Use p27KIP1 Degradation for Breast Cancer Diagnosis and Therapy
Abstract
It is well established that p27(KIP1), a CDK inhibitor, serves as an excellent prognostic marker for breast cancers. Loss or low levels of p27 are closely associated with poor prognosis in breast cancer patients. We have identified a ubiquitin E3 ligase complex, SCF(SKP2), that binds and targets p27 for ubiquitin-dependent proteolysis. We found that SKP2, the rate limiting component of SCF(SKP2) complex, is highly induced in many transformed cells. We proposed to determine whether there is an inverse relationship between the levels of p27 and SKP2 in breast cancer cells and tumor samples. In the past year, we have affinity purified antibodies against the components of SCF(SKP2) including anti-SKP2, SKP1, CUL-1, and p27 antibodies. The affinity purified antibodies were used to stain breast tumor samples. We also began to characterize the determinants on phospho-p27 peptide that mediate interaction between p27 and SKP2. Mutant peptides were made that contain altered amino acid residues around phosphorylated threonine187 in p27 to determine whether they are involved in SKP2 binding. They were used to determine the interaction between SKP2 and p27. We are testing whether silencing of SKP2 inhibits breast cancer cell growth by promoting p27 accumulation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2001
- Accession Number
- ADA396497
Entities
People
- Hui Zhang
Organizations
- Yale University