Increasing molar activity by HPLC purification improves 68Ga-DOTA-NAPamide tumor accumulation in a B16/F1 melanoma xenograft model

Mapping Intimacies ◽

10.1101/537258 ◽

2019 ◽

Author(s):

Jan Lennart von Hacht ◽

Sarah Erdmann ◽

Lars Niederstadt ◽

Sonal Prasad ◽

Asja Wagener ◽

...

Keyword(s):

Pet Imaging ◽

Xenograft Model ◽

Positron Emission Tomography Imaging ◽

Peptide Receptor Radionuclide Therapy ◽

Melanocortin Receptor ◽

Target Tissue ◽

Tumor Uptake ◽

Molar Activity ◽

Biodistribution Studies ◽

Unlabeled Peptide

AbstractPurposeMelanocortin receptor 1 is overexpressed in melanoma and may be a molecular target for imaging and peptide receptor radionuclide therapy. 68Gallium labeling of DOTA-conjugated peptides is an established procedure in the clinic for use in positron emission tomography imaging. Aim of this study was to compare a standard labeling protocol against the 68Ga-DOTA peptide purified from the excess of unlabeled peptide.ProceduresThe MC1R ligand DOTA-NAPamide was labeled with 68Ga using a standard clinical protocol. Radioactive peptide was separated from the excess of unlabeled DOTA-NAPamide by HPLC. Immediately after the incubation of peptide and 68Ga (95 °C, 15 min), the reaction was loaded on a C18 column and separated by a water/acetonitrile gradient, allowing fractionation in less than 20 minutes. Radiolabeled products were compared in biodistribution studies and PET imaging using nude mice bearing MC1R-expressing B16/F1 xenograft tumors.ResultsIn biodistribution studies, the non-purified 68Ga-DOTA-NAPamide did not show significant uptake in the tumor at 1 h post injection (0.78% IA/g). By the additional HPLC step, the molar activity was raised around 10,000-fold by completely removing unlabeled peptide. Application of this rapid purification strategy led to a more than 8-fold increase in tumor uptake (7.0% IA/g). The addition of various amounts of unlabeled DOTA-NAPamide to the purified product led to a blocking effect and a decreased specific tumor uptake, similar to the result seen with non-purified radiopeptide. PET imaging was performed using the same tracers for biodistribution. Purified 68Ga-DOTA-NAPamide, in comparison, showed superior tumor uptake.ConclusionsWe demonstrated that chromatographic separation of radiolabeled from excess unlabeled peptide is technically feasible and beneficial, even for short-lived isotopes such as 68Ga. Unlabeled peptide molecules compete with receptor binding sites in the target tissue. Purification of the radiopeptide therefore improved tumor uptake.

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Effects of novel heparin-derived compounds on tumor uptake of chemotherapeutics and chemoresponse

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.2537 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. 2537-2537 ◽

Cited By ~ 1

Author(s):

P. Phillips ◽

M. Yalcin ◽

H. Cui ◽

H. H. Abdel-Nabi ◽

M. Sajjad ◽

...

Keyword(s):

Tumor Growth ◽

Human Lung ◽

Lung Tumor ◽

Xenograft Model ◽

Chemotherapeutic Agents ◽

Tumor Xenograft ◽

Tumor Uptake ◽

Human Lung Tumor ◽

Biodistribution Studies ◽

Human Lung Carcinoma

2537 Thrombotic complications are the second most common cause of mortality in cancer patients and fibrin deposition in the tumor microenvironment might play a key role in tumor progression and inference with tumor chemotherapeutic uptake. Treatments that target these processes may result in improved uptake of chemotherapeutic agents and subsequent inhibition of tumor growth and metastasis. Tissue Factor (TF) is frequently associated with aggressive behavior and poor outcome in tumors. We have previously demonstrated potent anti-tumor efficacy for various mechanisms that interfere with TF/VIIa. The purpose of this study was to investigate the effects of low molecular weight heparins (LMWH) and sulfated non-anticoagulant LMWH (S-NACH) on tumor chemotherapeutic uptake. Studies: (1) Nude mice xenograft A549 human lung carcinoma: LMWH or S-NACH at 10 mg/kg S.C. daily effectively limited tumor growth. (2) LCC6 human lung tumor xenograft model: Paclitaxel alone or in combination with Tinzaparin or S-NACH on tumor re-growth after discontinuation of treatment: Paclitaxel + S-NACH treatment showed significant (P<0.01) tumor growth suppression and improved survival when compared to Paclitaxel. (3) Biodistribution studies: animals were injected with LMWH S.C. daily for 5 days (10 mg/kg) then injected i.v. with [124-I]-Paclitaxel. LMWH increased [124-I]-Paclitaxel uptake into LCC6 tumors with tumor: muscle ratios several fold greater than that of [124-I]-Paclitaxel alone at 24 hrs post injection. This is a highly significant result in the light of the fact that the FDA criterion for a clinically meaningful effect is a 15% increase in uptake. (4) HPLC studies of tumor uptake of Doxorubicin (DOX in mice treated with 10 mg/kg of LMWH or S-NACH for 10 days followed by Doxorubicin (2.5 mg/kg). Both LMWH and S-NACH significantly (P<0.01) increased the uptake of chemotherapeutic agent DOX in MCF7 DOX resistant tumors by 1.5–2 folds but not in heart or lung tissues, confirming the findings obtained with another agent [124-I]-Paclitaxel. Conclusions: LMWH or S-NACH increased chemotherapeutics uptake and hence chemoresponse. Protocols utilizing adjuvant or neo-adjuvant therapy with LMWH or S-NACH could lead to increase tumor chemo responsiveness and overcoming tumor chemo resistance. No significant financial relationships to disclose.

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64Cu-SARTATE PET Imaging of Patients with Neuroendocrine Tumors Demonstrates High Tumor Uptake and Retention, Potentially Allowing Prospective Dosimetry for Peptide Receptor Radionuclide Therapy

Journal of Nuclear Medicine ◽

10.2967/jnumed.118.217745 ◽

2018 ◽

Vol 60 (6) ◽

pp. 777-785 ◽

Cited By ~ 19

Author(s):

Rodney J. Hicks ◽

Price Jackson ◽

Grace Kong ◽

Robert E. Ware ◽

Michael S. Hofman ◽

...

Keyword(s):

Neuroendocrine Tumors ◽

Pet Imaging ◽

Radionuclide Therapy ◽

Peptide Receptor Radionuclide Therapy ◽

Tumor Uptake ◽

Peptide Receptor ◽

High Tumor Uptake

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89Zr-pembrolizumab biodistribution is influenced by PD-1-mediated uptake in lymphoid organs

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-000938 ◽

2020 ◽

Vol 8 (2) ◽

pp. e000938 ◽

Cited By ~ 1

Author(s):

Elly L van der Veen ◽

Danique Giesen ◽

Linda Pot-de Jong ◽

Annelies Jorritsma-Smit ◽

Elisabeth G E De Vries ◽

...

Keyword(s):

Bone Marrow ◽

Lymph Nodes ◽

Pet Imaging ◽

Immune Checkpoint ◽

Whole Body ◽

Lymphoid Tissues ◽

Tumor Uptake ◽

Body Distribution ◽

Biodistribution Studies

BackgroundTo better predict response to immune checkpoint therapy and toxicity in healthy tissues, insight in the in vivo behavior of immune checkpoint targeting monoclonal antibodies is essential. Therefore, we aimed to study in vivo pharmacokinetics and whole-body distribution of zirconium-89 (89Zr) labeled programmed cell death protein-1 (PD-1) targeting pembrolizumab with positron-emission tomography (PET) in humanized mice.MethodsHumanized (huNOG) and non-humanized NOG mice were xenografted with human A375M melanoma cells. PET imaging was performed on day 7 post 89Zr-pembrolizumab (10 µg, 2.5 MBq) administration, followed by ex vivo biodistribution studies. Other huNOG mice bearing A375M tumors received a co-injection of excess (90 µg) unlabeled pembrolizumab or 89Zr-IgG4 control (10 µg, 2.5 MBq). Tumor and spleen tissue were studied with autoradiography and immunohistochemically including PD-1.ResultsPET imaging and biodistribution studies showed high 89Zr-pembrolizumab uptake in tissues containing human immune cells, including spleen, lymph nodes and bone marrow. Tumor uptake of 89Zr-pembrolizumab was lower than uptake in lymphoid tissues, but higher than uptake in other organs. High uptake in lymphoid tissues could be reduced by excess unlabeled pembrolizumab. Tracer activity in blood pool was increased by addition of unlabeled pembrolizumab, but tumor uptake was not affected. Autoradiography supported PET findings and immunohistochemical staining on spleen and lymph node tissue showed PD-1 positive cells, whereas tumor tissue was PD-1 negative.Conclusion89Zr-pembrolizumab whole-body biodistribution showed high PD-1-mediated uptake in lymphoid tissues, such as spleen, lymph nodes and bone marrow, and modest tumor uptake. Our data may enable evaluation of 89Zr-pembrolizumab whole-body distribution in patients.

