To elucidate potential benefits of the Auger-electron-emitting radionuclide Tb, we compared the preclinical performance of the gastrin-releasing peptide receptor antagonists RM2 (DOTA-Pip-d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH) and AMTG (α-Me-Trp-RM2), each labeled with both Lu and Tb. Tb/Lu labeling (90°C, 5 min) and cell-based experiments (PC-3 cells) were performed. In vivo stability (30 min after injection) and biodistribution studies (1-72 h after injection) were performed on PC-3 tumor-bearing CB17-SCID mice. Gastrin-releasing peptide receptor affinity was high for all compounds (half-maximal inhibitory concentration [nM]: [Tb]Tb-RM2, 2.46 ± 0.16; [Tb]Tb-AMTG, 2.16 ± 0.09; [Lu]Lu-RM2, 3.45 ± 0.18; [Lu]Lu-AMTG, 3.04 ± 0.08), and 75%-84% of cell-associated activity was receptor-bound. In vivo, both AMTG analogs displayed distinctly higher stability (30 min after injection) and noticeably higher tumor retention than their RM2 counterparts. On the basis of preclinical results, [Tb]Tb-/[Lu]Lu-AMTG might reveal a higher therapeutic efficacy than [Tb]Tb-/[Lu]Lu-RM2, particularly [Tb]Tb-AMTG because of additional Auger-electron emissions at the cell membrane level.
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http://dx.doi.org/10.2967/jnumed.123.266233 | DOI Listing |
Clin Nucl Med
January 2025
From the Department of Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Purpose: The aim of this study was to investigate the value of 68Ga-NOTA-RM26 (68Ga-RM26), a gastrin-releasing peptide receptor-targeting antagonist labeled with the radionuclide 68Ga, in the diagnosis of high-grade gliomas and in combination with multiregional biopsies using PET/CT.
Patients And Methods: After institutional review board approval and informed consent, a total of 35 patients with suspected glioma lesions were enrolled in this study. All patients underwent 68Ga-RM26 PET/CT scans within 2 weeks before surgery.
Anticancer Drugs
January 2025
Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) effectively treat EGFR-mutant lung adenocarcinoma, demonstrating initial efficacy but eventually leading to acquired resistance. Small cell transformation is a rare resistance mechanism to EGFR-TKIs in lung adenocarcinoma, which can complicate clinical diagnosis and treatment. We present a patient with lung adenocarcinoma who underwent a prior pneumonectomy and adjuvant chemotherapy and was treated with osimertinib after the recurrence of lung cancer.
View Article and Find Full Text PDFCells
December 2024
Targeted Therapy Branch, Division of Rare and Refractory Cancer, Research Institute, National Cancer Center, Goyang 10408, Republic of Korea.
Metastasis is a leading cause of lung adenocarcinoma (LUAD)-related mortality and presents significant challenges for treatment. The gastrin-releasing peptide receptor (GRPR), a member of the G protein-coupled receptor (GPCR) family, has an unclear role in LUAD progression. This study aimed to investigate the function and underlying mechanisms of GRPR in LUAD metastasis.
View Article and Find Full Text PDFPhys Eng Sci Med
January 2025
Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, 14155-1339, Iran.
Gastrin-releasing peptide receptors (GRPRs) overexpressed in many cancers are known as promising biomarkers to target tumors such as prostate, breast, and lung cancers. As the early diagnosis of the cancers can serve for better treatment of the patients, [In]In-DOTA-Pip-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 ([In]In-RM2) was prepared using an in-house developed Sn/In generator. 0.
View Article and Find Full Text PDFJ Nucl Med
January 2025
Nuclear Medicine Department, Bordeaux University Hospital, Bordeaux, France.
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