Abstract 1059: EGF induces epithelial-mesenchymal transition and cancer stem cell properties in human oral squamous cell carcinoma

Abstract

Abstract Head and neck cancer is one of the 10 most common cancers worldwide. Despite advances in therapeutic research in the last few decades, morbidity and mortality remain unchanged. Recurrent and metastatic oral squamous cell carcinoma (OSCC) of the head and neck may have correlated with epithelial-mesenchymal transition (EMT), a property acquired by cancer stem cells (CSCs). In our study, SCC-1 cells (a human tongue cancer cell line) treated with epidermal growth factor (EGF) underwent EMT as confirmed by morphological changes and expression of EMT-related markers using Western blot, immunocytostaining, and flow cytometric analyses. Our data showed that, in comparison with non-treated cells, EGF treatment induced SCC-1 cells to undergo EMT, characterized by spindle-shaped mesenchymal-like morphology, an altered suppression of E-cadherin and promotion of vimentin expression, and an enhanced invasive capacity. Our results also indicated that EGF significantly enriched the fraction of CD44+/CD24low/- CSCs in SCC-1 cells, from 7∼8% to 25∼29%, and simultaneously increased the expression of aldehyde dehydrogenase 1 (ALDH1), a common marker for stem cells. Moreover, the purified CD44+/CD24low/- CSC population displayed stem cell properties associated with EMT phenotypes and increased migration and invasion abilities in vitro. Using a murine orthotopic tongue cancer model transplanted with stably GFP-expressing SCC-1 cells (GFP-SCC-1), we confirmed that EGF can promote tumor metastasis to cervical lymph nodes, and simultaneously augmented CD44 and ALDH1 expression in these invasive tumor cells. Taken together, we have demonstrated that EGF-induced EMT process is closely associated with the acquisition of CSC properties in human OSCC, which may contribute to the increased distant metastasis and recurrence of head and neck cancer. Further elucidation of the underlying mechanisms will facilitate development of new generation of effective therapies that aim to specifically target CSCs and eliminate the “root” of cancer recurrence. This work was supported by National Institute of Health Research Grant, R01DE 019932, Oral and Maxillofacial Surgery Foundation Research Support, 002894, and the Schoenleber funding support. Citation Format: Qilin Xu, Qunzhou Zhang, Anh Le. EGF induces epithelial-mesenchymal transition and cancer stem cell properties in human oral squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1059. doi:10.1158/1538-7445.AM2014-1059