Development of a genetic sensor that eliminates p53 deficient cells

Area of Science:

• Molecular Biology
• Cancer Genetics
• Synthetic Biology

Background:

• The TP53 gene is critical for cellular genetic stability but is frequently mutated in cancer.
• Loss of TP53 function compromises cellular defense against genetic damage, contributing to tumorigenesis.
• Currently, TP53 is not essential for cell survival, presenting a therapeutic challenge.

Purpose of the Study:

• To engineer a system that renders TP53 essential for cell survival.
• To develop a method for specifically targeting cancer cells with TP53 loss-of-function.
• To explore novel strategies for cancer therapy by programming intrinsic cellular protection.

Main Methods:

• Development of a genetic p53 sensor linking p53 loss to HSV-TK expression.
• Utilizing the Herpes Simplex Virus-Thymidine Kinase (HSV-TK) system for drug sensitivity.
• Distinguishing between TP53 wild-type, knockout, and mutated cells using the sensor.
• In vitro and in vivo validation of the sensor's targeting capability.

Main Results:

• The genetic sensor successfully coupled the loss of p53 to increased HSV-TK expression.
• The system accurately differentiated TP53 knockout and mutated cells from wild-type cells.
• TP53 loss-of-function cells were selectively targeted with the HSV-TK prodrug Ganciclovir.
• Effective targeting was demonstrated in both in vitro and in vivo experimental models.

Conclusions:

• A novel genetic sensor enables programming TP53 as an essential gene.
• This approach allows for the specific targeting of cancer cells with TP53 mutations.
• The system offers a promising new avenue for developing targeted cancer therapies.
• This work advances the concept of cell-intrinsic transformation protection systems.