Glycosaminoglycans Synthesized by Tumorigenic and Nontumorigenic Mouse Melanoma Cells in Culture<xref ref-type="fn" rid="fn2">2</xref>

Abstract

Glycosaminoglycans (GG) synthesized by two tumorigenic cell lines and a nontumorigenic, immunoprotective cell line derived from the B16 mouse melanoma were metabolically labeled with Na235SO4 and [3H]glucosamine. The radioactive GG synthesized at low and high cell densities were prepared from cells and culture media and analyzed by enzymatic and chromatographic methods. The cell-associated and medium GG from both low- and high-density cultures of the nontumorigenic, immunoprotective line contained a significantly higher proportion of heparin and heparan sulfate (85-95% of total) relative to comparable fractions from the tumorigenic lines. In addition to synthesizing less heparin and heparan sulfate and more chondroitin 4-sulfate plus chondroitin 6-sulfate, the tumorigenic lines differed in that the amelanotic line produced significant amounts of dermatan sulfate which remained cell associated. None of the lines produced measurable amounts of hyaluronic acid. In addition, the nontumorigenic immunoprotective line incorporated two to six times more precursor into total GG and released a higher proportion into the growth medium than did the tumorigenic lines.