title: A highly polymorphic CA repeat marker at the EBAG9/RCAS1 locus on 8q23 that detected frequent multiplication in breast cancer.
abstract: BACKGROUND
  Cloning of CpG binding sites in the human genome initially identified EBAG9 (estrogen receptor-binding fragment-associated gene 9), an estrogen-responsive gene mapped to chromosome 8q23. Its product was later found to be identical to RCAS1 (receptor-binding cancer antigen expressed on SiSo cells 1). RCAS1 was recently described as a cancer-surface antigen, implicated in immune escape in a human uterine adenocarcinoma cell line, which turned out to be identical to the EBAG9 molecule.
  
  
  OBJECTIVE
  The study seeks to isolate a highly polymorphic dinucleotide repeat at this locus that detects frequent multiplication of the EBAG9/RCAS1 gene.
  
  
  METHODS
  A fragment containing CA repeat was identified by Southern blotting of bacterial artificial chromosome (BAC) clone containing the EBAG9/RCAS1 gene digested by Hae III, Sau 3A or Rsa I with (GT)20 probe, subcloned and sequenced.
  
  
  RESULTS
  We isolated a polymorphic dinucleotide (CA) repeat sequence from a genomic clone containing the EBAG9/RCAS1 gene located at 8q23. High heterozygosity (0.859) makes this polymorphism a useful marker in genetic studies. This marker detected frequent multiplication of the EBAG9/RCAS1 gene in primary breast cancers (27 of 129 tumours).
  
  
  CONCLUSIONS
  This marker is useful for detecting frequent multiplication of the EBAG9/RCAS1 gene in primary breast cancers and other cancers.
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396, Kosugi-cho, Nakahara-ku, Kawasaki, 211-8533, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Tsuneizumi
authors.forename: Hisaki
authors.initials: H
authors.lastname: Nagai
authors.forename: Haruhito
authors.initials: H
authors.lastname: Harada
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Kazui
authors.forename: Mitsuu
authors.initials: M
authors.lastname: Emi
mesh_terms: D000483:Alleles; D000951:Antigens, Neoplasm; D000954:Antigens, Surface / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D018900:Dinucleotide Repeats / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D018807:Polymorphism, Single-Stranded Conformational
chemical_list: D000951:Antigens, Neoplasm; D000954:Antigens, Surface; C120762:EBAG9 protein, human