Targeting Telomerase Cajal Body Protein 1 (TCAB1) as a Novel Strategy for Discovering Potent Telomerase Inhibitors...

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Telomerase is crucial for tumor cell proliferation and a key anticancer target.
• Developing effective telomerase inhibitors is challenging due to telomerase's complex structure.

Purpose of the Study:

• To identify a novel strategy for telomerase inhibition by targeting TCAB1 and blocking telomerase assembly.
• To discover and characterize a potent small molecule inhibitor of telomerase assembly.

Main Methods:

• Screening for compounds that inhibit TCAB1 function.
• Biochemical assays to determine inhibitor potency (IC50) and mechanism of action.
• In vivo studies to evaluate therapeutic efficacy and combination potential with immunotherapy.

Main Results:

• Identified (R)-1b, a potent TCAB1-targeting compound with IC50 = 2.04 nM, which inhibits telomerase assembly by disrupting the TCAB1-hTR interaction.
• Characterized the binding pocket and critical residues of (R)-1b for future drug design.
• Demonstrated that (R)-1b enhances tumor response to PD-L1 inhibitors, leading to tumor regression in vivo.

Conclusions:

• Targeting TCAB1 to block telomerase assembly represents a novel and effective strategy for telomerase inhibition.
• (R)-1b is a promising lead compound for developing new cancer therapeutics, particularly in combination with immunotherapy.