Effects of novel isoform-selective phosphoinositide 3-kinase inhibitors on natural killer cell function.

ABSTRACT: Phosphoinositide 3-kinases (PI3Ks) are promising targets for therapeutic development in cancer. The class I PI3K isoform p110? has received considerable attention in oncology because the gene encoding p110? (PIK3CA) is frequently mutated in human cancer. However, little is known about the function of p110? in lymphocyte populations that modulate tumorigenesis. We used recently developed investigational inhibitors to compare the function of p110? and other isoforms in natural killer (NK) cells, a key cell type for immunosurveillance and tumor immunotherapy. Inhibitors of all class I isoforms (pan-PI3K) significantly impaired NK cell-mediated cytotoxicity and antibody-dependent cellular cytotoxicity against tumor cells, whereas p110?-selective inhibitors had no effect. In NK cells stimulated through NKG2D, p110? inhibition modestly reduced PI3K signaling output as measured by AKT phosphorylation. Production of IFN-? and NK cell-derived chemokines was blocked by a pan-PI3K inhibitor and partially reduced by a p110?inhibitor, with lesser effects of p110? inhibitors. Oral administration of mice with MLN1117, a p110? inhibitor in oncology clinical trials, had negligible effects on NK subset maturation or terminal subset commitment. Collectively, these results support the targeting of PIK3CA mutant tumors with selective p110? inhibitors to preserve NK cell function.

SUBMITTER: Yea SS 

PROVIDER: S-EPMC4051752 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature