Abstract 555: Gene expression profiling in recurrence of oral cancer involved in tumor microenvironment change and cancer stem cells

Abstract

Abstract Background: Local recurrence or lymph node metastasis is one of the critical events for the mortality of patients with oral cancer. Thus, it is essential to elucidate the mechanism of recurrence of oral cancer after treatment. It is recently thought that the cause of recurrence in advanced oral cancer is involvement of microenvironmental changes after treatment and signaling from cancer stem cells. In this study, we aimed to elucidate the molecular mechanism of cancer stem cell signaling that causes microenvironmental changes and the influx of bone marrow-derived cells that lead to revascularization following radiation. Materials and Methods: In order to analyze the function of cancer stem cells, we used YCUOC, a primary tissue obtained from biopsy sample of oral cancer. YCUOC and OSC-19 cell line as a control were inoculated at pre-irradiated site where local blood vessels were eradicated (recurrence model) and non-irradiated sites, and gene expression analysis in cancer tissues was performed. Results: Induction of CD11b-positive bone marrow-derived cells was observed in YCUOC cells, and the higher influx of Tie2-positive cells was observed at the pre-IR site, consistent with activation of HIF-1α. We identified several genes that were up-regulated only in YCUOC at pre-IR site, but neither OSC-19 nor non-IR site. Conclusion: The development of new therapies targeting tumor vasculogenesis is expected by elucidation of cancer stem cell-specific signals. Citation Format: Mitomu Kioi. Gene expression profiling in recurrence of oral cancer involved in tumor microenvironment change and cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 555.