Epigenetic-mediated upregulation of progesterone receptor B gene in endometrial cancer cell lines.

Abstract

OBJECTIVES:

To determine if epigenetic interference can restore progesterone receptor-B (PR-B) expression in PR-B negative endometrial adenocarcinoma cell lines, and to characterize the kinetics of PR-B induction mediated by DNA methyltransferase and histone deacetylase inhibitors.

METHODS:

The PR-B negative endometrioid cancer cell lines KLE and HEC-1B were used as study models. PR-B mRNA and protein expression levels were measured using real-time PCR and Western blot analysis, respectively. DNA methylation levels of the PR-B promoter were determined by methylation-specific PCR. Dose-response correlations and the duration of response to aza-deoxycytidine (ADC) and trichostatin A (TSA) were characterized. Cell responses to prolonged and repeated drug treatment were also examined.

RESULTS:

Relatively low concentrations of ADC and TSA over a 24-h period induced PR-B expression. Furthermore, ADC and TSA acted synergistically to reactivate PR-B expression. Depending on the cell line used, PR-B mRNA was induced 10-110 fold. This elevated PR-B expression continued for 48 h after drug withdrawal. Sustained upregulation of PR-B mRNA and protein was observed during prolonged and repeated drug treatment.

CONCLUSION:

The epigenetically silenced PR-B gene remains sensitive to changes in DNA demethylation and histone acetylation in uterine adenocarcinoma cell lines. Treatment with ADC and/or TSA results in a robust and sustainable PR-B upregulation. These small molecule epigenetic modifying agents may be used to sensitize poorly differentiated, PR-B negative endometrial cancers to progestational therapy.

• Authors: Yuning Xiong, Sean C Dowdy, Jesus Gonzalez Bosquet, Ying Zhao, Norman L Eberhardt, Karl C Podratz, Shi-Wen Jiang
• Journal: Gynecologic oncology (Gynecol Oncol) Vol. 99 Issue 1 Pg. 135-41 (Oct 2005) ISSN: 0090-8258 [Print] United States
• PMID: 16024066 (Publication Type: Journal Article)

Chemical References

• Enzyme Inhibitors
• Histone Deacetylase Inhibitors
• Hydroxamic Acids
• RNA, Messenger
• Receptors, Progesterone
• progesterone receptor B
• trichostatin A
• Decitabine
• Histone Deacetylases
• Azacitidine

Topics

• Adenocarcinoma (genetics, metabolism)
• Azacitidine (analogs & derivatives, pharmacology)
• Cell Line, Tumor
• DNA Methylation
• Decitabine
• Endometrial Neoplasms (genetics, metabolism)
• Enzyme Inhibitors (pharmacology)
• Epigenesis, Genetic
• Female
• Histone Deacetylase Inhibitors
• Histone Deacetylases (metabolism)
• Humans
• Hydroxamic Acids (pharmacology)
• Polymerase Chain Reaction
• RNA, Messenger (biosynthesis, genetics)
• Receptors, Progesterone (biosynthesis, genetics)
• Up-Regulation (drug effects)