title: Toxic effects of melphalan, topotecan and carboplatin on retinal pigment epithelial cells.
abstract: OBJECTIVE
  Clinical evidence of retinal pigment epithelium (RPE) alterations after intra-arterial (IAC) and intravitreal chemotherapy (IViC) of retinoblastoma has been reported. We, therefore, investigated the cellular toxic effects of melphalan, topotecan and carboplatin on the RPE in a cell culture model.
  
  
  METHODS
  The effects of melphalan, carboplatin and topotecan on ARPE19 cell morphology were examined by phase contrast microscopy. Cell proliferation was quantified by BrdU incorporation, cell viability studied via MTS assays, and cell densities were estimated by Crystal Violet staining, and apoptosis induction studied via caspase 3/7-activity assays after a 24-hr incubation period. Staurosporine, media without fetal bovine serum, diluents of melphalan, carboplatin and topotecan were applied as positive and negative controls, respectively.
  
  
  RESULTS
  We observed a concentration-dependent increase in the number and size of gaps in the ARPE19 cell layer with each drug. There was a significant decrease in proliferative activity and cell viability of RPE cells as well as an increase in apoptosis after 24 hrs culture in media supplemented with melphalan and topotecan. Carboplatin had comparable effects on cell proliferation and cell viability; however, no significant apoptotic impacts were observed. The three cytostatic drugs had insignificant effects on cell density measurements.
  
  
  CONCLUSIONS
  Morphological monitoring and toxicity assays indicate a direct toxic effect of melphalan and the other two cytostatic drugs on ARPE19 cells. Thus, a direct toxic effect of melphalan in vivo after IAC or IViC on the RPE seems probable and may explain the clinical and angiographic RPE alterations observed in some retinoblastoma patients.
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Süsskind
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Hagemann
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.|University Hospital of Ophthalmology, Carl-von-Ossietzky University, Oldenburg, Germany.
authors.forename: Merle
authors.initials: M
authors.lastname: Schrader
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Januschowski
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Schnichels
authors.affiliation: Centre for Ophthalmology, Eberhard-Karls University Tübingen, Tübingen, Germany.|University Hospital of Ophthalmology, Carl-von-Ossietzky University, Oldenburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Aisenbrey
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D016190:Carboplatin / Q000633:toxicity*; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008558:Melphalan / Q000633:toxicity*; D008858:Microscopy, Phase-Contrast; D055213:Retinal Pigment Epithelium / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D059004:Topoisomerase I Inhibitors / Q000633:toxicity*; D019772:Topotecan / Q000633:toxicity*
chemical_list: D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D019772:Topotecan; D016190:Carboplatin; D053148:Caspase 3; D053179:Caspase 7; D008558:Melphalan
keywords: chemotherapy; intra-ocular tumour; retinal pigment epithelium; retinoblastoma; toxicity