Establishment of an Orthotopic Xenograft Mice Model of Retinoblastoma Suitable for Preclinical Testing

Looking for In Vitro Models for Retinal Diseases

Retina is a layered structure of the eye, composed of different cellular components working together to produce a complex visual output. Because of its important role in visual function, retinal pathologies commonly represent the main causes of visual injury and blindness in the industrialized world. It is important to develop in vitro models of retinal diseases to use them in first screenings before translating in in vivo experiments and clinics. For this reason, it is important to develop bidimensional (2D) models that are more suitable for drug screening and toxicological studies and tridimensional (3D) models, which can replicate physiological conditions, for investigating pathological mechanisms leading to visual loss. This review provides an overview of the most common retinal diseases, relating to in vivo models, with a specific focus on alternative 2D and 3D in vitro models that can replicate the different cellular and matrix components of retinal layers, as well as injury insults that induce retinal disease and loss of the visual function.

Retinoblastoma: Etiology, Modeling, and Treatment

Retinoblastoma is a retinal cancer that is initiated in response to biallelic loss of RB1 in almost all cases, together with other genetic/epigenetic changes culminating in the development of cancer. RB1 deficiency makes the retinoblastoma cell-of-origin extremely susceptible to cancerous transformation, and the tumor cell-of-origin appears to depend on the developmental stage and species. These are important to establish reliable preclinical models to study the disease and develop therapies. Although retinoblastoma is the most curable pediatric cancer with a high survival rate, advanced tumors limit globe salvage and are often associated with high-risk histopathological features predictive of dissemination. The advent of chemotherapy has improved treatment outcomes, which is effective for globe preservation with new routes of targeted drug delivery. However, molecularly targeted therapeutics with more effectiveness and less toxicity are needed. Here, we review the current knowledge concerning retinoblastoma genesis with particular attention to the genomic and transcriptomic landscapes with correlations to clinicopathological characteristics, as well as the retinoblastoma cell-of-origin and current disease models. We further discuss current treatments, clinicopathological correlations, which assist in guiding treatment and may facilitate globe preservation, and finally we discuss targeted therapeutics for future treatments.

Development of In Vivo Model of Intraocular Retinoblastoma

Here we describe creation of a model of intraocular retinoblastoma on 4 mature immunodeficient BALB/c nude mice of both sexes. A suspension of the primary retinoblastoma culture was injected into each of the 8 eyes of the test animals. The injections were performed under the control of an operating microscope using insulin syringes with a diameter of 29G transsclerally into the subretinal space in a volume of 0.3 ml at a rate of 10,000 cells in 25 μl physiological saline. The culture of Rb10 cells derived from a patient with retinoblastoma passed 12 passages at the time of the experiments. After 9-week follow-up, a clinical (ophthalmoscopy) and instrumental (ultrasound) study was performed with visualization of the tumor mass on the fundus. After enucleation, a morphological study was performed. The retinoblastoma tumor nodes were identified in two eyes. The proposed model can be used for further research and for testing new chemotherapeutic drugs and treatment regimens for retinoblastoma.