Tumor Cell Secretomes in Response to Anti- and Pro-Tumorigenic Agents

Abstract

Tumor cells regulate their progression not only by the factors within their cell bodies but also by the secretome they produce and secrete. While their secretome significantly alters the fate of tumor cells themselves, they also regulate the growth of surrounding cells including both companion cancer and non-cancer cells. Tumor cell secretome consists of varying molecules that have been reported mostly tumor-promotive. Furthermore, their pro-tumor capability is enhanced by the application of chemotherapeutic agents. However, multiple lines of emerging evidence suggest that the tumor cell secretome can be tumor-suppressive in response to paracrine and endocrine signaling. This review introduces both tumor-promotive and tumor-suppressive secretomes, focusing on multi-tasking proteins in the intracellular and extracellular domains. We describe tumorigenic signaling that governs the nature of the tumor cell secretome and discuss the possibility of inducing tumor-suppressive proteomes as a novel option for cancer treatment. We evaluated the counterintuitive procedure to generate tumor-suppressive proteomes from a unique type of tumor-modifying cells, which are named “induced tumor-suppressing cells” (iTSCs).