph nodes (LN) and skin. The present study was designed to clarify the mechanism of invasion, by using a DNA array that allowed comparison of gene expression among ATLL cells in different sites, namely peripheral blood (PB), LN, and skin. The expression of matrix metalloproteinase 2 (MMP-2) mRNA was significantly up-regulated in skin relative to PB. Immunohistochemistry showed higher MMP-2 expression in ATLL cells found in the skin than in LN. Expression of membrane-type1-MMP (MT1-MMP), an activator of pro-MMP-2, was detected in fibroblasts present in the skin stroma. The proportion of MMP-2-positive cells in PB was not different between patients with or without skin invasion. Our results indicate that MMP-2 does not account for migration of ATLL cells to the skin, but once these cells reach the skin, this molecule seems to play an important role in proliferation of ATLL cells and/or their invasion of skin tissue.