Evaluation of a New 99mTc-labeled GnRH Analogue as a Possible Imaging Agent for Prostate Cancer Detection

Author(s): Arezou Masteri Farahani, Fariba Maleki, Nourollah Sadeghzadeh*, Saeid Abediankenari, Seyed Mohammad Abedi, Mostafa Erfani

Journal Name: Anti-Cancer Agents in Medicinal Chemistry
(Formerly Current Medicinal Chemistry - Anti-Cancer Agents)

Volume 20 , Issue 14 , 2020

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Graphical Abstract:


Introduction: Prostate cancer is a serious threat to men’s health so it is necessary to develop technics for early detection of this malignancy. The purpose of this research was the evaluation of a new99mTc-labeled GnRH analogue as an imaging probe for tumor targeting of prostate cancer.

Methods: 99mTc-labeled-DLys6-GnRH analogue was prepared based on HYNIC as a chelating agent and tricine/ EDDA as coligands for labeling with 99mTc. HYNIC was coupled to epsilon amino group of DLys6 through aminobutyric acid (GABA) as a linker. Radiochemical purity and stability in normal saline and serum, were determined by TLC and HPLC methods. Furthermore, calculation of protein-binding and partition coefficient constant were carried out for 99mTc labeled peptide. The cellular experiments including receptor binding specificity and affinity were studied using three prostate cancer cell lines LN-CaP, DU-145 and PC-3. Finally, the animal assessment and SPECT imaging of radiolabeled GnRH analogue were evaluated on normal mice and nude mice bearing LN-CaP tumor.

Results: The GnRH conjugate was labeled with high radiochemical purity (~97%). The radiolabeled peptide showed efficient stability in the presence of normal saline and human serum. The in vitro cellular assays on three prostate cancer cell lines indicated that the radiotracer was bound to LN-CaP cells with higher affinity compared to DU-145 and PC-3 cells. The Kd values of 99mTc- HYNIC (tricine/ EDDA)-Gaba-D-Lys6GnRH were 89.39±26.71, 93.57±30.49 and107.3±18.82 in LN-CaP, PC-3 and DU-145 cells respectively. The biodistribution studies in normal mice and LN-CaP tumor-bearing nude mice showed similar results including rapid blood clearance and low radioactivity accumulation in non-target organs. High kidney uptake proved that the main excretion route of radiopeptide was through the urinary system. The tumor uptake was 1.72±0.45 %ID/g at 1h p.i. decreasing to 0.70±0.06%ID/g at 4h p.i. for 99mTc-HYNIC-Gaba-D-Lys6GnRH. The maximum tumor/ muscle ratio was 2.30 at 1h p.i. Pre-saturation of receptor using an excess of unlabeled peptide revealed that the tumor uptake was receptor mediated. The results of the SPECT image of LN-CaP tumor were in agreement with the biodistribution data.

Conclusion: Based on this study, we suggest LN-CaP as a favorable cell line for in vivo studies on GnRH analogues. Moreover, this report shows that 99mTc-HYNIC (tricine/EDDA)-Gaba-D-Lys6GnRH may be a suitable candidate for further evaluation of prostate cancer.

Keywords: 99mTc, HYNIC, Gaba, GnRH, prostate cancer, imaging.

