LAUSR

Medulloblastoma (MB) is an aggressive brain tumor that predominantly affects children. Recent high-throughput sequencing studies suggest that the non-coding RNA genome, in particular long non-coding RNAs (lncRNAs), contributes to MB formation and tumor progression. Here we report the identification of a novel lncRNA, lnc-HLX-2-7, as a potential therapeutic target in group 3 MBs. In this study, we report that lnc-HLX-2-7 RNA specifically accumulates in the HLX (host gene of lnc-HLX-2-7) promoter region and activates HLX expression by recruiting multiple factors including enhancer elements. RNA sequencing and chromatin immunoprecipitation revealed that HLX directly binds to the promoters of several tumor-promoting genes, including MYC, and activates their expression. Furthermore, intravenous treatment with antisense oligonucleotides targeting lnc-HLX-2-7 coated with cerium-oxide nanoparticle (CNP-lnc-HLX-2-7) reduced tumor growth (40-50%) in intracranial MB xenograft mouse model (n=10, p<0.01, t-test). We found that the combinatorial therapy of CNP-lnc-HLX-2-7 and cisplatin further inhibits tumor growth and significantly prolongs mouse survival compared to CNP-lnc-HLX-2-7 monotherapy (n=10, p<0.01, t-test) only. We report here the importance of the lnc-HLX-2-7-HLX-MYC axis in regulating group 3 MB progression and provide a strong rationale for using lnc-HLX-2-7 as a specific and potent therapeutic target for the group 3 MBs in children. Citation Format: Keisuke Katsushima, Bongyong Lee, Menglang Yuan, Stacie Stapleton, George Jallo, Sudipta Seal, Charles G. Eberhart, Ranjan J. Perera. The therapeutic potential of lnc-HLX-2-7 in group 3 medulloblastomas in children. [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 4764.