Identification of markers with the potential to predict tumorigenic behavior is important in
breast cancer, due to the variability in clinical
disease progression. Genetic alterations during neoplastic progression may appear as changes in total
DNA content, single genes, or gene expression. Oncogenic alterations are thought to be prognostic indices for patients with
breast cancer.
Breast cancer deregulation can occur in the normal cellular process and can be measured by
microsatellite instability (MSI)/loss of heterozygosity (LOH). Chromosome 11 is unique in this respect, as three regions of MSI/LOH have been identified (11p15-p15.5, 11q13-q13.3 and 11q23-q24). There are many important families of genes, such as FGF, CCND1, FADD, BAD and GAD2, that are located on chromosome 11 and these play a crucial role in
breast cancer progression. Among them, different members of the
fibroblast growth factor (FGF) family of genes are clustered around human chromosome 11q13 amplicon, which are constantly altering during
breast cancer progression. Therefore, in this study, locus 11q13 and FGF3 gene (11q13) function were investigated in a radiation and
estrogen breast cancer model induced by high-LET (α-particle) radiation and
estrogen exposure. To assess the effect of ionizing radiation and
estrogen at chromosome 11q13 loci and the subsequent role of FGF3 gene expression, various microsatellite markers were chosen in this region, and allelic loses (~20-45%) were identified by PCR-SSCP analysis. Results showed an increase in FGF3
protein expression and a 6- to 8-fold change in gene expression of FGF3 and associated genes. These deregulations could be utilized as an appropriate target for therapeutic intervention in
breast cancer.