RESUMO
Cyclin-dependent kinases (CDKs), especially cyclin-dependent kinase 4/6 (CDK4/6), have been targets for the development of specific tumor imaging agents. Palbociclib is a highly selective CDK4/6 inhibitor. In this study, to develop a novel 18F-labeled palbociclib derivative for specific tumor imaging, we designed and synthesized a ligand (NOTA-PBB) consisting of palbociclib as the targeted pharmacophore and NOTA as the macrocyclic bifunctional chelator. The corresponding [18F]AlF-NOTA-PBB complex was prepared with high radiochemical purity (98.4 ± 0.15%) and yield (58.7 ± 4.5%) within 35 min without requiring HPLC purification through a simple one-step 18F-labeling strategy of NOTA-AlF chelation chemistry. The radiotracer was lipophilic (log P = 0.095 ± 0.003) and had good stability in vitro and in vivo. The cellular uptake studies performed on the MCF-7 breast cancer cell line (ER-positive and HER2-negative) showed that radioactive uptake was blocked by preincubating with a molar dose of palbociclib and it had a nanomolar binding affinity to CDK4/6 (IC50 = 16.23 ± 1.84 nM), demonstrating a CDK4/6-mediated uptake mechanism. Its ex vivo biodistribution in nude mice-bearing MCF-7 tumors showed obvious tumor uptake and a high tumor/muscle ratio of [18F]AlF-NOTA-PBB, and tumor uptake was inhibited with 100 µg of palbociclib, demonstrating specific binding to CDK4/6. Radioactivity accumulation in MCF-7 tumors was observed in PET imaging with [18F]AlF-NOTA-PBB. Based on the results of this work, [18F]AlF-NOTA-PBB has the promising capability as a CDK4/6-targeted tumor imaging agent.
Assuntos
Neoplasias , Animais , Camundongos , Quinase 4 Dependente de Ciclina , Camundongos Nus , Distribuição Tecidual , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , QuelantesRESUMO
Prostate-specific membrane antigen (PSMA) has been proved as a specific target for diagnosis and treatment of prostate cancer (PCa). Recently, oxalyldiaminopropionic acid (ODAP)-Urea-based ligands showed the potential as a new scaffold for developing radiotracers to image PCa. In this study, we synthesized seven ODAP-Urea-Lys derivatives characterized with p-bromobenzyl group conjugated to lysine. The ligands showed medium-to-high potency, with Ki values ranging from 27.9 nM to 0.94 nM. The ligands could be efficiently radiolabeled with 68Ga, in high purity. Radioligands were stable and showed PSMA specific cellular uptake, in PSMA++ LNCaP cells and PSMA+ 22Rv1 cells over PSMA- PC3 cells. MicroPET imaging was performed in 22Rv1 tumor-bearing mice and 68Ga-ligand-1 showed the best characteristics among the seven ligands, with the highest tumor uptake (SUVmax: 0.56 ± 0.07). A biodistribution study was also performed. ODAP-Urea-Lys-p-bromobenzyl could be used to image prostate cancer in vivo, and the ligands could have high binding potency. The future investigation is still necessary to improve the tumor-specific uptake of this class of ligands and reducing the non-specific uptake in normal organs.
