Role of CTCF in EGF-Induced Migration of Immortalized Human Corneal Epithelial Cells

Abstract

EGF-induced activation of the epigenetic CCCTC binding factor (CTCF) plays an important role in corneal epithelial cell proliferation by suppressing the Pax6 gene. The present study focused on further understanding the role of CTCF in mediating EGF-induced migration of immortalized human corneal epithelial cells. CTCF activities in human corneal epithelial cells immortalized by telomerase (HTCE cells) and SV-40 (HCE cells) transformation were suppressed and enhanced by CTCF mRNA knockdown and by overexpressing CTCF cDNA, respectively. EGF-induced cell migration was evaluated by linear scratch wound healing, a cell migration assay, and live cell motility GFP-tracking with a fluorescence microscope. Immunochemical analysis was performed for detecting focal adhesion changes in EGF-induced and CTCF activity-altered cells. EGF-induced wound closure and cell migration rates of human corneal epithelial cells were significantly suppressed and enhanced by CTCF mRNA knockdown and by overexpression of CTCF, respectively. CTCF mRNA knockdown also markedly suppressed cell motility, determined by using a live-cell-tracking system in GFP-tag-expressed HTCE cells. Finally, alterations of EGF-stimulated focal adhesion were observed in CTCF knockdown HTCE cells by immunostaining of F-actin and vinculin in cytoskeleton reorganization. CTCF, an epigenetic regulator and transcription factor, involves EGF-induced increases in cell motility and migration. CTCF plays an essential role in growth factor-regulated human corneal epithelial cell wound healing.