Orosphere assay: a method for propagation of head and neck cancer stem cells.
BACKGROUND
Recent evidence suggests that head and neck squamous cell carcinomas (HNSCCs) harbor a small subpopulation of highly tumorigenic cells, designated cancer stem cells. A limiting factor in cancer stem cell research is the intrinsic difficulty of expanding cells in an undifferentiated state in vitro.


METHODS
Here, we describe the development of the orosphere assay, a method for the study of putative head and neck cancer stem cells. An orosphere is defined as a nonadherent colony of cells sorted from primary HNSCCs or from HNSCC cell lines and cultured in 3-dimensional soft agar or ultralow attachment plates. Aldehyde dehydrogenase activity and CD44 expression were used here as stem cell markers.


RESULTS
This assay allowed for the propagation of head and neck cancer cells that retained stemness and self-renewal.


CONCLUSIONS
The orosphere assay is well suited for studies designed to understand the pathobiology of head and neck cancer stem cells.
Department of Restorative Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan, USA.
Sudha
S
Krishnamurthy
Jacques E
JE
Nör
D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005455:Fluorescent Antibody Technique; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D000077195:Squamous Cell Carcinoma of Head and Neck
D014408:Biomarkers, Tumor; D018960:Hyaluronan Receptors; D000444:Aldehyde Dehydrogenase