Low-dose Actinomycin-D treatment of ependymomas reactivates p53

Ependymomas are malignant pediatric brain tumors with frequent p53 inactivation. A TP53 mutation analysis of 130 primary ependymomas identified a mutation rate of only 3%. Immunohistochemical analysis of 398 ependymomas confirmed previous results correlating the accumulation of non-functional p53 with inferior outcome. In order to reactivate p53, we evaluated the effects of Actinomycin-D treatment of 2 ependymoma cell lines. The IC-50 of the agent was determined by cell viability assays (0.2–0.7 nM). Subsequenlty, we performed transcriptome analyses of high-dose (100nM), low-dose (5 nM) and non-treated cells sho…