First generation vanadium-based PTEN inhibitors: Comparative study in vitro and in vivo and identification of a novel mechanism of action.

PTEN, a tumor suppressor phosphatase, regulates cellular functions by antagonizing the growth promoting PI3K/Akt/mTOR pathway through the dephosphorylation of the second messenger PIP. Many preclinical cellular and animal studies have used PTEN inhibitors to highlight specific disease contexts where acute activation of PI3K/Akt/mTOR pathway might offer therapeutic advantages. In the present study we have re-evaluated first-generation PTEN inhibitors, including established bisperoxo-vanadium complexes (bpVs).

The orchestrated signaling by PI3Kα and PTEN at the membrane interface.

The oncogene PI3Kα and the tumor suppressor PTEN represent two antagonistic enzymatic activities that regulate the interconversion of the phosphoinositide lipids PI(4,5)P and PI(3,4,5)P in membranes. As such, they are defining components of phosphoinositide-based cellular signaling and membrane trafficking pathways that regulate cell survival, growth, and proliferation, and are often deregulated in cancer. In this review, we highlight aspects of PI3Kα and PTEN interplay at the intersection of signaling and membrane trafficking.