Discovery of Genomic Breakpoints Affecting Breast Cancer Progression and Prognosis
Abstract
157 genomic breakpoints could be confirmed as likely somatic mutations. We focused on breakpoints predicted to lead to fusion transcripts. By RT-PCR we determined that 4 showed a fusion mRNA. In the case of the ARFGEF2/SULF2, a non-functional Sulfatase 2 might be created. To give insight, SULF2 mRNA was knocked down using siRNA. Cells treated with SULF2 siRNA, exhibited a growth advantage enhanced survival, and an advantage in anchorage-independent growth compared to control siRNA. This implies that the presence of this fusion might mean a loss of function of the tumor suppressor Sulfatase 2. Another fusion, RAD51C/ATXN7 results in the truncation RAD51C, involved in double stranded break repair. We detected chimeric mRNA expression in 3 breast cancer cell lines, and a shorter form of RAD51C by western blot, indicating that the fusion introduces a truncation in RAD51C protein. To gain insight into the heterogeneity of genomic breakpoints, in seven MCF-7 sub-lines. There is an enrichment for breakpoints containing genes (50.3% vs 77.4%), and for fusion-containing breakpoints (6.4% vs 16.1%). When studying cell lines originating from a single cell, we discovered that there is very little genetic variability between them. A large effort has gone into the development of next-generation sequencing techniques for the discovery of genomic breaks and fusion in the breast cancer genome. We developed new techniques and validated them with standard PCR. The validation rate is very promising, and these new techniques will aid us in the discovery of breast cancer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2010
- Accession Number
- ADA559239
Entities
People
- Petra Den Hollander
Organizations
- Baylor College of Medicine