N‐myc enhances the expression of a large set of genes functioning in ribosome biogenesis and protein synthesis

The myc oncogenes are frequently activated in human tumors, but there is no comprehensive insight into the target genes and downstream cellular pathways of these transcription factors. We applied serial analysis of gene expression (SAGE) to identify targets of N‐myc in neuroblastomas. Analysis of 42 000 mRNA transcript tags in SAGE libraries of N‐myc‐ transfected and control neuroblastoma cells revealed 114 up‐regulated genes. The majority of these genes have a role in ribosome assembly and activity. Northern blot analysis confirmed up‐regulation of all tested transcripts. Induction was complete within 4 h after N‐myc expression. The large majority of the ribosomal proteins were induced, as well as genes controlling rRNA maturation. Cellular rRNA content was 45% induced. SAGE libraries and northern blot analysis confirmed up‐regulation of many of these genes in N‐myc‐amplified neuroblastomas. As N‐myc can functionally replace c‐myc, we analyzed whether N‐myc targets were induced by c‐myc as well. Approximately 40% of these N‐myc targets were up‐regulated in a c‐myc‐transfected melanoma cell line. These data suggest that myc genes function as major regulators of the protein synthesis machinery.

[1]  G. Janssen,et al.  Immunofluorescence studies of human fibroblasts demonstrate the presence of the complex of elongation factor-1 beta gamma delta in the endoplasmic reticulum. , 1996, Journal of cell science.

[2]  K. Isselbacher,et al.  Increased expression of eukaryotic translation initiation factors eIF-4E and eIF-2 alpha in response to growth induction by c-myc. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[3]  R. Eisenman,et al.  Myc‐Max heterodimers activate a DEAD box gene and interact with multiple E box‐related sites in vivo. , 1996, The EMBO journal.

[4]  J L Cleveland,et al.  The ornithine decarboxylase gene is a transcriptional target of c-Myc. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[5]  P. Bouvet,et al.  Structure and functions of nucleolin. , 1999, Journal of cell science.

[6]  Emmett V Schmidt,et al.  The role of c-myc in cellular growth control , 1999, Oncogene.

[7]  S. Altschul,et al.  A public database for gene expression in human cancers. , 1999, Cancer research.

[8]  M. Cole.  The myc oncogene: its role in transformation and differentiation. , 1986, Annual review of genetics.

[9]  M. Polymenis,et al.  An essential E box in the promoter of the gene encoding the mRNA cap-binding protein (eukaryotic initiation factor 4E) is a target for activation by c-myc , 1996, Molecular and cellular biology.

[10]  F. Alt,et al.  N-myc can functionally replace c-myc in murine development, cellular growth, and differentiation. , 2000, Genes & development.

[11]  R. Dildrop,et al.  Determination of the DNA sequence recognized by the bHLH-zip domain of the N-Myc protein. , 1992, Nucleic Acids Research.

[12]  C. Lehner,et al.  Major nucleolar proteins shuttle between nucleus and cytoplasm , 1989, Cell.

[13]  G. Janssen,et al.  Immunofluorescence studies of human fibroblasts demonstrate the presence of the complex of elongation factor-1βγδ in the endoplasmic reticulum , 1996 .

[14]  G. Mohapatra,et al.  Targeted expression of MYCN causes neuroblastoma in transgenic mice , 1997, The EMBO journal.

[15]  D. Prober,et al.  Drosophila myc Regulates Cellular Growth during Development , 1999, Cell.

[16]  A. Sewing,et al.  Cyclins D1 and D2 mediate Myc‐induced proliferation via sequestration of p27Kip1 and p21Cip1 , 1999, The EMBO journal.

[17]  B. Amati,et al.  Myc induces the nucleolin and BN51 genes: possible implications in ribosome biogenesis. , 2000, Nucleic acids research.

[18]  M. Wiedmann,et al.  A protein complex required for signal-sequence-specific sorting and translocation , 1994, Nature.

[19]  M. Pagano,et al.  Identification of a Myc‐dependent step during the formation of active G1 cyclin‐cdk complexes. , 1995, The EMBO journal.

[20]  J. Trent,et al.  Amplified DNA with limited homology to myc cellular oncogene is shared by human neuroblastoma cell lines and a neuroblastoma tumour , 1983, Nature.

[21]  P. Chomczyński,et al.  Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. , 1987, Analytical biochemistry.

[22]  Chi V. Dang,et al.  c-Myc Target Genes Involved in Cell Growth, Apoptosis, and Metabolism , 1999, Molecular and Cellular Biology.

[23]  E. Lander,et al.  Expression analysis with oligonucleotide microarrays reveals that MYC regulates genes involved in growth, cell cycle, signaling, and adhesion. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[24]  W. Ansorge,et al.  Direct induction of cyclin D2 by Myc contributes to cell cycle progression and sequestration of p27 , 1999, The EMBO journal.

[25]  M. Schwab,et al.  MycN sensitizes neuroblastoma cells for drug-induced apoptosis , 1999, Oncogene.

[26]  F. Speleman,et al.  Deletion mapping in neuroblastoma cell lines suggests two distinct tumor suppressor genes in the 1p35-36 region, only one of which is associated with N-myc amplification. , 1995, Oncogene.

[27]  J. Sedivy,et al.  Phenotypes of c-Myc-deficient rat fibroblasts isolated by targeted homologous recombination. , 1997, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[28]  P. Bouvet,et al.  Nucleolin functions in the first step of ribosomal RNA processing , 1998, The EMBO journal.

[29]  C. Dang,et al.  Induction of ribosomal genes and hepatocyte hypertrophy by adenovirus-mediated expression of c-Myc in vivo. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[30]  Ji Huang,et al.  [Serial analysis of gene expression]. , 2002, Yi chuan = Hereditas.

[31]  P. Farnham,et al.  Myc versus USF: discrimination at the cad gene is determined by core promoter elements , 1997, Molecular and cellular biology.

[32]  M. Henriksson,et al.  Proteins of the Myc network: essential regulators of cell growth and differentiation. , 1996, Advances in cancer research.

[33]  R. Versteeg,et al.  c‐myc down‐regulates class I HLA expression in human melanomas. , 1988, The EMBO journal.

[34]  R. Eisenman,et al.  Myc and Max function as a nucleoprotein complex , 1992, Current Biology.

[35]  F. Baas,et al.  The Human Transcriptome Map: Clustering of Highly Expressed Genes in Chromosomal Domains , 2001, Science.

[36]  J. Bishop,et al.  The MYC protein activates transcription of the alpha‐prothymosin gene. , 1991, The EMBO journal.

[37]  H. Sather,et al.  Association of multiple copies of the N-myc oncogene with rapid progression of neuroblastomas. , 1985, The New England journal of medicine.

[38]  J. Sedivy,et al.  Mysterious liaisons: the relationship between c-Myc and the cell cycle , 1999, Oncogene.

[39]  M. Schwab,et al.  Conditional expression of N-myc in human neuroblastoma cells increases expression of alpha-prothymosin and ornithine decarboxylase and accelerates progression into S-phase early after mitogenic stimulation of quiescent cells. , 1996, Oncogene.

[40]  R. Weinberg,et al.  N-myc amplification causes down-modulation of MHC class I antigen expression in neuroblastoma , 1986, Cell.

[41]  A. Iavarone,et al.  Id2 is a retinoblastoma protein target and mediates signalling by Myc oncoproteins , 2000, Nature.

[42]  R. Eisenman,et al.  c-Myc enhances protein synthesis and cell size during B lymphocyte development. , 1999, Proceedings of the National Academy of Sciences of the United States of America.