The functional role of the carbohydrate in human melanoma associated antigens. I. Antigen-antibody complex formation.

Messenger ribonucleic acids (mRNA) for tumor associated antigens (TAA) were isolated from human melanotic melanoma (HMMC-ShA, HMMC-WJP) and amelanotic melanoma (HMMC-Sr, HMMC-KM) cells. The melanoma cells were cultured in standard Eagle's MEM and in MEM supplemented with tunicamycin (Tu). The mRNAs were translated in vitro using wheat germ system. Using a standard immunodiffusion system, TAA from melanoma cells harvested from standard MEM differed from the TAA obtained from cells harvested from MEM supplemented with Tu, whereas, TAA pretreated with endo-beta-N-acetylglucosaminidase resembled TAA of cells harvested from MEM supplemented with Tu. The translation products synthesized by mRNA of melanotic melanoma cells resembled TAA extracted directly with 3 M KCl from the cells, but differed from TAA isolated directly from the cells or synthesized by mRNA from amelanotic melanoma cells. Therefore, the melanotic melanoma differed from the amelanotic melanoma cells in their genetic expression. The TAA-immunological reactivities are modulated by a post-translation step regulating genetic expression.