Signaling pathways influencing tumor microenvironment and their exploitation for targeted drug delivery

Abstract In the recent years, the “tumor microenvironment” has been receiving growing attention due to its involvement in neoplastic transformation, tumor growth, invasion, and protection of tumor cells from host immune response. All these events are facilitated by chemical signals produced by the tumor as well as the surrounding stromal cells. This review is divided into two main parts in which the first part discusses the receptor tyrosine kinase (RTK)-mediated growth factor signaling, steroid hormone (SH) signaling, ancient signaling pathways, and other molecules that are involved in tumorigenesis and how they interact with each other to create a complex tumor microenvironment. In the second part, we bring together the recent nanocarrier-mediated drug delivery approaches to target the signaling pathways/molecules present in the tumor microenvironment.