Mesenchymal stem cells and pathotropism: Regenerative potential and safety concerns

Abstract

Mesenchymal Stem cells (MSCs) are ubiquitously expressed in several organs, but the major sites in adults are bone marrow and adipose tissue. MSCs can form several cells belonging to all germ layers, such as neurons and cardiomyocytes. MSCs have the potential to be used in cell therapy for many clinical problems, e.g., tissue regeneration, replacement, and to suppress inflammatory processes. MSCs are attractive due to reduced ethical concerns, ease in expansion and ability to be used as 'off-the-shelf' cells. MSCs can be indicated for clinical disorders due to their homing to regions of high cytokines such as tissue insult. This process is generally referred as pathotropism. MSCs have been placed in numerous clinical trials. Thus far, there is no evidence of safety concerns. Besides transplantation of hematopoietic stem cells, treatments with other stem cells are relatively recent. Thus, MSC therapy requires strict monitoring for safety issues. The pathotropic effect of MSCs allows these cells to home to tumors. This property led to the use of MSCs as cellular vehicle for drugs. A major concern of using MSCs in regenerative medicine is their ability to protect and support tumor growth. This chapter focuses on the potential safety concerns of using MSCs. This issue is particularly important if the recipient of stem cells has an undiagnosed tumor or is in cancer remission.