{"title":"Development of a Specifically Labeled 89Zr Antibody for the Noninvasive Imaging of Tumors Overexpressing B7-H3","authors":"Meng Zheng, Qingfeng Liu, Hua Zhang, Yanan Wang, Kaijie Zhang, Huiwen Mu, Fengqing Fu, Xueguang Zhang*, Yan Wang* and Liyan Miao*, ","doi":"10.1021/acs.molpharmaceut.4c0059710.1021/acs.molpharmaceut.4c00597","DOIUrl":null,"url":null,"abstract":"<p >B7-H3 has emerged as a promising target and potential biomarker for diagnosing tumors, evaluating treatment efficacy, and determining patient prognosis. Hu4G4 is a recombinant humanized antibody that selectively targets the extracellular domain of human B7-H3. In this study, we describe the radiolabeling of hu4G4 with the positron emission tomography (PET) emitter radionuclide zirconium 89 (<sup>89</sup>Zr) and evaluate its potency as an immuno-PET tracer for B7-H3-targeted imaging by comparing it <i>in vitro</i> and <i>in vivo</i> to [<sup>89</sup>Zr]Zr-DFO–DS-5573a using various models. The radiolabeled compound, [<sup>89</sup>Zr]Zr-desferrioxamine-hu4G4 ([<sup>89</sup>Zr]Zr-DFO-hu4G4), demonstrated a high radiochemical purity (RCP) of greater than 99% and a specific activity of 74 MBq/mg following purification. Additionally, it maintained stability in human serum albumin (HSA) and acetate buffer, preserving over 90% of its RCP after 7 days. Three cell lines targeting human B7-H3(U87/CT26<sub><i>-CD276</i></sub>/GL261<sub><i>-CD276</i></sub>) were used. Flow cytometry analysis indicated that the B7-H3-positive cells (U87/CT26<sub><i>-CD276</i></sub>/GL261<sub><i>-CD276</i></sub>) had a higher B7-H3 protein level with no expression in the B7-H3-negative cells (CT26<sub><i>-wt</i></sub>/GL261<sub><i>-wt</i></sub>) (<i>P</i> < 0.001). Moreover, the cellular uptake was 45.71 ± 3.78% for [<sup>89</sup>Zr]Zr-DFO-hu4G4 in CT26<sub><i>-CD276</i></sub> cells versus only 0.93 ± 0.47% in CT26<sub><i>-wt</i></sub> cells and 30.26 ± 0.70% when [<sup>89</sup>Zr]Zr-DFO-hu4G4 in CT26<sub><i>-CD276</i></sub> cells were blocked with 100× 8H9. The cellular uptake of [<sup>89</sup>Zr]Zr-DFO-hu4G4 was akin to that observed with [<sup>89</sup>Zr]Zr-DFO-DS-5573a with no significant differences (45.71 ± 3.78 % vs 47.07 ± 0.86 %) in CT26<sub><i>-CD276</i></sub> cells. Similarly, the CT26<sub><i>-CD276</i></sub> mouse model demonstrated markedly low organ uptake and elevated tumor uptake 48 h after [<sup>89</sup>Zr]Zr-DFO-hu4G4 injection. PET/CT analysis showed that the tumor-to-muscle (T/M) ratios were substantially higher compared to other imaging groups: 27.65 ± 3.17 in CT26<sub><i>-CD276</i></sub> mice versus 11.68 ± 4.19 in CT26<sub><i>-wt</i></sub> mice (<i>P</i> < 0.001) and 16.40 ± 0.78 when 100× 8H9 was used to block [<sup>89</sup>Zr]Zr-DFO-hu4G4 in CT26<sub><i>-CD276</i></sub> mice (<i>P</i> < 0.01) at 48 h post-injection. Additionally, the tracer showed markedly high accumulation in the tumor region (22.57 ± 3.03% ID/g), comparable to the uptake of [<sup>89</sup>Zr]Zr-DFO–DS-5573a (24.76 ± 5.36% ID/g). A dosimetry estimation study revealed that the effective dose for [<sup>89</sup>Zr]Zr-DFO-hu4G4 was 2.96 × 10<sup>–01</sup> mSv/MBq, which falls within the acceptable range for further research in nuclear medicine. Collectively, these results indicated that [<sup>89</sup>Zr]Zr-DFO-hu4G4 was successfully fabricated and applied in B7-H3-targeted tumor PET/CT imaging, which showed excellent imaging quality and tumor detection efficacy in tumor-bearing mice. It is a promising imaging agent for identifying tumors that overexpress B7-H3 for future clinical applications.</p>","PeriodicalId":52,"journal":{"name":"Molecular Pharmaceutics","volume":null,"pages":null},"PeriodicalIF":4.5000,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Pharmaceutics","FirstCategoryId":"3","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.molpharmaceut.4c00597","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
