Cloning and Characterization of a Cell Senescence Gene for Breast Cancer
Abstract
Applying a functional strategy, starting with the transfer of an intact chromosome 16, we first mapped the position of a cell senescence gene, SEN16, at 16q24.3. Precise positional information led to the identification of YAC and BAC clones that restores normal growth pattern and senescence in breast tumor cells. cDNAs corresponding to the transcripts, encoded from the genomic region of the BAC, were isolated and sequenced. The sequence information of known cDNAs was used to isolate full length cDNA clone, encoded from SEN16 locus. Individual cDNAs were cloned into mammalian cell expression vectors and tested for the restoration of senescence. Ectopic expression of one of the cDNAs, in tumor cell lines led to terminal growth arrest and senescence. Analysis of breast tumor and other tumor cell lines revealed genomic rearrangements at SEN16 locus, as well as loss of expression of the complementing cDNA. These results suggest that the cDNA that we have cloned in deed is tumor suppressor gene. In future studies, we will clone the gene in an inducible vector for further analysis. An inducible vector will provide the benefit of controlled expression of the gene in tumor cells to examine the effect on the cell cycle. In silico analysis or the cDNA sequence revealed that predicted protein is a part of an ubiquitin - ligase complex that may function in protein degradative pathway. Malfunctioning of these pathways may contribute to the deregulation of cell cycle, leading to the development of cancer. Further characterization of SEN16, for the identification of signaling pathways will afford insight into deregulation of cell growth and senescence. We have already initiated the experiments, using yeast two hybrid system to identify interacting proteins. At the end we anticipate that our studies will lead to the identification of new diagnostic markers, which eventually may lead to the development of new diagnostic and therapeutic strategies. 2
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2005
- Accession Number
- ADA452288
Entities
People
- Raghbir S. Athwal
Organizations
- Temple University