A peptide fragment of azurin induces a p53-mediated cell cycle arrest in human breast cancer cells

Autor: Fatima Lekmine, Craig W. Beattie, Tohru Yamada, Dibyen Majumdar, Marissa L. King, Rajeshwari R. Mehta, Tapas K. Das Gupta, Albert Green, Anne Shilkaitis, Konstantin Christov, Laura Bratescu
Rok vydání: 2009
Předmět:
Zdroj: Molecular Cancer Therapeutics. 8:2947-2958
ISSN: 1538-8514
1535-7163
DOI: 10.1158/1535-7163.mct-09-0444
Popis: We report that amino acids 50 to 77 of azurin (p28) preferentially enter the human breast cancer cell lines MCF-7, ZR-75-1, and T47D through a caveolin-mediated pathway. Although p28 enters p53 wild-type MCF-7 and the isogenic p53 dominant-negative MDD2 breast cancer cell lines, p28 only induces a G2-M-phase cell cycle arrest and apoptosis in MCF-7 cells. p28 exerts its antiproliferative activity by reducing proteasomal degradation of p53 through formation of a p28:p53 complex within a hydrophobic DNA-binding domain (amino acids 80-276), increasing p53 levels and DNA-binding activity. Subsequent elevation of the cyclin-dependent kinase inhibitors p21 and p27 reduces cyclin-dependent kinase 2 and cyclin A levels in a time-dependent manner in MCF-7 cells but not in MDD2 cells. These results suggest that p28 and similar peptides that significantly reduce proteasomal degradation of p53 by a MDM2-independent pathway(s) may provide a unique series of cytostatic and cytotoxic (apoptotic) chemotherapeutic agents. [Mol Cancer Ther 2009;8(10):2947–58]
Databáze: OpenAIRE