Abstract
Antitumor effects of plasminogen activator (PA) inhibitors (PAIs) were analyzed in a mouse model of human colon cancer xenografts. Either recombinant PA inhibitor-1 (rPAI-1) or inhibitor-2 (rPAI-2) was injected intraperitoneally to nude mice bearing human colon cancer xenografts for 6 weeks. Primary tumors in rPAI-2-treated group were smaller (0.45±0.13 g, n=16) than in the other two groups (control: 0.73±0.24 g, n=15; rPAI-1: 0.62±0.29 g, n=19). Primary tumors in the rPAI-2-treated group exhibited less mature ductal structures and were significantly smaller. The apoptotic index was higher in the rPAI-2-treated group (4.64±2.12%) than in the other groups (control: 1.94±0.82%; rPAI-1: 2.08±1.07%). Liver metastasis was less frequent in the rPAI-1(5/19) and rPAI-2-treated groups (1/16) than in the control group (14/15). PAI-2 more effectively suppressed tumor metastasis and progression, probably by inducing apoptosis; some different unknown mechanism may cause the difference in both antitumor effect and the histological findings. This may indicate the therapeutic potential of these PAIs in malignant patients.
- Received July 16, 2007.
- Revision received December 5, 2007.
- Accepted December 18, 2007.
- Copyright© 2008 International Institute of Anticaner Research (Dr. John G. Delinassios), All rights reserved