Imaging of HER2/neu-positive BT-474 human breast cancer xenografts in athymic mice using 111In-trastuzumab (Herceptin) Fab fragments

Tang, Ying; Wang, Judy; Scollard, Deborah A.; Mondal, Hridya; Holloway, Claire; Kahn, Harriette J.; Reilly, Raymond M.

doi:10.1016/j.nucmedbio.2004.08.003

Cited by 125 publications

(115 citation statements)

References 25 publications

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“…The high tumor-to-liver ratio of both fragments favors their use as imaging agents even in the case of liver metastasis. A high tumor-to-blood ratio was obtained early, within 1-1.5 h after injection; however, this can be achieved only after several hours or days with conventional monoclonal antibodies and most antibody fragments (3,16,27,28). The tumor-to-background ratio was significantly higher for 99m Tc-7C12 than for 99m Tc-7D12.…”

Section: Discussionmentioning

confidence: 93%

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Gainkam¹,

et al. 2008

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Camelidae possess an unusual class of antibodies devoid of light chains. Nanobodies are intact antigen-binding fragments that are stable, easily generated against different targets, and fully functional. Their rapid clearance from the blood circulation favors their use as imaging agents. We compared the in vivo tumor uptake and biodistribution of 2 anti-epidermal growth factor receptor (anti-EGFR) Nanobodies, 99m Tc-7C12 and 99m Tc-7D12. Methods: Nanobodies were labeled via their hexahistidine tail with 99m Tc-tricarbonyl ( 99m Tc(CO) 3 ) generated from a kit. Mice bearing subcutaneous A431 (EGFR-positive) and R1M (EGFRnegative) xenografts were intravenously injected with 99m Tc-7C12 and 99m Tc-7D12 on separate days. Pinhole SPECT/ micro-CT images were acquired at 1 h after administration to assess noninvasively the biodistribution and tumor targeting of the labeled compounds. Pinhole SPECT and micro-CT images from the same mouse were automatically fused on the basis of a mathematic rigid-body-transformation algorithm using six 57 Co sources. Images were quantified, and tracer uptake was expressed as percentage injected activity per gram per cubic centimeter (%IA/cm 3 ) of tissue. Ex vivo biodistribution of mice bearing A431 injected with either 99m Tc-7C12 or 99m Tc-7D12 was also assessed; activity in the tumor and organs was recorded and expressed as percentage injected activity per gram (%IA/g). Results: Binding of both tracers was receptorspecific. Image analysis showed high and similar tumor uptake values for both 99m Tc-7C12 and 99m Tc-7D12 (4.55 6 0.24 %IA/ cm 3 and 4.62 6 0.36 %IA/cm 3 , respectively) in A431 xenografts, whereas the uptake in the negative tumor (R1M) was low (1.16 6 0.14 for 99m Tc-7C12 and 1.49 6 0.60 for 99m Tc-7D12). 99m Tc-7C12 showed significantly higher kidney uptake (63.48 6 2.36 vs. 56.25 6 2.46 %IA/cm 3 ) and lower liver uptake (2.55 6 0.26 vs. 4.88 6 0.86 %IA/cm 3 ) than did 99m Tc-7D12. The ex vivo analysis confirmed the image quantification with high tumor-tobackground ratio; however, 99m Tc-7C12 showed higher tumor uptake (9.11 6 1.12 %IA/g) than did 99m Tc-7D12 (6.09 6 0.77 %IA/g). 99m Tc-7D12 demonstrated significantly higher blood activity than did 99m Tc-7C12, but both showed short plasma half-lives (,10 min).Conclusion: The Nanobody fragments used here show high tumor uptake, low liver uptake, and rapid blood clearance. Nanobodies are promising probes for noninvasive radioimmunodetection of specific targets early after administration. On the basis of its favorable biodistribution, 99m Tc-7C12 was selected for further studies. Epi dermal growth factor receptor (EGFR or ErbB1) is a member of a receptor tyrosine kinase family together with Her-2-neu/ErbB2, HER-3/ErbB3, and HER-4/ErbB4. EGFR is implicated in many cellular processes such as proliferation, differentiation, and survival (1). Several reports have shown that EGFR signaling is abnormal in many tumors of epithelial origin, such as cancer of the breast, head and neck, prostate, lung, and skin. Aberrant signaling of...

