Cancer Stem Cells in Oral Cavity Squamous Cell Carcinoma: A Review

Abstract

Cancer stem cells (CSCs) have been identified in oral cavity squamous cell carcinoma (OCSCC). CSCs possess the ability for perpetual self-renewal and proliferation, producing downstream progenitor cells and cancer cells that drive tumor growth. Studies of many cancer types including OCSCC have identified CSCs using specific markers, but it is still unclear as to where in the stem cell hierarchy these markers fall. This is compounded further by the presence of multiple CSC subtypes within OCSCC, making investigation reliant on the use of multiple markers. This review examines the current knowledge in CSC markers OCT4, SOX2, NANOG, ALDH1, phosphorylated STAT3, CD44, CD24, CD133, and Musashi-1, specifically focusing on their use and validity in OCSCC CSC research and how they may be organized into the CSC hierarchy. OCSCC CSCs also express components of the renin–angiotensin system (RAS), which suggests CSCs may be novel therapeutic targets by modulation of the RAS using existing medications.

Overexpression of cysteine‐glutamate transporter and CD44 for prediction of recurrence and survival in patients with oral cavity squamous cell carcinoma

“…The cell adhesion molecule, CD44, is involved in cell‐to‐cell and cell‐to‐extracellular matrix interactions, including cell migration, adhesion, and some lymphocyte functions . The CD44 has been widely used as a CSC marker in human cancers, including oral cavity SCC . The CSCs have self‐renewal properties, are involved in tumor initiation and spread, and are associated with increasing resistance of head and neck cancers to chemotherapy and radiotherapy …”

“…20 The CD44 has been widely used as a CSC marker in human cancers, including oral cavity SCC. 21 The CSCs have selfrenewal properties, are involved in tumor initiation and spread, and are associated with increasing resistance of head and neck cancers to chemotherapy and radiotherapy. 12,22 The prognostic value of CD44 expression in oral cavity SCC remains unclear.…”

Identification of Cancer Stem Cells in Oral Squamous Cell Carcinoma Using Cripto-1.

“…This importance comes from their ability for perpetual selfrenewal and proliferation, producing downstream progenitor cells and cancer cells that drive tumor growth. Studies on many cancer types including OSCC identified CSCs using specific markers, but it is still unclear as to where in the stem cell hierarchy these markers fall (Baillie et al, 2017).…”

“…used in the above studies were empirical and derived from normal stem cells which are known to be largely tissue specific which inturn had raised an important question regarding the specificity and reliability of such CSC markers (Baillie et al, 2017 andLiu et al, 2017). …”

“…This finding is further complicated by the presence of multiple CSC subtypes within the same tumor and among different tumors, making the investigation more reliant on the use of multiple markers and rise the urge to identify a CSC marker specific for the OSCC in order to improve the diagnostic capabilities and treatment efficacy (Baillie et al, 2017).…”