The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
Xiaoyuan Chen - One of the best experts on this subject based on the ideXlab platform.
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small animal pet of tumors with 64cu labeled rgd Bombesin heterodimer
The Journal of Nuclear Medicine, 2009Co-Authors: Zhaofei Liu, Fan Wang, Qizhen Cao, Shuanglong Liu, Xiaoyuan ChenAbstract:The overexpression of gastrin-releasing peptide receptor (GRPR) in various tumor types suggests that GRPR is an attractive target for cancer imaging and therapy with radiolabeled Bombesin analogs. We recently reported the ability of 18F-labeled RGD-Bombesin heterodimer to be used for dual integrin αvβ3– and GRPR-targeted imaging. To further investigate the synergistic effect of the dual-receptor targeting of peptide heterodimers, we evaluated 64Cu-labeled RGD-Bombesin for PET imaging of tumors. Methods: RGD-Bombesin was coupled with 1,4,7,10-tetraazacyclododecane-N, N′, N′′, N′′′-tetraacetic acid (DOTA) and 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and the conjugates were labeled with 64Cu. The in vitro and in vivo characteristics of 64Cu-NOTA-RGD-Bombesin were compared with those of 64Cu-NOTA-RGD, 64Cu-NOTA-Bombesin, and 64Cu-DOTA-RGD-Bombesin. Results:64Cu-NOTA-RGD-Bombesin and 64Cu-DOTA-RGD-Bombesin had comparable dual integrin αvβ3– and GRPR-binding affinities in vitro, both of which were slightly lower than RGD for integrin binding and Bombesin for GRPR binding. 64Cu-NOTA-RGD-Bombesin possessed significantly higher tumor uptake than did 64Cu-NOTA-RGD, 64Cu-NOTA-Bombesin, the mixture of 64Cu-NOTA-RGD and 64Cu-NOTA-Bombesin, or 64Cu-DOTA-RGD-Bombesin in PC-3 prostate cancer. 64Cu-NOTA-RGD-Bombesin also showed improved in vivo kinetics such as lower liver and intestinal activity accumulation than did the Bombesin tracers. 64Cu-NOTA-RGD-Bombesin also outperformed 64Cu-NOTA-RGD in a 4T1 murine mammary carcinoma model that expresses integrin on tumor vasculature but no GRPR in tumor tissue, which had no uptake of 64Cu-NOTA-Bombesin. Conclusion: Compared with other tracers, 64Cu-NOTA-RGD-Bombesin showed favorable in vivo kinetics and enhanced tumor uptake, which warrants its further investigation for targeting tumors that express integrin or GRPR or that coexpress integrin and GRPR for imaging and therapeutic applications. The synergistic effect of RGD-Bombesin heterodimers observed in this study also encourages further investigations of novel heterodimers recognizing other cell surface receptors for tumor targeting.
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small animal pet of tumors with 64cu labeled rgd Bombesin heterodimer
The Journal of Nuclear Medicine, 2009Co-Authors: Zibo Li, Fan Wang, Xiaoyuan ChenAbstract:UNLABELLED: The overexpression of gastrin-releasing peptide receptor (GRPR) in various tumor types suggests that GRPR is an attractive target for cancer imaging and therapy with radiolabeled Bombesin analogs. We recently reported the ability of (18)F-labeled RGD-Bombesin heterodimer to be used for dual integrin alpha(v)beta(3)- and GRPR-targeted imaging. To further investigate the synergistic effect of the dual-receptor targeting of peptide heterodimers, we evaluated (64)Cu-labeled RGD-Bombesin for PET imaging of tumors. METHODS: RGD-Bombesin was coupled with 1,4,7,10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic acid (DOTA) and 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and the conjugates were labeled with (64)Cu. The in vitro and in vivo characteristics of (64)Cu-NOTA-RGD-Bombesin were compared with those of (64)Cu-NOTA-RGD, (64)Cu-NOTA-Bombesin, and (64)Cu-DOTA-RGD-Bombesin. RESULTS: (64)Cu-NOTA-RGD-Bombesin and (64)Cu-DOTA-RGD-Bombesin had comparable dual integrin alpha(v)beta(3)- and GRPR-binding affinities in vitro, both of which were slightly lower than RGD for integrin binding and Bombesin for GRPR binding. (64)Cu-NOTA-RGD-Bombesin possessed significantly higher tumor uptake than did (64)Cu-NOTA-RGD, (64)Cu-NOTA-Bombesin, the mixture of (64)Cu-NOTA-RGD and (64)Cu-NOTA-Bombesin, or (64)Cu-DOTA-RGD-Bombesin in PC-3 prostate cancer. (64)Cu-NOTA-RGD-Bombesin also showed improved in vivo kinetics such as lower liver and intestinal activity accumulation than did the Bombesin tracers. (64)Cu-NOTA-RGD-Bombesin also outperformed (64)Cu-NOTA-RGD in a 4T1 murine mammary carcinoma model that expresses integrin on tumor vasculature but no GRPR in tumor tissue, which had no uptake of (64)Cu-NOTA-Bombesin. CONCLUSION: Compared with other tracers, (64)Cu-NOTA-RGD-Bombesin showed favorable in vivo kinetics and enhanced tumor uptake, which warrants its further investigation for targeting tumors that express integrin or GRPR or that coexpress integrin and GRPR for imaging and therapeutic applications. The synergistic effect of RGD-Bombesin heterodimers observed in this study also encourages further investigations of novel heterodimers recognizing other cell surface receptors for tumor targeting.
