Abstract 1393: CD44v3-positive (CD44v3+) and CD24-negative (CD24−) cells possess cancer stem cell (CSC)-like properties in a human oral squamous cell carcinoma cell line

Abstract

Abstract Background: CSCs are defined as minor cell population which have higher tumor-initiating ability, self-renewal ability and multilineage potential. Although CSCs in oral squamous cell carcinoma (OSCC) were identified by several surface antigen (e.g., CD44, CD133) or ALDEFLOUR assay, it is still elusive which are universal markers for CSC in OSCC. The aim of this study is to clarify potential CSC markers for a OSCC cell line using a combination of cell surface markers, CD44v3 and CD24. Materials and Methods: A OSCC cell line, SAS, was used in the experiment. CD44v3+/CD24− cell fraction was sorted from SAS cells with a FACSAria II and compared with the other three fractions (CD44v3+/CD24+, CD44v3− /CD24−, CD44v3−/CD24+ cell fraction) in cell proliferation, drug resistance and sphere forming ability. mRNA expression levels of various genes, such as stemness genes, anti-apoptosis genes and hypoxia-related genes, were compared among the fractions using quantitative real-time reverse transcriptase-polymerase chain reaction. Results: The proportion of CD44v3+/CD24−, CD44v3+/CD24+, CD44v3−/CD24−, CD44v3−/CD24+ cells was 34.9%, 39.8%, 14.2% and 11.0%, respectively. CD44v3+/CD24− cells showed a higher sphere forming ability, and drug resistance for CDDP, 5-FU and Cetuximab and expressed higher mRNA levels of CSC property-related genes (ABCG2, Oct-4, Nanog) and a hypoxia-related gene (HIF-1α) than the other cell fractions. There were no significant differences in cell proliferation among the fractions. Conclusion: The results suggest that CD44v3+/CD24− cell fractions in SAS possess CSC-like properties. The investigation of tumorigenic capacity in NOD/SCID mice is now under way. Citation Format: Keita Todoroki, Sachiko Ogasawara, Jun Akiba, Masamichi Nakayama, Yoshiki Naito, Jingo Kusukawa, Hirohisa Yano. CD44v3-positive (CD44v3+) and CD24-negative (CD24−) cells possess cancer stem cell (CSC)-like properties in a human oral squamous cell carcinoma cell line. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1393. doi:10.1158/1538-7445.AM2015-1393