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Published on: February 6, 2015
Quantitative evaluation and comparison of two prodrug-activating suicide gene therapies on oral squamous cell
Naining Xu1,2, Honglei Tian3, Chun Po Fung3
1Department of Oral and Maxillofacial Surgery, Stomatological Center, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center Shenzhen, China.
Abstract:
Prodrug-activating suicide gene therapy (PA suicide gene therapy for short) for cancer is to introduce cancer cells with suicide genes. The enzyme encoded by suicide gene is not toxic but is able to kill cancer cells by converting a non-toxic prodrug into a toxic compound. This approach is a promising cancer gene therapy that could reduce non-specific toxicity to normal tissue. However, there is no quantitative method to evaluate efficacy of suicide gene therapy in preclinical study. The aim of this study is to develop a new method to quantitatively evaluate and compare prodrug-activating suicide gene therapies. This study was carried out on an oral squamous cell carcinoma (OSCC) cell line CAL-27. Suicide genes were integrated into ROSA26 locus of CAL-27 by CRISPR-Cas9. CAL-27 cell lines stably expressing herpes simplex virus-thymidine kinase (TK) or yeast cytosine deaminase (CD) were used to evaluate and compare PA suicide gene therapies. The efficacies of PA suicide gene therapies were quantitatively evaluated from three aspects: effective prodrug concentration, prodrug treatment time, and bystander effect. This method also could be used for different types of suicide gene therapies and different types of cancer. When the prodrug concentration, treatment time, and rate of suicide gene-positive cells (related to bystander effect) are fixed, anti-cancer effects could be quantitatively measured. This information is important for suicide gene therapy preclinical development.
Insights
This study introduces a new quantitative method to evaluate prodrug-activating suicide gene therapy efficacy in preclinical cancer research. This approach helps standardize the assessment of cancer gene therapy effectiveness.
Area of Science:
- Oncology
- Gene Therapy
- Biotechnology
Background:
- Prodrug-activating suicide gene therapy (PA suicide gene therapy) offers a promising approach for cancer treatment by converting non-toxic prodrugs into toxic compounds within cancer cells.
- Current preclinical studies lack standardized quantitative methods to accurately assess the efficacy of PA suicide gene therapy.
- This limitation hinders the development and comparison of different PA suicide gene therapy strategies.
Purpose of the Study:
- To develop and validate a novel quantitative method for evaluating and comparing the efficacy of PA suicide gene therapies in preclinical cancer models.
- To establish a standardized approach for measuring key parameters influencing therapy success, including prodrug concentration, treatment duration, and bystander effects.
- To provide a robust tool for the preclinical development of PA suicide gene therapies.
Main Methods:
- CRISPR-Cas9 technology was employed to integrate suicide genes into the *ROSA26* locus of the CAL-27 oral squamous cell carcinoma (OSCC) cell line.
- Stable CAL-27 cell lines expressing either herpes simplex virus-thymidine kinase (TK) or yeast cytosine deaminase (CD) were established.
- Quantitative evaluation of PA suicide gene therapy efficacy was performed by analyzing effective prodrug concentration, prodrug treatment time, and bystander effect.
Main Results:
- The developed method allows for the quantitative measurement of anti-cancer effects when prodrug concentration, treatment time, and the rate of suicide gene-positive cells are standardized.
- The study successfully demonstrated the evaluation and comparison of PA suicide gene therapies using TK and CD suicide gene systems.
- The findings provide a foundation for reproducible and comparable preclinical assessments of PA suicide gene therapy.
Conclusions:
- A new quantitative method has been successfully developed for evaluating PA suicide gene therapy efficacy in preclinical settings.
- This method is adaptable for various suicide gene therapies and cancer types, facilitating standardized preclinical development.
- The established quantitative framework is crucial for advancing the clinical translation of effective suicide gene therapies.