Teruko Nomoto - One of the best experts on this subject based on the ideXlab platform.
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Impairment of cold-induced increase in thyroxine 5′-deiodinase activity in mouse brown adipose tissue by the intracerebroventricular administration of Bombesin
Peptides, 1992Co-Authors: F Tsukahara, Y. Shibata, Takamura Muraki, Teruko NomotoAbstract:Abstract Effects of Bombesin on brown adipose tissue (BAT) thyroxine (T 4 ) 5′-deiodinase (5′D) activity and rectal temperature were examined in male mice. Immediately following an intracerebroventricular (ICV) or intravenous (IV) injection of Bombesin (0.1–100 ng/animal) or vehicle (20 mM bacitracin dissolved in 0.9% saline), the mice were placed in a room at 4°C or 22°C for 30, 60, 120 or 240 min. The ICV injection of Bombesin dose-dependently lessened cold-induced increase in BAT 5′D activity and increased hypothermia determined at 120 min of cold exposure, whereas the IV injection of Bombesin was without effect. Bombesin (ICV)-induced hypothermia preceded the inhibition of BAT 5′D activity by at least 30 min at 4°C. BAT 5′D activity was not affected by ICV injection of Bombesin in mice kept at 22°C, although the rectal temperature was significantly decreased. Bombesin thus appears to prevent cold-induced increase in T 4 5′D activity in mouse BAT by its central effect. Bombesin-induced excessive hypothermia itself and/or the decrease in sympathetic tone of BAT by Bombesin might decrease cold-induced increase in BAT 5′D activity.
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impairment of cold induced increase in thyroxine 5 deiodinase activity in mouse brown adipose tissue by the intracerebroventricular administration of Bombesin
Peptides, 1992Co-Authors: F Tsukahara, Y. Shibata, Takamura Muraki, Teruko NomotoAbstract:Abstract Effects of Bombesin on brown adipose tissue (BAT) thyroxine (T 4 ) 5′-deiodinase (5′D) activity and rectal temperature were examined in male mice. Immediately following an intracerebroventricular (ICV) or intravenous (IV) injection of Bombesin (0.1–100 ng/animal) or vehicle (20 mM bacitracin dissolved in 0.9% saline), the mice were placed in a room at 4°C or 22°C for 30, 60, 120 or 240 min. The ICV injection of Bombesin dose-dependently lessened cold-induced increase in BAT 5′D activity and increased hypothermia determined at 120 min of cold exposure, whereas the IV injection of Bombesin was without effect. Bombesin (ICV)-induced hypothermia preceded the inhibition of BAT 5′D activity by at least 30 min at 4°C. BAT 5′D activity was not affected by ICV injection of Bombesin in mice kept at 22°C, although the rectal temperature was significantly decreased. Bombesin thus appears to prevent cold-induced increase in T 4 5′D activity in mouse BAT by its central effect. Bombesin-induced excessive hypothermia itself and/or the decrease in sympathetic tone of BAT by Bombesin might decrease cold-induced increase in BAT 5′D activity.
