This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Original research
A Pretargeted Imaging Strategy for EGFR Positive Colorectal Carcinoma via the Modulation of Tz-radioligand Pharmacokinetics
Hongcheng Shi
Fudan University
Corresponding Author
ORCiD: https://orcid.org/0000-0003-1922-1359
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Objective: Previously, we successfully developed a pretargeted imaging strategy (Atezolizumab-TCO/99mTc-HYNIC-PEG11-Tz), which is a powerful tool for evaluating Programmed Cell Death Ligand-1 (PD-L1) expression in xenograft mice tumor models. However, the surplus unclicked 99mTc-HYNIC-PEG11-Tz is cleared somewhat sluggishly through the intestines. This is certainly not an ideal situation for imaging for colorectal cancer (CRC). In order to shift the excretion of the Tz-radioligand to the renal system, we have sought to develop a novel Tz-radioligand by adding a polypeptide linker between HYNIC and PEG11.
Methods: Pretargeted molecular probes 99mTc-HYNIC-Polypeptide-PEG11-Tz and Cetuximab-TCO were synthesized. The stability of 99mTc-HYNIC-Polypeptide-PEG11-Tz was evaluated in vitro, and its blood pharmacokinetic test was performed in vivo. In vitro ligation reactivity of 99mTc-HYNIC-Polypeptide-PEG11-Tz towards Cetuximab-TCO was tested. The biodistribution and imaging of 99mTc-HYNIC-Polypeptide-PEG11-Tz was performed to observe the clear pathway of this novel Tz-radioligand. Pretargeted biodistribution of three different accumulation intervals was performed to determine the optimal pretargeted interval time. Comparison of pretargeted (Cetuximab-TCO 48 h/99mTc-HYNIC-PEG11-Tz 6 h) and (Cetuximab-TCO 48 h/99mTc-HYNIC-Polypeptide-PEG11-Tz 6 h) imagings was performed to show the effect of the two Tz-radioligands with different excretion pathway on tumor imaging.
Results: 99mTc-HYNIC-Polypeptide-PEG11-Tz showed favorable in vitro stability and rapid blood clearance in mice. SEC-HPLC revealed almost complete reaction between Cetuximab-TCO and 99mTc-HYNIC-Polypeptide-PEG11-Tz in vitro, with the 8:1 Tz-to-mAb reaction providing a conversion yield of 87.83 ± 3.27%. The biodistribution and imaging of 99mTc-HYNIC-Polypeptide-PEG11-Tz demonstrated that the Tz-radioligand was cleared through kidneys. After allowing 24 h, 48 h and 72 h for accumulation of Cetuximab-TCO in HCT116 tumor, pretargeted biodistribution revealed the tumor-to-blood ratio was 0.83 ± 0.13, 1.40 ± 0.31, and 1.15 ± 0.21, respectively. Both pretargeted (Cetuximab-TCO 48 h/99mTc-HYNIC-PEG11-Tz 6 h) and (Cetuximab-TCO 48 h/99mTc-HYNIC-Polypeptide-PEG11-Tz 6 h) imaging delineated the HCT116 tumor clearly. However, pretargeted imaging strategy using Cetuximab-TCO/99mTc-HYNIC-Polypeptide-PEG11-Tz could be used for diagnosing CRC since the surplus unclicked 99mTc-HYNIC-Polypeptide-PEG11-Tz is cleared through urinary system and produces low abdominal uptake background.
Conclusion: We developed a novel pretargeted imaging strategy (Cetuximab-TCO/99mTc-HYNIC-Polypeptide-PEG11-Tz) for imaging CRC since the surplus unclicked 99mTc-HYNIC-Polypeptide-PEG11-Tz produces low abdominal uptake background, which broadens the application scope of pretargeted imaging strategy.
Keywords
Colorectal cancer, EGFR, Cetuximab, Pretargeted imaging, Click chemistry
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
This is a list of supplementary files associated with this preprint. Click to download.