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Evaluation of A Novel GLP-1R Ligand for PET Imaging of Prostate Cancer

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520618666180801101730 ◽

2019 ◽

Vol 19 (4) ◽

pp. 509-514 ◽

Cited By ~ 1

Author(s):

Yuanyuan Yue ◽

Yuping Xu ◽

Lirong Huang ◽

Donghui Pan ◽

Zhicheng Bai ◽

...

Keyword(s):

Prostate Cancer ◽

Pet Imaging ◽

Ex Vivo ◽

Xenograft Model ◽

Small Animal ◽

Small Animal Pet ◽

Great Promise ◽

Western Blots ◽

Biodistribution Studies

Background:Glucagon-like peptide 1 receptor (GLP-1R) is an important biomarker for diagnosis and therapy of the endocrine cancers due to overexpression. Recently, in human prostate cancer cell lines the receptor was also observed, therefore it may be a potential target for the disease. 18F-Al-NOTA-MAL-Cys39- exendin-4 holds great promise for GLP-1R. Therefore, the feasibility of the 18F-labeled exendin-4 analog for prostate cancer imaging was investigated.Methods:New probe 18F-Al-NOTA-MAL-Cys39-exendin-4 was made through one-step fluorination. Prostate cancer PC3 cell xenograft model mice were established to primarily evaluate the imaging properties of the tracer via small animal PET studies in vivo. Pathological studies and Western Blots were also performed.Results:PC-3 prostate xenografts were clearly imaged under baseline conditions. At 30 and 60 min postinjection, the tumor uptakes were 2.90±0.41%ID/g and 2.26±0.32 %ID/g respectively. The presence of cys39-exendin-4 significantly reduced the tumor uptake to 0.82±0.10 %ID/g at 60 min p.i. Findings of ex vivo biodistribution studies were similar to those of in vivo PET imaging. The tumors to blood and muscles were significantly improved with the increase of time due to rapid clearance of the tracer from normal organs. Low levels of radioactivity were also detected in the GLP-1R positive tumor and normal organs after coinjection with excessive unlabeled peptides. Immunohistochemistry and Western Blots results confirmed that GLP-1R was widely expressed in PC-3 prostate cancers.Conclusion:18F-Al labeled exendin-4 analog might be a promising tracer for in vivo detecting GLP-1R positive prostate cancer with the advantage of facile synthesis and favorable pharmacokinetics. It may be useful in differential diagnosis, molecularly targeted therapy and prognosis of the cancers.

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Combination of 131I-trastuzumab and lanatoside C enhanced therapeutic efficacy in HER2 positive tumor model

10.21203/rs.3.rs-120062/v1 ◽

2020 ◽

Author(s):

Nagarajan Vinod ◽

Jae Kim ◽

Seungbum Choi ◽

Ilhan Lim

Keyword(s):

