Development and tissue distribution assessment of a qPCR-based detection method for VGM-R02b in cynomolgus monkeys
10.3867/j.issn.1000-3002.2025.02.003
- VernacularTitle:基于qPCR的VGM-R02b定量检测方法建立及其在食蟹猴组织分布特征
- Author:
Caihong GAO
1
;
Xinyi REN
;
Wenjing LUO
;
Yufei ZHANG
;
Yuanguo CHENG
Author Information
1. 上海鼎岳生物技术有限公司,上海 201315;复旦大学生命科学学院,上海 200438
- Publication Type:Journal Article
- Keywords:
gene therapy;
quantitative real time polymerase chain reaction;
methodology;
valida-tion;
bioanalysis
- From:
Chinese Journal of Pharmacology and Toxicology
2025;39(2):100-108
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To develop a highly sensitive and specific quantitative real-time poly-merase chain reaction(qPCR)method for detecting the VGM-R02b(a gene therapy drug for glutaric acidemia type Ⅰ)gene in cynomolgus monkeys and analyze the biological distribution of VGM-R02b.METHODS A standard curve was constructed using the VGM-R02b standard plasmid[an adeno-associ-ated virus serotype 9(AAV9)capsid]on a qPCR platform.The detection method was optimized and validated for key parameters,including the quantitative range,accuracy,precision,dilution linearity,selectivity,specificity,stability,and parallelism.The established method was used to determine the target gene of VGM-R02b in the blood,brain,stomach,heart,liver,spleen,lung,kidney,thymus,and duodenum of cynomolgus monkeys on day 29(D29)and D92 after a single,unilateral intraventricular injection of VGM-R02b.The biodistribution of VGM-R02b in cynomolgus monkeys was analyzed.RESULTS A qPCR method for quantifying the VGM-R02b target gene in cynomolgus monkeys was established and validated.The standard curve demonstrated a quantitative range of 5.00×109 to 5.00×10^1 copies·μg-1 DNA,with excellent precision,accuracy,dilution linearity,selectivity,and specificity.The target gene in tissues remained stable after being stored at room temperature for 4 h,-15 to-25℃ for 9 d,-60 to-80℃ for 90 d and after five freeze-thaw cycles.Similarly,the target gene in whole blood remained stable after being stored at room temperature for 4 h,-15 to-25℃ for 93 d,-60 to-80℃ for 93 d and after five freeze-thaw cycles.Extracted nucleic acid samples also showed stability after being stored at room temperature for 4.25 h,2-8℃ for 24.16 h,-60 to-80℃ for 109 d and after five freeze-thaw cycles.The method was also applied to evaluate the biological distribution of the target gene in cynomolgus monkeys.In the control group,the target gene was undetectable on D29 and D92 post-administration,but in the drug administration group,the target gene was distributed across the tissues,with higher concen-trations observed in the brain,liver,spleen,and spinal cord,and there were no significant differences in the target gene content across the tissues between D29 and D92.CONCLUSION The established qPCR method is robust,reliable and suitable for determination of VGM-R02b target gene in cynomolgus monkeys.
