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.

Multimodality Imaging Methods for Assessing Retinoblastoma Orthotopic Xenograft Growth and Development

“…Traditionally, successful orthotopic xenografts were confirmed by fundus photography, signs such as progressive proptosis seen on examination as tumors grow, and postmortem histopathology. Recently, prior to xenografting into rodents, retinoblastoma cell lines have been genetically manipulated to express EGFP, luciferase, or a dual construct of both (EGFP-luc) as methods to follow tumor growth [12]–[14], [16], [17], [43]. More rapid and quantitative ascertainment of xenograft success and growth would be advantageous.…”

“…This neonate model offers two key advantages: 1) a developmentally appropriate host environment for these pediatric tumor cells, and 2) a naturally immunonaïve setting, circumventing the need for immunocompromised animals. To date, this model has been used for testing novel treatments such as topotecan/carboplatin and topotecan/vincristine combination therapies [12], [14], viral expression of interferon [15], a novel isoquinoline EDL-155 [16], and a histone deacetylase inhibitor MS-275 [17].…”

Efficacy and safety of aflibercept in in vitro and in vivo models of retinoblastoma

“…After obtaining a fundus image of each mouse with MICRON III (Phoenix, CA, USA), 1 × 10 5 (1 μl) Y-79 or WERI-Rb-1 cells were injected into the vitreous using a 30-gauge Hamilton syringe [44–46]. A fundus image of each mouse was also obtained 2 weeks after intravitreal Y-79 or WERI-Rb-1 cells injection to confirm that injected Y-79 or WERI-Rb-1 cells were successfully transplanted.…”

Preclinical Study of Potential Antiglioma Novel Tetrahydroisoquinoline Analogs: Pharmacokinetics and Mechanism of Action10.21007/etd.cghs.2012.0191

“…The decrease of cell density in treated wells in Figure 4-4 also suggests that other cell death pathways, such as autophagy, may already have taken place before the culmination of apoptosis, which should happen after that 60 hr caspase-3 peak time. Our collaborating laboratory has recently reported that EDL-155 can cause autophagy in Y79 retinoblastoma cells [120]. And after EDL-155 treatment, autophagosome-like double-membrane-bound large vacuoles in cytoplasm were found in rat C6 glioma cells but not in rat normal astrocytes [66].…”

“…Blood (100 µL) was collected into Microtainer ® tubes with lithium heparin and plasma separation gel (BD, Franklin Lakes, NJ, Catalog # 365958) from the jugular vein catheter at timed intervals 2,5,15,30,45,60,75,90,120,180,240,360,480, 600, 960, and 1440 min. Samples were centrifuged at 10,000 g, 4 °C for 2 min.…”