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Section: Discussionmentioning

confidence: 93%

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Gainkam¹,

et al. 2008

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“…Herceptin has a K d of 8-14 nM and targets Her2+ tumours, such as the BT474 human breast cancer line used in this study, which has 122 6 10 6 receptors per cell [22]. MCF-7 breast cancer cells (the negative control) lack the Her2 gene amplification and only express Her2 protein at low or basal levels, approximately 10 4 Her2 receptors per cell [18].…”

Section: Discussionmentioning

confidence: 99%

Micro-CT enables microlocalisation and quantification of Her2-targeted gold nanoparticles within tumour regions

Hainfeld

O’Connor²,

Dilmanian³

et al. 2011

BJR

222

183

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Objectives: Gold nanoparticles are of interest as potential in vivo diagnostic and therapeutic agents, as X-ray contrast agents, drug delivery vehicles and radiation enhancers. The aim of this study was to quantitatively determine their targeting and microlocalisation in mouse tumour models after intravenous injection by using micro-CT. Methods: Gold nanoparticles (15 nm) were coated with polyethylene glycol and covalently coupled to anti-Her2 antibodies (Herceptin). In vitro, conjugates incubated with Her2+ (BT-474) and Her2-(MCF7) human breast cancer cells showed specific targeted binding with a Her2+ to Her2-gold ratio of 39.4¡2.7:1. Nude mice, simultaneously bearing subcutaneous Her2+ and Her2-human breast tumours in opposite thighs were prepared. Gold nanoparticles alone, conjugated to Herceptin or to a non-specific antibody were compared. After intravenous injection of the gold nanoparticles, gold concentrations were determined by atomic absorption spectroscopy. Microlocalisation of gold was carried out by calibrated micro-CT, giving both the radiodensities and gold concentrations in tumour and non-tumour tissue. Results: All gold nanoparticle constructs showed accumulation, predominantly at tumour peripheries. However, the Herceptin-gold nanoparticles showed the best specific uptake in their periphery (15.8¡1.7% injected dose per gram), 1.6-fold higher than Her2-tumours and 22-fold higher than surrounding muscle. Imaging readily enabled detection of small, 1.5 mm-thick tumours. Conclusion: In this pre-clinical study, antibody-targeted 15 nm gold nanoparticles showed preferential uptake in cognate tumours, but even untargeted gold nanoparticles enhanced the visibility of tumour peripheries and enabled detection of millimetre-sized tumours. Micro-CT enabled quantification within various regions of a tumour.

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“…Moreover, coupling with therapeutic radionuclides allows targeted radionuclide therapy. Many different formats have been investigated including nanobodies, minibodies, diabodies (1)(2)(3)(4), scFvs, Fabs and F(ab)2 (5,6). Each format has its own pharmacokinetic profile with a blood clearance that is largely dependent on the molecular size.…”

Section: Introductionmentioning

confidence: 99%

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

Gainkam

Caveliers

Devoogdt

et al. 2010

Contrast Media & Molecular

116

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Background: Nanobodies are single-domain antigen binding fragments derived from functional heavy-chain antibodies elicited in Camelidae. They are powerful probes for radioimmunoimaging, but their renal uptake is relatively high. In this study we have evaluated the role of megalin on the renal uptake of anti-EGFR 99m Tc-7C12 nanobody and the potency of gelofusine and/or lysine to reduce renal uptake of 99m Tc-7C12. Methods: First we compared the renal uptake of 99m Tc-7C12 in megalin-deficient and megalin-wild-type mice using pinhole SPECT/microCT and ex vivo analysis. The effect of gelofusine and lysine administration on renal accumulation of 99m Tc-7C12 was analyzed in CD-1 mice divided into lysine preload at 30 min before tracer injection (LysPreload), LysPreload R gelofusine coadministration (LysPreload R GeloCoad), lysine coadministration (LysCoad), gelofusine coadministration (GeloCoad) and LysCoad R GeloCoad. The combined effect of gelofusine and lysine on tumor uptake was tested in mice xenografts. Results: Renal uptake of 99m Tc-7C12 was 44.22 W 3.46% lower in megalin-deficient compared with megalinwild-type mice. In CD-1 mice, lysine preload had no effect on the renal retention whereas coinjection of lysine or gelofusine with the tracer resulted in 25.12 W 2.99 and 36.22 W 3.07% reduction, respectively. The combined effect of gelofusine and lysine was the most effective, namely a reduction of renal retention of 45.24 W 2.09%. Gelofusine and lysine coadministration improved tumor uptake. Conclusion: Megalin contributes to the renal accumulation of 99m Tc-7C12. Gelofusine and lysine coinjection with the tracer reduces the renal uptake while tumor uptake is improved. Although this methodology allows for optimization of imaging protocol using nanobodies, further improvements are needed before using these molecules for radionuclide therapy.

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Imaging of HER2/neu-positive BT-474 human breast cancer xenografts in athymic mice using 111In-trastuzumab (Herceptin) Fab fragments

Cited by 125 publications

References 25 publications

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Micro-CT enables microlocalisation and quantification of Her2-targeted gold nanoparticles within tumour regions

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

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Imaging of HER2/neu-positive BT-474 human breast cancer xenografts in athymic mice using 111In-trastuzumab (Herceptin) Fab fragments

Cited by 125 publications

References 25 publications

Comparison of the Biodistribution and Tumor Targeting of Two 99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two 99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Micro-CT enables microlocalisation and quantification of Her2-targeted gold nanoparticles within tumour regions

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

Contact Info

Product

Resources

About

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT