title: Cancer stem cells in solid tumors: an overview and new approaches for their isolation and characterization.
abstract: Primary tumors are responsible for 10% of cancer deaths. In most cases, the main cause of mortality is the formation of metastases. Accumulating evidence suggests that a subpopulation of tumor cells with distinct stem-like properties is responsible for tumor initiation, invasive growth, and metastasis formation. This population is defined as cancer stem cells (CSCs). Existing therapies have enhanced the length of survival after diagnosis of cancer but have completely failed in terms of recovery. CSCs appear to be resistant to chemotherapy, may remain quiescent for extended periods, and have affinity for hypoxic environments. The CSCs can be identified and isolated by different methodologies, including isolation by CSC-specific cell surface marker expression, detection of side population phenotype by Hoechst 33342 exclusion, assessment of their ability to grow as floating spheres, and aldehyde dehydrogenase (ALDH) activity assay. None of the methods mentioned are exclusively used to isolate the solid tumor CSCs, highlighting the imperative to delineate more specific markers or to use combinatorial markers and methodologies. This review provides an overview of the main characteristics and approaches used to identify, isolate, and characterize CSCs from solid tumors.
authors.affiliation: Department of Experimental Medicine, Section of Histology and Embryology, Tissue Engineering and Regenerative Medicine Laboratory, Cancer Stem Cell Eradication Program, Second University of Naples, Naples, Italy.
authors.forename: Virginia
authors.initials: V
authors.lastname: Tirino
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Desiderio
authors.forename: Francesca
authors.initials: F
authors.lastname: Paino
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rosa
authors.forename: Federica
authors.initials: F
authors.lastname: Papaccio
authors.forename: Marcella
authors.initials: M
authors.lastname: La Noce
authors.forename: Luigi
authors.initials: L
authors.lastname: Laino
authors.forename: Francesco
authors.initials: F
authors.lastname: De Francesco
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Papaccio
mesh_terms: D002469:Cell Separation; D006801:Humans; D009369:Neoplasms / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*