Cancer therapy with a CRISPR-assisted telomerase-activating gene expression system

Area of Science:

• Oncology
• Molecular Biology
• Gene Therapy

Background:

• Cancer arises from genomic and epigenomic alterations, presenting complex treatment challenges.
• Telomerase, active in most cancers but not normal cells, is a key therapeutic target.
• Previous telomerase inhibitors failed due to side effects, necessitating alternative strategies.

Purpose of the Study:

• To develop a novel cancer gene therapy utilizing cancer-specific telomerase activity.
• To engineer a system that selectively targets and eliminates cancer cells.
• To evaluate the in vitro and in vivo safety and efficacy of this new approach.

Main Methods:

• Development of the telomerase-activating gene expression (Tage) system, incorporating a telomerase-recognizable DNA sequence and CRISPR-Cas9 components.
• In vitro testing against a panel of human and mouse cancer cell lines and normal cells.
• In vivo studies in mice using adeno-associated virus (AAV) vectors for systemic delivery.

Main Results:

• The Tage system demonstrated potent cancer cell killing across multiple cancer types (HepG2, HeLa, PANC-1, MDA-MB-453, A549, HT-29, SKOV-3, Hepa1-6, RAW264.7).
• Normal cells (MRC-5, HL7702, BMSC) remained unaffected, indicating high specificity.
• In vivo administration via AAV vectors led to significant and specific tumor cell reduction in mice without observable toxicity or side effects.

Conclusions:

• The Tage system represents a novel and effective strategy for cancer gene therapy by leveraging cancer-specific telomerase activation.
• This approach offers a safe and targeted method for eliminating cancer cells both in vitro and in vivo.
• The use of AAV vectors facilitates effective systemic delivery and therapeutic application.