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ABSTRACT: Purpose
This study aimed to investigate theranostic strategies in colorectal and skin cancer based on fragments of cetuximab, an anti-EGFR mAb, labeled with radionuclide with imaging and therapeutic properties, 111In and 177Lu, respectively.Methods
We designed F(ab')2-fragments of cetuximab radiolabeled with 111In and 177Lu. 111In-F(ab')2-cetuximab tumor targeting and biodistribution were evaluated by SPECT in BalbC nude mice bearing primary colorectal tumors. The efficacy of 111In-F(ab')2-cetuximab to assess therapy efficacy was performed on BalbC nude mice bearing colorectal tumors receiving 17-DMAG, an HSP90 inhibitor. Therapeutic efficacy of the radioimmunotherapy based on 177Lu-F(ab')2-cetuximab was evaluated in SWISS nude mice bearing A431 tumors.Results
Radiolabeling procedure did not change F(ab')2-cetuximab and cetuximab immunoreactivity nor affinity for HER1 in vitro. 111In-DOTAGA-F(ab')2-cetuximab exhibited a peak tumor uptake at 24 h post-injection and showed a high tumor specificity determined by a significant decrease in tumor uptake after the addition of an excess of unlabeled-DOTAGA-F(ab')2-cetuximab. SPECT imaging of 111In-DOTAGA-F(ab')2-cetuximab allowed an accurate evaluation of tumor growth and successfully predicted the decrease in tumor growth induced by 17-DMAG. Finally, 177Lu-DOTAGA-F(ab')2-cetuximab radioimmunotherapy showed a significant reduction of tumor growth at 4 and 8 MBq doses.Conclusions
111In-DOTAGA-F(ab')2-cetuximab is a reliable and stable tool for specific in vivo tumor targeting and is suitable for therapy efficacy assessment. 177Lu-DOTAGA-F(ab')2-cetuximab is an interesting theranostic tool allowing therapy and imaging.
SUBMITTER: Bellaye PS
PROVIDER: S-EPMC6223717 | biostudies-literature | 2018 Dec
REPOSITORIES: biostudies-literature
Bellaye P-S PS Moreau M M Raguin O O Oudot A A Bernhard C C Vrigneaud J-M JM Dumont L L Vandroux D D Denat F F Cochet A A Brunotte F F Collin B B
Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico 20180517 12
<h4>Purpose</h4>This study aimed to investigate theranostic strategies in colorectal and skin cancer based on fragments of cetuximab, an anti-EGFR mAb, labeled with radionuclide with imaging and therapeutic properties, <sup>111</sup>In and <sup>177</sup>Lu, respectively.<h4>Methods</h4>We designed F(ab')<sub>2</sub>-fragments of cetuximab radiolabeled with <sup>111</sup>In and <sup>177</sup>Lu. <sup>111</sup>In-F(ab')<sub>2</sub>-cetuximab tumor targeting and biodistribution were evaluated by SP ...[more]