A new role discovered for a familiar enzyme: PI3K and the regulation of cell survival

In recent studies headed by Dr Mark Guthridge in the Leukemia Research Laboratory at the Australian Centre for Blood Diseases, Monash University and published in PLOS Biology, a new role was identified for the protein kinase activity of PI3K in regulating the “survival-only” response of human hematopoietic (blood) cells. These studies provide the first evidence that the protein kinase activity of PI3K can control cell survival and that this activity is a therapeutic target in cancer.
These studies further showed that the protein kinase activity of PI3K can be hijacked to result in the uncontrolled survival of leukemic cells. The ability of cells to survive in the absence of proliferation (which we term the “survival-only” response) allows tissues to maintain cell populations that are poised for rapid responses to damage, infections or other physiological demands. Phosphoinositide 3-kinase (PI3K) is a dual specificity kinase (type of enzyme) that phosphorylates (adds a phosphate to a protein) both lipid and protein substrates and has been widely shown to be important in regulating cell survival and malignant transformation.

Reference Thomas et. al. Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival. PLoS Biol. (2013) 11:e1001515. Link: http://www.ncbi.nlm.nih.gov/pubmed/23775716
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