Fan Wang - One of the best experts on this subject based on the ideXlab platform.
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An Update of Radiolabeled Bombesin Analogs for Gastrin-Releasing Peptide Receptor Targeting
Current Pharmaceutical Design, 2013Co-Authors: Z. Yu, H. J. K. Ananias, Giuseppe Carlucci, Hilde D. Hoving, Igle J. De Jong, Wijnand Helfrich, Rudi Dierckx, Fan Wang, Philip H. ElsingaAbstract:Prostate cancer is a critical public health problem in USA and Europe. New non-invasive imaging methods are urgently needed, due to the low accuracy and specificity of current screen methods and the desire of localizing primary prostate cancer and bone metastasis. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are the non-invasive and sensitive imaging methods which have been widely used for diagnosing diseases in the clinic. Lack of suitable radiotracers is the major issue for nuclear imaging of prostate cancer, although radiolabeled Bombesin (BN) peptides targeting the Gastrin-Releasing Peptide Receptor (GRPR) on tumor cells are widely investigated. In this review we discuss the recent trends in the development of GRPRtargeted radiopharmaceuticals based on BN analogs with regard to their potential for imaging and therapy of GRPR-expressing malignancies. Following a brief introduction of GRPR and Bombesin peptides, we summarize the properties of prostate cancer specific radiolabeled Bombesins. New Bombesin tracers published in the last five years are reviewed and compared according to their novelties in biomolecules, radionuclides, labeling methods, bifunctional chelators and linkers. Hot topics such as multimerization, application of agonists and antagonists are highlighted in the review. Lastly, a few clinical trials of cancer nuclear imaging with radiolabeled Bombesin have been discussed.
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small animal pet of tumors with 64cu labeled rgd Bombesin heterodimer
The Journal of Nuclear Medicine, 2009Co-Authors: Zhaofei Liu, Fan Wang, Qizhen Cao, Shuanglong Liu, Xiaoyuan ChenAbstract:The overexpression of gastrin-releasing peptide receptor (GRPR) in various tumor types suggests that GRPR is an attractive target for cancer imaging and therapy with radiolabeled Bombesin analogs. We recently reported the ability of 18F-labeled RGD-Bombesin heterodimer to be used for dual integrin αvβ3– and GRPR-targeted imaging. To further investigate the synergistic effect of the dual-receptor targeting of peptide heterodimers, we evaluated 64Cu-labeled RGD-Bombesin for PET imaging of tumors. Methods: RGD-Bombesin was coupled with 1,4,7,10-tetraazacyclododecane-N, N′, N′′, N′′′-tetraacetic acid (DOTA) and 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and the conjugates were labeled with 64Cu. The in vitro and in vivo characteristics of 64Cu-NOTA-RGD-Bombesin were compared with those of 64Cu-NOTA-RGD, 64Cu-NOTA-Bombesin, and 64Cu-DOTA-RGD-Bombesin. Results:64Cu-NOTA-RGD-Bombesin and 64Cu-DOTA-RGD-Bombesin had comparable dual integrin αvβ3– and GRPR-binding affinities in vitro, both of which were slightly lower than RGD for integrin binding and Bombesin for GRPR binding. 64Cu-NOTA-RGD-Bombesin possessed significantly higher tumor uptake than did 64Cu-NOTA-RGD, 64Cu-NOTA-Bombesin, the mixture of 64Cu-NOTA-RGD and 64Cu-NOTA-Bombesin, or 64Cu-DOTA-RGD-Bombesin in PC-3 prostate cancer. 64Cu-NOTA-RGD-Bombesin also showed improved in vivo kinetics such as lower liver and intestinal activity accumulation than did the Bombesin tracers. 64Cu-NOTA-RGD-Bombesin also outperformed 64Cu-NOTA-RGD in a 4T1 murine mammary carcinoma model that expresses integrin on tumor vasculature but no GRPR in tumor tissue, which had no uptake of 64Cu-NOTA-Bombesin. Conclusion: Compared with other tracers, 64Cu-NOTA-RGD-Bombesin showed favorable in vivo kinetics and enhanced tumor uptake, which warrants its further investigation for targeting tumors that express integrin or GRPR or that coexpress integrin and GRPR for imaging and therapeutic applications. The synergistic effect of RGD-Bombesin heterodimers observed in this study also encourages further investigations of novel heterodimers recognizing other cell surface receptors for tumor targeting.
