Targeting class IA PI3K isoforms selectively impairs cell growth, survival, and migration in glioblastoma.

ABSTRACT: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is frequently activated in human cancer and plays a crucial role in glioblastoma biology. We were interested in gaining further insight into the potential of targeting PI3K isoforms as a novel anti-tumor approach in glioblastoma. Consistent expression of the PI3K catalytic isoform PI3K p110? was detected in a panel of glioblastoma patient samples. In contrast, PI3K p110? expression was only rarely detected in glioblastoma patient samples. The expression of a module comprising the epidermal growth factor receptor (EGFR)/PI3K p110?/phosphorylated ribosomal S6 protein (p-S6) was correlated with shorter patient survival. Inhibition of PI3K p110? activity impaired the anchorage-dependent growth of glioblastoma cells and induced tumor regression in vivo. Inhibition of PI3K p110? or PI3K p110? also led to impaired anchorage-independent growth, a decreased migratory capacity of glioblastoma cells, and reduced the activation of the Akt/mTOR pathway. These effects were selective, because targeting of PI3K p110? did not result in a comparable impairment of glioblastoma tumorigenic properties. Together, our data reveal that drugs targeting PI3K p110? can reduce growth in a subset of glioblastoma tumors characterized by the expression of EGFR/PI3K p110?/p-S6.

SUBMITTER: Holand K 

PROVIDER: S-EPMC3981776 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature