title: BMP signalling controls the malignant potential of ascites-derived human epithelial ovarian cancer spheroids via AKT kinase activation.
abstract: Epithelial ovarian cancer (EOC) cells have the ability to form multi-cellular aggregates in malignant ascites which dramatically alters cell signalling, survival, and metastatic potential. Herein, we demonstrate that patient ascites-derived EOC cells down-regulate endogenous bone morphogenetic protein (BMP) signalling by decreasing BMP ligand expression when grown in suspension culture to form spheroids. Enforced BMP signalling in these cells via constitutively-active BMP type I ALK3(QD) receptor expression causes the formation of smaller, more loosely-aggregated spheroids. Additionally, ALK3(QD)-expressing spheroids have an increased rate of adhesion and dispersion upon reattachment to substratum. Inhibition of endogenous BMP signalling using recombinant Noggin or small molecule inhibitor LDN-193189, on the other hand, opposed these phenotypic changes. To identify potential targets that impact the phenotype of EOC spheroids due to activated BMP signalling, we performed genome-wide expression analyses using Affymetrix arrays. Using the online Connectivity Map resource, the BMP signalling gene expression signature revealed that the AKT pathway is induced by activated BMP signalling in EOC cells; this finding was further validated by phospho-AKT immuno-blotting. In fact, treatment of EOC spheroids with an AKT inhibitor, Akti-1/2, reduced BMP-stimulated cell dispersion during reattachment as compared to controls. Thus, we have identified AKT as being one important downstream component of activated BMP signalling on EOC spheroid pathobiology, which may have important implications on the metastatic potential of this malignancy.
authors.affiliation: Translational Ovarian Cancer Research Program, London Regional Cancer Program, 790 Commissioners Road East, Room A4-836, London, ON N6A 4L6, Canada.
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Peart
authors.forename: Rohann J M
authors.initials: RJ
authors.lastname: Correa
authors.forename: Yudith Ramos
authors.initials: YR
authors.lastname: Valdes
authors.forename: Gabriel E
authors.initials: GE
authors.lastname: Dimattia
authors.forename: Trevor G
authors.initials: TG
authors.lastname: Shepherd
mesh_terms: D001201:Ascites / Q000473:pathology*; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000077216:Carcinoma, Ovarian Epithelial; D002352:Carrier Proteins / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D004789:Enzyme Activation; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D009375:Neoplasms, Glandular and Epithelial / Q000378:metabolism* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D018874:Spheroids, Cellular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured; D000099176:Noggin Protein
chemical_list: D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D051057:Proto-Oncogene Proteins c-akt; D011720:Pyrazoles; D011743:Pyrimidines; D000099176:Noggin Protein; C554430:LDN 193189; C054234:chordin