Potent Synergistic Effect on C-Myc-Driven Colorectal Cancers Using a Novel Indole-Substituted Quinoline with a Plk1...

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Colorectal cancer (CRC) remains challenging to treat, necessitating novel therapeutic strategies.
• Combinations of small-molecule inhibitors and immunotherapies offer potential for managing intractable CRC.
• Wnt signaling and oncogenic c-Myc are key drivers in CRC development.

Purpose of the Study:

• To identify novel small-molecule inhibitors for colorectal cancer.
• To investigate the mechanisms of action for indole-substituted quinolines (ISQs).
• To evaluate the therapeutic potential of ISQ-1 in combination with other agents.

Main Methods:

• High-throughput screening of colorectal cancer cell lines.
• In vitro assays to assess Wnt signaling inhibition and AMPK activation.
• Seahorse assays to measure mitochondrial respiration (oxygen consumption rate).
• In vitro and in vivo studies evaluating drug synergy and tumor remission.

Main Results:

• ISQ-1 identified as a potent in vitro inhibitor of multiple CRC cell lines.
• ISQ-1 inhibited Wnt signaling and activated adenosine monophosphate kinase (AMPK).
• ISQ-1 inhibited Complex I of the mitochondrial electron transport chain (ETC).
• ISQ-1 synergistically depleted c-Myc and induced tumor remission in vivo when combined with a Plk1 inhibitor.

Conclusions:

• ISQ-1 demonstrates dual activity against Wnt signaling and mitochondrial respiration in CRC cells.
• Combination therapy of ISQ-1 with a Plk1 inhibitor shows significant potential for treating c-Myc-driven cancers.
• Targeting the ETC and Plk-1 represents a promising strategy for novel CRC treatments.