ANTIMETASTATIC EFFECT OF YEAST MANNAN-BLEOMYCIN CONJUGATE AGAINST MOUSE LEWIS LUNG-CARCINOMA

A conjugate of bleomycin (BLM) and the mannan of bakers' yeast (Saccha romyces cerevisiae wild type strain) (WNM) was synthesized. The assay of its antimetastatic effect on Lewis lung carcinoma (3LL) implanted i n C57BL/6 mice showed that this conjugate exhibited a higher antimetas tatic effect and longer life-span elongation than those of free bleomy cin and mannan with corresponding doses. This conjugate was also found to kill the 3LL cells in vitro. C-14-Labeled mannan-bleomycin conjuga te was much more bound than C-14-labeled dextran-bleomycin conjugate t o the 3LL. It was concluded that the anti-cancer mechanism of this con jugate, WNM-BLM possessed a specific binding effect to the tumor cells and exhibited a cytocidal effect on the 3LL target cells.