Stem cells and neurogenesis in tumors.

Abstract

Bone-marrow-derived and tissue-resident stem cells promote repair of injured tissues by contributing to new blood vessel, muscle and nerve formation. These same stem cells may contribute to tumor growth and spread. Tumors express numerous growth factors that induce both angiogenesis and neurogenesis; these factors may also induce tissue-resident stem cell recruitment and differentiation. Tumors also recruit circulating bone-marrow-derived stem or progenitor cells, which play roles in promoting tumor growth and spread. As innervation of tumors promote cancer pain and can contribute to tumor spread, an understanding of the roles of stem cells in tumor innervation will assist in the development of new cancer therapies.