Tumor Progression ◽

Therapeutic Efficacy ◽

Xenograft Model ◽

Tumor Xenograft ◽

Potential Candidate ◽

Tumor Uptake ◽

Her2 Positive ◽

Biodistribution Studies ◽

Lanatoside C

Abstract Lanatoside C has a promising anti-tumor activity and is a potential candidate for radiosensitizers. In this study, we have investigated the therapeutic efficacy of the combination of 131I-trastuzumab and lanatoside C for inhibition of human epidermal growth factor receptor 2 (HER2) positive tumor progression in NCI-N87 xenograft model. The combination treatment (131I-trastuzumab and lanatoside C) showed highest cytotoxicity when compared to non-treated control or trastuzumab alone or 131I alone or 131I-trastuzumab alone in vitro. Biodistribution studies using 131I-trastuzumab or combination of 131I-trastuzumab and lanatoside C showed tumor uptake in BALB/c nude mice bearing HER2 positive NCI-N87 tumor xenograft model. The higher tumor uptake was observed in 131I-trastuzumab (19.40±0.04% ID/g) than in the combination of 131I-trastuzumab and lanatoside C (14.02±0.02% ID/g) at 24 hours post-injection. Most importantly, an antitumor effect was observed in mice that received the combination of 131I-trastuzumab and lanatoside C (p=0.009) when compared to control. In addition, mice received lanatoside C alone (p=0.085) or 131I-trastuzumab alone (p=0.160) did not significantly inhibit tumor progression compared with control. Taken together, our data suggest that combination of 131I-trastuzumab and lanatoside C might be a potential synergistic treatment for radioimmunotherapy to control the HER2 positive tumor.

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CMKLR1-targeting peptide tracers for PET/MR imaging of breast cancer

10.1101/575902 ◽

2019 ◽

Author(s):

Sarah Erdmann ◽

Lars Niederstadt ◽

Eva Jolanthe Koziolek ◽

Juan Daniel Castillo Gómez ◽

Sonal Prasad ◽

...

Keyword(s):

Breast Cancer ◽

Mr Imaging ◽

Ex Vivo ◽

Xenograft Model ◽

Organ Distribution ◽

Post Injection ◽

Tumor Uptake ◽

Biodistribution Studies ◽

Targeting Peptide

AbstractMolecular targeting remains to be a promising approach in cancer medicine. Knowledge about molecular properties such as overexpression of G protein-coupled receptors (GPCRs) is thereby offering a powerful tool for tumor-selective imaging and treatment of cancer cells. We utilized chemerin-based peptides for CMKLR1 receptor targeting in a breast cancer xenograft model. By conjugation with radiolabeled chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), we obtained a family of highly specific and affine tracers for hybridin vivoimaging with positron emission tomography (PET)/ magnetic resonance (MR) and concomitant biodistribution studies.MethodsWe developed five highly specific and affine peptide tracers targeting CMKLR1 by linker-based conjugation of chemerin peptide analogs (CG34 and CG36) with radiolabeled (68Ga) chelator DOTA. Our established xenograft model with target-positive DU4475 and negative A549 tumors in immunodeficient nude mice enabled CMKLR1-specific imagingin vivo. Therefore, we acquired small animal PET/MR images, assessed biodistribution byex vivomeasurements and investigated the tracer specificity by blocking experiments.ResultsThe family of five CMKLR1-targeting peptide tracers demonstrated high biological activity and affinityin vitrowith EC50and IC50values being below 2 nM. Our target-positive (DU4475) and target-negative (A549) xenograft model could be confirmed byex vivoanalysis of CMKLR1 expression and binding. After preliminary PET imaging, the three most promising tracers68Ga-DOTA-AHX-CG34,68Ga-DOTA-KCap-CG34 and68Ga-DOTA-ADX-CG34 with apparent DU4475 tumor uptake were further analyzed. Hybrid PET/MR imaging along with concomitant biodistribution studies revealed distinct CMKLR1-specific uptake (5.1% IA/g, 4.5% IA/g and 6.2% IA/g 1 h post-injection) of our targeted tracers in DU4475 tumor tissue. More strikingly, the tumor uptake could be blocked by excess of unlabeled peptide (6.4-fold, 7.2-fold and 3.4-fold 1 h post-injection) and further confirmed the CMKLR1 specificity. As our five tracers, each with particular degree of hydrophobicity, showed different results regarding tumor uptake and organ distribution, we identified these three tracers with moderate, balanced properties to be the most potent in receptor-mediated tumor targeting.ConclusionWith the breast cancer cell line DU4475, we established a model endogenously expressing our target CMKLR1 to evaluate our chemerin-based peptide tracers as highly affine and specific targeting agents. Eventually, we demonstrated the applicability of our68Ga-labeled tracers by visualizing CMKLR1-positive breast cancer xenografts in PET/MR imaging and thus developed promising theranostics for tumor treatment.

