Endothelin-1 is required during epithelial to mesenchymal transition in ovarian cancer progression.
In a range of human cancers, tumorigenesis is promoted by activation of the endothelin A receptor (ET(A)R)/endothelin-1 (ET-1) axis. ET-1 and ET(A)R are overexpressed in primary and metastatic ovarian carcinomas, and high levels of ET-1 are detectable in patient ascites, suggesting that ET-1 may promote tumor dissemination. Moreover, in these tumors, engagement of ET(A) receptor by ET-1 triggers tumor growth, survival, angiogenesis, and invasiveness. Thus, ET-1 enhances the secretion of matrix metalloproteinases, disrupts intercellular communications, and stimulates cell migration and invasion. Therefore, we investigated the role of the ET-1/ET(A)R autocrine axis in promoting epithelial to mesenchymal transition (EMT) in ovarian tumor cells, a key event in cancer metastasis, in which epithelial cells depolarize, disassemble cell-cell contacts, and adopt an invasive phenotype. Here, we examine the potential role of ET-1 in regulating cell morphology and behavior and epithelial and mesenchymal proteins employing an in vitro 3-D culture system. We found that in 3-D serum-free collagen I gel cultures, HEY and OVCA 433 ovarian carcinoma cells undergo fibroblast-like morphologic changes between 3 and 5 days of ET-1 treatment. In these cells, ET-1 induces loss of adherens and tight-junction protein expression, E-cadherin, beta-catenin, and zonula occludens-1, and gain of N-cadherin and vimentin expression. These results confirm the ability of ET-1 to promote EMT, a metastable process involving sustained loss of epithelial markers and gain of mesenchymal markers. Collectively, these findings provide evidence of a critical role for the ET-1/ET(A)R axis during distinct steps of ovarian carcinoma progression, thus underlining this axis as a potential target in the treatment of ovarian cancer.
Rosanò
Laura
L
Laboratory of Molecular Pathology and Ultrastructure, Regina Elena Cancer Institute, Via delle Messi D'Oro 156, 00158 Rome, Italy.
Spinella
Francesca
F
Di Castro
Valeriana
V
Decandia
Samantha
S
Nicotra
Maria Rita
MR
Natali
Pier Giorgio
PG
Bagnato
Anna
A
D045744:Cell Line, Tumor; D024042:Collagen Type I / Q000378:metabolism; D016895:Culture Media, Serum-Free; D018450:Disease Progression; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology*; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects; D005260:Female; D006801:Humans; D008648:Mesoderm / Q000166:cytology* / Q000187:drug effects; D009361:Neoplasm Invasiveness; D009924:Organ Culture Techniques; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D044022:Receptor, Endothelin A / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
D024042:Collagen Type I; D016895:Culture Media, Serum-Free; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D044022:Receptor, Endothelin A