Localization and production of proteoglycans by HT1080 cell lines with altered N-ras expression.

The alterations in the production of proteoglycans in relation to the expression of the malignant phenotype - controlled by the level of expression of activated N-ras gene - was studied in HT1080 human fibrosarcoma cells and in its revertant variants rev.1c and rev.10a. A decreased production of radiolabelled PGs - especially HSPGs - was observed in HT1080 cells, compared to the revertant lines. By immunofluorescence, the HSPG epitopes were localized mainly into the putative endoplasmic reticulum and/or Golgi zone in HT1080 cells, and to the diffuse cytoplasmic and membrane localization in the revertant lines. It is suggested, that the altered expression of PGs represents an important aspect of the transformed phenotype of HT1080 fibrosarcoma cells.