CD13/APN antagonists inhibit HUVEC capillary tube formation but not proliferation.

(A) HUVECs were plated on Matrigel basement membrane preparations and incubated with either the CD13/APN inhibitors amastatin or bestatin, or the anti-CD13/APN monoclonal antibody MY7; or the negative-control trypsin inhibitor or isotype-matched monoclonal antibodies. Plates were incubated for 24 hours before analysis. (B) HUVECs were plated on tissue culture dishes with anti-CD13/APN monoclonal antibody MY7 or isotype-matched control antibodies UPC10, and proliferation was assessed by accumulation of the fluorescent REDOX indicator at the indicated time intervals. The blank condition contained no cells.