B7-H3 has emerged as a promising target and potential biomarker for diagnosing tumors, evaluating treatment efficacy, and determining patient prognosis. Hu4G4 is a recombinant humanized antibody that selectively targets the extracellular domain of human B7-H3. In this study, we describe the radiolabeling of hu4G4 with the positron emission tomography (PET) emitter radionuclide zirconium 89 (89Zr) and evaluate its potency as an immuno-PET tracer for B7-H3-targeted imaging by comparing it in vitro and in vivo to [89Zr]Zr-DFO–DS-5573a using various models. The radiolabeled compound, [89Zr]Zr-desferrioxamine-hu4G4 ([89Zr]Zr-DFO-hu4G4), demonstrated a high radiochemical purity (RCP) of greater than 99% and a specific activity of 74 MBq/mg following purification. Additionally, it maintained stability in human serum albumin (HSA) and acetate buffer, preserving over 90% of its RCP after 7 days. Three cell lines targeting human B7-H3(U87/CT26-CD276/GL261-CD276) were used. Flow cytometry analysis indicated that the B7-H3-positive cells (U87/CT26-CD276/GL261-CD276) had a higher B7-H3 protein level with no expression in the B7-H3-negative cells (CT26-wt/GL261-wt) (P < 0.001). Moreover, the cellular uptake was 45.71 ± 3.78% for [89Zr]Zr-DFO-hu4G4 in CT26-CD276 cells versus only 0.93 ± 0.47% in CT26-wt cells and 30.26 ± 0.70% when [89Zr]Zr-DFO-hu4G4 in CT26-CD276 cells were blocked with 100× 8H9. The cellular uptake of [89Zr]Zr-DFO-hu4G4 was akin to that observed with [89Zr]Zr-DFO-DS-5573a with no significant differences (45.71 ± 3.78 % vs 47.07 ± 0.86 %) in CT26-CD276 cells. Similarly, the CT26-CD276 mouse model demonstrated markedly low organ uptake and elevated tumor uptake 48 h after [89Zr]Zr-DFO-hu4G4 injection. PET/CT analysis showed that the tumor-to-muscle (T/M) ratios were substantially higher compared to other imaging groups: 27.65 ± 3.17 in CT26-CD276 mice versus 11.68 ± 4.19 in CT26-wt mice (P < 0.001) and 16.40 ± 0.78 when 100× 8H9 was used to block [89Zr]Zr-DFO-hu4G4 in CT26-CD276 mice (P < 0.01) at 48 h post-injection. Additionally, the tracer showed markedly high accumulation in the tumor region (22.57 ± 3.03% ID/g), comparable to the uptake of [89Zr]Zr-DFO–DS-5573a (24.76 ± 5.36% ID/g). A dosimetry estimation study revealed that the effective dose for [89Zr]Zr-DFO-hu4G4 was 2.96 × 10–01 mSv/MBq, which falls within the acceptable range for further research in nuclear medicine. Collectively, these results indicated that [89Zr]Zr-DFO-hu4G4 was successfully fabricated and applied in B7-H3-targeted tumor PET/CT imaging, which showed excellent imaging quality and tumor detection efficacy in tumor-bearing mice. It is a promising imaging agent for identifying tumors that overexpress B7-H3 for future clinical applications.
期刊介绍:
Molecular Pharmaceutics publishes the results of original research that contributes significantly to the molecular mechanistic understanding of drug delivery and drug delivery systems. The journal encourages contributions describing research at the interface of drug discovery and drug development.
Scientific areas within the scope of the journal include physical and pharmaceutical chemistry, biochemistry and biophysics, molecular and cellular biology, and polymer and materials science as they relate to drug and drug delivery system efficacy. Mechanistic Drug Delivery and Drug Targeting research on modulating activity and efficacy of a drug or drug product is within the scope of Molecular Pharmaceutics. Theoretical and experimental peer-reviewed research articles, communications, reviews, and perspectives are welcomed.