Soluble Factors from Human Fetal Bone Marrow-Derived Mesenchymal Stem Cells: Preparation of Conditioned Medium and Its Effect on Tumor Cells.

Mesenchymal stem cells (MSCs) possess some unique features (inherent tumor tropism, anti-inflammatory and immunosuppressive properties) that are not commonly found in conventional anti-cancer agents. These cells are known to secrete a vast array of proteins including growth factors, cytokines, chemokines, extracellular matrix metalloproteinases, and their corresponding inhibitors which exhibit profound effects on the microenvironment. However, the lack of a uniform method for culturing MSCs and their paracrine factors has hindered our understanding of MSC biology. In this chapter, we describe methods for the isolation, in vivo expansion, and phenotypic characterization of MSCs. In addition, methods for the collection and concentration of conditioned medium from these MSCs are described. Using tumor cells that constitutively express fluorescence reporter proteins, the effect of conditioned medium on tumor cell viability can be easily tested in vitro.