Assuntos
Neoplasias da Próstata , Ureia , Masculino , Humanos , Animais , Camundongos , Ureia/química , Lisina/metabolismo , Radioisótopos de Gálio , Tomografia por Emissão de Pósitrons/métodos , Ligantes , Distribuição Tecidual , Linhagem Celular Tumoral , Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/metabolismo , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismoRESUMO
PURPOSE: Prostate-specific membrane antigen (PSMA) is a promising target for prostate cancer imaging and therapy. The most commonly used scaffold incorporates a glutamate-urea (Glu-Urea) function. We recently developed oxalyldiaminopropionic acid-urea (ODAP-Urea) PSMA ligands in an attempt to improve upon the pharmacokinetic properties of existing agents. Here, we report the synthesis of an optimized 68Ga-labeled ODAP-Urea-based ligand, [68Ga]Ga-P137, and first-in-human results. METHODS: Twelve ODAP-Urea-based ligands were synthesized and radiolabeled with 68Ga in high radiochemical yield and purity. Their PSMA inhibitory capacities were determined using the NAALADase assay. Radioligands were evaluated in mice-bearing 22Rv1 prostate tumors by microPET. Lead compound [68Ga]Ga-P137 was evaluated for stability, cell uptake, and biodistribution. PET imaging of [68Ga]Ga-P137 was performed in three patients head-to-head compared to [68Ga]Ga-PSMA-617. RESULTS: Ligands were synthesized in 11.1-44.4% yield and > 95% purity. They have high affinity to PSMA (Ki of 0.13 to 5.47 nM). [68Ga]Ga-P137 was stable and hydrophilic. [68Ga]Ga-P137 showed higher uptake than [68Ga]Ga-PSMA-617 in tumor-bearing mice at 6.43 ± 0.98%IA/g vs 3.41 ± 1.31%IA/g at 60-min post-injection. In human studies, the normal organ biodistribution of [68Ga]Ga-P137 was grossly equivalent to that of [68Ga]Ga-PSMA-617 except for within the urinary tract, in which [68Ga]Ga-P137 demonstrated lower uptake. CONCLUSION: The optimized ODAP-Urea-based ligand [68Ga]Ga-P137 can image PSMA in xenograft models and humans, with lower bladder accumulation to the Glu-Urea-based agent, [68Ga]Ga-PSMA-617, in a preliminary, first-in-human study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04560725, Registered 23 September 2020. https://clinicaltrials.gov/ct2/show/NCT04560725.
Assuntos
Glutamato Carboxipeptidase II , Neoplasias da Próstata , Diamino Aminoácidos , Animais , Antígenos de Superfície/metabolismo , Linhagem Celular Tumoral , Radioisótopos de Gálio , Glutamato Carboxipeptidase II/metabolismo , Humanos , Masculino , Camundongos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Distribuição Tecidual , UreiaRESUMO
PURPOSE: Radioligand therapy (RLT) targeting prostate-specific membrane antigen (PSMA) is emerging as an effective treatment option for metastatic castration-resistant prostate cancer (mCRPC). An imaging-based method to quantify early treatment responses can help to understand and optimize RLT. METHODS: We developed a self-triggered probe 2 targeting the colocalization of PSMA and caspase-3 for fluorescence imaging of RLT-induced apoptosis. RESULTS: The probe binds to PSMA potently with a Ki of 4.12 nM, and its fluorescence can be effectively switched on by caspase-3 with a Km of 67.62 µM. Cellular and in vivo studies demonstrated its specificity for imaging radiation-induced caspase-3 upregulation in prostate cancer. To identify the detection limit of our method, we showed that probe 2 could achieve 1.79 times fluorescence enhancement in response to 177Lu-RLT in a medium PSMA-expressing 22Rv1 xenograft model. CONCLUSION: Probe 2 can potently bind to PSMA, and the fluorescence signal can be sensitively switched on by caspase-3 both in vitro and in vivo. This method may provide an effective tool to investigate and optimize PSMA-RLT.
Assuntos
Lutécio , Neoplasias de Próstata Resistentes à Castração , Antígenos de Superfície , Caspase 3 , Dipeptídeos , Glutamato Carboxipeptidase II , Compostos Heterocíclicos com 1 Anel , Humanos , Lutécio/uso terapêutico , Masculino , Imagem Óptica , Neoplasias de Próstata Resistentes à Castração/diagnóstico por imagem , Neoplasias de Próstata Resistentes à Castração/radioterapia , Resultado do TratamentoRESUMO
Fibroblast activation protein (FAP) is overexpressed in cancer-associated fibroblasts (CAFs) in a majority of human epithelial cancers. With low expression in normal organs, FAP has become a promising molecular target for tumor theranostics. To develop a lower cost and more widely available alternative to positron emission tomography (PET), two isocyanide-containing FAP inhibitors (CN-C5-FAPI and CN-PEG4-FAPI) were synthesized and radiolabeled with 99mTc to obtain [99mTc][Tc-(CN-C5-FAPI)6]+ and [99mTc][Tc-(CN-PEG4-FAPI)6]+ in high yields (>95%). They showed good stability in saline and mouse serum. The partition coefficient (logâ¯P) values of [99mTc][Tc-(CN-C5-FAPI)6]+ and [99mTc][Tc-(CN-PEG4-FAPI)6]+ were -0.86 ± 0.03 and -2.38 ± 0.07, respectively, indicating that they were good hydrophilic complexes. The low nanomolar IC50 values of CN-C5-FAPI and CN-PEG4-FAPI indicated that they had specificity to FAP. In vitro cellular uptake and blocking experiments implied a FAP-targeted uptake mechanism. The nanomolar Kd values from the saturation binding assay indicated that they had significantly high target affinity to FAP. The biodistribution and blocking study in BALB/c nude mice bearing U87MG tumors showed that both exhibited specific tumor uptake. [99mTc][Tc-(CN-PEG4-FAPI)6]+ showed a higher tumor uptake and a higher tumor/nontarget ratio than [99mTc][Tc-(CN-C5-FAPI)6]+. The results of micro-single-photon emission computed tomography (SPECT) imaging studies of [99mTc][Tc-(CN-C5-FAPI)6]+ and [99mTc][Tc-(CN-PEG4-FAPI)6]+ were in accordance with the biodistribution results, suggesting that [99mTc][Tc-(CN-PEG4-FAPI)6]+ is a promising tumor imaging agent for targeting FAP.
