Fig. 1
From: Plasma membrane and nuclear phosphatidylinositol 4,5-bisphosphate signalling in cancer
The dynamic regulation of the cytosolic PI(4,5)P2/PI(3,4,5)P3 levels plays a crucial role in many key cell processes, including cell growth, proliferation or organisation of the actin cytoskeleton. The figure illustrates how the disruption of PI(4,5)P2 homeostasis modulates PI3K/Akt downstream signalling and actin cytoskeleton dynamics. (A) In normal cells, the two actin forms, monomeric actin (Gactin) and filamentous actin (F-actin) are under constant dynamic conversion driven by PI(4,5)P2 via actin regulatory proteins. (B) In cancer cells, the imbalanced PI(4,5)P2/PI(3,4,5)P2 levels influence the hyperactivation of Akt. This, in turn, leads to alterations in actin remodelling dynamics, which can be observed as increased actin polymerisation, invadopodia formation and, in consequence, enhanced cell motility, invasivity and metastasis