Drosophila Brat and Human Ortholog TRIM3 Maintain Stem Cell Equilibrium and Suppress Brain Tumorigenesis by Attenuating Notch Nuclear Transport.

Cancer stem cells exert enormous influence on neoplastic behavior, in part by governing asymmetric cell division and the balance between self-renewal and multipotent differentiation. Growth is favored by deregulated stem cell division, which enhances the self-renewing population and diminishes the differentiation program. Mutation of a single gene in Drosophila, Brain Tumor (Brat), leads to disrupted asymmetric cell division resulting in dramatic neoplastic proliferation of neuroblasts and massive larval brain overgrowth. To uncover the mechanisms relevant to deregulated cell division in human glioma stem cells, we first developed a novel adult Drosophila brain tumor model using brat-RNAi driven by the neuroblast-specific promoter inscuteable Suppressing Brat in this population led to the accumulation of actively proliferating neuroblasts and a lethal brain tumor phenotype. brat-RNAi caused upregulation of Notch signaling, a node critical for self-renewal, by increasing protein expression and enhancing nuclear transport of Notch intracellular domain (NICD). In human glioblastoma, we demonstrated that the human ortholog of Drosophila Brat, tripartite motif-containing protein 3 (TRIM3), similarly suppressed NOTCH1 signaling and markedly attenuated the stem cell component. We also found that TRIM3 suppressed nuclear transport of active NOTCH1 (NICD) in glioblastoma and demonstrated that these effects are mediated by direct binding of TRIM3 to the Importin complex. Together, our results support a novel role for Brat/TRIM3 in maintaining stem cell equilibrium and suppressing tumor growth by regulating NICD nuclear transport. Cancer Res; 76(8); 2443-52. ©2016 AACR.

[1]  D. Brat,et al.  Cancer stem cell division: when the rules of asymmetry are broken. , 2015, Stem cells and development.

[2]  Erwin G. Van Meir,et al.  Human Brat ortholog TRIM3 is a tumor suppressor that regulates asymmetric cell division in glioblastoma. , 2014, Cancer research.

[3]  Thomas R. Burkard,et al.  Ecdysone and Mediator Change Energy Metabolism to Terminate Proliferation in Drosophila Neural Stem Cells , 2014, Cell.

[4]  H. Komori,et al.  Brain tumor specifies intermediate progenitor cell identity by attenuating β-catenin/Armadillo activity , 2014, Development.

[5]  Abhinava K. Mishra,et al.  The Drosophila Importin-α3 Is Required for Nuclear Import of Notch In Vivo and It Displays Synergistic Effects with Notch Receptor on Cell Proliferation , 2013, PloS one.

[6]  Freddy Radtke,et al.  Stem cells living with a Notch , 2013, Development.

[7]  C. Brennan,et al.  TRIM3, a tumor suppressor linked to regulation of p21Waf1/Cip1 , 2013, Oncogene.

[8]  J. Barnholtz-Sloan,et al.  CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2007-2011. , 2012, Neuro-oncology.

[9]  F. Roegiers,et al.  Endocytosis and control of Notch signaling. , 2012, Current opinion in cell biology.

[10]  M. Baron.  Endocytic routes to Notch activation. , 2012, Seminars in cell & developmental biology.

[11]  L. Couturier,et al.  Endocytosis by Numb breaks Notch symmetry at cytokinesis , 2012, Nature Cell Biology.

[12]  J. Girault,et al.  Signaling from the Cytoplasm to the Nucleus in Striatal Medium-Sized Spiny Neurons , 2011, Front. Neuroanat..

[13]  Juergen A. Knoblich,et al.  Asymmetric cell division: recent developments and their implications for tumour biology , 2010, Nature Reviews Molecular Cell Biology.

[14]  E. Kremmer,et al.  Notch Activity Levels Control the Balance between Quiescence and Recruitment of Adult Neural Stem Cells , 2010, The Journal of Neuroscience.

[15]  R. Depping,et al.  Notch1 signaling is mediated by importins alpha 3, 4, and 7 , 2010, Cellular and Molecular Life Sciences.

[16]  Hans Skovgaard Poulsen,et al.  The functional role of Notch signaling in human gliomas. , 2010, Neuro-oncology.

[17]  T. Schüpbach,et al.  The vacuolar proton pump, V-ATPase, is required for notch signaling and endosomal trafficking in Drosophila. , 2009, Developmental cell.

[18]  K. Kalland,et al.  Highly infiltrative brain tumours show reduced chemosensitivity associated with a stem cell‐like phenotype , 2009 .

