Figure 3.

Receptor-mediated mechanism underlying the internalization of mouse monoclonal anti-FSHR antibody coupled to colloidal gold in ECs of tumor blood vessels associated with tumors generated by the prostate cancer line LNCaP in nude mice. After 20 min of perfusion of FSHR-Au5_nm the tracer was bound to the plasma membrane (A), to diaphragms of fenestrae (B), to luminal clathrin-coated pits (C), and internalized in clathrin-coated pits (D), early endosomes (E), and multivesicular bodies (F). No tracer was internalized in the caveolae open to the lumen of the tumor blood vessel (C,D). No tracer particles crossed the endothelial barrier through the junctions (G). No tracer particles were seen associated with the microvascular ECs in the normal lung (H). Scale bars represent 50 nm in panels (A–F) and H, and 100 nm in panel G. Reprinted with permission from ref. [94]. Copyright 2010 Massachusetts Medical Society.