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Updated: Apr 14, 2026
Radionuclide-fluorescence Reporter Gene Imaging to Track Tumor Progression in Rodent Tumor Models
Published on: March 13, 2018
Tumor-specific expression and detection of a CEST reporter gene
Il Minn1, Amnon Bar-Shir1,2, Keerthi Yarlagadda1
1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Purpose:
To develop an imaging tool that enables the detection of malignant tissue with enhanced specificity using the exquisite spatial resolution of MRI.
Methods:
Two mammalian gene expression vectors were created for the expression of the lysine-rich protein (LRP) under the control of the cytomegalovirus (CMV) promoter and the progression elevated gene-3 promoter (PEG-3 promoter) for constitutive and tumor-specific expression of LRP, respectively. Using those vectors, stable cell lines of rat 9L glioma, 9L(CMV-LRP) and 9L(PEG-LRP) , were established and tested for CEST contrast in vitro and in vivo.
Results:
9L(PEG-LRP) cells showed increased CEST contrast compared with 9L cells in vitro. Both 9L(CMV-LRP) and 9L(PEG-LRP) cells were capable of generating tumors in the brains of mice, with a similar growth rate to tumors derived from wild-type 9L cells. An increase in CEST contrast was clearly visible in tumors derived from both 9L(CMV-LRP) and 9L(PEG-LRP) cells at 3.4 ppm.
Conclusion:
The PEG-3 promoter:LRP system can be used as a cancer-specific, molecular-genetic imaging reporter system in vivo. Because of the ubiquity of MR imaging in clinical practice, sensors of this class can be used to translate molecular-genetic imaging rapidly.
