Cathepsin D (cath-D), an estrogen-regulated protease appears mostly to incr
ease the number of tumor cells rather than their invasion or motility throu
gh the extracellular matrix. Estradiol is mitogenic but in vitro it also in
hibits invasion and motility. In this review, we discuss the mechanism of t
his inhibition and the hormonal regulation of other proteases and protease
inhibitors possibly involved in the control of tumor cell invasion by estro
gens. (C) 2001 Elsevier Science Ltd. All rights reserved.