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 2
Posted 14 Apr, 2020
No community comments so far
No comments provided
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Learn more about our company.
This is a preprint. It has not completed peer review.
Original research
A Pretargeted Imaging Strategy for EGFR Positive Colorectal Carcinoma via the Modulation of Tz-radioligand Pharmacokinetics
Hongcheng Shi
Fudan University
Corresponding Author
ORCiD: https://orcid.org/0000-0003-1922-1359
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 2
Posted 14 Apr, 2020
No community comments so far
No comments provided
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Objective: Previously, we successfully developed a pretargeted imaging strategy (Atezolizumab-TCO/99mTc-HYNIC-PEG11-Tz), which is a powerful tool for evaluating Programmed Cell Death Ligand-1 (PD-L1) expression in xenograft mice tumor models. However, the surplus unclicked 99mTc-HYNIC-PEG11-Tz is cleared somewhat sluggishly through the intestines. This is certainly not an ideal situation for imaging for colorectal cancer (CRC). In order to shift the excretion of the Tz-radioligand to the renal system, we have sought to develop a novel Tz-radioligand by adding a polypeptide linker between HYNIC and PEG11.
Methods: Pretargeted molecular probes 99mTc-HYNIC-Polypeptide-PEG11-Tz and Cetuximab-TCO were synthesized. The stability of 99mTc-HYNIC-Polypeptide-PEG11-Tz was evaluated in vitro, and its blood pharmacokinetic test was performed in vivo. In vitro ligation reactivity of 99mTc-HYNIC-Polypeptide-PEG11-Tz towards Cetuximab-TCO was tested. The biodistribution and imaging of 99mTc-HYNIC-Polypeptide-PEG11-Tz was performed to observe the clear pathway of this novel Tz-radioligand. Pretargeted biodistribution of three different accumulation intervals was performed to determine the optimal pretargeted interval time. Comparison of pretargeted (Cetuximab-TCO 48 h/99mTc-HYNIC-PEG11-Tz 6 h) and (Cetuximab-TCO 48 h/99mTc-HYNIC-Polypeptide-PEG11-Tz 6 h) imagings was performed to show the effect of the two Tz-radioligands with different excretion pathway on tumor imaging.
Results: 99mTc-HYNIC-Polypeptide-PEG11-Tz showed favorable in vitro stability and rapid blood clearance in mice. SEC-HPLC revealed almost complete reaction between Cetuximab-TCO and 99mTc-HYNIC-Polypeptide-PEG11-Tz in vitro, with the 8:1 Tz-to-mAb reaction providing a conversion yield of 87.83 ± 3.27%. The biodistribution and imaging of 99mTc-HYNIC-Polypeptide-PEG11-Tz demonstrated that the Tz-radioligand was cleared through kidneys. After allowing 24 h, 48 h and 72 h for accumulation of Cetuximab-TCO in HCT116 tumor, pretargeted biodistribution revealed the tumor-to-blood ratio was 0.83 ± 0.13, 1.40 ± 0.31, and 1.15 ± 0.21, respectively. Both pretargeted (Cetuximab-TCO 48 h/99mTc-HYNIC-PEG11-Tz 6 h) and (Cetuximab-TCO 48 h/99mTc-HYNIC-Polypeptide-PEG11-Tz 6 h) imaging delineated the HCT116 tumor clearly. However, pretargeted imaging strategy using Cetuximab-TCO/99mTc-HYNIC-Polypeptide-PEG11-Tz could be used for diagnosing CRC since the surplus unclicked 99mTc-HYNIC-Polypeptide-PEG11-Tz is cleared through urinary system and produces low abdominal uptake background.
Conclusion: We developed a novel pretargeted imaging strategy (Cetuximab-TCO/99mTc-HYNIC-Polypeptide-PEG11-Tz) for imaging CRC since the surplus unclicked 99mTc-HYNIC-Polypeptide-PEG11-Tz produces low abdominal uptake background, which broadens the application scope of pretargeted imaging strategy.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11