Effect of Antisense Inhibition of Urokinase Receptor on Malignancy

Abstract

Plasminogen activator of the urokinase type (uPA) has been shown to be overexpressed in most experimental malignant tumors and human cancers (Dano et al. 1985; DeBruin et al. 1987; Sappino et al. 1987; Markus 1988; Sim et al. 1988; Duffy et al. 1990; Janicke et al. 1990; Testa and Quigley 1990; Sappino et al. 1991; Mignatti and Rifkin 1993). The overproduction of uPA by tumor cells was detected in primary cultures, organ cultures, and cancer cell lines. However, examination by in situ analyses (both immunocytochemistry and in situ hybridization) of sections of human tumors consisting of multiple cell types identified in some instances cells other than cancer cells as the uPA producers. Depending on the type of cancer, and in some instances the laboratory and the reagents used to perform the analysis, tumor, stromal, and sometimes infiltrating macrophages were found to be the main source of uPA and/or its receptor (Grondahl-Hansen et al. 1991; Pyke et al. 1991, 1993; Bianchi et al. 1994; Carriero et al. 1994). Regardless of its source, however, it has been firmly established in several human cancers that high levels of uPA are predictive of more aggressive disease with shorter relapse-free survival (Duffy et al. 1990; Janicke et al. 1990, 1991; Grondahl-Hansen et al. 1993; Kobayashi et al. 1994).

I dedicate this review to a very young Colleague, Dr. Yu Wu, whose pain and premature death from breast cencer mobilized us all to resolve to do everything in our power to improve the outcome of cencer therapy.