Phosphoinositide 3-kinase signaling pathway (PI3K signaling pathway)

The **phosphoinositide 3-kinase signaling pathway** (PI3K pathway) is a fundamental intracellular signal transduction pathway that regulates a wide range of cellular processes, including cell growth, survival, proliferation, metabolism, and apoptosis. It is activated by various receptor classes, notably receptor tyrosine kinases and G protein-coupled receptors, leading to the generation of lipid second messengers that activate downstream effectors such as AKT and mTOR. Aberrant activation or mutation of pathway components is among the most frequent alterations in human cancers, making this pathway a pivotal focus of anticancer drug development. Despite the widespread use of drugs that inhibit nodes within this pathway (such as PI3K, AKT, or mTOR inhibitors), challenges remain in optimizing efficacy and overcoming resistance and side effects. The PI3K signaling pathway is not a single molecular target but a collection of interrelated enzymes and effectors, thus not itself a direct drug target or individual molecule[1][2][3].

Other names

PI3K pathwayPI3K/AKT pathwayphosphoinositide-3-kinase pathwayPI3K-AKT-mTOR pathway

Inhibition of phosphoinositide 3-kinase catalytic activity Downregulation of AKT signaling Dual inhibition of PI3K/mTOR Suppression of metabolic, proliferative, and cell survival signals