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Updated: Aug 21, 2026
Reconstruct Human Retinoblastoma In Vitro
Published on: October 11, 2022
Targeting MYCN Degradation by HLB-0532259 Induces Senescence in Retinoblastoma
Junjie Tang1, Zhihui Zhang1, Jianjie Lv1
1State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
Purpose:
Amplification of MYCN is a primary driver of aggressive retinoblastoma (RB), yet it remains a challenging therapeutic target. This study aimed to evaluate the therapeutic potential of the PROTAC molecule HLB-0532259 in degrading MYCN and suppressing RB growth.
Methods:
Y79 and WERI-Rb1 RB cell lines were treated with HLB-0532259, and MYCN protein degradation, cell viability, and time-dependent transcriptional changes were assessed by Western blotting, cell viability assays, RNA-seq, and proteomics. The therapeutic potential was further validated in an orthotopic Y79 xenograft mouse model through intravitreal administration, with tumor burden evaluated by histology and immunohistochemistry.
Results:
HLB-0532259 induced dose-dependent degradation of MYCN in both cell lines, with Y79 cells showing higher sensitivity. Transcriptomic and proteomic analyses revealed rapid activation of the p53-p21 pathway, downregulation of DNA repair and epigenetic regulators, and accumulation of DNA damage. Proteomic profiling confirmed upregulation of senescence-associated secretory phenotype factors and downregulation of MYCN-dependent effectors, including HMGA1 and TRAF6. In orthotopic xenografts, intravitreal administration of HLB-0532259 reduced intraocular tumor burden, decreased Ki-67 and MYCN-positive cells, and activated p53, p21, and NF-κB signaling.
Conclusions:
Targeted MYCN degradation by HLB-0532259 effectively inhibits RB growth and induces a DNA damage-associated senescence program, highlighting targeted MYCN degradation as a promising therapeutic strategy for MYCN-driven RB.
Insights
Targeted MYCN degradation using HLB-0532259 effectively inhibits retinoblastoma (RB) growth. This PROTAC molecule induces DNA damage and senescence, offering a promising therapeutic strategy for MYCN-driven RB.
Area of Science:
- Oncology
- Molecular Biology
- Drug Discovery
Background:
- MYCN amplification drives aggressive retinoblastoma (RB), presenting a significant therapeutic challenge.
- Developing targeted therapies for MYCN-driven RB is crucial for improving patient outcomes.
Purpose of the Study:
- To evaluate the therapeutic potential of the PROTAC molecule HLB-0532259.
- To assess HLB-0532259's efficacy in degrading MYCN and suppressing RB growth.
Main Methods:
- RB cell lines (Y79, WERI-Rb1) were treated with HLB-0532259.
- MYCN degradation, cell viability, and transcriptional changes were analyzed using Western blotting, cell viability assays, RNA-seq, and proteomics.
- Therapeutic potential was validated in an orthotopic Y79 xenograft mouse model via intravitreal administration.
Main Results:
- HLB-0532259 induced dose-dependent MYCN degradation in RB cells, with Y79 cells showing higher sensitivity.
- Transcriptomic and proteomic analyses revealed p53-p21 pathway activation, DNA repair downregulation, and DNA damage accumulation.
- Intravitreal HLB-0532259 administration reduced tumor burden, decreased MYCN-positive cells, and activated key signaling pathways in vivo.
Conclusions:
- Targeted MYCN degradation by HLB-0532259 effectively inhibits RB growth.
- HLB-0532259 induces a DNA damage-associated senescence program in RB.
- Targeted MYCN degradation represents a promising therapeutic strategy for MYCN-driven retinoblastoma.
