title: Two distinct tumor cell growth-inhibiting factors from a human rhabdomyosarcoma cell line.
abstract: Tumor cell growth-inhibiting factors (TIFs) have been shown to inhibit the growth of tumor cell lines in culture. TIF-1, the first TIF to be described, is a low-molecular-weight, acid- and heat-stable polypeptide with no antiviral activity. A second class of TIFs (TIF-2) has now been isolated from the conditioned media of a human rhabdomyosarcoma cell line and partially purified by polyacrylamide gel filtration, cation exchange, and reverse-phase high-pressure liquid chromatography. Partially purified preparations of TIF-2 inhibit the growth of a variety of human tumor cells in soft agar and monolayer cultures and are mitogenic for normal human and mouse cells. TIF-2 has no antiviral activity. The growth-inhibitory effects of TIF-2 are reversible when the affected cells are no longer exposed to the factor. Although both TIF-1 and TIF-2 are obtained from the same source, they can be distinguished by their molecular weight, heat lability, elution pattern from reverse-phase high-pressure liquid chromatography, and their effect on the growth of mink lung epithelial cells. The growth of a human tumor cell variant, selected for resistance to growth inhibition by TIF-1, is inhibited by TIF-2. TIFs may therefore be a family of related polypeptides which selectively inhibit the growth of tumor cells.
authors.forename: C M
authors.initials: CM
authors.lastname: Fryling
authors.forename: K K
authors.initials: KK
authors.lastname: Iwata
authors.forename: P A
authors.initials: PA
authors.lastname: Johnson
authors.forename: W B
authors.initials: WB
authors.lastname: Knott
authors.forename: G J
authors.initials: GJ
authors.lastname: Todaro
mesh_terms: D002460:Cell Line; D006131:Growth Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D007372:Interferons / Q000494:pharmacology; D010455:Peptides / Q000032:analysis; D012208:Rhabdomyosarcoma / Q000032:analysis*; D015291:Transforming Growth Factors
chemical_list: D006131:Growth Inhibitors; D010455:Peptides; D015291:Transforming Growth Factors; D007372:Interferons