TY - JOUR
T1 - The PI3-kinase isoform p110δ is essential for cell transformation induced by the D816V mutant of c-Kit in a lipid-kinase-independent manner
AU - Sun, J.
AU - Mohlin, S.
AU - Lundby, A.
AU - Kazi, J.U.
AU - Hellman, U.
AU - Påhlman, S.
AU - Olsen, J.V.
AU - Rönnstrand, L.
PY - 2013/11/11
Y1 - 2013/11/11
N2 - PI3-kinase has a crucial role in transformation mediated by the oncogenic c-Kit mutant D816V. In this study, we demonstrate that the c-Kit/D816V-mediated cell survival is dependent on an intact direct binding of PI3-kinase to c-Kit. However, mutation of this binding site had little effect on the PI3-kinase activity in the cells, suggesting that c-Kit/D816V-mediated cell survival is dependent on PI3-kinase but not its kinase activity. Furthermore, inhibition of the lipid kinase activity of PI3-kinase led only to a slight inhibition of cell survival. Knockdown of the predominant PI3-kinase isoform p110δ in c-Kit/D816V-expressing Ba/F3 cells led to reduced cell transformation both in vitro and in vivo without affecting the overall PI3-kinase activity. This suggests that p110δ has a lipid-kinase-independent role in c-Kit/D816V-mediated cell transformation. We furthermore demonstrate that p110δ is phosphorylated at residues Y524 and S1039 and that phosphorylation requires an intact binding site for PI3-kinase in c-Kit/D816V. Overexpression of p110δ carrying the Y523F and S1038A mutations significantly reduced c-Kit/D816V-mediated cell survival and proliferation. Taken together, our results demonstrate an important lipid-kinase-independent role of p110δ in c-Kit/D816V-mediated cell transformation. This furthermore suggests that p110δ could be a potential diagnostic factor and selective therapeutic target for c-Kit/D816V-expressing malignancies.Oncogene advance online publication, 11 November 2013; doi:10.1038/onc.2013.479.
AB - PI3-kinase has a crucial role in transformation mediated by the oncogenic c-Kit mutant D816V. In this study, we demonstrate that the c-Kit/D816V-mediated cell survival is dependent on an intact direct binding of PI3-kinase to c-Kit. However, mutation of this binding site had little effect on the PI3-kinase activity in the cells, suggesting that c-Kit/D816V-mediated cell survival is dependent on PI3-kinase but not its kinase activity. Furthermore, inhibition of the lipid kinase activity of PI3-kinase led only to a slight inhibition of cell survival. Knockdown of the predominant PI3-kinase isoform p110δ in c-Kit/D816V-expressing Ba/F3 cells led to reduced cell transformation both in vitro and in vivo without affecting the overall PI3-kinase activity. This suggests that p110δ has a lipid-kinase-independent role in c-Kit/D816V-mediated cell transformation. We furthermore demonstrate that p110δ is phosphorylated at residues Y524 and S1039 and that phosphorylation requires an intact binding site for PI3-kinase in c-Kit/D816V. Overexpression of p110δ carrying the Y523F and S1038A mutations significantly reduced c-Kit/D816V-mediated cell survival and proliferation. Taken together, our results demonstrate an important lipid-kinase-independent role of p110δ in c-Kit/D816V-mediated cell transformation. This furthermore suggests that p110δ could be a potential diagnostic factor and selective therapeutic target for c-Kit/D816V-expressing malignancies.Oncogene advance online publication, 11 November 2013; doi:10.1038/onc.2013.479.
UR - http://www.scopus.com/inward/record.url?scp=84887030794&partnerID=8YFLogxK
U2 - 10.1038/onc.2013.479
DO - 10.1038/onc.2013.479
M3 - Journal article
C2 - 24213578
JO - Oncogene
JF - Oncogene
SN - 0950-9232
ER -