Neuroblastoma, a tumor of neural crest origin, is the most common extra-cranial solid tumor of childhood. Amplification of MYCN, a MYC family ontogeny, occurs in ~25% of neuroblastoma and marks high-risk disease. Neuroblastoma is unique among solid tumors in that all patients typically respond to initial chemotherapy. Risk is thus associated with relapse, which is typically therapy-resistant. Contributing to this resistance a large proportion of relapsed tumors have therapy-induced mutations in p53 pathway genes, not evident at initial presentation. Mirroring human disease, the TH-MYCN mouse model of neuroblastoma is responsive to chemotherapy. In order to provide a mouse model of chemotherapy resistant, relapsed disease, we have crossed TH-MYCN mice to mice knocked-in for p53ER, which are p53 deficient at baseline. Exposure to hydroxytamoxifen allows rapid and reversible p53 restoration. Resulting neuroblastoma tumors show increased penetrance and decreased latency at baseline. When p53 is restored, mice show initially improved survival followed by relapse.
In Aim 1, I will characterize how tumors evade reactivation of p53 to enable. I will then characterize the importance of p53 in chemotherapy resistance to existent conventional and targeted therapies, establishing a baseline for pre-clinical development of novel therapeutic agents, including those generated in Aim 2. The stability of MYCN protein in neuroblastoma is tightly regulated by upstream signaling through the PI3K/mTOR pathway as well as by a kinase-independent scaffolding function of the Aurora A protein.
In Aim 2, I will characterize a novel class of Type II inhibitors of Aurora A kinase designed specifically to alter the secondary structure of Aurora A and disrupt the kinase-independent stabilization of MYCN. In pilot studies I have identified candidate inhibitors that dramatically decrease MYCN protein in neuroblastoma cells and that appear to do so by the destabilization mechanism proposed. I will complete structure activity relationship studies to further refine these candidate compounds. Successful completion will result in both an improved model of chemo-resistant neuroblastoma as well as a new class of targeted Aurora A inhibitors, predicted to be both highly potent and specific against neuroblastoma.

Public Health Relevance

Neuroblastoma is one of the most common and deadly solid tumors of childhood. Relapsed and MYCN amplified high-risk neuroblastoma is highly resistant to current therapies.
This research aims to improve therapy for these patients by proposing a new mouse model of resistant disease and characterizing a new class of neuroblastoma-targeted drugs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
1K08NS079485-01
Application #
8353311
Study Section
NST-2 Subcommittee (NST)
Program Officer
Fountain, Jane W
Project Start
2012-08-01
Project End
2017-07-31
Budget Start
2012-08-01
Budget End
2013-07-31
Support Year
1
Fiscal Year
2012
Total Cost
$184,127
Indirect Cost
$13,639
Name
University of California San Francisco
Department
Pediatrics
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Lee, John K; Phillips, John W; Smith, Bryan A et al. (2016) N-Myc Drives Neuroendocrine Prostate Cancer Initiated from Human Prostate Epithelial Cells. Cancer Cell 29:536-547
Yu, Dan; Dong, Zhiqiang; Gustafson, William Clay et al. (2016) Rational design of a monomeric and photostable far-red fluorescent protein for fluorescence imaging in vivo. Protein Sci 25:308-15
Chen, Justin; Hackett, Christopher S; Zhang, Shile et al. (2015) The genetics of splicing in neuroblastoma. Cancer Discov 5:380-95
Cage, Tene Aneka; Chanthery, Yvan; Chesler, Louis et al. (2015) Downregulation of MYCN through PI3K Inhibition in Mouse Models of Pediatric Neural Cancer. Front Oncol 5:111
Yu, Dan; Gustafson, William Clay; Han, Chun et al. (2014) An improved monomeric infrared fluorescent protein for neuronal and tumour brain imaging. Nat Commun 5:3626
Johnson, Brett E; Mazor, Tali; Hong, Chibo et al. (2014) Mutational analysis reveals the origin and therapy-driven evolution of recurrent glioma. Science 343:189-193
Hackett, Christopher S; Quigley, David A; Wong, Robyn A et al. (2014) Expression quantitative trait loci and receptor pharmacology implicate Arg1 and the GABA-A receptor as therapeutic targets in neuroblastoma. Cell Rep 9:1034-46
Gustafson, William Clay; Meyerowitz, Justin Gabriel; Nekritz, Erin A et al. (2014) Drugging MYCN through an allosteric transition in Aurora kinase A. Cancer Cell 26:414-427
Fan, Qi-Wen; Cheng, Christine K; Gustafson, W Clay et al. (2013) EGFR phosphorylates tumor-derived EGFRvIII driving STAT3/5 and progression in glioblastoma. Cancer Cell 24:438-49
Puissant, Alexandre; Frumm, Stacey M; Alexe, Gabriela et al. (2013) Targeting MYCN in neuroblastoma by BET bromodomain inhibition. Cancer Discov 3:308-23

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