Exploring bat-inspired cyclic tryptophan diketopiperazines as ABCB1 Inhibitors

Area of Science:

• Biochemistry
• Pharmacology
• Cancer Biology

Background:

• Chemotherapy resistance, driven by ATP binding cassette subfamily B member 1 (ABCB1) transporter overexpression, is a significant cause of cancer mortality.
• Existing ABCB1 inhibitors have shown limited clinical success, necessitating novel therapeutic strategies.

Purpose of the Study:

• To develop a new class of ABCB1 inhibitors based on tryptophan, inspired by bats' low cancer incidence and high ABCB1 expression.
• To identify and synthesize a potent ABCB1 inhibitor capable of restoring chemotherapy sensitivity in resistant cancer cells.

Main Methods:

• Molecular simulations were employed to study ABCB1-substrate interactions.
• A benzylated Cyclo-tryptophan derivative (C3N-Dbn-Trp2) was synthesized.
• The efficacy of C3N-Dbn-Trp2 was evaluated in drug-resistant human cancer cells.

Main Results:

• C3N-Dbn-Trp2 demonstrated potent inhibition of ABCB1 activity, comparable or superior to verapamil.
• The compound restored sensitivity to chemotherapy in drug-resistant cancer cells.
• C3N-Dbn-Trp2 exhibited no adverse effects on cancer cell proliferation.

Conclusions:

• The novel tryptophan-derived compound C3N-Dbn-Trp2 is a promising lead for developing effective ABCB1 inhibitors.
• This approach offers a potential strategy to overcome chemotherapy resistance in various cancers.
• Further development of C3N-Dbn-Trp2 could lead to improved cancer treatment outcomes.