Delivery of ATP-Raf to Tumor-Associated Blood Vessels Causes Endothelial and Tumor Cell Apoptosis

(A-C) Athymic WEHI models were subcutaneously implanted with M21-L melanoma, and tumors were allowed to grow to ~400 mm³. Models were then given a single i.v. injection of a_vb₃-NP-Raf(-). Controls were injected with the a_vb₃-NP coupled to a shuttle vector. After 24 or 72 hours, the tumors were resected, fixed, sectioned, and stained.

(A)
Tumors harvested 24 hours after treatment were immunostained for VE-Cadherin (endothelial cells), FLAG (gene expression), and TUNEL (apoptosis) (bar=50 microns). Asterisks denote blood vessels.

(B)
Tumors harvested 72 hours after treatment were stained as above (bar = 50 microns). Arrowheads denote ring of tumor cells undergoing apoptosis.

(C)
Tumors harvested 72 hours after treatment with a_vb₃-NP-Raf(-) (left and center panel) or controls (right panel) were stained with hematoxylin and eosin. Necrotic tissues are denoted by N (bar = 50 microns, left panel and 100 microns, center and right panel).

Reprinted with permission from Science. Copyright 2002 American Association for the Advancement of Science.