Could cancer and infection be adverse effects of mesenchymal stromal cell therapy?

Abstract

Multipotent mesenchymal stromal cells [also referred to as mesenchymal stem cells (MSCs)] are a heterogeneous subset of stromal cells. They can be isolated from bone marrow and many other types of tissue. MSCs are currently being tested for therapeutic purposes (i.e., improving hematopoietic stem cell engraftment, managing inflammatory diseases and regenerating damaged organs). Their tropism for tumors and inflamed sites and their context-dependent potential for producing trophic and immunomodulatory factors raises the question as to whether MSCs promote cancer and/or infection. This article reviews the effect of MSCs on tumor establishment, growth and metastasis and also susceptibility to infection and its progression. Data published to date shows a paradoxical effect regarding MSCs, which seems to depend on isolation and expansion, cells source and dose and the route and timing of administration. Cancer and infection may thus be adverse or therapeutic effects arising form MSC administration.

Keywords: Cancer; Infection; Mesenchymal stem cells; Therapy; Biosafety

Core tip: Mesenchymal stem cells (MSCs) derived from different origins have recently received much attention as potential therapeutic. However, such cells also appear to have essential functions in building and supporting tumor microenvironments. Here, we review the effect of MSCs on tumor establishment, as also susceptibility to infection and its progression. The literature reveals incongruity regarding the impact of MSCs on the development of cancer and infection; such paradoxical effect might be attributed to differences in isolation and expansion conditions, the source and dose of the cells, the administration route and its timing and host characteristics. MSCs immunomodulatory potential seems to be the leading mechanism responsible for such effects.