Neoplastic stem cells: current concepts and clinical perspectives.
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.
Schulenburg
Axel
A
Bone Marrow Transplantation Unit, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria. axel.schulenburg@meduniwien.ac.at
Brämswig
Kira
K
Herrmann
Harald
H
Karlic
Heidrun
H
Mirkina
Irina
I
Hubmann
Rainer
R
Laffer
Sylvia
S
Marian
Brigitte
B
Shehata
Medhat
M
Krepler
Clemens
C
Pehamberger
Hubert
H
Grunt
Thomas
T
Jäger
Ulrich
U
Zielinski
Christoph C
CC
Valent
Peter
P
D000818:Animals; D006801:Humans; D009369:Neoplasms / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*