Title:Involvement of Mesenchymal Stem Cells in Cancer Progression and Metastases
VOLUME: 15 ISSUE: 2
Author(s):Astra I. Chang, Aaron H. Schwertschkow, Jan A. Nolta and Jian Wu
Affiliation:University of California Davis Medical Center, Institute for Regenerative Cures, 2921 Stockton Blvd, Suite 1610, Sacramento, CA 95817, USA.
Keywords:Cancer metastasis, cancer stem cells, circulating tumor cells, exosomes, mesenchymal stem cells,
microenvironment.
Abstract:Mesenchymal stem/stromal cells (MSCs) are known to be the helpers for the healing of
tissue damage, often referred to as ambulatory cells. However, MSCs are also recruited by cancer
cells to similarly aid in tumor growth and progression. In this review, some of the key steps in cancer
progression and metastases are described including the various steps in which MSCs participate and
may play important roles. MSCs aid in cancer cells’ ability to evade immune attack, while promoting tumor angiogenesis,
even being counter-acting against chemotherapeutics and other drugs used to fight various cancers. Furthermore, MSCs
participate in many of the crucial steps in invasion and metastasis, including stimulating the epithelial-mesenchymal
transition (EMT) and induction of stem-like properties that allow cancer stem cells to increase their survivability through
the circulation. These steps are described in detail. Differences between circulating tumor cells (CTCs) and cancer stem
cells (CSCs) are discussed, along with descriptions of the formation of a pre-metastatic niche, the role of exosomes from
both cancer cells and MSCs in metastasis and tumor reseeding (self-seeding). More and more, MSCs are being proposed
as a promising tumor targeting drug-delivery tool. In order to fulfill this promise, further understanding of the precise
roles that MSCs play in the process of cancer metastases must be achieved, in attempting to create remedies that will
improve the outcome of available therapeutics.