RB355 Xenograft Model Service for Retinoblastoma

The RB355 Xenograft Model Service for Retinoblastoma provides a robust, clinically relevant preclinical platform for evaluating novel therapeutic strategies against one of the most aggressive pediatric ocular malignancies. Alfa Cytology leverages its extensive expertise in tumor model development to deliver precisely characterized RB355 xenograft systems, enabling researchers to accelerate drug discovery and translational research in retinoblastoma with confidence and reproducibility.

Overview of RB355 Xenograft Model for Retinoblastoma

Retinoblastoma represents the most common intraocular malignancy in children, accounting for approximately 4% of all pediatric cancers, with most cases diagnosed before the age of three years. The RB355 cell line was originally established from a non-familial, bilaterally affected 18-month-old child and was first characterized by Dr. Brenda Gallie at the University of Toronto. This cell line harbors genetic mutations in the RB1 gene, including a C>T mutation on exon 19 and a T>A mutation at exon 22, and exhibits MYCN amplification exceeding fourfold, making it a representative model for the aggressive, invasive subtype of retinoblastoma that frequently demonstrates choroidal and optic nerve invasion.

The RB355 xenograft model has been extensively validated across multiple species and platforms, including orthotopic transplantation in immunodeficient mice and zebrafish models. Studies demonstrate that RB355 cells retain their invasive characteristics in vivo, with observable migration into the brain and ventricles of the forebrain, midbrain, and hindbrain, closely mimicking human metastatic patterns. The cell line grows as an adherent monolayer in culture and exhibits high SYK expression, rendering it sensitive to SYK inhibitors such as BAY 61-3606 and R406, which has significant implications for targeted therapy development. These molecular and phenotypic features position the RB355 xenograft as a critical tool for preclinical evaluation of chemotherapeutic agents, targeted therapies, and novel drug delivery systems in retinoblastoma research.

• Efficacy Testing: Evaluating the in vivo anti-tumor activity of novel compounds, small molecules, biologics, or combination therapies targeting retinoblastoma.
• Mechanistic Studies: Investigating the complex molecular pathways driving retinoblastoma progression and invasion, and how treatments intersect with these pathways.
• Biomarker Discovery: Identifying and validating potential biomarkers for treatment response or resistance in a controlled in vivo environment.

Figure 1. MTT assay showing the effects of 8-deoxylactucin on the viability of RB355 retinoblastoma and normal RPE cells. (Guiying, Tan, et al., 2019)

Cell Line Information: RB355

The RB355 cell line is a well-established human retinoblastoma cell line with comprehensive molecular characterization. Its ability to retain invasive phenotypes and metastatic potential in vivo makes it unique among available retinoblastoma cell lines and essential for aggressive subtype research.

Our Services

Alfa Cytology specializes in the development and validation of clinically relevant preclinical tumor models, offering comprehensive RB355 xenograft services that encompass model establishment, tumor monitoring, therapeutic intervention, and endpoint analysis. Our integrated approach combines rigorous quality control, standardized protocols, and customized study designs to ensure reliable, reproducible data that accelerates your retinoblastoma drug development pipeline from early-stage screening through translational validation.

Workflow of RB355 Xenograft Model Construction

The construction of the RB355 xenograft model follows a systematic, standardized workflow designed to ensure tumor engraftment consistency, reproducible growth kinetics, and reliable therapeutic response assessment. At Alfa Cytology, we adhere to an optimized, multi-step workflow to ensure maximum take rates and reproducible growth kinetics. The streamlined workflow involves:

