title: Distinct mechanisms contribute to acquired cisplatin resistance of urothelial carcinoma cells.
abstract: Cisplatin (CisPt) is frequently used in the therapy of urothelial carcinoma (UC). Its therapeutic efficacy is limited by inherent or acquired drug resistance. Here, we comparatively investigated the CisPt-induced response of two different parental urothelial carcinoma cell lines (RT-112, J-82) with that of respective drug resistant variants (RT-112R, J-82R) obtained upon month-long CisPt selection. Parental RT-112 cells were ~2.5 fold more resistant to CisPt than J-82 cells and showed a different expression pattern of CisPt-related resistance factors. CisPt resistant RT-112R and J-82R variants revealed a 2-3-fold increased CisPt resistance as compared to their corresponding parental counterparts. Acquired CisPt resistance was accompanied by morphological alterations resembling epithelial mesenchymal transition (EMT). RT-112R cells revealed lower apoptotic frequency and more pronounced G2/M arrest following CisPt exposure than RT-112 cells, whereas no differences in death induction were observed between J-82 and J-82R cells. CisPt resistant J-82R cells however were characterized by a reduced formation of CisPt-induced DNA damage and related DNA damage response (DDR) as compared to J-82 cells. Such difference was not observed between RT-112R and RT-112 cells. J-82R cells showed an enhanced sensitivity to pharmacological inhibition of checkpoint kinase 1 (Chk1) and, moreover, could be re-sensitized to CisPt upon Chk1 inhibition. Based on the data we suggest that mechanisms of acquired CisPt resistance of individual UC cells are substantially different, with apoptosis- and DDR-related mechanisms being of particular relevance. Moreover, the findings indicate that targeting of Chk1 might be useful to overcome acquired CisPt resistance of certain subtypes of UC.
authors.affiliation: Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Höhn
authors.affiliation: Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Krüger
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Margaretha A
authors.initials: MA
authors.lastname: Skowron
authors.affiliation: Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Bormann
authors.affiliation: Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Schumacher
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Schulz
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Michèle J
authors.initials: MJ
authors.lastname: Hoffmann
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Niegisch
authors.affiliation: Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fritz
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002945:Cisplatin / Q000627:therapeutic use*; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006801:Humans; D015398:Signal Transduction / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D019459:Urothelium / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin
keywords: DNA damage response; DNA repair; cisplatin; cisplatin resistance; urothelial carcinoma