Fani, M.; Maecke, H.R.; Okarvi, S.M. Radiolabeled peptides: Valuable tools for the detection and treatment of cancer. Theranostics, 2012, 2(5), 481-501.
[http://dx.doi.org/10.7150/thno.4024] [PMID: 22737187]
Nanda, P.K.; Lane, S.R.; Retzloff, L.B.; Pandey, U.S.; Smith, C.J. Radiolabeled regulatory peptides for imaging and therapy. Curr. Opin. Endocrinol. Diabetes Obes., 2010, 17(1), 69-76.
[http://dx.doi.org/10.1097/MED.0b013e32833392ac] [PMID: 19901831]
Laverman, P.; Sosabowski, J.K.; Boerman, O.C.; Oyen, W.J. Radiolabelled peptides for oncological diagnosis. Eur. J. Nucl. Med. Mol. Imaging, 2012, 39(1)(Suppl. 1), S78-S92.
[http://dx.doi.org/10.1007/s00259-011-2014-7] [PMID: 22388627]
Lee, J.W.; Lee, Y.J.; Shin, U.C.; Kim, S.W.; Kim, B.I.; Lee, K.C.; Kim, J.Y.; Park, J-A. Improved pharmacokinetics following PEGylation and dimerization of ac (RGD-ACH-K) conjugate used for tumor positron emission tomography imaging. Cancer Biother. Radiopharm., 2016, 31(8), 295-301.
[http://dx.doi.org/10.1089/cbr.2016.2036] [PMID: 27754748]
Shi, J.; Wang, F.; Liu, S. Radiolabeled cyclic RGD peptides as radiotracers for tumor imaging. Biophys. Rep., 2016, 2(1), 1-20.
[http://dx.doi.org/10.1007/s41048-016-0021-8] [PMID: 27819026]
Okarvi, S.M. Peptide-based radiopharmaceuticals: Future tools for diagnostic imaging of cancers and other diseases. Med. Res. Rev., 2004, 24(3), 357-397.
[http://dx.doi.org/10.1002/med.20002] [PMID: 14994368]
Flanagan, C.A.; Fromme, B.J.; Davidson, J.S.; Millar, R.P. A high affinity Gonadotropin-Releasing Hormone (GnRH) tracer, radioiodinated at position 6, facilitates analysis of mutant GnRH receptors. Endocrinology, 1998, 139(10), 4115-4119.
[http://dx.doi.org/10.1210/endo.139.10.6260] [PMID: 9751490]
Gali, H.; Hoffman, T.J.; Sieckman, G.L.; Owen, N.K.; Katti, K.V.; Volkert, W.A. Synthesis, characterization, and labeling with 99mTc/188Re of peptide conjugates containing a dithia-bisphosphine chelating agent. Bioconjug. Chem., 2001, 12(3), 354-363.
[http://dx.doi.org/10.1021/bc000077c] [PMID: 11353532]
Guo, H.; Gallazzi, F.; Sklar, L.A.; Miao, Y. A novel indium-111-labeled gonadotropin-releasing hormone peptide for human prostate cancer imaging. Bioorg. Med. Chem. Lett., 2011, 21(18), 5184-5187.
[http://dx.doi.org/10.1016/j.bmcl.2011.07.055] [PMID: 21821417]
Li, M.; Tang, Z.; Zhang, Y.; Lv, S.; Li, Q.; Chen, X. Targeted delivery of cisplatin by LHRH-peptide conjugated dextran nanoparticles suppresses breast cancer growth and metastasis. Acta Biomater., 2015, 18, 132-143.
[http://dx.doi.org/10.1016/j.actbio.2015.02.022] [PMID: 25735801]
Schottelius, M.; Berger, S.; Poethko, T.; Schwaiger, M.; Wester, H-J. Development of novel 68Ga- and 18F-labeled GnRH-I analogues with high GnRHR-targeting efficiency. Bioconjug. Chem., 2008, 19(6), 1256-1268.
[http://dx.doi.org/10.1021/bc800058k] [PMID: 18510351]
Guo, H.; Lu, J.; Hathaway, H.; Royce, M.E.; Prossnitz, E.R.; Miao, Y. Synthesis and evaluation of novel gonadotropin-releasing hormone receptor-targeting peptides. Bioconjug. Chem., 2011, 22(8), 1682-1689.
