Date of Award

Spring 5-21-2018

Document Type


Degree Name

Doctor of Philosophy (PhD)


Biological Science

First Advisor

Zhengxin Wang, Ph.D.

Second Advisor

Shafiq Khan, Ph.D.

Third Advisor

JoAnn Powell, Ph.D.


Prostate cancer is the most commonly diagnosed malignancy among men, but few genetic factors that drive prostate cancer initiation have been identified. The WD repeat domain 77 (Wdr77) protein is essential for cellular proliferation when it localizes in the cytoplasm of epithelial cells at the early stage of prostate development. In the adult prostate, it is transported into the nucleus and functions as a co-regulator of the androgen receptor to promote cellular differentiation and prostate function. This developmental process is reversed during prostate tumorigenesis i.e., Wdr77 is translocated from the nucleus into the cytoplasm to drive proliferation of prostate cancer cells. In this study, we used in vivo genetic studies to investigate the role of Wdr77 in prostate tumorigenesis. We found that prostate-specific deletion of Wdr77 abolished prostate tumor initiation induced by loss of the tumor suppressor Pten. Mechanistically, Wdr77 ablation inhibited E2F3 activation and enhanced TGFb signaling, leading to attenuated cellular proliferation induced by loss of Pten. These findings establish an essential role of Wdr77 for prostate tumor initiation.