Title: Role of WNT5A receptors FZD5 and RYK in prostate cancer cells
Abstract: // Stefanie Thiele 1, 2 , Ariane Zimmer 1, 2 , Andy Göbel 1, 2 , Tilman D. Rachner 1, 2 , Sandra Rother 3 , Susanne Fuessel 4 , Michael Froehner 4 , Manfred P. Wirth 4 , Michael H. Muders 5 , Gustavo B. Baretton 5 , Franz Jakob 6 , Martina Rauner 1, 2 and Lorenz C. Hofbauer 1, 2, 7 1 Division of Endocrinology and Metabolic Bone Diseases, Department of Medicine III, Dresden, Germany 2 Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany 3 Institute of Materials Science, Max Bergmann Center of Biomaterials, Technische Universität Dresden, Dresden, Germany 4 Department of Urology, Technische Universität Dresden, Dresden, Germany 5 Institute of Pathology, Technische Universität Dresden, Dresden, Germany 6 Orthopedic Center for Musculoskeletal Research, University of Würzburg, Würzburg, Germany 7 German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany Correspondence to: Lorenz C. Hofbauer, email: [email protected] Keywords: prostate cancer; WNT5A; Wnt receptors; Frizzled; RYK Received: November 06, 2017 Accepted: May 11, 2018 Published: June 05, 2018 ABSTRACT Prostate cancer is the most common malignancy in men and has a high propensity to metastasize to bone. WNT5A has recently been implicated in the progression of prostate cancer, however, the receptors that mediate its effects remain unknown. Here, we identified Wnt receptors that are highly expressed in prostate cancer and investigated which of these receptors mediate the anti-tumor effects of WNT5A in prostate cancer in vitro . Extensive in vitro analyses revealed that the WNT5A receptors FZD5 and RYK mediate the anti-tumor effects of WNT5A on prostate cancer cells. Knock-down of FZD5 completely abrogated the anti-proliferative effect of WNT5A in PC3 cells. In contrast, knock-down of RYK and FZD8 did not rescue the inhibition of proliferation after WNT5A overexpression. In contrast, RYK knock-down inhibited the pro-apoptotic effect of WNT5A in PC3 cells by 60%, whereas the knock-down of either FZD5 or FZD8 further stimulated apoptosis after WNT5A overexpression (by 33% and 234%, respectively). Surface plasmon resonance analysis indicated that WNT5A has a 30% stronger binding response to FZD5 than to RYK. Further investigations using a tissue microarray revealed that expression of RYK is increased in advanced prostate cancer tumor stages, but is not associated with survival of prostate cancer patients. In contrast, patients with low local FZD5 expression, in particular in combination with low WNT5A expression, showed a longer disease-specific survival. In conclusion, WNT5A/FZD5 and WNT5A/RYK signaling are both involved in mediating the pro-apoptotic and anti-proliferative effects of WNT5A in prostate cancer.