Ito Y, Hart JR, Ueno L, Vogt PK
Proc Natl Acad Sci U S A. 2014 Nov 25;111(47):16826-9. doi: 10.1073/pnas.1420281111. Epub 2014 Nov 10.
Expression of the regulatory subunit p85beta of PI3K induces oncogenic transformation of primary avian fibroblasts. The transformed cells proliferate at an increased rate compared with nontransformed controls and show elevated levels of PI3K signaling. The oncogenic activity of p85beta requires an active PI3K-TOR signaling cascade and is mediated by the p110alpha and p110beta isoforms of the PI3K catalytic subunit. The data suggest that p85beta is a less effective inhibitor of the PI3K catalytic subunit than p85alpha and that this reduced level of p110 inhibition accounts for the oncogenic activity of p85beta.