The ubiquitin ligase RNF181 stabilizes ERα and modulates breast cancer progression

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Estrogen receptor alpha (ERα) positive breast cancer constitutes 70% of malignancies and is typically treated with endocrine therapy.
• Endocrine resistance is a major clinical challenge, occurring in over half of patients, often due to alterations in ERα signaling pathways.
• Understanding ERα regulation is crucial for improving breast cancer therapeutics.

Purpose of the Study:

• To identify molecular mechanisms controlling ERα expression and stability.
• To investigate the role of the ubiquitin ligase RNF181 in ERα stabilization and breast cancer progression.

Main Methods:

• Correlation analysis of RNF181 and ERα expression in human breast tumors.
• In vitro and in vivo studies involving RNF181 depletion.
• RNA sequencing to assess RNF181's impact on ERα target genes.
• Immunoprecipitation assays to determine RNF181-ERα interaction and ubiquitination status.

Main Results:

• RNF181 expression correlates with ERα levels and predicts poor survival in endocrine-treated patients.
• RNF181 depletion inhibits breast cancer progression, reduces ERα protein levels, and decreases expression of ERα target genes (e.g., PS2, GREB1).
• RNF181 associates with ERα, promoting its stability possibly through K63-linked poly-ubiquitination.

Conclusions:

• RNF181 stabilizes ERα protein, thereby facilitating breast cancer progression.
• RNF181 influences ERα target gene expression through a non-genomic mechanism, highlighting its role in endocrine resistance.
• Targeting RNF181 may represent a novel therapeutic strategy for ERα-positive breast cancer.