Discovery of small-sized tris-aryl imidazoles as bifunctional ligands for c-Myc and KRAS G-quadruplexes

Area of Science:

• Oncology
• Medicinal Chemistry
• Molecular Biology

Background:

• Overlapping c-Myc and KRAS pathways promote tumor growth.
• G-quadruplexes (G4s) in c-Myc and KRAS promoters offer therapeutic targets.
• Dual-targeting ligands for G4s are an emerging area in drug discovery.

Purpose of the Study:

• To design and synthesize novel tris-aryl imidazole analogs targeting c-Myc and KRAS G4s.
• To evaluate the antitumor efficacy and mechanism of action of lead compounds.
• To assess the in vivo efficacy and immunomodulatory effects of the most promising compound.

Main Methods:

• Synthesis of tris-aryl imidazole analogs.
• G-quadruplex binding assays to confirm target engagement.
• In vitro studies in MDA-MB-231 breast cancer cells to assess cell death pathways (ferroptosis, apoptosis, ICD).
• In vivo studies in BALB/c mice to evaluate tumor growth inhibition and immune cell modulation.

Main Results:

• HZ-1 identified as a promising G4 ligand with selectivity for parallel G4s.
• HZ-1 induced ferroptosis, apoptosis, and immunogenic cell death (ICD) in breast cancer cells via the NRF2-XCT-GPX4 pathway.
• HZ-1 demonstrated potent in vivo tumor growth inhibition in mice with no significant adverse effects.
• HZ-1 promoted CD8+ cytotoxic T lymphocytes and CD4+ helper T lymphocytes in spleen and tumor tissues.

Conclusions:

• Tris-aryl imidazole analogs, exemplified by HZ-1, represent a novel class of dual-targeting G4 ligands.
• HZ-1 exhibits significant anticancer activity through multiple cell death pathways and immune system activation.
• This study establishes a new concept for anticancer strategies based on targeting multiple G4s.