First Author | Srinivasan S | Year | 2011 |
Journal | Biochim Biophys Acta | Volume | 1809 |
Issue | 2 | Pages | 119-27 |
PubMed ID | 20826237 | Mgi Jnum | J:170215 |
Mgi Id | MGI:4944150 | Doi | 10.1016/j.bbagrm.2010.08.011 |
Citation | Srinivasan S, et al. (2011) E3 ubiquitin protein ligase, E6-associated protein (E6-AP) regulates PI3K-Akt signaling and prostate cell growth. Biochim Biophys Acta 1809(2):119-27 |
abstractText | This study elucidates the role of E6-associated protein, E6-AP (a dual function steroid hormone receptor coactivator and ubiquitin-protein ligase) in the regulation of PI3K-Akt signaling pathway, prostate gland growth and proliferation. Here, we report the generation of transgenic mice and prostate cancer cell line, LNCaP cells that overexpress E6-AP protein. Using these models we show that the levels of total Akt and phosphorylated Akt (active Akt) are increased in E6-AP overexpressing prostate gland and LNCaP cells suggesting that E6-AP regulates the PI3K-Akt signaling pathway. The prostate glands in our transgenic mice are ~20% larger and produce preneoplastic lesions at the age of 18 months. Our data also suggest that E6-AP modulates PI3K-Akt signaling pathway by both androgen-independent and -dependent mechanisms. In the androgen-independent mechanism, E6-AP modulates PI3K-Akt signaling by regulating the protein levels of RhoA, a small GTPase, which is a negative regulator of the Akt signaling pathway. Further, we show that E6-AP, a known coactivator of AR, amplifies the androgen-dependent activation of PI3K-Akt signaling pathway. In addition, we show that stable overexpression of E6-AP in prostate cancer cells results in increased cell size and proliferation. Overall our data suggests that E6-AP regulates both the positive and negative modulators of the PI3K-Akt pathway in prostate cells which results in increased prostate cell growth, proliferation and decreased apoptosis.This article is part of a Special Issue entitled The 26S Proteasome: When degradation is just not enough! |