Assuntos
Proteínas de Membrana/antagonistas & inibidores , Compostos Radiofarmacêuticos , Tecnécio , Animais , Linhagem Celular Tumoral , Endopeptidases/metabolismo , Feminino , Glioblastoma/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Prostate-specific membrane antigen (PSMA) is emerging as a promising target to specifically image prostate cancer. Dual-modality probe combining radionuclide imaging and near-infrared fluorescence navigation targeting PSMA would enable both the preoperative staging and intraoperative detection of the tumor lesions. To overcome one of the key barriers for achieving high contrast imaging at both early and late time points, we optimized the pharmacokinetics of dual-modality probes based on oxalyldiaminopropionic acid-urea (ODAP-Urea) PSMA inhibitors recently developed. Four dual-modality probes with variable hydrophilicity were synthesized and evaluated. They displayed good optical properties (λem max = 835 nm, QY = 0.67%-1.50%), high affinity to PSMA (Ki = 2.09 ± 1.71-4.15 ± 2.20 nM) and PSMA specific cellular uptake (0.48 ± 0.01% - 0.64 ± 0.04% IA/105 LNCaP cells) upon labeled with 68Ga. In vivo studies showed that [68Ga]Ga-P3 exhibited an optimum pharmacokinetic property with high specific tumor uptake (SUVmax = 1.88 ± 0.36, at 1 h) in medium level PSMA expressing 22Rv1 tumor model and high tumor-to-muscle ratio (12.56 ± 2.63, at 1 h). Specific fluorescence imaging could also be achieved with high contrast for later time points (tumor-to-background ratio = 11.63 ± 4.16 at 24 h). This study demonstrates that ODAP-Urea-based P3 has the potential for PET imaging and intraoperative optical imaging of prostate cancer.
Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Diamino Aminoácidos , Linhagem Celular Tumoral , Radioisótopos de Gálio , Glutamato Carboxipeptidase II/metabolismo , Humanos , Masculino , Imagem Óptica/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Distribuição Tecidual , UreiaRESUMO
Arg-Arg-Leu (RRL) is a potent tumor-homing tripeptide. However, the binding target is unclear. In this study, we intended to identify the binding target of RRL and evaluate the tumor targeting of 99mTc-MAG3-RRL in vivo. Biotin-RRL, 5-TAMRA-RRL, and 99mTc-MAG3-RRL were designed to trace the binding target and tumor lesion. Immunoprecipitation-mass spectrometry was conducted to identify the candidate proteins and determination of the subcellular localization was also performed. A pull-down assay was performed to demonstrate the immunoprecipitate. Fluorescence colocalization and cell uptake assays were performed to elucidate the correlation between the selected binding protein and RRL, and the internalization mechanism of RRL. Biodistribution and in vivo imaging were performed to evaluate the tumor accumulation and targeting of 99mTc-MAG3-RRL. The target for RRL was screened to be heat shock protein 70 (HSP70). The prominent uptake distribution of RRL was concentrated in the membrane and cytoplasm. A pull-down assay demonstrated the existence of HSP70 in the biotin-RRL captured complex. Regarding fluorescence colocalization and cell uptake assays, RRL may interact with HSP70 at the nucleotide-binding domain (NBD). Clathrin-dependent endocytosis and macropinocytosis could be a vital internalization mechanism of RRL. In vivo imaging and biodistribution both demonstrated that 99mTc-MAG3-RRL can trace tumors with satisfactory accumulation in hepatoma xenograft mice. The radioactive signals accumulated in tumor lesions can be blocked by VER-155008, which can bind to the NBD of HSP70. Our findings revealed that RRL may interact with HSP70 and that 99mTc-MAG3-RRL could be a prospective probe for visualizing overexpressed HSP70 tumor sections.
Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Neoplasias/diagnóstico por imagem , Oligopeptídeos/metabolismo , Animais , Sítios de Ligação , Feminino , Citometria de Fluxo , Células HeLa/metabolismo , Células Hep G2/metabolismo , Humanos , Imunoprecipitação , Células MCF-7/metabolismo , Espectrometria de Massas , Camundongos , Camundongos Nus , Imagem Óptica , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Prostate-specific membrane antigen (PSMA) is a well-established biological target that is overexpressed on the surface of prostate cancer lesions. Radionuclide-labeled small-molecule PSMA inhibitors have been shown to be promising PSMA-specific agents for the diagnosis and therapy of prostate cancer. In this study, a glutamate-urea-based PSMA-targeted ligand containing an isonitrile (CNGU) was synthesized and labeled with 99mTc to prepare [99mTc]Tc-CNGU with a high radiochemical purity (RCP). The CNGU ligand showed a high affinity toward PSMA (Ki value is 8.79 nM) in LNCaP cells. The [99mTc]Tc-CNGU exhibited a good stability in vitro and hydrophilicity (log P = -1.97 ± 0.03). In biodistribution studies, BALB/c nude mice bearing LNCaP xenografts showed that the complex had a high tumor uptake with 4.86 ± 1.19% ID/g, which decreased to 1.74 ± 0.90% ID/g after a pre-injection of the selective PSMA inhibitor ZJ-43, suggesting that it was a PSMA-specific agent. Micro-SPECT imaging demonstrated that the [99mTc]Tc-CNGU had a tumor uptake and that the uptake was reduced in the image after blocking with ZJ-43, further confirming its PSMA specificity. All of the results in this work indicated that [99mTc]Tc-CNGU is a promising PSMA-specific tracer for the imaging of prostate cancer.
Assuntos
Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/metabolismo , Imagem Molecular/métodos , Nitrilas/química , Compostos de Organotecnécio/química , Traçadores Radioativos , Compostos Radiofarmacêuticos , Tecnécio/química , Animais , Humanos , Masculino , Camundongos , Estrutura Molecular , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
In this study, a d-glucosamine derivative with an isonitrile group (CN5DG) was synthesized and it was chosen to coordinate with 99mTc for preparing 99mTc-CN5DG. 99mTc-CN5DG could be readily obtained with high radiochemical purity (>95%) and had great in vitro stability and metabolic stability in urine. The radiotracer demonstrated a positive response to the administration of glucose and insulin in S180 and A549 tumor cells in vitro, suggesting the mechanism of 99mTc-CN5DG into tumor cells was related to glucose transporters. Biodistribution studies in mice bearing A549 xenografts showed 99mTc-CN5DG had a high tumor uptake and high tumor-to-background ratios. SPECT/CT images further supported its ability for tumor imaging. As a cheap, conveniently made and widely available probe, 99mTc-CN5DG would become a potential "working horse" and be a breakthrough in 99mTc-labeled radiopharmaceuticals for tumor detection.
Assuntos
Glucosamina/administração & dosagem , Neoplasias/diagnóstico por imagem , Compostos de Organotecnécio/administração & dosagem , Tecnécio/administração & dosagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Células A549 , Animais , Feminino , Glucosamina/química , Glucosamina/farmacocinética , Humanos , Camundongos , Neoplasias/patologia , Compostos de Organotecnécio/química , Compostos de Organotecnécio/farmacocinética , Tecnécio/química , Tecnécio/farmacocinética , Distribuição Tecidual , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Achieving a (99m)Tc labeled thymidine radiotracer for single photon emission tomography (SPECT) is considered to be of interest. In this study, four novel thymidine analogs, 6a, 6b, 6c and 6d, were successfully synthesized via "click reaction" route and then radiolabeled using a [(99m)Tc(CO)3]⺠core to prepare the corresponding (99m)Tc(CO)3 complexes in high yields. These complexes were hydrophilic and had good in vitro stability. Biodistribution of these complexes in mice bearing S180 tumors showed that all of them exhibited accumulation in the tumors, suggesting that they would be potential tumor imaging agents.
