Cancer stem cells werehave originally been identified in leukemia and later in several solid tumor types. They have very different properties from the bulk of the tumor, as they divide much more slowly and have very efficient drug- resistance mechanisms. Current treatments might largely spare cancer stem cells, thus leading to tumor recurrence and metastasis. The recent identification of growth and differentiation pathways responsible for cancer stem cell proliferation and survival will help in the discovery identification of novel therapeutic targets. Developing selective drugs against cancer stem cells offers great therapeutic opportunities but also provides for major challenges regarding preclinical models, therapeutic windows, and clinical study end points.

Niche for Normal and Cancer Stem Cells

c-Myc and Activated Ras During Skin Tumorigenesis: Cooperation at the Cancer Stem Cell Level?
Wnt Signaling in Stem Cells and Lung Cancer
Bone Morphogenetic Proteins Regulate Tumorigenicity in Human Glioblastoma Stem Cells
Strategies to Induce Nuclear Reprogramming
The Intestinal Stem Cell Niche Studied Through Conditional Transgenesis
The Migrating Cancer Stem Cells Model - A Conceptual Explanation of Malignant Tumour Progression
Bone Marrow Niche and Leukemia
Breast Stem Cells and Cancer
Prostate Cancer Stem Cells: A Target for New Therapies
The Hedgehog Signaling Network, Mammary Stem Cells, and Breast Cancer: Connections and Controversies
Strategies to Eliminate Cancer Stem Cells
DNA Repair in Stem Cell Maintenance and Conversion to Cancer Stem Cells
Tumorigenic Epithelial Stem Cells and Their Normal Counterparts.