Table of Contents
ISRN Oncology
Volume 2012 (2012), Article ID 392647, 10 pages
http://dx.doi.org/10.5402/2012/392647
Review Article

The Stemness Phenotype Model

1Department of Clinical Neuroscience R54, Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden
2Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
3Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile
4Center for Radiological Research, Columbia University Medical Center, New York, NY, USA

Received 26 April 2012; Accepted 23 May 2012

Academic Editors: H. Rizos and G. Schiavon

Copyright © 2012 M. H. Cruz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The identification of a fraction of cancer stem cells (CSCs) associated with resistance to chemotherapy in most solid tumors leads to the dogma that eliminating this fraction will cure cancer. Experimental data has challenged this simplistic and optimistic model. Opposite to the classical cancer stem cell model, we introduced the stemness phenotype model (SPM), which proposed that all glioma cells possess stem cell properties and that the stemness is modulated by the microenvironment. A key prediction of the SPM is that to cure gliomas all gliomas cells (CSCs and non-CSCs) should be eliminated at once. Other theories closely resembling the SPM and its predictions have recently been proposed, suggesting that the SPM may be a useful model for other type of tumors. Here, we review data from other tumors that strongly support the concepts of the SPM applied to gliomas. We include data related to: (1) the presence of a rare but constant fraction of CSCs in established cancer cell lines, (2) the clonal origin of cancer, (3) the symmetrical division, (4) the ability of “non-CSCs” to generate “CSCs,” and (5) the effect of the microenvironment on cancer stemness. The aforenamed issues that decisively supported the SPM proposed for gliomas can also be applied to breast, lung, prostate cancer, and melanoma and perhaps other tumors in general. If the glioma SPM is correct and can be extrapolated to other types of cancer, it will have profound implications in the development of novel modalities for cancer treatment.