Collagen biosynthesis in human neuroblastoma cell lines: evidence for expression of glial cell properties

An analysis was done on the synthesis of collagen, an extracellular matrix protein synthesized by Schwann cells, by several human neuroblastoma lines. Cultured cells were incubated in the presence of L-[2,3-3H]proline, and the collagens synthesized and secreted into the culture medium were analyzed by electrophoresis on acrylamide gels, ion exchange chromatography, and immunoprecipitation. The amount of collagen secreted by 4 cell lines tested represented less than 3% of the total protein synthesis, indicating a low degree of collagen biosynthesis by this tumor type. Analysis of collagen types secreted by all cell lines revealed the presence of a high-molecular-weight collagen precursor (Mr = 165,000) identified as type IV procollagen. In addition, several cell lines synthesized stromal type I and type III collagens. These studies show that neuroblastoma cells produce collagenous proteins including basement membrane collagen (type IV) and stromal collagens (types I and III), indicating that these cells express properties of glial cells such as Schwann cells.