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small animal pet of tumors with 64cu labeled rgd Bombesin heterodimer
The Journal of Nuclear Medicine, 2009Co-Authors: Zibo Li, Fan Wang, Xiaoyuan ChenAbstract:UNLABELLED: The overexpression of gastrin-releasing peptide receptor (GRPR) in various tumor types suggests that GRPR is an attractive target for cancer imaging and therapy with radiolabeled Bombesin analogs. We recently reported the ability of (18)F-labeled RGD-Bombesin heterodimer to be used for dual integrin alpha(v)beta(3)- and GRPR-targeted imaging. To further investigate the synergistic effect of the dual-receptor targeting of peptide heterodimers, we evaluated (64)Cu-labeled RGD-Bombesin for PET imaging of tumors. METHODS: RGD-Bombesin was coupled with 1,4,7,10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic acid (DOTA) and 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and the conjugates were labeled with (64)Cu. The in vitro and in vivo characteristics of (64)Cu-NOTA-RGD-Bombesin were compared with those of (64)Cu-NOTA-RGD, (64)Cu-NOTA-Bombesin, and (64)Cu-DOTA-RGD-Bombesin. RESULTS: (64)Cu-NOTA-RGD-Bombesin and (64)Cu-DOTA-RGD-Bombesin had comparable dual integrin alpha(v)beta(3)- and GRPR-binding affinities in vitro, both of which were slightly lower than RGD for integrin binding and Bombesin for GRPR binding. (64)Cu-NOTA-RGD-Bombesin possessed significantly higher tumor uptake than did (64)Cu-NOTA-RGD, (64)Cu-NOTA-Bombesin, the mixture of (64)Cu-NOTA-RGD and (64)Cu-NOTA-Bombesin, or (64)Cu-DOTA-RGD-Bombesin in PC-3 prostate cancer. (64)Cu-NOTA-RGD-Bombesin also showed improved in vivo kinetics such as lower liver and intestinal activity accumulation than did the Bombesin tracers. (64)Cu-NOTA-RGD-Bombesin also outperformed (64)Cu-NOTA-RGD in a 4T1 murine mammary carcinoma model that expresses integrin on tumor vasculature but no GRPR in tumor tissue, which had no uptake of (64)Cu-NOTA-Bombesin. CONCLUSION: Compared with other tracers, (64)Cu-NOTA-RGD-Bombesin showed favorable in vivo kinetics and enhanced tumor uptake, which warrants its further investigation for targeting tumors that express integrin or GRPR or that coexpress integrin and GRPR for imaging and therapeutic applications. The synergistic effect of RGD-Bombesin heterodimers observed in this study also encourages further investigations of novel heterodimers recognizing other cell surface receptors for tumor targeting.
Jenn-tser Pan - One of the best experts on this subject based on the ideXlab platform.
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Stimulatory effects of Bombesin-like peptides on hypothalamic arcuate neurons in rat brain slices
Brain research bulletin, 1994Co-Authors: Jing-ying Lin, Jenn-tser PanAbstract:Abstract The effects of Bombesin, gastrin-releasing peptide, neuromedin C, ranatensin, and neuromedin B on hypothalamic arcuate neurons were tested in this study using extracellular single-unit recording in fresh brain tissue slices. Adult ovariectomized Sprague-Dawley rats were used for preparation of brain slices. All Bombesin-like peptides in pmol ranges exhibited potent stimulatory effects on the firing of arcuate neurons i.e., gastrin-releasing peptide stimulated 90.9% ( n = 22), Bombesin 78.0% ( n = 41), neuromedin C 63.2% ( n = 19), ranatensin 58.0% ( n = 22), and neuromedin B 50.0% ( n = 6) of arcuate neurons tested. Pretreatments with either [Leu 13 -gy(CH 2 NH)-Leu 14 ]-Bombesin or [D-Phe 6 , Des-Met 14 ]-Bombesin 6−14 ethylamide, two Bombesin antagonists, significantly blocked most of the actions of Bombesin-like peptides tested. The present results further support the notion that Bombesin-like peptides may play a significant role in the arcuate nucleus.
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Stimulatory effects of Bombesin-like peptides on suprachiasmatic neurons in brain slices.
