[Experimental study of tumor directed therapy with gastric cancer monoclonal antibody-mitomycin conjugate combined with propranolol or angiotensin II].

The effects of vasoactive agents propranolol hydrochloride and angiotensin (AT-II) on improving the directed therapy of cancer with the use of conjugate of gastric cancer monoclonal antibody (3H11) and mitomycin C (MMC) were studied. The antibody activity of the conjugate (3H11-HSA-MMC) was retained with the molecular ratio of 1:2:60. In tests with tumor-bearing nude mice, the tumor inhibitory rate of the conjugate alone was found to be 50%, while in conjugate treated mice that also received propranolol or AT-II the tumor inhibitory rate were 79% and 60%, respectively. In tumor-bearing nude mice given 131I-3H11 both propranolol and AT-II increased the tumor uptake of 131I-3H11. These results indicate that these vasoactive agents can change the tissue perfusion ratio via the effect on tumor blood vessels and increase the access of the conjugate to tumor, thereby, enhancing the effectiveness of tumor directed therapy with the use of conjugates.