Anuja Sathe1, Nicole Koshy1, Sebastian C Schmid1, Mark Thalgott1, Sarah M Schwarzenböck1, Bernd J Krause1, Per S Holm1, Juergen E Gschwend1, Margitta Retz1, Roman Nawroth2. 1. Department of Urology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Department of Nuclear Medicine, Rostock University Medical Centre (SMS, BJK), Rostock, Germany. 2. Department of Urology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Department of Nuclear Medicine, Rostock University Medical Centre (SMS, BJK), Rostock, Germany. Electronic address: roman.nawroth@lrz.tu-muenchen.de.
Abstract
PURPOSE: The retinoblastoma signaling network is frequently altered in advanced bladder cancer. We investigated the potential of CDK4/6 as a therapeutic target and determined biomarkers for patient stratification. MATERIALS AND METHODS: Genetic alterations were analyzed using public databases, including TCGA (The Cancer Genome Atlas), COSMIC (Catalogue of Somatic Mutations in Cancer) and CCLE (Cancer Cell Line Encyclopedia). Effects of the CDK4/6-inhibitor PD-0332991 or LY2835219 were examined in 10 bladder cancer cell lines by immunoblot, cell viability, apoptosis and cell cycle progression. Efficacy of the PD-0332991 and cisplatin combination was analyzed using the combination index. Gene expression level was determined by quantitative polymerase chain reaction. Cytomegalovirus promoter regulated recombinant retinoblastoma was used for reconstitution. Three-dimensional xenografts were grown on chicken chorioallantoic membrane and analyzed by measuring tumor weight and immunohistochemical expression of total retinoblastoma and Ki-67. RESULTS: PD-0332991 treatment decreased the proliferation of retinoblastoma positive bladder cancer cell lines and was synergistic in combination with cisplatin. PD-0332991 or LY2835219 treatment decreased the phosphorylation, total protein and transcript level of retinoblastoma. Treatment resulted in a decrease in E2F target gene expression (CCNA2 and CCNE2) and cell cycle progression from G0/G1 to the S-phase but did not affect apoptosis. In retinoblastoma negative cells reconstituted with recombinant retinoblastoma PD-0332991 affected only phosphorylation and not the total retinoblastoma level. These cells remained resistant to treatment. In 3-dimensional retinoblastoma xenografts, treatment resulted in reduced tumor weight and decreased expression of total retinoblastoma and Ki-67. CONCLUSIONS: We provide preclinical evidence that CDK4/6 inhibition is a potential therapeutic strategy for retinoblastoma positive bladder cancer that probably acts by negatively regulating retinoblastoma transcription.
PURPOSE: The retinoblastoma signaling network is frequently altered in advanced bladder cancer. We investigated the potential of CDK4/6 as a therapeutic target and determined biomarkers for patient stratification. MATERIALS AND METHODS: Genetic alterations were analyzed using public databases, including TCGA (The Cancer Genome Atlas), COSMIC (Catalogue of Somatic Mutations in Cancer) and CCLE (Cancer Cell Line Encyclopedia). Effects of the CDK4/6-inhibitor PD-0332991 or LY2835219 were examined in 10 bladder cancer cell lines by immunoblot, cell viability, apoptosis and cell cycle progression. Efficacy of the PD-0332991 and cisplatin combination was analyzed using the combination index. Gene expression level was determined by quantitative polymerase chain reaction. Cytomegalovirus promoter regulated recombinant retinoblastoma was used for reconstitution. Three-dimensional xenografts were grown on chicken chorioallantoic membrane and analyzed by measuring tumor weight and immunohistochemical expression of total retinoblastoma and Ki-67. RESULTS:PD-0332991 treatment decreased the proliferation of retinoblastoma positive bladder cancer cell lines and was synergistic in combination with cisplatin. PD-0332991 or LY2835219 treatment decreased the phosphorylation, total protein and transcript level of retinoblastoma. Treatment resulted in a decrease in E2F target gene expression (CCNA2 and CCNE2) and cell cycle progression from G0/G1 to the S-phase but did not affect apoptosis. In retinoblastoma negative cells reconstituted with recombinant retinoblastomaPD-0332991 affected only phosphorylation and not the total retinoblastoma level. These cells remained resistant to treatment. In 3-dimensional retinoblastoma xenografts, treatment resulted in reduced tumor weight and decreased expression of total retinoblastoma and Ki-67. CONCLUSIONS: We provide preclinical evidence that CDK4/6 inhibition is a potential therapeutic strategy for retinoblastoma positive bladder cancer that probably acts by negatively regulating retinoblastoma transcription.
Authors: Teena Dhir; Christopher W Schultz; Aditi Jain; Samantha Z Brown; Alex Haber; Austin Goetz; Chunhua Xi; Gloria H Su; Liang Xu; James Posey; Wei Jiang; Charles J Yeo; Talia Golan; Michael J Pishvaian; Jonathan R Brody Journal: Mol Cancer Res Date: 2019-08-05 Impact factor: 5.852
Authors: Florian G Klein; Charlène Granier; Yuling Zhao; Qi Pan; Zhichao Tong; Jürgen E Gschwend; Per Sonne Holm; Roman Nawroth Journal: J Pers Med Date: 2021-04-24
Authors: Anuja Sathe; Géraldine Chalaud; Immanuel Oppolzer; Kit Yeng Wong; Margarita von Busch; Sebastian C Schmid; Zhichao Tong; Margitta Retz; Juergen E Gschwend; Wolfgang A Schulz; Roman Nawroth Journal: PLoS One Date: 2018-01-22 Impact factor: 3.240