title: CDB-4124 does not cause apoptosis in cultured fibroid cells.
abstract: OBJECTIVE
  Selective progesterone receptor modulators (SPRMs), such as asoprisnil (J867) and ulipristal (CDB-2914), have been shown to reduce fibroid volume in vivo and to induce apoptosis in vitro. CDB-4124 (telapristone), a SPRM with different side groups, also reduced fibroid volume in vivo, and we hypothesized that this SPRM would also cause apoptosis in cultured fibroid cells.
  
  
  METHODS
  Immortalized, progesterone receptor-positive fibroid cells, known to be capable of apoptosis, were grown to 80% confluence in serum-containing media. Cells were then treated for 48 hours in serum-free media with 0, 10, 100, or 1000 nmol/L CDB-4124. Actinomycin-D and staurosporine were used as positive controls to induce apoptosis. Apoptosis was quantified using a TUNEL-fluorescein kit. Images were captured with a widefield-fluorescence microscope and analyzed using MetaMorph image analysis software. To validate results, Western blots of total cell lysates were probed for cleaved caspase-3 (c-CASP3). Experiments were repeated 3 times using independent cell batches.
  
  
  RESULTS
  Analysis of 19 712 nuclei indicated 14.8% ± 10.9% (mean ± SEM), 8.4% ± 4.6%, 8.2% ± 4.7%, and 9.3% ± 6.3% apoptosis in 0, 10, 100, and 1000 nmol/L CDB-4124-treated cells, respectively. There was no evidence of elevated c-CASP3 over vehicle control after treatment with CDB-4124.
  
  
  CONCLUSIONS
  CDB-4124 did not significantly induce apoptosis in cultured fibroid cells under the conditions described suggesting apoptosis may not be the main pathway responsible for CDB-4124-induced fibroid shrinkage. Variations in SPRM biological effects may be due to differences in fibroid source cells, binding kinetics, or extracellular matrix characteristics, and can be exploited in further investigations of the mechanisms of action of SPRMs in fibroid biology.
authors.affiliation: Department of Obstetrics & Gynecology, Duke University, Durham, NC 27710, USA.
authors.forename: Hilary
authors.initials: H
authors.lastname: Roeder
authors.forename: Friederike
authors.initials: F
authors.lastname: Jayes
authors.forename: Liping
authors.initials: L
authors.lastname: Feng
authors.forename: Phyllis C
authors.initials: PC
authors.lastname: Leppert
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D007889:Leiomyoma / Q000188:drug therapy / Q000473:pathology*; D009649:Norpregnadienes / Q000494:pharmacology*; D011980:Receptors, Progesterone / Q000037:antagonists & inhibitors / Q000378:metabolism; D014594:Uterine Neoplasms / Q000188:drug therapy / Q000473:pathology*
chemical_list: D009649:Norpregnadienes; D011980:Receptors, Progesterone; C461063:telapristone acetate