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