Identification of CT46/HORMAD1, an immunogenic cancer/testis antigen encoding a putative meiosis-related protein

Cancer Immun. 2005 Jul 7;5:9.


Transcripts with ESTs derived exclusively or predominantly from testis, and not from other normal tissues, are likely to be products of genes with testis-restricted expression, and are thus potential cancer/testis (CT) antigen genes. A list of 371 genes with such characteristics was compiled by analyzing publicly available EST databases. RT-PCR analysis of normal and tumor tissues was performed to validate an initial selection of 20 of these genes. Several new CT and CT-like genes were identified. One of these, CT46/HORMAD1, is expressed strongly in testis and weakly in placenta; the highest level of expression in other tissues is <1% of testicular expression. The CT46/HORMAD1 gene was expressed in 31% (34/109) of the carcinomas examined, with 11% (12/109) showing expression levels >10% of the testicular level of expression. CT46/HORMAD1 is a single-copy gene on chromosome 1q21.3, encoding a putative protein of 394 aa. Conserved protein domain analysis identified a HORMA domain involved in chromatin binding. The CT46/HORMAD1 protein was found to be homologous to the prototype HORMA domain-containing protein, Hop1, a yeast meiosis-specific protein, as well as to asy1, a meiotic synaptic mutant protein in Arabidopsis thaliana.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Neoplasm / chemistry
  • Antigens, Neoplasm / genetics*
  • Base Sequence
  • Humans
  • Male
  • Meiosis / immunology*
  • Molecular Sequence Data
  • Reverse Transcriptase Polymerase Chain Reaction
  • Testis / immunology*


  • Antigens, Neoplasm