Retinoic acids reduce matrilysin (matrix metalloproteinase 7) and inhibit tumor cell invasion in human colon cancer.

All-trans retinoic acid (ATRA), 9-cis retinoic acid and 13-cis retinoic acid are naturally occurring retinoids used in the prevention and therapy of various preneoplastic and neoplastic diseases. It was previously reported that matrilysin, one of the matrix metalloproteinases (MMP-7), plays a critical role in the invasion and metastasis of gastrointestinal cancers. Moreover, it has been shown that ATRA downregulates matrilysin expression and prevents in vitro invasion by colon cancer cells. In this study, three retinoids were used, both in Matrigel invasion assays and in subcutaneous xenografts in mice, to evaluate the effects of retinoids on invasion by colon cancer cell lines (CHC-Y1, DLD-1, HT-29, BM314, CaR-1 and WiDr). All three retinoic acids tested reduced matrilysin expression and suppressed the invasiveness of colon cancer cell lines in vitro. Retinoic acids also reduced tumor invasion in mice without influencing tumor growth. Matrilysin expression in these tumors was clearly reduced. These data support the use of retinoic acids as useful reagents to manage patients with colorectal carcinoma. Copyright 2001 S. Karger AG, Basel