Comprehensive analysis of disulfidoptosis-related genes reveals molecular heterogeneity and key regulators in retinoblastoma progression.

Background: Disulfidoptosis, a newly recognised form of cell death, has been studied in many cancers but not in retinoblastoma. Therefore, this study aimed to investigate the role of disulfidoptosis-related genes (DRGs) in retinoblastoma.

Methods: Three retinoblastoma datasets (GSE208143, GSE97508, and GSE24673) were obtained from the Gene Expression Omnibus database. Differentially expressed DRGs (DE-DRGs) in retinoblastoma were identified, and key genes were screened using machine learning algorithms. Consensus cluster analysis was applied to identify the disulfidoptosis-based molecular subtypes. The pathways and immune characteristics of the subtypes were examined via gene set variation analysis, single-sample gene set enrichment analysis, and ESTIMATE. The expression of key genes was validated in retinoblastoma cells, and their roles were explored through functional experiments.

Results: Compared with controls, the disulfidoptosis score was significantly lower (P<0.05) in retinoblastoma, and eight DE-DRGs were identified, suggesting the potential involvement disulfidoptosis in retinoblastoma. Consensus clustering revealed two molecular subtypes (C1 and C2). The C2 subtype exhibited multiple activated oncogenic pathways associated with tumourigenesis, lower infiltration levels of immune cells, lower immune and stromal scores, and reduced immune checkpoint expression. Least absolute shrinkage and selection operator and support vector machine-recursive feature elimination algorithms identified two key down-regulated genes-EPAS1 and SLC7A11-in retinoblastoma. The expression of EPAS1 and SLC7A11 was significantly correlated with oxidative phosphorylation and immune cell infiltration levels. EPAS1 overexpression significantly inhibited the viability, migration, and invasion of retinoblastoma cells and induced their apoptosis (P<0.05). Furthermore, EPAS1 overexpression significantly increased the relative nicotinamide adenine dinucleotide phosphate (NADP)+/reduced NADP (NADPH) ratio in retinoblastoma cells (P<0.05).

Conclusions: This study highlights the involvement of DRGs in retinoblastoma progression and molecular subtype heterogeneity. EPAS1 and SLC7A11 may serve as key targets for the diagnosis and treatment of retinoblastoma.