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Combination of 131I-trastuzumab and lanatoside C enhanced therapeutic efficacy in HER2 positive tumor model

Scientific Reports ◽

10.1038/s41598-021-92460-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nagarajan Vinod ◽

Jae Hyung Kim ◽

Seungbum Choi ◽

Ilhan Lim

Keyword(s):

Tumor Progression ◽

Therapeutic Efficacy ◽

Xenograft Model ◽

Tumor Xenograft ◽

Potential Candidate ◽

Tumor Uptake ◽

Her2 Positive ◽

Biodistribution Studies ◽

Lanatoside C

AbstractLanatoside C has a promising anti-tumor activity and is a potential candidate for radiosensitizers. In this study, we have investigated the therapeutic efficacy of the combination of 131I-trastuzumab and lanatoside C for inhibition of human epidermal growth factor receptor 2 (HER2) positive tumor progression in NCI-N87 xenograft model. The combination treatment (131I-trastuzumab and lanatoside C) showed highest cytotoxicity when compared to non-treated control or trastuzumab alone or 131I alone or 131I-trastuzumab alone in vitro. Biodistribution studies using 131I-trastuzumab or combination of 131I-trastuzumab and lanatoside C showed tumor uptake in BALB/c nude mice bearing HER2 positive NCI-N87 tumor xenograft model. The higher tumor uptake was observed in 131I-trastuzumab (19.40 ± 0.04% ID/g) than in the combination of 131I-trastuzumab and lanatoside C (14.02 ± 0.02% ID/g) at 24 h post-injection. Most importantly, an antitumor effect was observed in mice that received the combination of 131I-trastuzumab and lanatoside C (p = 0.009) when compared to control. In addition, mice received lanatoside C alone (p = 0.085) or 131I-trastuzumab alone (p = 0.160) did not significantly inhibit tumor progression compared with control. Taken together, our data suggest that combination of 131I-trastuzumab and lanatoside C might be a potential synergistic treatment for radioimmunotherapy to control the HER2 positive tumor.

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Intraindividual comparison of [177Lu]Lu-DOTA-EB-TATE and [177Lu]Lu-DOTA-TOC

European Journal of Nuclear Medicine and Molecular Imaging ◽

10.1007/s00259-020-05177-z ◽

2021 ◽

Author(s):

Heribert Hänscheid ◽

Philipp E. Hartrampf ◽

Andreas Schirbel ◽

Andreas K. Buck ◽

Constantin Lapa

Keyword(s):

Radionuclide Therapy ◽

Therapeutic Agent ◽

Somatostatin Receptor ◽

Absorbed Dose ◽

Peptide Receptor Radionuclide Therapy ◽

Somatostatin Analogue ◽

Target Tissue ◽

Peptide Receptor ◽

Intraindividual Comparison ◽

Administered Activity

Abstract Purpose The radiolabelled somatostatin analogue [177Lu]Lu-DOTA-EB-TATE binds to albumin via Evans blue, thereby increasing the residence time in the blood and potentially allowing more therapeutic agent to be absorbed into the target tissue during peptide receptor radionuclide therapy. It was tested in selected patients whether the substance is superior to [177Lu]Lu-DOTA-TOC. Methods Activity kinetics in organs and tumours after [177Lu]Lu-DOTA-EB-TATE and [177Lu]Lu-DOTA-TOC were compared intraindividually in five patients with progressive somatostatin receptor-positive disease scheduled for radionuclide therapy. Results In comparison to [177Lu]Lu-DOTA-TOC, tumour doses per administered activity were higher for [177Lu]Lu-DOTA-EB-TATE in 4 of 5 patients (median ratio: 1.7; range: 0.9 to 3.9), kidney doses (median ratio: 3.2; range: 1.6 to 9.8) as well as spleen doses (median ratio: 4.7; range 1.2 to 6.2) in all patients, and liver doses in 3 of 4 evaluable patients (median ratio: 4.0; range: 0.7 to 4.9). The tumour to critical organs absorbed dose ratios were higher after [177Lu]Lu-DOTA-TOC in 4 of 5 patients. Conclusions Prior to a treatment with [177Lu]Lu-DOTA-EB-TATE, it should be assessed individually whether the compound is superior to established substances.

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