BALB/c mouse 3T3 cells transformed by simian virus 40 (SV3T3), baby hamster kidney cells transformed by polyoma virus or Rous sarcoma virus, and a range of neoplastic human cell lines release material that inhibits the migration of macrophages and lymphocytes. Similar migration-inhibitory factor (MIF) activity was not detected in supernatants from cultures of untransformed 3T3 or baby hamster kidney cells and a variety of human diploid cell strains. Physicochemical characterization of the MIF produced by SV3T3 and HeLa cells revealed substantial similarities with the MIF produced by mitogen-activated human peripheral lymphocytes. MIF released by tumor cells is inhibited by pancreatic and soybean trypsin inhibitors and by diiso-propylfluorophosphate, indicating that it is a serine-protease. Comparison of MIF produced by SV3T3 cells with a serine-protease plasminogen activator released by the same cells indicated that the latter is more heat labile and has a more heterogenous elution profile after chromatography on Sephadex G-75. The possible role of MIF in causing proteolytic modification of the surface properties of tumor cells and in altering cell-mediated immune responses to neoplastic cells is discussed.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Sep 1975|
ASJC Scopus subject areas
- Cancer Research