Assuntos
Compostos de Organotecnécio/síntese química , Compostos Radiofarmacêuticos/síntese química , Sarcoma/diagnóstico por imagem , Timidina/análogos & derivados , Animais , Linhagem Celular Tumoral , Proliferação de Células , Química Click , Estabilidade de Medicamentos , Camundongos , Transplante de NeoplasiasRESUMO
Prostate-specific membrane antigen (PSMA), a well-established biological marker for prostate cancer (PCa) imaging and therapy, is overexpressed on the surface of prostate cancer lesions. In this study, a triazole ring was introduced into the linker by click chemistry to generate a HYNIC-derived ligand (T), which exhibited good PSMA affinity (Ki = 2.23 nM). Eight stable 99mTc-labeled complexes, [99mTc]Tc-T-Mn (n = 1-8), with hydrophilic properties were synthesized by incorporating different coligands at high radiochemical yields and purities without purification. The radioligands were concentrated in the kidneys of healthy Kunming male mice and were significantly blocked by the PSMA inhibitor ZJ-43. The uptake of the optimized complex [99mTc]Tc-T-M2 was correlated with PSMA, and it had good PSMA affinity (Kd = 5.42 nM). [99mTc]Tc-T-M2 accumulated on LNCaP (PSMA++) tumors and was significantly blocked by ZJ-43 at 2 h p.i., indicating high PSMA specificity. Relatively suitable kidney uptake was beneficial for reducing kidneys exposure in patients. SPECT/CT imaging of [99mTc]Tc-T-M2 in LNCaP (PSMA++) or 22Rv1 (PSMA+) tumor-bearing mice revealed high tumor uptake, low background uptake (especially low kidney uptake (49.06 ± 9.20 %ID/g) at 2 h p.i.), and obvious inhibition by ZJ-43, whereas PC-3 (PSMA-) tumors were undetectable. A freeze-dried [99mTc]Tc-T-M2 kit was successfully developed (T-M2 kit). Preliminary clinical trials showed that [99mTc]Tc-T-M2 clearly identified small prostate cancer lesions and has potential for clinical application.
RESUMO
Nectin cell adhesion molecule 4 (nectin-4) is a transmembrane protein overexpressed on a variety of cancers and plays an important role in oncogenic and metastatic processes. The nectin-4-targeted antibody-drug conjugate enfortumab vedotin has been approved for treating locally advanced or metastatic urothelial cancer, but the efficacy in other types of cancer remains to be explored. The aim of this study was to evaluate the feasibility of nectin-4-targeted PET imaging with 68Ga-N188 as a noninvasive method to quantify membranous nectin-4 expression in multiple tumor types-an approach that may provide insight for patient stratification and treatment selection. Methods: Sixty-two patients with 16 types of cancer underwent head-to-head 68Ga-N188 and 18F-FDG PET/CT imaging for initial staging or detection of recurrence and metastases. Correlation between lesion SUVmax and nectin-4 expression determined by immunohistochemistry staining was analyzed in 36 of 62 patients. Results: The SUVmax of 68Ga-N188 had a positive correlation with membranous nectin-4 expression in the various tumor types tested (r = 0.458; P = 0.005), whereas no association was observed between the SUVmax and cytoplasmic nectin-4 expression. The detection rates for patient-based analysis of 68Ga-N188 and 18F-FDG PET/CT examinations were comparable (95.00% [57/60] vs. 93.33% [56/60]). In patients with pancreatic cancer, 68Ga-N188 exhibited a potential advantage for detecting residual or locally recurrent tumors; this advantage may assist in clinical decision-making. Conclusion: The correlation between nectin-4-targeted 68Ga-N188 PET imaging and membranous nectin-4 expression indicates the potential of 68Ga-N188 as an effective tool for selecting patients who may benefit from enfortumab vedotin treatment. The PET imaging results provided evidence to explore nectin-4-targeted therapy in a variety of tumors. 68Ga-N188 may improve the restaging of pancreatic cancer but requires further evaluation in a powered, prospective setting.