1. Cell Line Authentication and Preparation: RB355 cells are authenticated via short tandem repeat (STR) profiling and RB1 mutational status verification. Cells are maintained in optimized culture conditions, harvested at logarithmic growth phase, and viability is confirmed to exceed 95% prior to implantation.
2. Host Animal Selection and Preparation: Immunodeficient recipient mice (e.g., SCID, NOD-SCID, or nude mice) are selected based on study requirements and acclimatized for a minimum of one week. Animals are screened for health status and randomly assigned to experimental groups.
3. Orthotopic or Subcutaneous Implantation: For orthotopic models, RB355 cells are injected into the subretinal space or vitreous cavity under microscopic guidance. For subcutaneous models, cells are implanted into the flank region. Cell density typically ranges from 1x10^6 to 5x10^6 cells per injection site, suspended in a 1:1 mixture of culture medium and Matrigel or PBS.
4. Tumor Establishment Monitoring: Tumor growth is monitored through palpation (subcutaneous) or non-invasive imaging modalities including bioluminescence imaging (BLI), optical coherence tomography (OCT), or fluorescence microscopy (orthotopic). Tumor volume is calculated using caliper measurements or imaging-based volumetric analysis.
5. Randomization and Treatment Initiation: Upon reaching a predetermined tumor volume (typically 100-200 mm^3 for subcutaneous models or established fluorescence signal for orthotopic models), animals are randomized into treatment and control cohorts. Baseline measurements are recorded prior to therapeutic intervention.
6. Therapeutic Intervention and Monitoring: Test compounds are administered according to predefined dosing schedules (route, frequency, and duration). Tumor growth, body weight, and general health status are monitored at regular intervals throughout the treatment period.
7. Endpoint Analysis and Sample Collection: At study termination, tumors are excised, weighed, and processed for downstream analyses including histopathology (H&E staining), immunohistochemistry, Western blot, flow cytometry, and molecular profiling. Metastatic dissemination to regional lymph nodes, liver, and brain is assessed as applicable.

Figure 2: Schematic workflow illustrating the derivation and construction of the RB355 Xenograft Model at Alfa Cytology.

Case Study-RB355 Xenograft Model Development

Alfa Cytology has successfully established and validated the RB355 xenograft model across multiple immunodeficient host platforms, demonstrating consistent tumor engraftment rates, predictable growth kinetics, and robust response to reference compounds. Our internal validation studies confirm that RB355 xenografts retain the molecular characteristics of the parental cell line, including RB1 mutation status and MYCN amplification, while exhibiting invasive behavior and therapeutic sensitivity profiles consistent with published literature. Detailed growth curves, pharmacokinetic data, and histopathological analyses are available upon request through our scientific team.

Why Choose Alfa Cytology?

Alfa Cytology delivers comprehensive, scientifically rigorous preclinical services tailored to accelerate retinoblastoma therapeutic development. Our RB355 xenograft model service is distinguished by the following core competencies:

• Extensive Experience: Extensive experience in pediatric ocular tumor model development with validated RB355 xenograft systems across multiple host strains.
• Comprehensive Molecular Characterization: Comprehensive molecular characterization including RB1 mutational analysis, MYCN amplification status, and STR authentication for every study.
• Flexible Study Designs: Flexible study designs accommodating subcutaneous, orthotopic, and metastatic model configurations with integrated imaging capabilities.
• Standardized Protocols: Standardized protocols ensuring reproducible tumor growth kinetics and statistically powered cohort designs for robust efficacy assessment.
• Integrated Downstream Analysis: Integrated downstream analysis services including histopathology, immunohistochemistry, flow cytometry, and molecular profiling from a single provider.
• Dedicated Project Management: Dedicated project management with regular progress updates, detailed study reports, and consultation throughout the engagement lifecycle.

Contact Us

Ready to advance your retinoblastoma therapeutic pipeline with a validated, clinically relevant preclinical model? Contact us today to discuss your specific research objectives, study design requirements, and timeline. Our scientific team is prepared to collaborate with you in developing a customized RB355 xenograft study that delivers actionable, high-quality data to support your drug development decisions. Please reach out to us today via our inquiry form or email to learn more about our RB355 Xenograft Model services.

For research use only. Not intended for any clinical use.