This study was designed to investigate the changes of matrix metalloproteinase (MMP)-2 and MMP-9 in host tissues in response to the growth of tumor cells. Zymogram showed that the responses of both MMPs in the host tissues were differential but concurrent. The liver, a prime target of metastases, had profound increases in MMP-2 and -9. The other usual targets had significant increases in MMP-9. MMP-2 was specifically increased in the spleen. These results indicate that the growth of tumor cells at the primary site could influence the MMP system of host tissues located at the distance.
