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Updated: Oct 27, 2025
Examination of Anatomical Features of Retinal Ganglion Cells Under N-methyl-D-aspartic Acid (NMDA)-induced Excitotoxicity
Published on: September 19, 2025
AUY922 induces retinal toxicity through attenuating TRPM1
Che-Hung Shen1,2, Chi-Che Hsieh3, Kuan-Ying Jiang3
1National Institute of Cancer Research, National Health Research Institutes, No. 367, Sheng-Li Rd., North District, Tainan, 70456, Taiwan. chshen@nhri.edu.tw.
Background:
Ocular adverse events are common dose-limiting toxicities in cancer patients treated with HSP90 inhibitors, such as AUY922; however, the pathology and molecular mechanisms that mediate AUY922-induced retinal toxicity remain undescribed.
Methods:
The impact of AUY922 on mouse retinas and cell lines was comprehensively investigated using isobaric tags for relative and absolute quantitation (iTRAQ)‑based proteomic profiling and pathway enrichment analysis, immunohistochemistry and immunofluorescence staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, MTT assay, colony formation assay, and western blot analysis. The effect of AUY922 on the Transient Receptor Potential cation channel subfamily M member 1 (TRPM1)-HSP90 chaperone complex was characterized by coimmunoprecipitation. TRPM1-regulated gene expression was analyzed by RNAseq analysis and gene set enrichment analysis (GSEA). The role of TRPM1 was assessed using both loss-of-function and gain-of-function approaches.
Results:
Here, we show that the treatment with AUY922 induced retinal damage and cell apoptosis, dysregulated the photoreceptor and retinal pigment epithelium (RPE) layers, and reduced TRPM1 expression. Proteomic profiling and functional annotation of differentially expressed proteins reveals that those related to stress responses, protein folding processes, regulation of apoptosis, cell cycle and growth, reactive oxygen species (ROS) response, cell junction assembly and adhesion regulation, and proton transmembrane transport were significantly enriched in AUY922-treated cells. We found that AUY922 triggered caspase-3-dependent cell apoptosis, increased ROS production and inhibited cell growth. We determined that TRPM1 is a bona fide HSP90 client and characterized that AUY922 may reduce TRPM1 expression by disrupting the CDC37-HSP90 chaperone complex. Additionally, GSEA revealed that TRPM1-regulated genes were associated with retinal morphogenesis in camera-type eyes and the JAK-STAT cascade. Finally, gain-of-function and loss-of-function analyses validated the finding that TRPM1 mediated the cell apoptosis, ROS production and growth inhibition induced by AUY922.
Conclusions:
Our study demonstrates the pathology of AUY922-induced retinal toxicity in vivo. TRPM1 is an HSP90 client, regulates photoreceptor morphology and function, and mediates AUY922-induced cytotoxicity.
Insights
Heat shock protein 90 (HSP90) inhibitor AUY922 causes retinal damage by reducing the expression of TRPM1, a key protein involved in photoreceptor function and cell survival. This study elucidates the molecular mechanisms underlying this toxicity.
Area of Science:
- Oncology
- Ophthalmology
- Molecular Biology
Background:
- Ocular adverse events are common dose-limiting toxicities in cancer patients treated with HSP90 inhibitors like AUY922.
- The specific pathology and molecular mechanisms of AUY922-induced retinal toxicity are not well understood.
Purpose of the Study:
- To investigate the pathological and molecular mechanisms of AUY922-induced retinal toxicity.
- To identify key molecular players involved in AUY922 retinal damage.
Main Methods:
- Proteomic profiling (iTRAQ) and pathway analysis were used to assess AUY922's impact on mouse retinas and cell lines.
- Immunohistochemistry, TUNEL assay, MTT assay, and western blot analysis were employed to evaluate retinal damage and apoptosis.
- Co-immunoprecipitation and RNAseq were used to characterize the interaction between TRPM1 and HSP90 and analyze TRPM1-regulated gene expression.
Main Results:
- AUY922 treatment induced retinal damage, apoptosis, and dysregulation of photoreceptor and RPE layers, with reduced TRPM1 expression.
- Proteomic analysis revealed enrichment of pathways related to stress responses, apoptosis, ROS production, and cell adhesion in AUY922-treated cells.
- TRPM1 was identified as an HSP90 client, and its reduced expression by AUY922 was linked to disruption of the CDC37-HSP90 chaperone complex, mediating cytotoxicity.
Conclusions:
- AUY922 induces retinal toxicity in vivo through mechanisms involving TRPM1.
- TRPM1 is an HSP90 client protein crucial for photoreceptor morphology and function.
- TRPM1 plays a mediating role in the cytotoxicity induced by AUY922, highlighting it as a potential therapeutic target or biomarker.
