In vitro and in vivo characterization of cancer stem cell subpopulations in oral squamous cell carcinoma

Author(s)

Amor, Nadia Ghinelli ^[1] ; Buzo, Rodrigo Fonseca ^[1] ; Ortiz, Rafael Carneiro ^[1] ; Lopes, Nathalia Martins ^[1] ; Saito, Luciana Mieli ^[1] ; Mackenzie, Ian Campbell ^[2] ; Rodini, Camila Oliveira ^[1]

Affiliation

^[1] Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, Al Octavio Pinheiro Brisolla 9-75, Bauru, SP - Brazil

^[2] Queen Mary Univ London, Blizard Inst, Barts & London Sch Med & Dent, London - England

• Document type: Journal article
• Source: JOURNAL OF ORAL PATHOLOGY & MEDICINE; v. 50, n. 1 SEP 2020.
• Web of Science Citations: 1

Abstract

Background Despite advances in cancer diagnosis and therapeutics, the overall 5-year survival rate of oral squamous cell carcinoma (OSCC) remains low. Tumor formation, progression, recurrence, and chemo-resistance are associated with the presence of cancer stem cells (CSC) that show phenotypic heterogeneity, but how they influence tumor behavior remains poorly understood. We aimed to describe how two CSC phenotypes from an OSCC cell line, CD44(High)ESA(High)(Epi-CSC) and CD44(High)ESA(Low)(EMT-CSC), behave in vitro and in vivo. Methods In vitro behavior of FACS-sorted Epi-CSC and EMT-CSC from OSCC cells was characterized by their ability to form colonies, migrate, proliferate, and to invade a solid matrix. In vivo experiments were conducted in immunodeficient (NOD/SCID) mice by orthotopic xenografting of FACS-sorted OSCC subpopulations. Results In vitro, the Epi-CSC phenotype was more proliferative and generated more holoclones than the EMT phenotype. On the other hand, EMT-CSC migrate and invaded more than Epi-CSC cells in 3D culture, suggesting the CSC phenotype affects tumor cell behavior. When inoculated orthotopically into the tongues of immunodeficient mice, both subpopulations generated OSCC, but EMT-CSC formed fewer and smaller tumors. Conclusions Our results suggest that while cells in the Epi-CSC form the subpopulation that enables tumor growth, the EMT-CSC are related to migration and invasion. Clinically, this may reflect the importance of Epi-CSC for tumorigenesis and of the EMT-CSC for metastasis and highlights that variation in the proportion of CSC phenotypes from patient to patient may be relevant to the design of individual treatment protocols. (AU)

• FAPESP's process: 13/07245-9 - Investigation of the role of cancer stem cells and microenvironment on epithelial-to-mesenchymal transition, invasion and metastasis in oral squamous cell carcinoma
• Grantee: Camila de Oliveira Rodini Pegoraro
• Support Opportunities: Research Grants - Young Investigators Grants