Retinoblastoma is the most common intraocular
malignancy in children with poor prognosis. The progression of
retinoblastoma is dependent on a robust angiogenic response. Targeting both
retinoblastoma cells and angiogenesis may therefore provide an alternative therapeutic strategy in
retinoblastoma. Here, we demonstrated the inhibitory effects of
tigecycline, a FDA-approved
antibiotic, in
retinoblastoma and angiogenesis in vitro and in vivo. We showed that
tigecycline significantly inhibited growth and induced caspase-dependent apoptosis of multiple
retinoblastoma cell lines.
Tigecycline also effectively inhibited angiogenesis through suppressing capillary network formation, migration, proliferation and survival of human
retinal microvascular endothelial cell (HREC). Mechanistically,
tigecycline acts on both
retinoblastoma cells and HREC via inhibiting
mitochondrial protein translation, resulting in
mitochondrial dysfunction, energy crisis, and oxidative damage. Importantly, we demonstrated the in vivo efficacy of
tigecycline in inhibiting
retinoblastoma and angiogenesis, and inducing oxidative stress on xenograft mouse model. In addition,
ATP levels and growth rates were largely affected in
retinoblastoma ρ0 cells that lacked mitochondrial respiration. Our work provides systematic pre-clinical evidence for repurposing
tigecycline from its traditional use for
retinoblastoma treatment. Our work demonstrates the essential roles of mitochondrial metabolism in both
retinoblastoma and its angiogenesis.