Journal: International Journal of Molecular Sciences
Article Title: Human Retinal Organoid Modeling Defines Developmental Window and Therapeutic Vulnerabilities in MYCN-Amplified Retinoblastoma
doi: 10.3390/ijms26178675
Figure Lengend Snippet: Transcriptomic profiling reveals distinct molecular signatures and oncogenic pathways in MYCN-overexpressing retinoblastoma organoids (MYCN O/E -RBOs) and similarity to patient-derived tumors. ( A ) Principal component analysis (PCA) comparing transcriptomic profiles among MYCN-overexpressing retinal organoids (MYCN O/E -RBOs), MYCN O/E -RBOs derived cell lines (MYCN O/E -cells), normal retinal organoids (nROs), and Y79 retinoblastoma cells (RB1 -/- /MYCN A ). MYCN O/E samples formed distinct clusters separate from nROs and Y79, indicating unique transcriptional programs driven by MYCN overexpression. ( B ) Volcano plot showing significantly upregulated (1533 genes, yellow) and downregulated (892 genes, blue) differentially expressed genes (DEGs) between MYCN O/E -RBOs and nROs (adjusted p < 0.05, |Log2FC| > 1). ( C ) Gene Ontology (GO) enrichment analysis highlighting significantly downregulated biological processes (photoreceptor differentiation, phototransduction, sensory perception of light stimulus) and significantly upregulated biological processes (cell cycle phase transitions, mitotic cell cycle regulation, DNA repair pathways) in MYCN O/E -RBOs compared to nROs. ( D , E ) Gene Set Enrichment Analysis (GSEA) demonstrated significant enrichment of MYC target genes, unfolded protein response, mTORC1 signaling, and hypoxia-related pathways in MYCN O/E -RBOs ( D ) and independent MYCN-amplified patient tumor datasets ( E ). Concordant pathway activation between MYCN O/E -RBOs and patient-derived tumors supports the clinical relevance of this organoid model. ( F ) Schematic summary highlighting key molecular signatures identified from transcriptomic analyses. MYCN overexpression in retinoblastoma drives increased expression of MYC target genes, enhanced mTORC1 signaling, activation of cell-cycle-related and neural/retinal ganglion cell (RGC)-related genes, and downregulation of photoreceptor differentiation-related genes, collectively promoting a proliferative, undifferentiated retinal progenitor-like phenotype.
Article Snippet: Retinoblastoma cell lines (Y79 and WERI-Rb1; ATCC, Manassas, VA, USA) were grown in suspension cultures in RPMI-1640 medium (GibcoTM, cat. no. A1049101, Carlsbad, CA, USA) supplemented with 20% fetal bovine serum (FBS; Rd Tech, cat. no. A1500m, Namyangju, Republic of Korea) and 1% penicillin/streptomycin (Thermo Fisher Scientific, cat. no. 15140-122, Waltham, MA, USA).
Techniques: Derivative Assay, Over Expression, Amplification, Activation Assay, Expressing