[http://dx.doi.org/10.1021/bc200252j] [PMID: 21749045]
Huang, S.; Li, H.; Han, Y.; Fu, L.; Ren, Y.; Zhang, Y.; Li, Y.; Sun, P.; Wang, M.; Wu, H. Synthesis and evaluation of 18F-labeled peptide for gonadotropin-releasing hormone receptor imaging. Contrast Media Mol. Imag., 2019, 2019, Article ID 563269..
Grzegorzewski, W.J.; Skipor, J.; Wasowska, B.; Krzymowski, T. Countercurrent transfer of 125I-LHRH in the perihypophyseal cavernous sinus-carotid rete vascular complex, demonstrated on isolated pig heads perfused with autologous blood. Domest. Anim. Endocrinol., 1997, 14(3), 149-160.
[http://dx.doi.org/10.1016/S0739-7240(97)00004-0] [PMID: 9171973]
Beckers, T.; Bernd, M.; Kutscher, B.; Kühne, R.; Hoffmann, S.; Reissmann, T. Structure-function studies of linear and cyclized peptide antagonists of the GnRH receptor. Biochem. Biophys. Res. Commun., 2001, 289(3), 653-663.
[http://dx.doi.org/10.1006/bbrc.2001.5939] [PMID: 11726197]
Nagy, A.; Schally, A.V.; Armatis, P.; Szepeshazi, K.; Halmos, G.; Kovacs, M.; Zarandi, M.; Groot, K.; Miyazaki, M.; Jungwirth, A.; Horvath, J. Cytotoxic analogs of luteinizing hormone-releasing hormone containing doxorubicin or 2-pyrrolinodoxorubicin, a derivative 500-1000 times more potent. Proc. Natl. Acad. Sci. USA, 1996, 93(14), 7269-7273.
[http://dx.doi.org/10.1073/pnas.93.14.7269] [PMID: 8692981]
Guo, H.; Hathaway, H.; Royce, M.E.; Prossnitz, E.R.; Miao, Y. Influences of hydrocarbon linkers on the receptor binding affinities of gonadotropin-releasing hormone peptides. Bioorg. Med. Chem. Lett., 2013, 23(20), 5484-5487.
[http://dx.doi.org/10.1016/j.bmcl.2013.08.075] [PMID: 24018188]
Shamshirian, D.; Erfani, M.; Beiki, D.; Fallahi, B.; Shafiei, M. Development of a (99m)Tc-labeled lactam bridge-cyclized alpha-MSH derivative peptide as a possible single photon imaging agent for melanoma tumors. Ann. Nucl. Med., 2015, 29(8), 709-720.
[http://dx.doi.org/10.1007/s12149-015-0998-y] [PMID: 26152564]
Jamous, M.; Haberkorn, U.; Mier, W. Synthesis of peptide radiopharmaceuticals for the therapy and diagnosis of tumor diseases. Molecules, 2013, 18(3), 3379-3409.
[http://dx.doi.org/10.3390/molecules18033379] [PMID: 23493103]
Liu, S. Bifunctional coupling agents for radiolabeling of biomolecules and target-specific delivery of metallic radionuclides. Adv. Drug Deliv. Rev., 2008, 60(12), 1347-1370.
[http://dx.doi.org/10.1016/j.addr.2008.04.006] [PMID: 18538888]
Jia, B.; Liu, Z.; Shi, J.; Yu, Z.; Yang, Z.; Zhao, H.; He, Z.; Liu, S.; Wang, F. Linker effects on biological properties of 111In-labeled DTPA conjugates of a cyclic RGDfK dimer. Bioconjug. Chem., 2008, 19(1), 201-210.
[http://dx.doi.org/10.1021/bc7002988] [PMID: 18069778]
Emrarian, I.; Sadeghzadeh, N.; Abedi, S.M.; Abediankenari, S. New neurotensin analogue radiolabeled by 99m-technetium as a potential agent for tumor identification. Chem. Biol. Drug Des., 2018, 91(1), 304-313.
[http://dx.doi.org/10.1111/cbdd.13082] [PMID: 28816013]
