Anionic polysaccharide production and tyrosinase activation in cultured human melanoma cells

A human melanoma cell line established in our laboratory was characterized in terms of tyrosinase activity and anionic polysaccharide production. Tyrosinase levels were diluted during the growth phase and increased after the cell culture became confluent. The anionic polysaccharides produced included hyaluronic acid, heparitin sulfate, and a high-molecular-weight condroitin 4-sulfate. In contrast, a primary culture of human melanocytes derived from embryonic iris produced much greater amounts of hyaluronic acid, about 30-fold less heparitin sulfate, and a mixture of chondroitin 4-sulfate and dermatan sulfate. Saccharides secreted into the culture medium were generally identical to those remaining cell associated except for the melanoma heparitin sulfate, wherein the latter fraction appeared to be of lower molecular weight.