Epithelial-to-mesenchymal transition and cancer stem(-like) cells in head and neck squamous cell carcinoma

Expression of ZEB factors in oral squamous cell carcinoma.

“…Another area of concern regarding OSCC is the fact that in many cases the carcinomas are initially responsive to treatments such as radiotherapy and chemotherapy, but relapse is common (Chen, Zimmermann et al 2013). Treatment relapse occurs both at local and distant sites.…”

“…One such mechanism that has been implicated in tumor invasion is the epithelial to mesenchymal transition (EMT) (Chu, Hu et al 2013). This process allows cells to increase their invasiveness by undergoing changes in morphology, loss of polarity, and loss of cell to cell contacts (Chen, Zimmermann et al 2013). EMT is not exclusively a tumorigenic process-it is present during embryonic development and homeostatic processes such as wound healing.…”

“…EMT of carcinoma cells has been linked to the acquisition of cancer stem cell traits such as resistance to chemotherapy and increased tumorgenicity, the reason for this being that once epithelial cells become more mesenchymal they also resist senescence 6 and apoptosis (Lamouille, Xu et al 2014). There are several transcription factors that have been implicated in driving EMT, including ZEB1, ZEB2, TWIST, and Slug (Chen, Zimmermann et al 2013). Since metastasis is a leading cause of mortality for patients with OSCC, the process and those transcription factors that govern it should be further analyzed.…”

“…There have been some studies that show that the anti-diabetic drug Metformin can decrease the expression of EMT-inducing factors such as Slug, ZEB1, ZEB2, and Twist (Chen, Zimmermann et al 2013). Theoretically, blocking transcription factors that induce EMT should be a favorable therapy, but before that may be done their exact roles should be understood.…”

“…An improved understanding of EMT in OSCC is needed in order to effectively block EMT (Chen, Zimmermann et al 2013).…”