Poster Presentation 29th Lorne Cancer Conference 2017

E6AP negatively regulates p27 expression to promote prostate cancer (#252)

Dinesh Raghu 1 2 , Paul J Piotr 1 , Twishi Gulati 1 2 , Elena Takano 1 , Deb Siddhartha 1 , Stephen Fox 1 , Sue Haupt 1 , Cristina Gamell 1 , Ygal Haupt 1 2
  1. Peter MacCallum Cancer centre, East Melbourne, VIC, Australia
  2. Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia

Prostate cancer (PC) is the most common cancer among men in Australia and other parts of the world. The E6–associated protein (E6AP), an E3 ubiquitin ligase is involved in the pathogenesis of Human Papilloma Virus (HPV) dependent-cancers1. Recent work from our lab and others provided evidence-associating E6AP with HPV-independent cancers (Eg. B-cell lymphoma2) including PC3. The p27 protein is an important negative regulator of the cell cycle and found to be expressed at low levels in cancers including PC leading to poor prognosis4. Further, p27 was found to be negatively regulated by E6AP in a neuron cell line5. We therefore hypothesized that p27 is targeted by E6AP in PC. We tested the significance of E6AP/p27 axis in PC and found a subset of patients with E6AP-high and p27-low expression profile. We showed that E6AP knockdown restores p27 expression by activating its E2F1-mediated transcription. Overall we unravelled a novel molecular mechanism by which E6AP negatively regulates p27 in the promotion of PC, and propose that restoration of p27 by targeting E6AP is a novel therapeutic approach for the treatment of PC.

 

 

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