Phosphoinositide 3-kinase beta (PI3Kβ) and Phosphoinositide 3-kinase delta (PI3Kδ) (PI3Kβ, PI3Kδ)

Phosphoinositide 3-kinase beta (PI3Kβ) and phosphoinositide 3-kinase delta (PI3Kδ) are isoforms of class I phosphoinositide 3-kinases, a family of intracellular enzymes that phosphorylate phosphatidylinositols and mediate signal transduction from cell surface receptors, including receptor tyrosine kinases and G-protein-coupled receptors. PI3Kβ is ubiquitously expressed and participates in cellular proliferation, survival, and cytoskeletal rearrangement, while PI3Kδ is most highly expressed in leukocytes and plays a critical role in immune cell development and function, notably in B cell maturation and survival. Aberrant activation or mutation of these isoforms—either via activating mutations, loss of regulatory mechanisms (e.g., loss of PTEN), or upstream oncogenic signaling—contributes to the pathogenesis of cancer and immune diseases. PI3Kβ and PI3Kδ are validated drug targets, with several small-molecule inhibitors developed and clinically approved for hematological malignancies and other disorders, but their inhibition can also suppress normal immune function and cause significant adverse effects[1][2][3][4][5][6].

Other names

PI3K-betaPI3K-deltap110-beta (PIK3CB)p110-delta (PIK3CD)Class IA phosphoinositide 3-kinase beta/deltaPIK3CB (gene, for PI3Kβ)PIK3CD (gene, for PI3Kδ)Phosphatidylinositol 3-kinase beta/delta

Inhibition of PI3K kinase activity; Blockade of PI3K-dependent signal transduction (PI3K/AKT pathway); Induction of apoptosis in malignant cells via AKT/mTOR suppression; Modulation of immune cell signaling