Fetal mesenchymal stem cells in cancer therapy

There is compelling evidence that mesenchymal stem cells (MSCs) can be utilized as delivery vehicles for cancer therapeutics. During the last decade, bone marrow MSCs have been used as delivery vehicles for the local production of therapeutic proteins in multiple tumor types, taking advantage of their innate tropism to the tumor site and their low immunogenicity. More recently, MSCs have been isolated from fetal tissues during gestation or after birth. Fetal MSCs derived from amniotic fluid, amniotic membrane, umbilical cord matrix (Wharton's jelly) and umbilical cord blood are more advantageous than adult MSCs, as they can be isolated noninvasively in large numbers without the ethical reservations associated with embryo research. Several studies have documented that fetal MSCs harbor a therapeutic potential in cancer treatment, as they can home to the tumor site and reduce tumor burden. This natural tumor tropism together with their low immunogenicity renders fetal MSCs as powerful therapeutic tools in gene therapy-based cancer therapeutic schemes. This review summarizes various approaches where the tumor-homing capacity of fetal MSCs has been employed for the localized delivery of anti-tumor therapeutic agents.