Role of p53 in Mammary Epithelial Cell Senescence
Abstract
The tumor suppressor p53 plays an important role in a variety of cancers including breast cancer. It inhibits the growth of malignant cells either by inducing G1 arrest, apoptosis or senescence. We are determining the role of p53 in human mammary epithelial cell (HMEC) senescence and the requirement of p53 inactivation in transformation of HMECs. In this report, we have found that p53 downregulation is required to overcome H-Ras induced senescence during transformation of HMECs. Downregulation of p53 resulted due to cooverexpression of Bmi-1 with H-Ras in transforming MCF10A strain of HMECs. We also continued to perform chromatin immunoprecipitaion linked PCR (ChIP) assay to identify targets of p53 involved in replicative senescence of HMECs. ChIP assays were performed using senescent 76N cells. The DNA obtained after chromatin IP of senescent cells using p53 antibody was amplified using linkers and cloned in a pGEM plasmid vector. Several clones were selected and sequenced to identify p53 regulated genes. Many clones contained p53 binding sites suggesting that genes represented in these particular clones are regulated by p53 during HMEC senescence. These genes are likely to have a role in p53-medaited tumor-suppression.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2007
- Accession Number
- ADA476193
Entities
People
- Goberdhan P. Dimri