PI3K/Akt/mTOR pathway inhibitors in cancer: a perspective on clinical progress.

The phosphoinositide 3-kinase (PI3K)/serine-theronine protein kinase Akt (also known as protein kinase B (PKB))/mammalian target of rapamycin (mTOR) pathway is a vital transduction cascade that is connected with many essential cellular activities, such as growth and survival. Along with extensive pharmacological studies validating the therapeutic potential of targeting the PI3K/Akt/mTOR pathway for the treatment of cancer, kinase inhibitors targeting significant knots of this pathway including PI3K, Akt, mTOR, and 3-phosphoinositide-dependent protein kinase-1 (PDK-1) keep arising and entering clinical studies. Herein, we review the most up-to-date landscape on developing small-molecule kinase inhibitors targeting the PI3K/Akt/mTOR pathway, with emphasis on small-molecule inhibitors which have been progressed into clinical studies.