Assuntos
Moléculas de Adesão Celular , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Humanos , Moléculas de Adesão Celular/metabolismo , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Adulto , Anticorpos Monoclonais/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Idoso de 80 Anos ou mais , Pesquisa Translacional Biomédica , NectinasRESUMO
(S)-3-(Carboxyformamido)-2-(3-(carboxymethyl)ureido)propanoic acid (EuK) is a known binder toward the prostate-specific membrane agent (PSMA) with strong affinity, making it a popular choice for prostate cancer medicine development. However, during the probe modification, a new EuK-based PSMA tetramer, Bone-1064, was discovered to have an unexpected and intense uptake in bone, which has not yet been reported in any previous studies yet. After administration, Bone-1064 allowed for high contrast visualization of the bone from surrounding tissues with a signal-to-background ratio of 10.22 at 24 h postinjection. In contrast, the tumor had a blurry contour, and the maximum tumor-to-normal-tissue ratio was only 2.22. Further imaging studies revealed that Bone-1064 binds specifically to hydroxyapatite in bone tissues, instead of PSMA. Overall, Bone-1064 is an excellent bone probe with a unique structure that can be used for NIR-II fluorescence imaging in animal models. Meanwhile, this modification study might also inspire further PSMA probe designations.
Assuntos
Próstata , Neoplasias da Próstata , Humanos , Masculino , Animais , Próstata/metabolismo , Próstata/patologia , Glutamato Carboxipeptidase II/metabolismo , Antígenos de Superfície/metabolismo , Neoplasias da Próstata/patologia , Linhagem Celular TumoralRESUMO
Genetic encoding of noncanonical amino acid (ncAA) for site-specific protein modification has been widely applied for many biological and therapeutic applications. To efficiently prepare homogeneous protein multiconjugates, we design two encodable noncanonical amino acids (ncAAs), 4-(6-(3-azidopropyl)-s-tetrazin-3-yl) phenylalanine (pTAF) and 3-(6-(3-azidopropyl)-s-tetrazin-3-yl) phenylalanine (mTAF), containing mutually orthogonal and bioorthogonal azide and tetrazine reaction handles. Recombinant proteins and antibody fragments containing the TAFs can easily be functionalized in one-pot reactions with combinations of commercially available fluorophores, radioisotopes, PEGs, and drugs in a plug-and-play manner to afford protein dual conjugates to assess combinations of tumor diagnosis, image-guided surgery, and targeted therapy in mouse models. Furthermore, we demonstrate that simultaneously incorporating mTAF and a ketone-containing ncAA into one protein via two non-sense codons allows preparation of a site-specific protein triconjugate. Our results demonstrate that TAFs are doubly bio-orthogonal handles for efficient and scalable preparation of homogeneous protein multiconjugates.
Assuntos
Aminoácidos , Aminoacil-tRNA Sintetases , Animais , Camundongos , Aminoácidos/metabolismo , Proteínas Recombinantes/genética , Fenilalanina , Aminoacil-tRNA Sintetases/metabolismoRESUMO
PURPOSE: Nectin-4 is an emerging biomarker for cancer diagnosis and therapy. Recently, enfortumab vedotin (EV) was approved by the FDA as the first nectin-4 targeting antibody-drug conjugate for treating advanced urothelial carcinoma (UC). A PET imaging method to noninvasively quantify nectin-4 expression level would potentially help to select patients most likely to respond to EV and predict the response. EXPERIMENTAL DESIGN: In this study, we designed a bicyclic peptide-based nectin-4 targeting radiotracer 68Ga-N188. Initially, we performed preclinical evaluations of 68Ga-N188 in UC cell lines and xenograft mouse models. Next, we performed the translational study in healthy volunteers and a pilot cohort of patients with advanced UC on uEXPLORER total-body PET/CT. RESULTS: In the preclinical study, 68Ga-N188 showed high affinity to nectin-4, specific uptake in a nectin-4(+) xenograft mouse model, and suitable pharmacokinetic and safety profiles. In the translational study, 2 healthy volunteers and 14 patients with advanced UC were enrolled. The pharmacokinetic profile was determined for 68Ga-N188, and the nectin-4 relative expression level in different organs was quantitatively imaged. CONCLUSIONS: A clear correlation between PET SUV value and nectin-4 expression was observed, supporting the application of 68Ga-N188 PET as a companion diagnostic tool for optimizing treatments that target nectin-4. See related commentary by Jiang et al., p. 3259.
