Ashraf A Khalil
Institute of Genetic Engineering and Biotechnology, Egypt
Title: Genomics of regulatory crosstalk between PPAR gamma and 14-3-3 genes in breast cancer cells
Biography
Biography: Ashraf A Khalil
Abstract
PPARγ, a ligand-stimulated transcription factor with differentiation promoting activity is overexpressed in a variety of cancers. Perturbation of PPAR-γ signaling is now believed to be a strategy for treatment of several cancers, including breast cancer. A set of genes regulated by PPAR-γ ligands is expected to mediate the antiproliferative and prodifferentiation effects in cancer cells. Because 14-3-3 family of proteins shows a debatable activity and varying expression levels in different tumors, in the studies presented here we explored the transcriptional regulatory role of Pioglitazone on the seven 14-3-3 isoforms presenting in MCF-7 breast cancer cells. This study demonstrated that the potent PPAR-γ agonist, Pioglitazone exerted a regulatory role on expression of 14-3-3 genes where it upregulated 14-3-3 gamma, epsilon, zeta and tau by 3.8, 5.2, 2.7 and 739 folds, respectively. However, it had a negative regulatory effect on 14-3-3 beta, sigma and Eta by 16.94, 4.58 and 2.12 folds, respectively compared with control cells. These results correlated with growth arrest and a great increase in BRCA1 gene expression by 1076 folds. In summary, these findings are the first time showing that PPAR-γ regulates 14-3-3 genes and raises question whether PPAR-γ ligands mediate their anticancer effects via regulation of 14-3-3 proteins.