Oral cancer stem cells - properties and consequences

Abstract

Research on cancer stem cells (CSCs) has greatly increased in the field of medicine and pathology; however, some conceptual misunderstandings are still present among the public as well as within the general scientific community that is not yet familiar with the subject. The very first problem is the misinterpretation of CSCs as a synonym of their normal counterparts, the well-known stem cells (SCs). Particularly in Dentistry, another common mistake is the misinterpretation of oral CSCs as normal tooth-derived SCs. The present review aims to clarify important concepts related to normal SCs and CSCs, as well as discuss the relevance of CSCs to the development, metastasis and therapy resistance of oral squamous cell carcinoma.

Immunolocalization of Cancer Stem Cells Marker ALDH1 and its Association with Tumor Budding in Oral Squamous Cell Carcinoma

“…Accordingly, only cells of the oral mucosa epithelium with phenotypic characteristics of stem cells -for example, a capacity for self-renewal and survival -can undergo the genetic and epigenetic changes that prompt tumor development. In this new alternative model of oral carcinogenesis, oncogenically transformed stem cells, now called CSC, are responsible for the genesis, sustainable growth, and metastatic dissemination of OSCC [30][31][32][33].…”

Loss of oral mucosal stem cell markers in oral submucous fibrosis and their reactivation in malignant transformation

“…The OM-SCs in the basal layer of the oral mucosa are the normal stem cells essential for maintaining the integrity of the oral mucosa. 21 Contact with the basement membrane is required to maintain basal keratinocyte stemness. The severity of the contact of OM-SCs with the basement membrane promotes their differentiation.…”

“…Although the stem cells associated with cancer are quite similar to normal stem cells and express the same markers, certain unique characteristics, such as the loss of growth control, justify their separate designation as cancer stem cells (CSCs) or tumourinitiating cells. 21,23,24 Several studies have shown that CSCs play a crucial role in the growth, spread and recurrence of oral cancer. [25][26][27][28][29][30][31] CSCs in oral cancer demonstrate elevated expression levels of stem cell markers, such as Oct-4, SOX2, Nanog, Nestin, CK19, B-cellspecific Moloney murine leukaemia virus integration site 1 (Bmi-1), CD117 (c-kit), CD44 and CD133, and decreased expression levels of involucrin and CK-13.…”

“…Although the stem cells associated with cancer are quite similar to normal stem cells and express the same markers, certain unique characteristics, such as the loss of growth control, justify their separate designation as cancer stem cells (CSCs) or tumour-initiating cells. 21 , 23 , 24 …”

Estudo da frequência relativa e participação de subpopulações de células-tronco de câncer no processo de metástase em carcinoma epidermóide de boca

“…Figura 2 -Comparação entre origem, trajetória e atuação de SC e CSC no organismo humano. (A) SC: evidencia a origem embrionária e/ou em tecidos adultos, a capacidade de autorrenovação e a possibilidade de diferenciação in vitro em vários tipos de células; (B) CSC: é possível localizar a origem no tecido adulto, a transformação maligna, a capacidade de autorrenovação, proliferação e diferenciação, contribuindo para o desenvolvimento do câncer, inclusive na geração de metástases (Rodini et al, 2016).…”