Abstract

Stem cells are characterized by their self-renewal capacity and the ability to differentiate into any type of mature cell. In addition to normal stem cells, cancerous stem cells have been found to be responsible for the growth and spread of tumors. According to the CSC hypothesis CSC leads to tumorigenesis and tumor growth. Head and neck cancer are the sixth most common cancer and about 300,000 new cases are diagnosed every year. Despite progress in treatment, the 5-year survival rate for this cancer has not improved over the past 30 years. In the hierarchical structure of stem cells present in the human oral epithelium, it is clear that stem cells are the only long-lived inhabitants of the oral epithelium and, therefore, the only cells capable of accumulating the required number of genetic changes for the development of malignancy. The major surface phenotypic markers associated with SC and CSC characteristics include CD133, CD44 and CD24.

Abbreviations: CSC: Cancer Stem Cells; SC: Stem Cells; HNSCC: Head and Neck Squamous Carcinoma Cells; ATC: Amplifying Transitory Cells; NOD/ SCID: Non-obese diabetic/Severe Combined Immunodeficiency; OSCC: Oral Squamous Cell Carcinoma; DNA: Deoxyribonucleic Acid; EMT: Epithelial Mesenchymal Transition; SP: Sidepopulation; HPV: Human Papillomavirus; HNC: Head and Neck Cancer; UADT: Upper Aerodigestion Cancer