Assuntos
Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Camundongos , Animais , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Carcinoma de Células de Transição/diagnóstico por imagem , Carcinoma de Células de Transição/tratamento farmacológico , Nectinas , Neoplasias da Bexiga Urinária/patologia , Medicina de Precisão , Tomografia por Emissão de Pósitrons , Moléculas de Adesão Celular/genéticaRESUMO
The chlorambucil l-histidine conjugate was synthesized and radiolabeled with [(99m)Tc(CO)(3)](+) core to form the (99m)Tc(CO)(3)(His-CB) complex. The radiochemical purity of the complex was over 90%. It had good hydrophilicity and was stable at room temperature. The high initial tumor uptake with certain retention, fast clearance from background, good tumor/non-tumor ratios and satisfactory scintigraphic images highlighted the potential of (99m)Tc(CO)(3)(His-CB) as a tumor imaging agent.
Assuntos
Meios de Contraste , Neoplasias Experimentais/diagnóstico , Compostos de Organotecnécio , Animais , Meios de Contraste/síntese química , Meios de Contraste/farmacocinética , Camundongos , Estrutura Molecular , Compostos de Organotecnécio/síntese química , Compostos de Organotecnécio/farmacocinética , Distribuição TecidualRESUMO
Clinical trials have shown the significant efficacy of [177Lu]Lu-PSMA-617 for treating prostate cancer. However, the pharmacokinetic characteristics and therapeutic performance of [177Lu]Lu-PSMA-617 still need further improvement to meet clinical expectations. The aim of this study was to evaluate the feasibility and therapeutic potential of three novel 177Lu-labeled ligands for the treatment of prostate cancer. The novel ligands were efficiently synthesized and radiolabeled with non-carrier added 177Lu; the radiochemical purity of the final products was determined by Radio-HPLC. The specific cell-binding affinity to PSMA was evaluated in vitro using prostate cancer cell lines 22Rv1and PC-3. Blood pharmacokinetic analysis, biodistribution experiments, small animal SPCET imaging and treatment experiments were performed on normal and tumor-bearing mice. Among all the novel ligands developed in this study, [177Lu]Lu-PSMA-Q showed the highest uptake in 22Rv1 cells, while there was almost no uptake in PC-3 cells. As the SPECT imaging tracer, [177Lu]Lu-PSMA-Q is highly specific in delineating PSMA-positive tumors, with a shorter clearance half-life and higher tumor-to-background ratio than [177Lu]Lu-PSMA-617. Biodistribution studies verified the SPECT imaging results. Furthermore, [177Lu]Lu-PSMA-Q serves well as an effective therapeutic ligand to suppress tumor growth and improve the survival rate of tumor-bearing mice. All the results strongly demonstrate that [177Lu]Lu-PSMA-Q is a PSMA-specific ligand with significant anti-tumor effect in preclinical models, and further clinical evaluation is worth conducting.
RESUMO
OBJECTIVE: Pep-1 (CGEMGWVRC) can potently bind to interleukin 13 receptor α 2 (IL-13Rα2), a tumor-restricted receptor found to be expressed in various malignancies. In this study, we intended to prepare a 99mTc-labeled probe and evaluate its in vivo tumor accumulation properties in a cervical cancer xenograft model. METHODS: The Pep-1 was designed and radiolabeled with 99mTc by conjugation with mercaptoacetyl-triglycine (MAG3). The labeling yield, radiochemical purity and stability were characterized in vitro. Cell uptake assays and fluorescence imaging were conducted for qualitative and quantitative evaluation of the specificity and affinity of Pep-1. Flow cytometry and tissue immunofluorescence were used to confirm the IL-13Rα2 expression in cervical cancer. Biodistribution and in vivo imaging were performed periodically to evaluate the imaging value of 99mTc-MAG3-Pep-1 in cervical cancer xenograft model. RESULTS: 99mTc-MAG3-Pep-1 was successfully prepared with a high labeling yield and radiochemical purity (> 95%). Specific cell uptake was demonstrated by scramble control and unlabeled MAG3-Pep-1 blockade. Flow cytometry and tissue immunofluorescence also confirmed the mild IL-13Rα2 expression of HeLa. In the gamma imaging study and biodistribution, the tumors were imaged clearly at 2-6 h after injection of 99mTc-MAG3-Pep-1 and the accumulation of 99mTc-MAG3-Pep-1 in tumor was significantly higher than that in the blocking and scramble controls, demonstrating ligand-receptor binding specificity. CONCLUSIONS: This work demonstrated that 99mTc-MAG3-Pep-1 can bind to cervical cancer with high affinity and specificity. MAG3-Pep-1 may be a prospective precursor for IL-13Rα2-expressing cancer therapy.
