The long-range objective of the proposal is to develop plasma membrane modifiers and inhibitors affecting the viability and social behavior of the cancer cells and hopefully increasing their immunogenicity. This approach also has promise in metastatic tumors. The following approaches are being pursued: (a) synthesis of D-mannosamine, sialic acid, CMP, and CMP-NANA analogs to inhibit specifically sialic acid biosynthesis and its transfer to the glycoconjugate; (b) synthesis of D-galactosamine analogs; (c) synthesis of D-glucosamine analogs modified in the 3 and 4 positions; (d) exploration of membrane sugar esters as prodrugs; (e) hexokinases and glycosidases as an in vitro test system; (f) biological evaluation of metabolic and specific membrane effects of carbohydrate analogs.