Abstract for presentation at 11th International Congress of Human Genetics

Recurrent homozygous deletion on chromosome 18q22.3 in prostate cancer

  • Xavier Reveles, University of Texas Health Science Center at San Antonio, United States
  • Mr Devon Hall, University of Texas Health Science Center at San Antonio, United States
  • Dr Sapna Vijayakumar, Mount Sinai School of Medicine, United States
  • Dr Dean Troyer, University of Texas Health Science Center at San Antonio, United States
  • Dr Susan Naylor, University of Texas Health Science Center at San Antonio, United States
  • Dr Teresa Johnson-Pais, University of Texas Health Science Center at San Antonio, United States
  • Robin Leach, University of Texas Health Science Center at San Antonio, United States

    • Prostate cancer has a major genetic component. Chromosomal deletions, as well as amplification, are a common finding in these tumors. The majority of the chromosome losses involve the loss of a single copy of a gene and/or regions. Here we report a homozygous deletion on chromosome 18q22.3 which was present in the majority (11/19) of prostate tumors evaluated by a high resolution genomic array developed for the distal end of chromosome 18q. Fluorescence in situ hybridization (FISH) analysis of paraffin-embedded tumor samples verified the deletion in 100% of the original prostate samples analyzed (5/5). Further characterization of tumors on tissue arrays demonstrated that the homozygous deletion was present in a subset of breast tumors but absent in 10 other tumors types including colorectal, esophageal , stomach, renal, lung, bladder, thyroid, liver, ovary and pancreas. Using tyramide signal amplification (TSA) FISH analysis, the region of loss has been narrowed to less than 160 kb, contained within bacterial artificial chromosome clone RPCI 11-25L3. This region does not appear to contain any genes that are expressed in the prostate. However, it does contain putative estrogen response elements and the loss is limited to cancer with are hormonally regulated. Therefore, this region could harbor a cryptic tumor suppressor gene and/or regulatory sequence that has yet to be identified. Alternatively, the loss of this region may be the result of a genomic instability phenotype that is tumor-specific.

    Conference Organiser - ICMS Pty Ltd