Targeting Protein Translation by Rocaglamide and Didesmethylrocaglamide to Treat MPNST and Other Sarcomas

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Malignant peripheral nerve sheath tumors (MPNST) often overexpress eukaryotic initiation factor 4F (eIF4F) components.
• Silvestrol, an eIF4A inhibitor, effectively suppresses MPNST growth but has poor drug-like properties, including low oral bioavailability and toxicity.

Purpose of the Study:

• To evaluate silvestrol analogs, specifically rocaglamides lacking the dioxanyl ring, for improved therapeutic potential against MPNST.
• To compare the efficacy and pharmacokinetic properties of rocaglamide (Roc) and didesmethylrocaglamide (DDR) with silvestrol.

Main Methods:

• Structure-activity relationship analysis of ten silvestrol-related rocaglates.
• Assessment of cell cycle arrest, apoptosis induction, and DNA damage response markers (γH2A.X).
• Pharmacokinetic studies, in vivo efficacy testing in an MPNST mouse model, and evaluation in other sarcoma models.

Main Results:

• Didesmethylrocagamide (DDR) and rocaglamide (Roc) exhibited growth-inhibitory activity comparable to silvestrol.
• Roc demonstrated 50% oral bioavailability and potent antitumor effects in vivo without inducing pulmonary toxicity.
• Roc and DDR suppressed MPNST and other sarcoma growth, reducing oncogenic kinases like IGF-1R and inducing apoptosis.

Conclusions:

• Didesmethylrocagamide (DDR) and rocaglamide (Roc) possess improved drug-like properties compared to silvestrol.
• Roc shows significant potential as a viable therapeutic agent for MPNST and other sarcomas due to its efficacy and favorable pharmacokinetics.