Therapeutic suppression of translation initiation factor eIF4E expression reduces tumor growth without toxicity

Area of Science:

• Oncology
• Molecular Biology
• Drug Development

Background:

• Elevated eukaryotic translation initiation factor 4E (eIF4E) expression is common in cancers, driving tumor growth and angiogenesis.
• eIF4E promotes the translation of key malignancy-associated proteins like VEGF and cyclin D1, making it a potential therapeutic target.
• No eIF4E-specific therapies have been successfully developed to date.

Purpose of the Study:

• To develop and evaluate eIF4E-specific antisense oligonucleotides (ASOs) for systemic anticancer therapy.
• To assess the efficacy and safety of eIF4E-targeted ASOs in preclinical cancer models.

Main Methods:

• Designed and synthesized eIF4E-specific ASOs with enhanced tissue stability and nuclease resistance.
• Tested ASO activity in cultured mammalian cells, assessing mRNA/protein levels and cellular processes.
• Administered ASOs intravenously in human tumor xenograft and mouse models to evaluate in vivo efficacy and toxicity.

Main Results:

• ASOs specifically degraded eIF4E mRNA in cultured cells, reducing eIF4E-regulated proteins and inhibiting angiogenesis.
• Intravenous ASO administration significantly reduced eIF4E expression in tumor xenografts, suppressing tumor growth.
• eIF4E reduction in normal mouse tissues by 80% did not cause adverse effects on body weight, organ weight, or liver enzymes.

Conclusions:

• eIF4E-specific ASOs are a promising therapeutic strategy for cancer treatment.
• Cancers may exhibit greater susceptibility to eIF4E inhibition than normal tissues, suggesting a favorable therapeutic window.
• These findings support the initiation of clinical trials for eIF4E-specific ASO cancer therapy.