Abstract

The activity of the phosphatase and tensin homologue (PTEN) is known to be suppressed via post-translational modification. However, the mechanism and physiological significance by which post-translational modifications lead to PTEN suppression remain unclear. Here we demonstrate that PTEN destabilization is induced by EGFR- or oncogenic PI3K mutation-mediated AKT activation in cervical cancer. EGFR/PI3K/AKT-mediated ubiquitination and degradation of PTEN are dependent on the MKRN1 E3 ligase. These processes require the stabilization of MKRN1 via AKT-mediated phosphorylation. In cervical cancer patients with high levels of pAKT and MKRN1 expression, PTEN protein levels are low and correlate with a low 5-year survival rate. Taken together, our results demonstrate that PI3K/AKT signals enforce positive-feedback regulation by suppressing PTEN function.

Mutations and post-translational modifications of the PI3K/AKT pathway inhibitor PTEN are a feature of many cancers, but these have not been associated with cervical cancer. Here, the authors identify a PI3K/AKT-mediated ubiquitination degradation pathway of PTEN that occurs in patients with cervical cancer.

Details

Title
PI3K/AKT activation induces PTEN ubiquitination and destabilization accelerating tumourigenesis
Author
Min-Sik, Lee 1 ; Man-Hyung, Jeong 1 ; Hyun-Woo, Lee 2 ; Hyun-Ji, Han 1 ; Ko, Aram 1 ; Hewitt, Stephen M 3 ; Jae-Hoon, Kim 4 ; Kyung-Hee, Chun 2 ; Joon-Yong, Chung 3 ; Lee, Cheolju 5 ; Cho Hanbyoul 4 ; Song Jaewhan 1 

 College of Life Science and Biotechnology, Yonsei University, Department of Biochemistry, Seoul, Republic of Korea (GRID:grid.15444.30) (ISNI:0000 0004 0470 5454) 
 Yonsei University College of Medicine, Department of Biochemistry and Molecular Biology, Seoul, Republic of Korea (GRID:grid.15444.30) (ISNI:0000 0004 0470 5454) 
 Experimental Pathology Laboratory, Center for Cancer Research, National Cancer Institute, NIH MSC 1500, Bethesda, USA (GRID:grid.417768.b) (ISNI:0000 0004 0483 9129) 
 Gangnam Severance Hospital, Yonsei University College of Medicine, Department of Obstetrics and Gynecology, Seoul, Republic of Korea (GRID:grid.15444.30) (ISNI:0000 0004 0470 5454); Institute of Women’s Life Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea (GRID:grid.15444.30) (ISNI:0000 0004 0470 5454) 
 BRI, Korea Institute of Science and Technology, Seoul, Korea (GRID:grid.35541.36) (ISNI:0000000121053345) 
Publication year
2015
Publication date
2015
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2473269764
Copyright
© The Author(s) 2015. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.