Palomid 529 (P529) is a novel potent antitumour PI3K/Akt/mTOR inhibitor with a GI50 of <35 μM in the NCI-60 cell lines panel.[1] Palomid 529 inhibits both VEGF-driven and bFGF-driven endothelial cell proliferation with IC50 of 20 nM and 30 nM, respectively.
PI3K activates AKT,then AKT activate CREB,inhibit p27locate FOXO in the cytoplasm, activate PtdIns-3ps, and mTOR which can effect transcription of p70 or 4EBP1.[2,3]
In many cancers, this pathway is overactive, thus reducing apoptosis and allowing proliferation. This pathway is necessary, however, to promote growth and proliferation over differentiation of adult stem cells, neural stem cells specifically. Additionally, this pathway has been found to a be a necessary component in neural long term potentiation.[4]Lowering the effect of the PI3K pathway and increasing the effect of GSK3β and HB9 in NSCs is a potential way of generating these cells better for survival of the neurons. Amplifying the PI3K/AKT pathway increases this neural outgrowth which can determine appropriate treatment concentrations of bisperoxovanadium to stimulate axonal outgrowth but not cause cancer.Not only Palomid 529 inhibits radiation-induced overexpression of Id-1 and VEGF, but also down-regulates radiation-induced MMP-2 and MMP-9. [5]
Reference:
1 Xue Q, et al. “Palomid 529, a novel small-molecule drug, is a TORC1/TORC2 inhibitor that reduces tumor growth, tumor angiogenesis, and vascular permeability.” Cancer Res, 2008, 68(22), 9551-9557.
2 Rafalski, V. A.; Brunet, A. "Energy metabolism in adult neural stem cell fate". Progress in Neurobiology . 2011, 93 (2): 182–203.
3 Ojeda, L. et al. "Critical role of PI3K/Akt/GSK3β in motoneuron specification from human neural stem cells in response to FGF2 and EGF". PLoS ONE 2011, 6 (8): e23414.
4 Sui, L; Wang, J; Li, B. M. "Role of the phosphoinositide 3-kinase-Akt-mammalian target of the rapamycin signaling pathway in long-term potentiation and trace fear conditioning memory in rat medial prefrontal cortex". Learning & Memory 2008,15 (10): 762–76.
5 Diaz R, et al. “The novel Akt inhibitor Palomid 529 (P529) enhances the effect of radiotherapy in prostate cancer” .Br J Cancer 2009, 100(6), 932-940.
