MAGE-A4 Interacts with the Liver Oncoprotein Gankyrin and Suppresses Its Tumorigenic Activity*

Hepatocellular carcinoma ranks among the most common malignancies in Southeast Asia and South Africa. Although there are many modalities of treatment, the recurrence and metastasis rates are high, and the prognosis is unsatisfactory. Gankyrin, a recently found oncoprotein, is a promising target for drug therapy because it is overexpressed in all studied hepatocellular carcinomas. Gankyrin contains six ankyrin repeats and interacts with Rb, Cdk4, and the S6 ATPase of the 26 S proteasome. In this study, a yeast two-hybrid screen with gankyrin has identified MAGE-A4 as another interacting protein. The interaction, mediated by the C-terminal half of MAGE-A4, was reproduced in mammalian cells. The interaction was specific to MAGE-A4, because other MAGE family proteins structurally similar to MAGE-A4,i.e. MAGE-A1, MAGE-A2, and MAGE-A12, did not bind to gankyrin. MAGE-A4 partially suppressed both anchorage-independent growth in vitro and tumor formation in athymic mice of gankyrin-overexpressing cells. The ability of mutant MAGE-A4 to interact with gankyrin correlated with the ability to suppress the anchorage-independent growth. These results demonstrate that MAGE-A4 binds to gankyrin and suppresses its oncogenic activity. So far, the major focus of studies on the MAGE proteins has been on their potential for cancer immunotherapy. Our results may also shed light on novel functions for MAGE-A proteins.

[1]  J. Fujita,et al.  A novel protein overexpressed in hepatoma accelerates export of NF-kappa B from the nucleus and inhibits p53-dependent apoptosis. , 2002, Cancer cell.

[2]  Hong-Yang Wang,et al.  Overexpression of p28/gankyrin in human hepatocellular carcinoma and its clinical significance. , 2002, World journal of gastroenterology.

[3]  F. Lemonnier,et al.  Generation of CTL Recognizing an HLA-A*0201-Restricted Epitope Shared by MAGE-A1, -A2, -A3, -A4, -A6, -A10, and -A12 Tumor Antigens: Implication in a Broad-Spectrum Tumor Immunotherapy1 , 2002, The Journal of Immunology.

[4]  W. Hahn,et al.  Modelling the molecular circuitry of cancer , 2002, Nature Reviews Cancer.

[5]  R. Baker,et al.  Gankyrin Is an Ankyrin-repeat Oncoprotein That Interacts with CDK4 Kinase and the S6 ATPase of the 26 S Proteasome* , 2002, The Journal of Biological Chemistry.

[6]  P. Barker,et al.  The MAGE proteins: Emerging roles in cell cycle progression, apoptosis, and neurogenetic disease , 2002, Journal of neuroscience research.

[7]  H. Okayama,et al.  Cdc6 requires anchorage for its expression , 2002, Oncogene.

[8]  M. Tsai,et al.  Novel insights into the INK4-CDK4/6-Rb pathway: counter action of gankyrin against INK4 proteins regulates the CDK4-mediated phosphorylation of Rb. , 2002, Biochemistry.

[9]  Y. Wang,et al.  Evaluation of MAGE-1 and MAGE-3 as tumour-specific markers to detect blood dissemination of hepatocellular carcinoma cells , 2002, British Journal of Cancer.

[10]  K. Naito,et al.  The Trophinin Gene Encodes a Novel Group of MAGE Proteins, Magphinins, and Regulates Cell Proliferation during Gametogenesis in the Mouse* , 2001, The Journal of Biological Chemistry.

[11]  R. Götz,et al.  Neurotrophin Receptor-interacting Mage Homologue Is an Inducible Inhibitor of Apoptosis Protein-interacting Protein That Augments Cell Death* , 2001, The Journal of Biological Chemistry.

[12]  M. Bertrand,et al.  An overview of the MAGE gene family with the identification of all human members of the family. , 2001, Cancer research.

[13]  G. Evan,et al.  Proliferation, cell cycle and apoptosis in cancer , 2001, Nature.

[14]  Yun‐Sil Lee,et al.  Sequential changes in hepatocarcinogenesis induced by diethylnitrosamine plus thioacetamide in Fischer 344 rats: Induction of gankyrin expression in liver fibrosis, pRB degradation in cirrhosis, and methylation of p16INK4A exon 1 in hepatocellular carcinoma , 2001, Molecular carcinogenesis.

[15]  J. Levine,et al.  Surfing the p53 network , 2000, Nature.

[16]  Philippe P Roux,et al.  NRAGE, A Novel MAGE Protein, Interacts with the p75 Neurotrophin Receptor and Facilitates Nerve Growth Factor–Dependent Apoptosis , 2000, Neuron.

[17]  G. Cornelis,et al.  A MAGE‐A4 peptide presented by HLA‐A2 is recognized by cytolytic T lymphocytes , 1999, European journal of immunology.

[18]  K. Yoshikawa,et al.  Physical and Functional Interactions of Neuronal Growth Suppressor Necdin with p53* , 1999, The Journal of Biological Chemistry.

[19]  J. Sheu,et al.  High frequency of expression of MAGE genes in human hepatocellular carcinoma. , 1999, Liver.

[20]  M. Makuuchi,et al.  Expression of the MAGE gene family in human hepatocellular carcinoma , 1999, Cancer.

[21]  R. Weinberg,et al.  The retinoblastoma protein and cell cycle control , 1995, Cell.

[22]  P. Chomez,et al.  A gene encoding an antigen recognized by cytolytic T lymphocytes on a human melanoma. , 1991, Science.

[23]  V. Freedman,et al.  Tumorigenicity of virus-transformed cells in nude mice is correlated specifically with anchorage independent growth in vitro. , 1975, Proceedings of the National Academy of Sciences of the United States of America.

[24]  Katsuhiko Itoh,et al.  Reduced stability of retinoblastoma protein by gankyrin, an oncogenic ankyrin-repeat protein overexpressed in hepatomas , 2000, Nature Medicine.