Gliomas are aggressive brain tumors that affect children. Current treatment of high-grade glioma, most often involving surgery, radiation, and cytotoxic chemotherapy, only extend median survival of affected children to14 months, and results in significant morbidity. Low-grade glioma, that cannot be completely resected aretreated with radiation, typically after failure of chemotherapy approaches, with significant resulting neuro-cognitive and developmental risks. This project addresses a specific oncogene alteration, BRAFV600E occurring in as many as 14% of pediatric high-grade glioma. For certain subtypes of pediatric glioma thefrequency of BRAFV600E is much higher (66% in pleomorphic xanthoastrocytoma). Inhibitors that specifically target BRAFV600E have been developed and have shown remarkable efficacy against melanomas that harborthis mutation. One such inhibitor, vemurafenib, has now been FDA-approved for melanoma, and is underinvestigation for treating a number of other BRAFV600E malignancies. We have shown that BRAFV600E inhibitor treatment significanfiy extends survival of intracranial BRAFV600E glioma-bearing animals. We have also noted the activation of tumor feedback mechanisms may limit drug efficacy, suggesting that combination therapies targeting these mechanisms may further improve the response of BRAFV600E glioma to BRAF inhibitor therapy. Our preliminary studies have highlighted three specific and targetable activities that might be exploitable for this purpose. First, we have observed that CDKN2A inactivation and resultant increased CDK4/6 signaling occurs in the majority of BRAFV600E high grade glioma, and that concurrent treatment with CDK4/6 and BRAFV600E inhibitors provides additional survival benefit to animals bearing BRAFV600E and CDKN2A deficient tumors. Second, we observed that the reactivation of ERK signaling following BRAF inhibitor monotherapy is prevented by addition of a MEK inhibitor, which also increases anti-proliferative effect and survival for animais with intracranial BRAFV600E glioma. Finally, we have observed that BRAF-targeted treatment of BRAFV600E glioma results in EGFR feedback activation, suggesting that BRAF + EGFR combination therapy may augment the anti-tumor effect of BRAF monotherapy. Although these combination strategies appear to enhance BRAF inhibitor efficacy we do not fully understand the mechanistic basis for their actions, which of these combination approaches may be the most effective alone or combined with radiotherapy, or if BRAF inhibitors alone or in combination are safe in the pediatric population. These issues will be addressed in association with the proposed research that follows.

Public Health Relevance

This is a highly translational project that will further investigate and see to the clinical testing of a targeted therapeutic treatment of children with a specific, genetically-defined type of glioma. Other than surgery and radiation, there are currentiy no effective treatments for glioma in children, and the effective treatments only provide short-term relief from the cancer, while substantially contributing to patient morbidity. The research proposed here will see to the rigorous preclinical and clinical testing of novel treatments for this cancer patient population, and that hold substantial promise for improving outcomes for children with glioma.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Specialized Center (P50)
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Special Emphasis Panel (ZCA1-RPRB-7)
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University of California San Francisco
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Takahashi, Hannah; Cornish, Alex J; Sud, Amit et al. (2018) Mendelian randomisation study of the relationship between vitamin D and risk of glioma. Sci Rep 8:2339
Amirian, E Susan; Ostrom, Quinn T; Armstrong, Georgina N et al. (2018) Aspirin, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), and Glioma Risk: Original Data from the Glioma International Case-Control Study and a Meta-Analysis. Cancer Epidemiol Biomarkers Prev :
Griveau, Amelie; Seano, Giorgio; Shelton, Samuel J et al. (2018) A Glial Signature and Wnt7 Signaling Regulate Glioma-Vascular Interactions and Tumor Microenvironment. Cancer Cell 33:874-889.e7
Disney-Hogg, Linden; Cornish, Alex J; Sud, Amit et al. (2018) Impact of atopy on risk of glioma: a Mendelian randomisation study. BMC Med 16:42
Wang, Qianghu; Hu, Baoli; Hu, Xin et al. (2018) Tumor Evolution of Glioma-Intrinsic Gene Expression Subtypes Associates with Immunological Changes in the Microenvironment. Cancer Cell 33:152
Salas, Lucas A; Wiencke, John K; Koestler, Devin C et al. (2018) Tracing human stem cell lineage during development using DNA methylation. Genome Res 28:1285-1295
Ostrom, Quinn T; Kinnersley, Ben; Wrensch, Margaret R et al. (2018) Sex-specific glioma genome-wide association study identifies new risk locus at 3p21.31 in females, and finds sex-differences in risk at 8q24.21. Sci Rep 8:7352
Salas, Lucas A; Koestler, Devin C; Butler, Rondi A et al. (2018) An optimized library for reference-based deconvolution of whole-blood biospecimens assayed using the Illumina HumanMethylationEPIC BeadArray. Genome Biol 19:64
Choi, Serah; Yu, Yao; Grimmer, Matthew R et al. (2018) Temozolomide-associated hypermutation in gliomas. Neuro Oncol 20:1300-1309
Jacobs, Daniel I; Liu, Yanhong; Gabrusiewicz, Konrad et al. (2018) Germline polymorphisms in myeloid-associated genes are not associated with survival in glioma patients. J Neurooncol 136:33-39

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