title: Antisense suppression of p107 inhibits 3T3-L1 adipocyte differentiation.
abstract: The murine 3T3-L1 preadipocyte cell line is well characterized for its capacity to undergo differentiation into adipocytes under appropriate hormonal stimulation. p107, a member of the retinoblastoma tumor suppressor gene family has been shown to be dramatically upregulated during the early requisite clonal expansion phase of 3T3-L1 adipogenesis; however, a functional consequence has yet to be described. A phosphorothioate antisense RNA approach was utilized to determine if inhibition of p107 expression would block or perturb adipocyte differentiation. A series of three phosphorothioate oligonucleotides in antisense orientation was generated, designated AS1, AS2, and AS3 along with a sense control oligonucleotide complementary to AS1 and added to postconfluent cells at a concentration of 20 and 50 microM throughout hormonally stimulated differentiation. Treatment of cells with either concentration of the sense, AS1, AS2, or 20 microM AS3 oligonucleotides had little effect on either Oil Red O lipid accumulation or induction of p107 protein levels. In contrast, treatment with 50 microM AS3 inhibited the increase in p107 protein levels and led to a complete block in differentiation as detected by Oil Red O lipid accumulation and inhibition of adipocyte-specific mRNA expression. In addition, treatment with AS3 led to a significant inhibition of cellular proliferation associated with clonal expansion. Combined, these results provide strong evidence supporting a functional role for p107 in 3T3-L1 adipocyte differentiation.
authors.affiliation: Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, Arkansas 72205, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: May
authors.forename: A M
authors.initials: AM
authors.lastname: Prince
authors.forename: R E
authors.initials: RE
authors.lastname: Lyle
authors.forename: R E
authors.initials: RE
authors.lastname: McGehee
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D051379:Mice; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D050720:Retinoblastoma-Like Protein p107
chemical_list: D009687:Nuclear Proteins; D016376:Oligonucleotides, Antisense; C489485:Rbl1 protein, mouse; D050720:Retinoblastoma-Like Protein p107