title: Contact inhibitory factor also restores anchorage and serum dependence to hamster melanoma cells.
abstract: Conditioned medium (CM) from confluent cultures of the contact-inhibited hamster melanocytic cell line, FF, contains a biologic activity, contact inhibitory factor (CIF), which reversibly restores density-dependent growth to melanoma cells. When a hydrophobic affinity-concentrated extract of CIF-containing CM was incorporated in agarose at a concentration of 1000 micrograms protein/ml, it restored anchorage-dependent growth to RPMI 1846 hamster melanoma cells. Colony-forming efficiency in CIF-treated wells decreased to 5% from levels of 51.5% in controls prepared with regular growth medium. In addition, CIF-containing CM restored serum-dependent growth to RPMI 1846 cells, markedly restricting proliferation in 1% calf serum-containing medium. Control cultures containing 1% calf serum and either complete growth medium or CM from the non-contact-inhibited hamster melanoma line itself, supported proliferation of RPMI 1846 cells to levels 3.9 X and 3.7 X that of CIF-treated cultures, respectively. CIF is the first factor derived from contact-inhibited mammalian cell cultures that has been shown to restore density-, anchorage-, and serum-dependent growth to malignant melanoma cells.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002453:Cell Cycle; D002460:Cell Line; D002999:Clone Cells / Q000502:physiology; D003260:Contact Inhibition; D006224:Cricetinae; D003470:Culture Media; D006128:Growth; D008545:Melanoma / Q000473:pathology*
chemical_list: D003470:Culture Media