Neoplastic stem cells: Current concepts and clinical perspectives
Accepted 6 January 2010. published online 26 February 2010. Corrected Proof
Abstract
Neoplastic stem cells have initially been characterized in myeloid leukemias where NOD/SCID mouse-repopulating progenitors supposedly reside within a CD34+/Lin− subset of the malignant clone. These progenitors are considered to be self-renewing cells responsible for the in vivo long-term growth of neoplastic cells in leukemic patients. Therefore, these cells represent an attractive target of therapy. In some lymphoid leukemias, NOD/SCID mouse-repopulating cells were also reported to reside within the CD34+/Lin− subfraction of the clone. More recently, several attempts have been made to transfer the cancer stem cell concept to solid tumors and other non-hematopoietic neoplasms. In several of these tumors, the cell surface antigens AC133 (CD133) and CD44 are considered to indicate the potential of a cell to initiate permanent tumor formation in vivo. However, several questions concerning the phenotype, self-renewal capacity, stroma-dependence, and other properties of cancer- or leukemia-initiating cells remain to be solved. The current article provides a summary of our current knowledge on neoplastic (cancer) stem cells, with special emphasis on clinical implications and therapeutic options as well as a discussion about conceptual and technical limitations.
aBone Marrow Transplantation Unit, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
bDivision of Clinical Oncology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
cDivision of Hematology and Hemostaseology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
dLudwig Boltzmann Cluster Oncology, Vienna, Austria
eDepartment of Internal Medicine I, Institute for Cancer Research, Medical University of Vienna, Vienna, Austria
fDepartment of Dermatology, Medical University of Vienna, Vienna, Austria
Corresponding author at: Department of Medicine I, Stem Cell Transplantation Unit, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Wien, Austria. Tel.: +43 1 404006085; fax: +43 1 404005701.