Microsatellite and Chromosomal Instability in Breast Cancer
Abstract
During the reporting period, the authors analyzed a set of breast tumors for chromosomal and microsatellite instabilities, two fundamental pathways of genomic instability that play a critical role in the pathogenesis of several types of human cancers. They found that 22% of all breast cancer cases have allelic imbalances in one or more of 14 microsatellite markers, which covered a region of 21MB of chromosome 7 around the EGFR gene. They found both amplifications (8%) and losses of heterozygosity (14%) of the EGFR-containing region of chromosome 7. Microsatellite instability (MSI) was assessed with the use of 3 mononucleotide and 4 dinucleotide markers. None of the 202 samples analyzed showed any frameshift mutations in the mononucleotide repeats, including polyA sequences in cancer susceptibility genes BRCA1 and BRCA2. One breast cancer tumor showed MSI at all four dinucleotide markers used for MSI status evaluation, but not at the mononucleotide markers. These data indicate that microsatellite instability is very uncommon (less than 0.5%) in breast cancer tumors. The data show that MSI is not important in the pathogenesis or progression of breast cancer in contrast to other genetic mechanisms, notably recurrent chromosomal imbalances that dysregulate function of genes controlling cell growth, differentiation, and apoptosis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2004
- Accession Number
- ADA430384
Entities
People
- Svetlana Baranovskaya
Organizations
- Sanford Burnham Prebys Medical Discovery Institute