title: Treating retinoblastoma in tissue culture and in a rat model with a novel isoquinoline derivative.
abstract: PURPOSE. To investigate the effectiveness of a novel isoquinoline derivative, EDL-155, in killing retinoblastoma in vitro and in vivo. METHODS. Dose-response curves were generated in which Y79 retinoblastoma cells tagged with luciferase (Y79-Luc) were treated with serial concentrations of EDL-155. Electron microscopy was used to evaluate the ultrastructural morphology of EDL-155-treated Y79 cells. To determine whether autophagy was induced in EDL-155-treated Y79-Luc cells, staining with acridine orange and LC-3 immunoblot analysis was performed. To evaluate the efficacy of EDL-155 in vivo, Y79-Luc retinoblastoma cells were injected into the vitreous cavity of newborn rats, followed by periocular injections of EDL-155 (20 mg/kg/day) or an equivalent dosage of saline. RESULTS. EDL-155 appeared to destroy the retinoblastoma cells in vitro with an EC(50) of 9.1 micriM. EDL-155-treated retinoblastoma cells displayed a lack of viable mitochondria and the presence of autophagosomes wrapped in the characteristic double membranes. Acridine orange staining of EDL-155-treated retinoblastoma cells demonstrated the accumulation of vacuoles, and the immunoblots displayed a shift in molecular weight of LC-3, indicative of incorporation into autophagosome vesicles. In the retinoblastoma animal model, four doses of EDL-155 were delivered over 4 days, which was sufficient to see a significant decrease (P = 0.01) in viable intraocular tumors. Seven of the 25 rats treated with EDL-155 had no detectable living tumor. No significant decrease in viable tumor was observed in control animals. CONCLUSIONS. EDL-155 appears to eliminate retinoblastoma cells by disrupting mitochondria and inducing autophagy. Local delivery of EDL-155 may be an effective therapy for some types of ocular cancers.
authors.affiliation: Department of Ophthalmology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Nassr
authors.forename: Xiangdi
authors.initials: X
authors.lastname: Wang
authors.forename: Suchareeta
authors.initials: S
authors.lastname: Mitra
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Freeman-Anderson
authors.forename: Renukadevi
authors.initials: R
authors.lastname: Patil
authors.forename: C Ryan
authors.initials: CR
authors.lastname: Yates
authors.forename: Duane D
authors.initials: DD
authors.lastname: Miller
authors.forename: Eldon E
authors.initials: EE
authors.lastname: Geisert
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001343:Autophagy; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006801:Humans; D015151:Immunoblotting; D007267:Injections; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000648:ultrastructure; D009368:Neoplasm Transplantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000648:ultrastructure; D012175:Retinoblastoma / Q000188:drug therapy* / Q000648:ultrastructure; D044005:Tetrahydroisoquinolines / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; C529597:EDL-155; D044005:Tetrahydroisoquinolines