CD24 Regulates Cell Proliferation and Transforming Growth Factor ß1 -Induced Epithelial to Mesenchymal Transition
Incheol Shin
Incheol Shin
Department of Life Science
Hanyang University
Seoul, South Korea
Abstract:
Cluster of Differentiation 24 (CD24) is known to regulate metastasis in cancer. CD24 is expressed in a variety of human carcinomas. To determine the role of CD24 in breast cancer cells, we knocked down CD24 in MCF-7 human breast cancer cell with retroviral delivery of shRNA. CD24 knock-downed MCF-7 (MCF-7 hCD24 shRNA) cells exhibited decreased cell proliferation and cell adhesion as compared to control MCF-7 mCD24 shRNA cells. Decreased proliferation of MCF-7 hCD24 shRNA cells was resulted from the inhibition of cell cycle progression from G1 to S phase. The specific inhibition of MEK/ERK signaling by CD24 ablation might be responsible for the inhibition of cell proliferation. Phosphorylation of Src and FAK was also down-regulated in MCF-7 hCD24 shRNA cells. Moreover, down-regulation of FAK activity decreased TGF-β1-mediated epithelial to mesenchymal transition. These results may suggest that down-regulation of MEK/ERK signaling via Src/FAK is a major mechanism that is responsible for CD24 ablation-induced decrease in cell proliferation and adhesion.
