Mouse Models of Human Brain Tumors: From Cage to Clinic David H. Gutmann, MD, PhD Donald O. Schnuck Family Professor Department of Neurology Washington University School of Medicine Director, Neurofibromatosis Center Co-Director, Neuro-Oncology Program © Washington University, 2009

Brain Tumors Leading cause of cancer-related death in children 4 th leading cause of cancer-related death in adults © Washington University, 2009

GeneChromosomeProtein Cyclin-dependent kinase inhibitor 2A 9pp16 Cyclin-dependent kinase inhibitor 2B 9pp15 Cyclin-dependent kinase 4 12qcdk4 Epidermal growth factor receptor 7qEGF-R Murine double minutes 12qMDM2 Phosphatase and tensin homology 10qPTEN p14 alternative reading frame 9pp14-ARF Retinoblastoma 1 13qRb TP53 17pp53 Tumor gradep5317p LOH10q LOHEGF-R amp WHO grade I71% 0% 0% 0% WHO grade II63% 0% 0% 0% WHO grade III63% 31% 13% 6% WHO grade IV68% 26% 38% 21% © Washington University, 2009

Limited insights into the molecular and cellular changes critical for tumor formation or continued growth Paleo-neuro-oncology © Washington University, 2009

sporadic cancer cancer predisposition syndrome loss of tumor suppressor gene function increased cell proliferation CANCER © Washington University, 2009

Familial syndromes associated with nervous system tumors SyndromeGenes Nervous system tumors von Hippel-LindauvHL (3p25-26)hemangioblastoma Tuberous sclerosis complexTSC1 (9p34) TSC2 (16p13)subependymal giant cell astrocytoma Li-Fraumenip53 (17p13)astrocytoma primitive neuroectodermal tumor Neurofibromatosis 1NF1 (17q11)optic pathway glioma, astrocytoma neurofibroma Neurofibromatosis 2NF2 (22q12)schwannoma, meningioma ependymoma © Washington University, 2009

15-20% of children with NF1 Typically young children WHO grade I pilocytic astrocytoma Commonly involving optic pathway Composed of GFAP- immunoreactive (glial) cells Brain Tumors in NF1 © Washington University, 2009

Neurofibromatosis type 1 as a model system for understanding the molecular and cellular pathogenesis of glioma? Most common inherited genetic mutation in pediatric low-grade glioma One of the most common genetic mutations in adult high-grade glioma (TCGA) © Washington University, 2009

+/- -/- +/+ +/- wild-type viable embryonic lethal Nf1 Nf1 gene neo E no gliomas no neurofibromas Brannan C. et al., Genes & Development 1994 Jacks T. et al., Nature Genetics 1994 © Washington University, 2009

Nf1 gene LoxP Cre recombinase disrupted Nf1 gene LoxP Zhu Y. et al., Genes & Development 2001 © Washington University, 2009

Bajenaru ML, Mol Cell Biol LoxP hGfap promoterCreIRESnLacZ Nf1 flox alleles Nf1-deficient normal NO BRAIN TUMORS © Washington University, 2009

NF1+/- (body) NF1-/- (tumor) © Washington University, 2009 Nf1-deficient astrocytes Nf1+/- LoxP hGfap promoterCreIRES nLacZ Nf1 flox allele Nf1 mut allele neo R Bajenaru ML, Cancer Res OPTIC GLIOMAS

Opportunities 1.Identify new targets for therapeutic drug design 2.Determine why certain therapies fail 3.Evaluate new therapies in preclinical models © Washington University, 2009

Nf1-deficient normal Nf1-deficient astrocytes Nf1+/- NO TUMOR TUMOR contribution(s) of other cell types in the tumor microenvironment © Washington University, 2009

Appropriate stromal cells and signals Susceptible preneoplastic cells © Washington University, 2009

1. What stromal cell types and molecular signals drive NF1 brain tumor cell growth? normal Enhance tumor growth by secreting cytokines and growth factors Increase tumor invasiveness Evade immune surveillance Bajenaru ML, Annals of Neurology 2005 © Washington University, 2009 MICROGLIA

1.Nf1+/-, but not wild-type, microglia promote Nf1-/- astrocyte proliferation in vitro 2.Nf1+/- microglia elaborate paracrine factors that promote Nf1-/- astrocyte proliferation in vitro brain microglia/astrocyte co-cultures brain microglia cultures (Nf1+/+ or Nf1+/-) culture supernatant Daginakatte & Gutmann, Human Mol. Genet © Washington University, 2009

equilibrationenhancementelimination © Washington University, 2009 “specialized” microglia

tumor elimination promote tumor growth endothelial cells CSCs glioma cells © Washington University, 2009

blood vessel cancer stem cells stromal cells differentiated tumor cells endothelial cells Future targeted therapies © Washington University, 2009 microglia microglia-produced growth factors

cell growth GDP ras GTP ras neurofibromin “active”“inactive” cell growth “ON”“OFF” X cell growth neurofibromin GDP GTP © Washington University, Evaluate why certain therapies fail

K-RASH-RASN-RAS Blocked by FTIs Not blocked by FTIs neurofibromin X cell growth farnesyltransferase inhibitors GDP GTP RAS “active” “inactive” © Washington University, 2009

treatment vehicle week old Nf1+/- GFAP CKO mice © Washington University, Evaluate new therapies in preclinical models

Treatment with chemotherapy used for children with low- grade brain tumors blocks mouse optic glioma tumor growth in vivo © Washington University, 2009

Mechanism of action Target validation “Off-target” effects Effect on normal brain © Washington University, 2009

PATIENTS molecular & cellular targets blood vessel cancer stem cells stromal cells differentiated tumor cells endothelial cells targeted treatment strategies surrogate outcome measurements mouse models © Washington University, 2009