title: Targeting the Wnt/β-catenin pathway in primary ovarian cancer with the porcupine inhibitor WNT974.
abstract: Preclinical studies in ovarian cancer have demonstrated upregulation of the Wnt/β-catenin pathway promoting tumor proliferation and chemoresistance. Our objective was to evaluate the effect of the Wnt/β-catenin pathway inhibitor, WNT974, in primary ovarian cancer ascites cells. Ascites cells from patients with papillary serous ovarian cancer were isolated and treated with 1 μM WNT974±100 μM carboplatin. Viability was evaluated with the ATPlite assay. The IC50 was calculated using a dose-response analysis. Immunohistochemistry (IHC) was performed on ascites cells and tumor. Expression of R-spondin 2 (RSPO2), RSPO3, PORCN, WLS, AXIN2, and three previously characterized RSPO fusion transcripts were assessed using Taqman assays. Sixty ascites samples were analyzed for response to WNT974. The ascites samples that showed a decrease in ATP concentration after treatment demonstrated no difference from the untreated cells in percent viability with trypan blue staining. Flow cytometry demonstrated fewer cells in the G2 phase and more in the G1 and S phases after treatment with WNT974. Combination therapy with WNT974 and carboplatin resulted in a higher percentage of samples that showed ≥30% reduction in ATP concentration than either single drug treatment. IHC analysis of Wnt pathway proteins suggests cell cycle arrest rather than cytotoxicity after WNT974 treatment. QPCR indicated that RSPO fusions are not prevalent in ovarian cancer tissues or ascites. However, higher PORCN expression correlated to sensitivity to WNT974 (P=0.0073). In conclusion, WNT974 produces cytostatic effects in patient ascites cells with primary ovarian cancer through inhibition of the Wnt/β-catenin pathway. The combination of WNT974 and carboplatin induces cytotoxicity plus cell cycle arrest in a higher percentage of ascites samples than with single drug treatment. RSPO fusions do not contribute to WNT974 sensitivity; however, higher PORCN expression indicates increased WNT974 sensitivity.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Boone
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Arend
authors.affiliation: HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA.
authors.forename: Bobbi E
authors.initials: BE
authors.lastname: Johnston
authors.affiliation: HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Cooper
authors.affiliation: University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Gilchrist
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Denise K
authors.initials: DK
authors.lastname: Oelschlager
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Grizzle
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Gerald
authors.initials: G
authors.lastname: McGwin
authors.affiliation: Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Gangrade
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Straughn
authors.affiliation: Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Buchsbaum
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001201:Ascites / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000737:chemistry / Q000378:metabolism*; D010053:Ovary / Q000737:chemistry; D051153:Wnt Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000187:drug effects*; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D051153:Wnt Proteins; D051176:beta Catenin