Growth arrest and apoptosis induction in androgen receptor-positive human breast cancer cells by inhibition of USP14-mediated androgen receptor deubiquitination.

Abstract

It has been well known that androgen receptor (AR) is critical to prostate cancer development and progression. It has also been documented that AR is expressed in more than 60% of breast tumors, which promotes the growth of estrogen receptor-negative (ER-)/AR-positive (AR+) breast cancer cells. Thus, AR might be a potential therapeutic target for AR-positive/ER-negative breast cancer patients. Previously we reported that in prostate cancer cells proteasome-associated deubiquitinase ubiquitin-specific protease 14 (USP14) stabilized AR protein level by removing its ubiquitin chain. In the current study, we studied the USP14-AR protein interaction and cell proliferation status after USP14 reduction or inhibition in breast cancer cells, and our results support the conclusion that targeting USP14 is a novel strategy for treating AR-responsive breast cancer. We found that inhibition of USP14 accelerated the K48-ubiquitination and proteasome-mediated degradation of AR protein. Additionally, both genetic and pharmacological inhibition of USP14 significantly suppressed cell proliferation in AR-responsive breast cancer cells by blocking G0/G1 to S phase transition and inducing apoptosis. Moreover, AR overexpression inhibited USP14 inhibition-induced events, suggesting that AR deubiquitination by USP14 is critical for breast cancer growth and USP14 inhibition is a possible strategy to treat AR-positive breast cancer.

• Authors: Yuning Liao, Xiaohong Xia, Ningning Liu, Jianyu Cai, Zhiqiang Guo, Yanling Li, Lili Jiang, Q Ping Dou, Daolin Tang, Hongbiao Huang, Jinbao Liu
• Journal: Oncogene (Oncogene) Vol. 37 Issue 14 Pg. 1896-1910 (04 2018) ISSN: 1476-5594 [Electronic] England
• PMID: 29353883 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• AR protein, human
• Enzyme Inhibitors
• Receptors, Androgen
• USP14 protein, human
• Ubiquitin Thiolesterase

Topics

• Apoptosis (drug effects, physiology)
• Breast Neoplasms (metabolism)
• Cell Cycle Checkpoints (drug effects)
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Enzyme Inhibitors (pharmacology)
• Female
• Humans
• MCF-7 Cells
• Receptors, Androgen (metabolism)
• Signal Transduction (drug effects)
• Ubiquitin Thiolesterase (antagonists & inhibitors, physiology)
• Ubiquitination (drug effects)
• Up-Regulation (drug effects)