Several landmark discoveries in cancer genetics have come from studies on a rare childhood cancer of the developing retina called retinoblastoma. In parallel, advances in preclinical testing and clinical research has led to improvements in outcome for children with this devastating disease. Despite these advances, there are still fundamental questions in the retinoblastoma field that remain unanswered. Are retinal cells fully transformed once they sustain biallelic inactivation of the RB1 gene or is retinoblastoma tumorigenesis a multistage process? Why do some family members with the same germline RB1 mutation have bilateral multifocal retinoblastoma at a young age while others have no evidence of disease? Can treatment induce a process of tumor cell clonal evolution and selection that leads to tumor progression and enucleation? These questions have been impossible to answer because retinoblastomas are not biopsied and enucleation is only performed for advanced stage eyes. In order to overcome this barrier in the field, we have developed the first spontaneous human retinoblastoma tumor model using 3D retinal organoids produced from patients with germline RB1 mutations. I have assembled a multidisciplinary team with expertise in computational and stem cell biology, oncology, pathology, epidemiology and biostatistics to use this innovative new model of retinoblastoma to answer fundamental questions in 3 specific aims. We will determine if retinoblastoma progresses through a multistep process (Aim 1), if molecular, cellular or genetic factors contributes to differences in penetrance and expressivity (Aim 2) and if there is clonal selection with treatment (Aim 3). I have a proven record in retinoblastoma genetics and of moving basic science discoveries into clinical trials. This proposal will impact patients with retinoblastoma through preclinical testing of a novel maintenance therapy (Aim 3) to prevent new tumors from forming in the peripheral retina in the first few months after completion of chemotherapy. It may also help to identify a subset of retinoblastoma survivors with germline RB1 mutations that have an ultra-high risk of developing a 2nd malignancy and require more extensive cancer screening (Aim 2). No other center has the team, resources, expertise, or tools available to perform the studies presented here and efficiently move the most promising findings directly into a clinical trial.

Public Health Relevance

(Relevance Statement): We have developed the first spontaneous human retinoblastoma tumor model by using iPSCs from patients with germline RB1 mutations. Using this model combined with our extensive collection of orthotopic patient- derived xenografts we will determine if retinoblastoma tumorigenesis is a multistep process and study the clonal evolution and selection of tumor cells during treatment.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA245508-01A1
Application #
10051623
Study Section
Cancer Molecular Pathobiology Study Section (CAMP)
Program Officer
Fingerman, Ian M
Project Start
2020-05-15
Project End
2025-04-30
Budget Start
2020-05-15
Budget End
2021-04-30
Support Year
1
Fiscal Year
2020
Total Cost
Indirect Cost
Name
St. Jude Children's Research Hospital
Department
Type
DUNS #
067717892
City
Memphis
State
TN
Country
United States
Zip Code
38105