Angiostatin gene transfer: Inhibition of tumor growth in vivo by blockage of endothelial cell proliferation associated with a mitosis arrest

Angiostatin gene transfer: Inhibition of tumor growth in vivo by blockage of endothelial cell proliferation associated with a mitosis arrest

^*le Centre National de la Recherche Scientifique Unite de Recherche Associée 1301/Rhône-Poulenc Rorer Gencell, Institut Gustave Roussy, 94805 Villejuif, France; ^‡Service d’hématologie biologique, Institut Gustave Roussy, 94805 Villejuif, France; ^§Laboratoire de biochimie Aet Sainte Marie, Hôtel Dieu, 75004 Paris, France; ^¶l’Institut National de la Santé et de la Recherche Médicale U353, Hôpital St. Louis, Avenue Claude Vellefaux, 75010 Paris, France; and ^‖DIFEMA, faculté de Médecine, 76000 Rouen, France

Communicated by N. M. Le Douarin, College de France, Nogent-sur-Marne, France (received for review October 24, 1997)

Abstract

The antitumoral effects that follow the local delivery of the N-terminal fragment of human plasminogen (angiostatin K3) have been studied in two xenograft murine models. Angiostatin delivery was achieved by a defective adenovirus expressing a secretable angiostatin K3 molecule from the cytomegalovirus promoter (AdK3). In in vitro studies, AdK3 selectively inhibited endothelial cell proliferation and disrupted the G₂/M transition induced by M-phase-promoting factors. AdK3-infected endothelial cells showed a marked mitosis arrest that correlated with the down-regulation of the M-phase phosphoproteins. A single intratumoral injection of AdK3 into preestablished rat C6 glioma or human MDA-MB-231 breast carcinoma grown in athymic mice was followed by a significant arrest of tumor growth, which was associated with a suppression of neovascularization within and at the vicinity of the tumors. AdK3 therapy also induced a 10-fold increase in apoptotic tumor cells as compared with a control adenovirus. Furthermore, we showed that systemic injection of AdK3 delayed C6 tumor establishment and growth, confirming that angiostatin can function in a paracrin manner. Our data support the concept that targeted antiangiogenesis, using adenovirus-mediated gene transfer, represents a promising alternative strategy for delivering antiangiogenic factors as their bolus injections present unsolved pharmacological problems.

Footnotes

↵ † To whom reprint requests should be addressed. e-mail: grisceli{at}igr.fr.
A commentary on this article begins on page 5843.
ABBREVIATIONS:

CMV,

cytomegalovirus;

Plg,

plasminogen;

pfu,

plaque-forming units;

moi,

multiplicity of infection;

HMEC,

human microcapillary endothelial cells;

vWF,

von Willebrand factor;

Ad,

adenovirus