THE ANTITUMOR ACTIVITY OF BOVINE SERUM ALBUMIN-MEDIATED CONJUGATE OF HEMATOPORPHYRIN DERIVATIVE WITH ANTIGASTRIC CANCER MONOCLONAL ANTIBODY

Hematoporphyrin derivative (HPD) was conjugated with a murine monoclonal antibody (3H11) against human gastric cancer through bovine serum albumin (BSA) as an intermediate. In this paper, the antitumor activity of indirect conjugate 3H11-BSA-HPD was demonstrated and compared with that of direct conjugate 3H11-HPD in vitro and in vivo. The molar ratios of the conjugates 3H11-BSA-HPD and 3H11-HPD were 1:200 and 1:37, respectively. The cytotoxicities of 3H11 - BSA - HPD and 3H11 - HPD plus exposure to light were shown to be similar, and much greater than those of free HPD at equivalent HPD concentration in vitro. When tumor-bearing nude mice were treated with the different conjugates or HPD plus exposure to light, all the six mice of the control group formed tumor within 13 days after inoculation of BGC 823 cells (2×10⁵ cells /mouse), whereas five of the six mice treated with 3H11-BSA-HPD or 3H11-HPD were tumor, free for the observation period of 34 days.