INHIBITION OF HUMAN PANCREATIC-CANCER GROWTH IN NUDE-MICE BY BORON NEUTRON-CAPTURE THERAPY

Immunoliposomes were prepared by conjugating anti-carcinoembryonic ant ige (CEA) monoclonal antibody with liposomes containing [B-10]compound . These immunoliposomes were shown to bind selectively to human pancre atic carcinoma cells (AsPC-1) bearing CEA on their surface. The cytoto xic effects of locally injected [B-10]compound, multilamellar liposome s containing [log]compound or [B-10]immunoliposomes (anti-CEA) on huma n pancreatic carcinoma xenografts in nude mice were evaluated with the rmal neutron irradiation. After thermal neutron irradiation of mice in jected with [B-10]solution, B-10-containing liposomes or [B-10]immunol iposomes, AsPC-1 tumour growth was suppressed relative to controls. In jection of [B-10]immunoliposomes caused the greatest tumour suppressio n with thermal neutron irradiation in vivo. Histopathologically, hyali nization and necrosis were found in B-10-treated tumours, while tumour tissue injected with saline or saline-containing immunoliposomes show ed neither destruction nor necrosis. These results suggest that intrat umoral injection of boronated immunoliposomes can increase the retenti on of B-10 atoms by tumour cells, causing tumour growth suppression in vivo upon thermal neutron irradiation. Boron neutron capture therapy (BNCT) with intratumoral injection of immunoliposomes is able to destr oy malignant cells in the marginal portion between normal tissues and cancer tissues from the side of He-4 generation.