Abstract 1122: CD44 as potential therapeutic target for medulloblastoma metastasis

Medulloblastoma (MB) is a commonly diagnosed pediatric brain tumor that shows highly variable rates of morbidity and mortality. Metastasis is the leading cause of death in patients with MB, approximately 30% of MB patients have metastatic tumors right at diagnosis. Therefore, there is a critical need to dissect the molecular mechanisms that govern MB progression and metastasis. In our previous work, we found that DHA and VP16 synergistically inhibit MB cell proliferation and induce cell death accompanied with a marked reduction in the expression of CD44 standard form (CD44s). In this study, we show that MB cells express CD44s mainly and the elevated level of CD44s enhances MB cell invasion, suggesting that CD44s may play a crucial role in MB metastasis. In addition, we observed CD44s expression only in MB patients with metastasis using a small cohort of samples. Large database analysis show that MB patients with elevated levels of CD44 have poorer outcomes. Moreover, CD44 knockdown markedly reduces the expressions of transcription factor c-Myc and the platelet derived growth factor receptor (PDGFR) β, both are therapeutic targets for MB. Interestingly, PDGFRβ knockdown abolishes CD44s expression and downregulates the level of c-Myc. However, there is no expression change of CD44s and PDGFR β after the knockdown of c-Myc. These results indicate that the expression and function of CD44s could be critical to MB progression and metastasis, highlighting the potential therapeutic targets for MBs with metastasis. Citation Format: Dan Qi, Fengfei Wang, Ekokobe Fonkem, Jason H. Huang, Erxi Wu. CD44 as potential therapeutic target for medulloblastoma metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1122.