In vitro inhibition of human malignant brain tumour cell line proliferation by anti-urokinase-type plasminogen activator monoclonal antibodies

Abstract

Summary A brain tumour-associated marker, urokinase (UK), was investigated using rabbit anti-UK polyclonal and munne anti-UK monoclonal antibodies, which were prepared by immunization with low molecular weight UK (LMW-UK) and high molecular weight urokinase (HMW-UK) synthetic peptide respectively. The polyclonal antibody cross-reacted with both LMW-UK and HMW-UK. whereas the murne MAbs were specific for HMW-UK. These immunological probes were used to study urokinase in glioma extracts, tissues, sera and cell lines that had been prepared from prmary cultures of freshly dissected gliomas. Radioimmunoassays showed that glioma extracts had much higher level (5-to 44-fold) of UK than normal human brain extracts. This result was confirmed by immunoblotting of electrophoresis gels of glioma and human brain extracts. Immunohistochemical study using anti-UK MAb demonstrated much higher levels of UK in glioma tissue than normal brain tissue. Immunohistochemical study using anti-UK MAbs localized UK on the cell surface of glioma cells. Anti-UK MAbs inhibited the proliferation of AA cell lines and GB cell lines (500c to > 90%) and exerted minor effects (< 20%) on normal human liver, intestine and lymphocyte cell lines. Taken together, these results suggest that anti-UK MAbs may have therapeutic potential for human gliomas and cancer metastasis.Keywords: glioma; cell line: anti-UK-MAb; expression: surface location: anti-proliferative activity Considerable indirect ex idence from model tumour svstems has accumulated to show that invasion and metastasis in solid tumours require the action of tumour-associated proteases that promote the dissolution of the surrounding tumour matrix and the basement membranes. Receptor-bound urokinase-txpe plasminogen actixvator (uPA) appears to play a key role in these ex ents (Dano et al. 1986: Duffx. 1987and Zucker. 1988 Correspondence to M-SI Abaza membrane. Hence. receptor-bound uPA v ill promote plasminogen actixation and thus the dissolution of the tumour matrix and the basement membrane. which is a prerequisite for invasion and metastasis.Plasminogen actix ators in tumours of the central nernous sx stem hax e not been studied extensix ely despite the intense in estigation into their possible role in cancer biologv Hoosein et al. 1991: Foekens et al. 1992: Hollas et al. 1992: Kobaxashi et al. 1992 Reith and Rucklidge et al. 1992: Sumivoshi et al. 1992: Hsui et al. 1993: Janicke et al. 1993: Pujade-Lauraine et al. 1993: Yamashita et al. 1993: Achbarou et al. 1994: Bianchi et al. 1994: Bouchet et al. 1994and Young et al. 1994. In this study. we report the oxverexpression of urokinasetype plasminogen activator in -liomas. its localization on human glioma cell surface and the antitumorigenic effect of anti-UK MAbs against human malignant brain tumour cell lines. MATERIALS AND METHODS MaterialsBrain tumour extracts were prepared from wet tissue samples (2 g) homocenized by biohomogenizer (Fisher Scientific) in 10 mxis phosphate-buffered saline (PBS) buffer (pH 7.2) at 4 C wxith 100 nvm pheny...

Anti-Urokinase-Type Plasminogen Activator Monoclonal Antibodies Inhibit the Proliferation of Human Breast Cancer Cell Lines in vitro

“…Irrelevant MAbs of the same isotype and concentrations showed no effects on the proliferation of the breast cancer, normal human lymphocyte and liver cell lines. Our results were consistent with those reported by other investigators [3,35,37]. At this stage, it is unclear to us how anti-UK-MAbs lyse the breast cancer cells.…”

“…Very recently Abaza et al [35] reported the inhibition of proliferation of human malignant brain tumor cell lines by anti-UK MAbs.…”

“…Two main forms of PA are known: tissuetype PA and u-PA [18]. Elevated concentrations of UK have been detected in many types of malignant extracts: colorectal [26], lung [27], breast [28][29][30][31][32], uterus [33], prostate [34] and glioma [35].…”

“…Elevated concentrations of UK have been detected in many types of malignant tissue extracts: colorectal [26], lung [27], breast [28][29][30][31][32], uterus [33], prostate [34] and glioma [35] carcinomas. Many studies of PA in human tumors and tumor models have demonstrated a correlation between PA production and the aggressive malignant phenotype [3,23,36,37].…”