PI3K in cancer-stroma interactions: bad in seed and ugly in soil

Abstract

Over the past decade the phosphoinositide-3 kinase (PI3K) signaling pathway emerged as an important player for tumor initiation and growth and, currently, PI3K inhibition constitutes a promising therapeutic approach for solid and hematological tumors. Beside its role in tumor cell evolution, PI3K signaling also provides integral functions for noncancerous cells that reside in healthy tissues surrounding the tumor, also referred as tumor microenvironment (TME). This review will address how PI3K signaling participates to the tumorigenic process and discuss the interaction between tumor cells and the surrounding TME, with particular focus on the role of PI3Ks in tumor-associated immune responses, tumor angiogenesis and metastasis formation.