The locus of the polymorphic epithelial mucin (PEM) tumour antigen on chromosome 1q21 shows a high frequency of alteration in primary human breast tumours

Int J Cancer. 1990 Mar 15;45(3):431-5. doi: 10.1002/ijc.2910450309.


Tumour and blood leukocyte DNAs from sporadic breast cancer patients were examined for chromosome 1 loss of heterozygosity using a probe for a polymorphic epithelial mucin, PEM, which is expressed in greater than 92% of breast carcinomas as well as in normal lactating breast tissue. Expression is detected by the monoclonal antibodies (MAbs) HMFG-1, -2 and SM-3 which react with epitopes in the 20 amino-acid repeat unit of the core protein. The PEM probe has been mapped to the chromosome band 1q21, a region that is often incriminated in chromosomal rearrangements in breast tumours. Loss of heterozygosity or alteration at the PEM locus was detected in 34% of the 70 informative patients examined. Twenty of the 24 individuals showed loss of an allele, whereas 4 showed gain of an additional allele or amplification of an existing allele. Twenty-eight percent of informative cases exhibited alterations at the MS32 locus, 1q42-43, and 20% had alterations at the short arm locus MS1 at 1p33-35. These findings identify the long arm of chromosome 1 and in particular the region around the PEM gene for localization of a gene whose loss or alteration may, in some tumours, contribute to the progression of disease in breast cancer patients.

MeSH terms

  • Antigens, Neoplasm / genetics*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / immunology
  • Chromosome Aberrations*
  • Chromosome Mapping*
  • Chromosomes, Human, Pair 1*
  • Chromosomes, Human, Pair 5
  • Chromosomes, Human, Pair 7
  • Female
  • Gene Rearrangement / genetics*
  • Heterozygote
  • Humans
  • Mucins / genetics
  • Mucins / immunology*


  • Antigens, Neoplasm
  • Mucins