Brain research, 1993Co-Authors: K C Tang, Jenn-tser PanAbstract:The effects of Bombesin on hypothalamic suprachiasmatic (SCN) neurons were tested in this study using extracellular single-unit recording in brain tissue slices. Fresh slices containing the SCN were obtained from adult ovariectomized Sprague-Dawley rats. Bombesin in pmol ranges stimulated 75% of irregular firing SCN neurons (n = 113), while it stimulated and inhibited 17% and 34% of regular firing units, respectively. Half of the regular firing SCN units, however, were not responsive to Bombesin (49% of 61 units). A dose-dependent (from 5 to 500 pmol) excitatory effect of Bombesin on SCN neurons was also observed. Pretreatment with [Leu13-psi(CH2NH)-Leu14]-Bombesin, a Bombesin receptor antagonist, blocked the action of Bombesin in 67% of 18 units responded to Bombesin, indicating a specific receptor is involved in the action. Gastrin-releasing peptide, a well-recognized Bombesin-like peptide in mammals, behaved almost the same as Bombesin did in most SCN neurons tested (same responses in 24 of 25 units). The present finding indicates that bomesin-like peptides may play a significant role in the SCN for the rhythmic control mechanism.
F Tsukahara - One of the best experts on this subject based on the ideXlab platform.
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Impairment of cold-induced increase in thyroxine 5′-deiodinase activity in mouse brown adipose tissue by the intracerebroventricular administration of Bombesin
Peptides, 1992Co-Authors: F Tsukahara, Y. Shibata, Takamura Muraki, Teruko NomotoAbstract:Abstract Effects of Bombesin on brown adipose tissue (BAT) thyroxine (T 4 ) 5′-deiodinase (5′D) activity and rectal temperature were examined in male mice. Immediately following an intracerebroventricular (ICV) or intravenous (IV) injection of Bombesin (0.1–100 ng/animal) or vehicle (20 mM bacitracin dissolved in 0.9% saline), the mice were placed in a room at 4°C or 22°C for 30, 60, 120 or 240 min. The ICV injection of Bombesin dose-dependently lessened cold-induced increase in BAT 5′D activity and increased hypothermia determined at 120 min of cold exposure, whereas the IV injection of Bombesin was without effect. Bombesin (ICV)-induced hypothermia preceded the inhibition of BAT 5′D activity by at least 30 min at 4°C. BAT 5′D activity was not affected by ICV injection of Bombesin in mice kept at 22°C, although the rectal temperature was significantly decreased. Bombesin thus appears to prevent cold-induced increase in T 4 5′D activity in mouse BAT by its central effect. Bombesin-induced excessive hypothermia itself and/or the decrease in sympathetic tone of BAT by Bombesin might decrease cold-induced increase in BAT 5′D activity.
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impairment of cold induced increase in thyroxine 5 deiodinase activity in mouse brown adipose tissue by the intracerebroventricular administration of Bombesin
Peptides, 1992Co-Authors: F Tsukahara, Y. Shibata, Takamura Muraki, Teruko NomotoAbstract:Abstract Effects of Bombesin on brown adipose tissue (BAT) thyroxine (T 4 ) 5′-deiodinase (5′D) activity and rectal temperature were examined in male mice. Immediately following an intracerebroventricular (ICV) or intravenous (IV) injection of Bombesin (0.1–100 ng/animal) or vehicle (20 mM bacitracin dissolved in 0.9% saline), the mice were placed in a room at 4°C or 22°C for 30, 60, 120 or 240 min. The ICV injection of Bombesin dose-dependently lessened cold-induced increase in BAT 5′D activity and increased hypothermia determined at 120 min of cold exposure, whereas the IV injection of Bombesin was without effect. Bombesin (ICV)-induced hypothermia preceded the inhibition of BAT 5′D activity by at least 30 min at 4°C. BAT 5′D activity was not affected by ICV injection of Bombesin in mice kept at 22°C, although the rectal temperature was significantly decreased. Bombesin thus appears to prevent cold-induced increase in T 4 5′D activity in mouse BAT by its central effect. Bombesin-induced excessive hypothermia itself and/or the decrease in sympathetic tone of BAT by Bombesin might decrease cold-induced increase in BAT 5′D activity.