In vitro three-dimensional tumor microenvironment models for anticancer drug discovery.

Anticancer drug discovery has long been hampered by the poor predictivity of the preclinical models. There is a growing realization that the tumor microenvironment is a critical determinant of the response of cancer cells to therapeutic agents. The past 5 years have seen a great deal of progress in our understanding of how the three-dimensional microenvironment modulates the signaling behavior of tumor cells. The present review discusses how three-dimensional in vitro cell culture models can benefit cancer drug discovery through an accurate modeling of the tumor microenvironment, leading to more physiologically relevant experimental outcomes.