ERK-dependent suicide gene therapy for selective targeting of RTK/RAS-driven cancers

Area of Science:

• Oncology
• Molecular Biology
• Gene Therapy

Background:

• Suicide gene therapy offers selective cancer cell targeting through viral tropism or transcriptional regulation.
• Extracellular signal-regulated kinase (ERK) is frequently overactive in cancers due to receptor tyrosine kinases or RAS mutations.
• Current strategies rely on transcriptional control for selectivity, which can limit therapeutic gene expression.

Purpose of the Study:

• To develop a novel suicide gene therapy approach that utilizes ERK pathway activity for enhanced tumor selectivity.
• To engineer a chimeric protein whose stability is regulated by ERK, enabling high-level expression from constitutive promoters.

Main Methods:

• Designed a suicide gene therapy system where the therapeutic gene product is phosphorylated and stabilized by ERK.
• Utilized herpes simplex virus thymidine kinase or yeast cytosine deaminase as gene products.
• Validated the approach through in vitro and in vivo experiments.

Main Results:

• Demonstrated that ERK activity stabilizes the therapeutic protein, leading to selective expression in cancer cells.
• Showcased the potential for high-copy expression using constitutive viral promoters.
• Confirmed tumor selectivity in contexts of elevated ERK signaling.

Conclusions:

• The developed suicide gene therapy effectively targets cancer cells by exploiting the ERK pathway's role in protein stabilization.
• This strategy converts a cancer survival pathway into a vulnerability, offering a promising new therapeutic avenue.
• The approach holds potential for treating various cancers with elevated ERK activity.