Phosphatidylinositol 3-kinase (PI3-K) amplification and phosphatase and tensin homolog (PTEN) deletion-caused Akt activation contribute to the development of prostate cancer. Mammalian target of rapamycin complex 2 (mTORC2) is a kinase complex comprised of mTOR, Rictor, mSin1, mLST8/GβL and PRR5 and functions in the phosphorylation of Akt at Ser473. Herein, we report that mTORC2 plays an important role in PC3 androgen refractory prostate cell proliferation and anchorage-independent growth. Aloe-emodin, a natural compound found in aloe, inhibited both proliferation and anchorage-independent growth of PC3 cells. Protein content analysis suggested that activation of the downstream substrates of mTORC2, Akt and PKCα, was inhibited by aloe-emodin treatment. Pull-down assay and in vitro kinase assay results indicated that aloe-emodin could bind with mTORC2 in cells and inhibit its kinase activity. Aloe-emodin also exhibited tumor suppression effects in vivo in an athymic nude mouse model. Collectively, our data suggest that mTORC2 plays an important role in prostate cancer development and aloe-emodin suppresses prostate cancer progression by targeting mTORC2.
Written by:
Liu K, Park C, Li S, Lee KW, Liu H, He L, Soung NK, Ahn JS, Bode AM, Dong Z, Kim BY, Dong Z Are you the author?
The World Class Institute and Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, Ochang, Cheongwon 363-883, Republic of Korea
Reference: Carcinogenesis. 2012 May 7
doi: 10.1093/carcin/bgs156
PubMed Abstract
PMID: 22532249