The objectives of this Program Project are aimed at studying the various aspects of the behavior and characteristics of normal and malignant cells, with a special emphasis on cells of the intestinal tract and liver. Major areas of investigation will include the following: (1) Alterations in transport of nutrients, especially sugars and amino acids, between normal and malignant fibroblasts and epithelial cells. Major emphasis will be placed on surface membrane changes in relation to transport and the technique of measuring translocation across membrane vesicles and reconstituted vesicles (i.e., liposomes) will be used. (2) We will continue to assess the clinical significance of a tumor-associated isoenzyme of galactosyltransferase activity found in the sera and tumors of animals and patients with malignant neoplasms. This isoenzyme and a recently detected inhibitor of tumor growth found in animals with large tumors will be studied for their effects on cell growth in tissue culture systems and animal tumor models. (3) In addition, an in-depth investigation into the synthesis of surface glycoproteins and the role of lipid intermediates in glycoprotein synthesis, especially of intestinal cells, will be carried out. (4) We plan to purify a tumor associated alpha-H2globulin, a recently described oncofetal protein, and tumor associated isoferritins, from liver and intestinal tract tumors. We plan to develop antisera to these tumor associated proteins which may be of diagnostic significance.