title: Induction of transforming growth factor beta 1 and its receptors during all-trans-retinoic acid (RA) treatment of RA-responsive human neuroblastoma cell lines.
abstract: Recent work on a variety of normal and malignant cell lines has shown that induction and secretion of biologically active TGF-beta may occur after exposure to all-trans-retinoic acid (RA), coincident with decreased growth rate and/or differentiation. This study evaluates the expression and regulation of transforming growth factor beta (TGF-beta) and its receptors during RA-induced cell growth arrest and induction of differentiation in the RA-sensitive human neuroblastoma cell line SMS-KCNR and the RA-resistant neuroblastoma cell line SK-N-AS. RA treatment of SMS-KCNR cells results in a 40-fold increase in TGF-beta 1 mRNA after 4 days of RA, a dose-dependent increase in TGF-beta 1 secretion, an increase in types I (TBRI) and III (TBRIII) TGF-beta receptor proteins, and an increase in type II TGF-beta receptor (TBRII) mRNA coincident with RA-responsiveness of the cells. However, in the RA-resistant line SK-N-AS, TGF-beta 1 is constitutively secreted at levels that are unchanged after RA treatment, and although TBRI and TBRIII mRNA is expressed in untreated SK-N-AS cells, levels of TBRI and TBRIII protein and TBRII mRNA decrease after RA treatment. Thus, in RA-sensitive neuroblastoma cells, RA treatment may result in the induction of a negative autocrine TGF-beta 1 growth regulatory loop. These results suggest the hypothesis that: (a) induction of a TGF-beta 1 negative autocrine growth loop may be a necessary component for RA-responsiveness of neuroblastoma cells in vivo; and (b) the inability to induce or maintain this TGF-beta 1 negative autocrine growth loop may be a mechanism of RA resistance in neuroblastoma.
authors.affiliation: Department of Pediatrics, Harbor-University of California, Los Angeles Medical Center, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Cohen
authors.forename: J J
authors.initials: JJ
authors.lastname: Letterio
authors.forename: C
authors.initials: C
authors.lastname: Gaetano
authors.forename: J
authors.initials: J
authors.lastname: Chan
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: M B
authors.initials: MB
authors.lastname: Sporn
authors.forename: C J
authors.initials: CJ
authors.lastname: Thiele
mesh_terms: D001483:Base Sequence; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D005069:Evaluation Studies as Topic; D015870:Gene Expression / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D014212:Tretinoin