[19]  N. Suzuki,et al.  Abnormal expression of TIP30 and arrested nucleocytoplasmic transport within oligodendrocyte precursor cells in multiple sclerosis. , 2008, The Journal of clinical investigation.

[20]  S. Bowman,et al.  The tumor suppressors Brat and Numb regulate transit-amplifying neuroblast lineages in Drosophila. , 2008, Developmental cell.

[21]  G. Reifenberger,et al.  Loss of NOTCH2 Positively Predicts Survival in Subgroups of Human Glial Brain Tumors , 2007, PloS one.

[22]  M. Nakafuku,et al.  Cross Talk between Notch and Growth Factor/Cytokine Signaling Pathways in Neural Stem Cells , 2007, Molecular and Cellular Biology.

[23]  G. Rosas-Acosta,et al.  Nuclear Import of Bovine Papillomavirus Type 1 E1 Protein Is Mediated by Multiple Alpha Importins and Is Negatively Regulated by Phosphorylation near a Nuclear Localization Signal , 2006, Journal of Virology.

[24]  Frank Hirth,et al.  The brain tumor gene negatively regulates neural progenitor cell proliferation in the larval central brain of Drosophila , 2006, Development.

[25]  F. Radtke,et al.  Multiple functions of Notch signaling in self‐renewing organs and cancer , 2006, FEBS letters.

[26]  E. Caussinus,et al.  Induction of tumor growth by altered stem-cell asymmetric division in Drosophila melanogaster , 2005, Nature Genetics.

[27]  Vikram Devgan,et al.  p21WAF1/Cip1 is a negative transcriptional regulator of Wnt4 expression downstream of Notch1 activation. , 2005, Genes & development.

[28]  Yoshiyuki Matsuura,et al.  Structural basis for nuclear import complex dissociation by RanGTP , 2005, Nature.

[29]  Ugo Orfanelli,et al.  Isolation and Characterization of Tumorigenic, Stem-like Neural Precursors from Human Glioblastoma , 2004, Cancer Research.

[30]  Nathan T. Mortimer,et al.  Differential Effects of Drosophila Mastermind on Asymmetric Cell Fate Specification and Neuroblast Formation , 2004, Genetics.

[31]  Cynthia Hawkins,et al.  Identification of a cancer stem cell in human brain tumors. , 2003, Cancer research.

[32]  W. Hahn,et al.  Activation of Notch-1 signaling maintains the neoplastic phenotype in human Ras-transformed cells , 2002, Nature Medicine.

[33]  Jan J. Heimans,et al.  Impact of brain tumour treatment on quality of life , 2002, Journal of Neurology.

[34]  M. Hatten,et al.  Activated Notch2 Signaling Inhibits Differentiation of Cerebellar Granule Neuron Precursors by Maintaining Proliferation , 2001, Neuron.

[35]  D. Osoba,et al.  Effect of disease burden on health-related quality of life in patients with malignant gliomas. , 2000, Neuro-oncology.

[36]  A. Shearn,et al.  Mutations in the β-propeller domain of the Drosophila brain tumor (brat) protein induce neoplasm in the larval brain , 2000, Oncogene.

[37]  A. Capobianco,et al.  Neoplastic Transformation by Notch Requires Nuclear Localization , 2000, Molecular and Cellular Biology.

[38]  E. Knust,et al.  Bazooka provides an apical cue for Inscuteable localization in Drosophila neuroblasts , 1999, Nature.

[39]  D. Sassoon,et al.  Notch4/int-3, a mammary proto-oncogene, is an endothelial cell-specific mammalian Notch gene. , 1996, Development.

[40]  S. Artavanis-Tsakonas,et al.  Alterations in Notch signaling in neoplastic lesions of the human cervix. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[41]  J. Sklar,et al.  TAN-1, the human homolog of the Drosophila Notch gene, is broken by chromosomal translocations in T lymphoblastic neoplasms , 1991, Cell.

[42]  D. Gallahan,et al.  Mammary tumorigenesis in feral mice: identification of a new int locus in mouse mammary tumor virus (Czech II)-induced mammary tumors , 1987, Journal of virology.

[43]  J. Barnholtz-Sloan,et al.  CBTRUS statistical report: Primary brain and central nervous system tumors diagnosed in the United States in 2006-2010. , 2013, Neuro-oncology.

[44]  A. Wagers,et al.  Notch signaling in the regulation of stem cell self-renewal and differentiation. , 2010, Current topics in developmental biology.