CD44 super(high)/ALDH1 super(high) head and neck squamous cell carcinoma cells exhibit mesenchymal characteristics and GSK3 beta -dependent cancer stem cell properties

• Published in: Journal of oral pathology & medicine Vol. 45; no. 3; pp. 180 - 188
• Main Authors: Seino, Sayaka, Shigeishi, Hideo, Hashikata, Miho, Higashikawa, Koichiro, Tobiume, Kei, Uetsuki, Ryo, Ishida, Yoko, Sasaki, Kazuki, Naruse, Takako, Rahman, Mohammad Zeshaan, Ono, Shigehiro, Simasue, Hiroshi, Ohta, Kouji, Sugiyama, Masaru, Takechi, Masaaki
• Format: Journal Article
• Language: English
• Published: 01-03-2016
• ISSN: 0904-2512; 1600-0714
• DOI: 10.1111/jop.12348

Background CD44 and aldehyde dehydrogenase 1 (ALDH1) have been shown to be useful markers for identification of cancer stem cells (CSCs). We previously reported that glycogen synthase kinase 3 beta (GSK3 beta ) is involved in regulation of the self-renewal ability of head and neck squamous cell carcinoma (HNSCC) CSCs. The purpose of the present study was to clarify the role of GSK3 beta in CD44 super(high)/ALDH1 super(high) HNSCC cells. Methods Cells with greater expression of CD44 and higher ALDH1 enzymatic activity were FACS sorted from the OM-1 HNSCC cell line. The self-renewal ability of CD44 super(high)/ALDH1 super(high) cells was then examined using a tumor sphere formation assay. mRNA expressions of the stem cell markers Sox2, Oct4, and Nanog, as well as GSK3 beta were evaluated by real-time RT-PCR. Results CD44 super(high)/ALDH1 super(high) cells exhibited higher tumor sphere forming ability and increased expression of stem cell markers as compared with CD44 super(high)/ALDH1 super(low) cells. Interestingly, spindle-shaped cells positive for vimentin were found in the CD44 super(high)/ALDH1 super(high) but not the CD44 super(high)/ALDH1 super(low) cell population. In addition, the ALDH1 activity and sphere forming ability of CD44 super(high)/ALDH1 super(high) cells was significantly inhibited by GSK3 beta knockdown. On the other hand, CD44 super(high)/ALDH1 super(low) cells exhibited high epidermal growth factor receptor (EGFR) expression and increased cell growth. Conclusions Our results show that GSK3 beta plays a major role in maintenance of stemness of CD44 super(high)/ALDH1 super(high) HNSCC cells. Additionally, they indicate a close relationship between CSC and mesenchymal characteristics in HNSCC.