Selective progesterone receptor modulator asoprisnil induces endoplasmic reticulum stress in cultured human uterine leiomyoma cells.

Abstract

A recent clinical trial (Chwalisz K, Larsen L, Mattia-Goldberg C, Edmonds A, Elger W, Winkel CA. Fertil Steril 87: 1399-1412, 2007) has demonstrated that the selective progesterone receptor modulator asoprisnil efficiently causes the shrinkage of uterine leiomyoma. The present study was conducted to examine whether asoprisnil elicits endoplasmic reticulum (ER) stress-induced apoptosis in cultured human uterine leiomyoma cells. After subculture in phenol red-free DMEM supplemented with 10% FBS for 120 h, cultured cells were stepped down to serum-free conditions with or without graded concentrations of asoprisnil. ER stress-associated and apoptosis-related proteins were assessed by reverse transcription-PCR analysis or Western blot analysis. RNA interference of growth-arrest- and DNA-damage-inducible gene 153 (GADD153) was performed using small interfering RNA. Terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL)-positive rates were assessed by TUNEL assay. Compared with untreated control cultures, treatment with 10(-7) M asoprisnil significantly (P < 0.05) increased the protein contents of ubiquitin at 2 h and phospho-double-stranded RNA-activated protein kinase-like ER kinase, phospho-eukaryotic initiation factor 2alpha, activating transcription factor 4, and glucose-regulated protein 78 kDa at 4 h, followed by the significant (P < 0.05) increase in GADD153 protein content at 6 h and cleaved poly(adenosine 5'-diphosphate ribose)polymerase (PARP) at 8 h. RNA interference of GADD153 suppressed protein contents of asoprisnil-induced cleaved PARP, Bax, Bak, GADD34, and tribbles-related protein 3 (TRB3) and TUNEL-positive rate but attenuated asoprisnil-induced reduction in Bcl-2 protein content in cultured leiomyoma cells. These results suggest that asoprisnil elicits ER stress-induced apoptosis in cultured leiomyoma cells and that GADD153 plays a role in asoprisnil-induced apoptosis by modulating the Bcl-2 family of proteins, GADD34, and TRB3.

• Authors: Qin Xu, Noriyuki Ohara, Jin Liu, Koji Nakabayashi, Deborah DeManno, Kristof Chwalisz, Shigeki Yoshida, Takeshi Maruo
• Journal: American journal of physiology. Endocrinology and metabolism (Am J Physiol Endocrinol Metab) Vol. 293 Issue 4 Pg. E1002-11 (Oct 2007) ISSN: 0193-1849 [Print] United States
• PMID: 17652152 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DDIT3 protein, human
• Estrenes
• Oximes
• Progesterone Congeners
• Receptors, Progesterone
• Ubiquitin
• Tunicamycin
• Transcription Factor CHOP
• asoprisnil
• Poly(ADP-ribose) Polymerases

Topics

• Adult
• Apoptosis (drug effects, genetics)
• Dose-Response Relationship, Drug
• Endoplasmic Reticulum (drug effects, metabolism)
• Estrenes (pharmacology)
• Female
• Humans
• Leiomyoma (metabolism, pathology)
• Middle Aged
• Oximes (pharmacology)
• Poly(ADP-ribose) Polymerases (metabolism)
• Progesterone Congeners (pharmacology)
• Protein Folding
• Protein Processing, Post-Translational (drug effects)
• Receptors, Progesterone (agonists)
• Substrate Specificity
• Transcription Factor CHOP (genetics, metabolism)
• Tumor Cells, Cultured
• Tunicamycin (pharmacology)
• Ubiquitin (metabolism)
• Uterine Neoplasms (metabolism, pathology)