Establishment of a novel retinoblastoma (Rb) nude mouse model by intravitreal injection of human Rb Y79 cells – comparison of in vivo analysis versus histological follow up

Abstract

Retinoblastoma (Rb) is the most frequent primary intraocular tumour in children and, if left untreated, can cause death. Preclinical animal models that mimic molecular, genetic, and cellular features of cancers are essential for studying cancer and searching for promising diagnosis and treatment modalities. There are several models described for Rb, but none of them fully meet our requirements. The aim of this study was to create a novel xenograft-nude mouse-model with broad application possibilities, which closely resembles the clinical observations of Rb patients and which could be used to investigate the development and spread of the tumour by using scanning laser ophthalmoscopy/optical coherence tomography (SLO/OCT) as well as histology methods. We injected human retinoblastoma Y79 cells intravitreally in both eyes of immune-deficient nude mice. The incidences of retinoblastoma as well as growth velocity were analysed 3, 6, 9 and 12 weeks after cell injection in vivo by SLO/OCT as well as ex vivo by electron microscopy (EM) and hematoxylin/eosin (HE) staining. Moreover, internal organs were histologically screened for potentially occurring metastases. Three weeks post-injection, animals developed a retinoblastoma, and after five weeks tumour growth resulted in swelling of the eyes in individual animals, showing a similar phenotype to that of untreated Rb patients at advanced stages of tumour-development. After 12 weeks, 67.5% of all analysed eyes (29 of 42) contained a retinoblastoma. At early stages of Rb development, the SLO/OCT analysis correlated with the histology results. If the tumours were too large, only histological investigations were feasible. The ultrastructural characteristics of the xenograft-tumours were very similar to those described for patient's tumours. In one mouse, brain metastases were observed. Our retinoblastoma mouse model closely resembles the human disease. SLO/OCT can be used for the detection of Rb at early stages of development and could be used for monitoring the success of future therapies.

Antagonists of growth hormone-releasing hormone receptor induce apoptosis specifically in retinoblastoma cells

“…Our findings indicate that GHRH-R is differentially expressed in the RB cell line Y79, which was the first human RB cell line established more than 40 y ago (20 the study of RB, including by direct injection into nude mice (21). In this reported study, 67.5% of the Y79-injected eyes developed RB after 12 wk, suggesting that Y79 is a good cellular model of RB (21).…”

“…In this reported study, 67.5% of the Y79-injected eyes developed RB after 12 wk, suggesting that Y79 is a good cellular model of RB (21). Y79 cells express GHRH-R throughout the population, with subcellular localizations in the nucleus and cytoplasm.…”

Retinoblastoma, the visible CNS tumor: A review

“…More recently, using a commercially available small-animal OCT system, we showed that this technique can detect the earliest signs of tumors in the TAg-RB model, corresponding to their first appearance by histology (Figure 3g) (Wenzel, O'Hare, Shadmand, & Corson, 2015), and we used this finding to show that overexpression of the oncogene OCT has proven useful for xenografts: intravitreal xenografts could be monitored Tschulakow, Schraermeyer, Rodemann, & Julien-Schraermeyer, 2016) and subretinal xenografts could be rapidly assessed by a combination of OCT and funduscopy (Lemaitre et al, 2017). Of course, OCT assessment of morphology of xenografts is less clinically relevant than the morphology of tumors arising intraretinally as in genetic retinoblastoma models.…”

“…OCT has proven useful for xenografts: intravitreal xenografts could be monitored (Corson et al, ; Tschulakow, Schraermeyer, Rodemann, & Julien‐Schraermeyer, ) and subretinal xenografts could be rapidly assessed by a combination of OCT and funduscopy (Lemaitre et al, ). Of course, OCT assessment of morphology of xenografts is less clinically relevant than the morphology of tumors arising intraretinally as in genetic retinoblastoma models.…”

A bilayer photoreceptor-retinal tissue model with gradient cell density design: A study of microvalve-based bioprinting

“…Experimental animal plays a significant role in current scientific and medical research and assists scientists to progressively understand various diseases. Some novel medicines and treatments are developed by the advance of animal research, for example, to investigate the development and spread of retinal tumour (Tschulakow, Schraermeyer, Rodemann, & Julien‐Schraermeyer, ). However, the retinal models in primate and rodent may take months to develop designed symptoms (Di Marco et al, ; Katt, Placone et al ; Lamba, Gust, & Reh, ; Shirai & Mandai, ).…”