Specific changes in the surface glycoprotein pattern of a human leukemic null cell line NALL-1 associated with morphologic and biological alterations induced by phorbol-ester

Abstract

Summary 12-0-tetradecanoylphorbol-13-acetate, a highly active tumor-promoting agent, inhibits cell proliferation of human leukemic null cell line NALL-1 at a dose range of 10 −9 – 10 −7 M. Soon after the addition of 12-0-tetradecanoylphorbol-13-acetate to suspension culture, cells began to adhere to the substratum. Associated with the change in cell behavior, rate of DNA synthesis decreased rapidly but rate of RNA and protein synthesis remained essentially unchanged. After 48hr treatment with 12-0-tetradecanoylphorbol-13-acetate, adherent and growth arrested cells were all alive. Changes in surface glycoproteins of these cells were analyzed by the neuraminidase/galactose oxidase or periodate/NaB[ 3 H 4 ] surface-labeling technique followed by polyacrylamide gel electrophoresis and fluorography. In 12-0-tetradecanoylphorbol-13-acetate treated cells, a glycoprotein with an apparent molecular weight of 145,000 was strongly labeled. The amount of HLA-DR antigen was also increased. These and other observations suggest that NALL-1 cells are induced by 12-0-tetradecanoylphorbol-13-acetate to differentiate into mature cells having some properties of B-cell blasts.