title: Constitutive expression of insulin-like growth factor 1 and insulin-like growth factor 1 receptor abrogates all requirements for exogenous growth factors.
abstract: BALB/c3T3 cells are exquisitely growth regulated and require both platelet-derived growth factor and insulin-like growth factor-1 (IGF-1) for optimal proliferation. BALB/c3T3 cells that constitutively express IGF-1 and elevated levels of IGF-1 receptor (IGF-1R) are capable of growth in serum-free medium without the addition of any exogenous growth factors. BALB/c3T3 cells overexpressing only the IGF-1R plasmid required IGF-1 or insulin for serum-free growth. Antisense oligodeoxynucleotides complementary to IGF-1R mRNA inhibited IGF-1-mediated cell growth. Under these conditions, neither the epidermal growth factor receptor nor phospholipase C gamma 1 was autophosphorylated. These findings indicate that constitutive expression of IGF-1 and IGF-1R allows 3T3 cells to grow in serum-free medium without addition of those exogenous growth factors that are required by the parent cell line.
authors.affiliation: Jefferson Cancer Institute, Jefferson Medical College, Philadelphia, Pennsylvania 19107.
authors.forename: Z
authors.initials: Z
authors.lastname: Pietrzkowski
authors.forename: R
authors.initials: R
authors.lastname: Lammers
authors.forename: G
authors.initials: G
authors.lastname: Carpenter
authors.forename: A M
authors.initials: AM
authors.lastname: Soderquist
authors.forename: M
authors.initials: M
authors.lastname: Limardo
authors.forename: P D
authors.initials: PD
authors.lastname: Phillips
authors.forename: A
authors.initials: A
authors.lastname: Ullrich
authors.forename: R
authors.initials: R
authors.lastname: Baserga
mesh_terms: D016475:3T3 Cells / Q000166:cytology* / Q000187:drug effects; D000818:Animals; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D016895:Culture Media, Serum-Free; D004247:DNA / Q000235:genetics; D066246:ErbB Receptors / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D016372:RNA, Antisense / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000502:physiology*; D017451:Receptors, Somatomedin; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000502:physiology*; D014162:Transfection
chemical_list: D016895:Culture Media, Serum-Free; D010982:Platelet-Derived Growth Factor; D016372:RNA, Antisense; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D011993:Recombinant Fusion Proteins; D007334:Insulin-Like Growth Factor I; D004247:DNA; D066246:ErbB Receptors