Abstract
Liver metastases present a serious problem in the therapy of advanced colorectal cancer (CRC), as more than 20% of patients have distant metastases at the time of diagnosis with less than 5% being cured. Consequently, new therapeutic approaches are of major need together with high-resolution imaging methods that allow highly specific detection of small metastases. The unique combination of reporter and therapy gene function of the sodium iodide symporter (NIS) may represent a promising theranostic strategy for CRC liver metastases allowing non-invasive imaging of functional NIS expression and therapeutic application of I-131. For targeted NIS gene transfer polymers containing linear polyethylenimine (LPEI), polyethylene glycol (PEG) and the epidermal growth factor receptor (EGFR)specific ligand GE11 were complexed with human NIS DNA (LPEI-PEG-GE11/NIS). Tumor specificity and transduction efficiency were examined in high EGFR-expressing LS174T metastases by non-invasive imaging using F-18-tetrafluoroborate (F-18-TFB) as novel NIS PET tracer. Mice that were injected with LPEI-PEG-GE11/NIS 48 h before F-18-TFB application showed high tumoral levels (4.8 +/- 0.6% of injected dose) of NIS-mediated radionuclide uptake in comparison to low levels detected in mice that received untargeted control polyplexes. Three cycles of intravenous injection of EGFR-targeted NIS polyplexes followed by therapeutic application of 55.5 MBq I-131 resulted in marked delay in metastases spread, which was associated with improved animal survival. In conclusion, these preclinical data confirm the enormous potential of EGFR-targeted synthetic polymers for systemic NIS gene delivery in an advanced multifocal CRC liver metastases model and open the exciting prospect of NIS-mediated radionuclide therapy in metastatic disease.
Item Type: | Journal article |
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Faculties: | Medicine Chemistry and Pharmacy > Department of Pharmacy |
Subjects: | 600 Technology > 610 Medicine and health 500 Science > 540 Chemistry |
ISSN: | 1949-2553 |
Language: | English |
Item ID: | 49981 |
Date Deposited: | 14. Jun 2018, 09:42 |
Last Modified: | 04. Nov 2020, 13:27 |