title: TGFβ and EGF synergistically induce a more invasive phenotype of epithelial ovarian cancer cells.
abstract: The epithelial-mesenchymal transition (EMT) is associated with progression and metastasis of epithelial ovarian cancer (EOC). Snail and Slug (two members of the Snail family of transcription factors) down-regulate the expression of the adhesion molecule E-cadherin and thus function as positive regulators of EMT. Their expression is associated with a more invasive phenotype of EOC. However, how their expression in EOC cells is regulated needs to be further defined. Here, we show that transforming growth factor β (TGFβ) and epidermal growth factor (EGF) synergistically induce the expression of Slug and Snail at both mRNA and protein levels in an EOC cell line OVCA429 cells. Using specific chemical inhibitors, we demonstrate that Slug and Snail expression induced by TGFβ is mediated by TGFβ/ALK5 pathway, and EGF-induced expression of Slug and Snail is MEK1/2-dependent. Interestingly, TGFβ-induced Slug expression is also MEK1/2-dependent. Further, we demonstrate that combined TGFβ and EGF stimulation is more potent than either alone in repressing the expression of E-cadherin. Functionally, combined stimulation of TGFβ and EGF enhances the mobility of OVCA429 cells and induces the production of MMP2 by OVCA429 cells more potently than either alone. Taken together, our data demonstrate that TGFβ and EGF signaling pathways synergistically induce EMT and render EOC cells a more invasive phenotype.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Xu
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Helen
authors.initials: H
authors.lastname: Steed
authors.forename: Sandra
authors.initials: S
authors.lastname: Davidge
authors.forename: Yangxin
authors.initials: Y
authors.lastname: Fu
mesh_terms: D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D048370:MAP Kinase Kinase 2 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D008648:Mesoderm / Q000473:pathology; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology*; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D015820:Cadherins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; C482128:MAP2K2 protein, human; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; D020778:Matrix Metalloproteinase 2