title: Efficacy of LGD1069 (Targretin), a retinoid X receptor-selective ligand, for treatment of uterine leiomyoma.
abstract: The conventional treatment of uterine leiomyomas, or fibroids, with gonadotropin-releasing hormone (GnRH) agonists is often associated with serious side effects, necessitating short-term, palliative use of this therapy. Therefore, we examined a retinoid X receptor (RXR)-selective ligand, LGD1069, as a possible treatment for leiomyoma. LGD1069 has demonstrated efficacy as a chemopreventive agent in the N-nitroso-N-methylurea (NMU)-induced rat mammary carcinoma model and is a therapeutic agent in several epithelial tumor models. Previous studies have shown that it has both antitumor effects and antiestrogenic activity in the rat uterus, suggesting the potential utility of this agent for treatment of hormonally dependent uterine fibroids. The expression of retinoid receptors in tumors and cell lines derived from leiomyomas arising in the Eker rat was confirmed by Northern analysis. After treatment for 4 months with LGD1069, the number of grossly observable tumors was substantially reduced although the total incidence of tumors, including microscopic lesions, remained unaffected, suggesting an effect of the compound on tumor growth kinetics rather than on tumor initiation. Analysis of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining and determination of 5-bromo-2-deoxyuridine (BrdU) incorporation indicated that the reduction in grossly observable tumors that occurred in treated animals was mediated by a significant increase in the level of apoptosis rather than a decrease in cell proliferation. These results suggest that LGD1069 may be an effective therapeutic agent for uterine leiomyoma that may inhibit tumor growth and, consequently, alleviate the symptoms associated with this disease.
authors.affiliation: Department of Carcinogenesis, M. D. Anderson Cancer Center, University of Texas, Smithville, Texas 78957, USA. rofy@sprd1.mdacc.tmc.edu
authors.forename: S D
authors.initials: SD
authors.lastname: Gamage
authors.forename: E D
authors.initials: ED
authors.lastname: Bischoff
authors.forename: K D
authors.initials: KD
authors.lastname: Burroughs
authors.forename: W W
authors.initials: WW
authors.lastname: Lamph
authors.forename: M M
authors.initials: MM
authors.lastname: Gottardis
authors.forename: C L
authors.initials: CL
authors.lastname: Walker
authors.forename: R
authors.initials: R
authors.lastname: Fuchs-Young
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D000077610:Bexarotene; D002455:Cell Division / Q000187:drug effects; D004717:Endometrium / Q000187:drug effects; D005260:Female; D007889:Leiomyoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008024:Ligands; D051381:Rats; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D047488:Retinoid X Receptors; D013764:Tetrahydronaphthalenes / Q000378:metabolism / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014621:Vagina / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D008024:Ligands; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D013764:Tetrahydronaphthalenes; D014157:Transcription Factors; D000077610:Bexarotene