Assuntos
Neoplasias do Colo do Útero , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Peptídeos , Estudos Prospectivos , Receptores de Interleucina-13 , Tecnécio/química , Distribuição Tecidual , Neoplasias do Colo do Útero/diagnóstico por imagemRESUMO
Purpose: This study aimed to introduce a novel [18F]AlF-labeled ODAP-Urea-based Prostate-specific membrane antigen (PSMA) probe, named [18F]AlF-PSMA-137, which was derived from the successful modification of glutamate-like functional group. The preclinically physical and biological characteristics of the probe were analyzed. Polit clinical PET/CT translation was performed to analyze its feasibility in clinical diagnosis of prostate cancer. Methods: [18F]AlF-PSMA-137 was maturely labeled with the [18F]AlF2+ labeling technique. It was analyzed by radio-HPLC for radiochemical purity and stability analysis in vitro and in vivo. The PSMA specificity was investigated in PSMA-positive (LNCaP) and PSMA-negative (PC3) cells, and the binding affinity was evaluated in LNCaP cells. Micro-PET/CT imaging was performed in mice bearing LNCaP or PC3 tumors. Thirteen patients with newly diagnosed prostate cancer were included for [18F]AlF-PSMA-137 PET/CT imaging. Physiologic biodistribution and tumor burden were semi-quantitatively evaluated and the radiation dosimetry of [18F]AlF-PSMA-137 was estimated. Results: The radiochemical yield of [18F]AlF-PSMA-137 was 54.2 ± 10.7% (n = 16) with the radiochemical purity over 99% and the specific activity of 26.36 ± 7.33 GBq/µmol. The binding affinity to PSMA was 2.11 ± 0.63 nM. [18F]AlF-PSMA-137 showed high cell/tumor uptake which can be specifically blocked by PSMA inhibitor. According to the biodistribution in patients, [18F]AlF-PSMA-137 was mainly accumulated in kidneys, lacrimal glands, parotid glands, submandibular glands and liver which was similar to the extensive Glu-Ureas based probes. A total of 81 lesions were detected in PET/CT imaging and over 91% of lesions increased between 1 h p.i. (SUVmean: 10.98 ± 18.12) and 2 h p.i. (SUVmean: 14.25 ± 21.28) (p < 0.001). Additionally, the probe showed intensive accumulation in lesions which provided excellent imaging contrast with the high tumor-to-muscle ratio of 15.57 ± 27.21 at 1 h p.i. and 25.42 ± 36.60 at 2 h p.i. (p < 0.001), respectively. The effective dose of [18F]AlF-PSMA-137 was estimated as 0.0119 ± 0.0009 mSv/MBq. Conclusion: An ODAP-Urea-based PSMA probe [18F]AlF-PSMA-137 was successfully prepared with high specificity and binding affinity to PSMA. Micro-PET/CT imaging study demonstrated its feasibility for prostate cancer imaging. Pilot clinical study showed its potential for delay-imaging and prostate cancer detection.
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Owing to the complex anatomical structure, precise resection of a tumor while maintaining adjacent tissue is a challenge in radical prostatectomy for prostate cancer (PCa). Optical imaging in near-infrared window II (NIR-II) is a promising technology for intraoperative guidance, whereas there is no available probe for PCa yet. In this article, a novel probe (PSMA-1092) bearing two prostate-specific membrane antigen (PSMA) binding motifs was developed, displaying excellent optical properties (λmax = 1092 nm) and ultrahigh affinity (Ki = 80 pM) toward PSMA. The tumor was visualized with high resolution (tissue-to-normal tissue ratio = 7.62 ± 1.05) and clear margin by NIR-II imaging using PSMA-1092 in a mouse model. During the tumor resection, residual tumors missed by visible inspection were detected by the real-time imaging. Overall, PSMA-1092 displayed excellent performance in delineating the tumor margin and detecting residual tumors, demonstrating promising potential for precise PCa tumor resection in clinical practice.