Antitumor effects of β-elemene via targeting the phosphorylation of insulin receptor

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Ewing sarcoma family tumors (ESFTs) are aggressive, metastatic cancers with limited treatment options.
• Insulin-like growth factor 1 receptor (IGF1R) blockade is a targeted therapy for ESFTs, but drug resistance and recurrence occur due to activated insulin receptor (IR) signaling.
• Understanding resistance mechanisms is crucial for developing effective ESFT therapies.

Purpose of the Study:

• To investigate the anti-cancer effects of beta-elemene on ESFT cells and its underlying mechanisms.
• To evaluate beta-elemene's potential to overcome resistance to IGF1R inhibitors.
• To determine if beta-elemene specifically targets IR signaling in tumor cells.

Main Methods:

• Assessed beta-elemene's effect on ESFT cell proliferation, noting caspase involvement.
• Investigated beta-elemene's impact on IR signaling, PI3K, and mTOR pathways, both in vitro and in vivo.
• Utilized ESFT xenograft models to evaluate therapeutic efficacy and molecular targets.

Main Results:

• Beta-elemene suppressed ESFT cell proliferation and mTOR activation, with effects modulated by caspase inhibition.
• Combined beta-elemene with IGF1R inhibitors enhanced anti-proliferative effects and suppressed PI3K phosphorylation.
• Beta-elemene specifically inhibited insulin-driven IR phosphorylation and downstream signaling in tumor cells, with lower toxicity to normal hepatocytes.
• In vivo studies showed beta-elemene inhibited ESFT xenograft growth and repressed IR and S6 ribosomal protein phosphorylation.

Conclusions:

• Beta-elemene targets IR phosphorylation to specifically inhibit tumor cell proliferation.
• Beta-elemene enhances the efficacy of IGF1R inhibitors in ESFTs.
• Beta-elemene represents a potential therapeutic agent for ESFTs, particularly those resistant to IGF1R blockade, and for tumors with hyperactivated IR signaling.