Abrams, M.J.; Juweid, M.; tenKate, C.I.; Schwartz, D.A.; Hauser, M.M.; Gaul, F.E.; Fuccello, A.J.; Rubin, R.H.; Strauss, H.W.; Fischman, A.J. Technetium-99m-human polyclonal IgG radiolabeled via the hydrazino nicotinamide derivative for imaging focal sites of infection in rats. J. Nucl. Med., 1990, 31(12), 2022-2028.
[PMID: 2266401]
Gandomkar, M.; Najafi, R.; Shafiei, M.; Mazidi, M.; Goudarzi, M.; Mirfallah, S.H.; Ebrahimi, F.; Heydarpor, H.R.; Abdie, N. Clinical evaluation of antimicrobial peptide [(99m)Tc/Tricine/HYNIC(0)] ubiquicidin 29-41 as a human-specific infection imaging agent. Nucl. Med. Biol., 2009, 36(2), 199-205.
[http://dx.doi.org/10.1016/j.nucmedbio.2008.11.003] [PMID: 19217532]
Mohammadgholi, M.; Sadeghzadeh, N.; Erfani, M.; Abediankenari, S.; Abedi, S.M.; Emrarian, I.; Jafari, N.; Behzadi, R. Human Fibronectin Extra-Domain B (EDB)-Specific Aptide (APTEDB) Radiolabelling with Technetium-99m as a potent targeted tumour-imaging agent. Anticancer. Agents Med. Chem., 2018, 18(2), 277-285.
Montagnani Marelli, M.; Moretti, R.M.; Mai, S.; Procacci, P.; Limonta, P. Gonadotropin-releasing hormone agonists reduce the migratory and the invasive behavior of androgen-independent prostate cancer cells by interfering with the activity of IGF-I. Int. J. Oncol., 2007, 30(1), 261-271.
[http://dx.doi.org/10.3892/ijo.30.1.261] [PMID: 17143537]
Bateman, T.M. Advantages and disadvantages of PET and SPECT in a busy clinical practice. J. Nucl. Cardiol., 2012, 19(1)(Suppl. 1), S3-S11.
[http://dx.doi.org/10.1007/s12350-011-9490-9] [PMID: 22259006]
Rezazadeh, F.; Sadeghzadeh, N. Tumor targeting with 99m Tc radiolabeled peptides: Clinical application and recent development. Chem. Biol. Drug Des., 2019, 93(3), 205-221.
[http://dx.doi.org/10.1111/cbdd.13413] [PMID: 30299570]
Gründker, C.; Emons, G. The role of gonadotropin-releasing hormone in cancer cell proliferation and metastasis. Front. Endocrinol. (Lausanne), 2017, 8, 187-197.
[http://dx.doi.org/10.3389/fendo.2017.00187] [PMID: 28824547]
Cheung, L.W.; Yung, S.; Chan, T-M.; Leung, P.C.; Wong, A.S. Targeting gonadotropin-releasing hormone receptor inhibits the early step of ovarian cancer metastasis by modulating tumor-mesothelial adhesion. Mol. Ther., 2013, 21(1), 78-90.
[http://dx.doi.org/10.1038/mt.2012.187] [PMID: 23164934]
Halmos, G.; Nagy, A.; Lamharzi, N.; Schally, A.V. Cytotoxic analogs of luteinizing hormone-releasing hormone bind with high affinity to human breast cancers. Cancer Lett., 1999, 136(2), 129-136.
[http://dx.doi.org/10.1016/S0304-3835(98)00316-4] [PMID: 10355741]
Liu, S.; Edwards, D.S.; Looby, R.J.; Harris, A.R.; Poirier, M.J.; Barrett, J.A.; Heminway, S.J.; Carroll, T.R. Labeling a hydrazino nicotinamide-modified cyclic IIb/IIIa receptor antagonist with 99mTc using aminocarboxylates as coligands. Bioconjug. Chem., 1996, 7(1), 63-71.
[http://dx.doi.org/10.1021/bc950069+] [PMID: 8741992]
Decristoforo, C.; Mather, S.J. The influence of chelator on the pharmacokinetics of 99mTc-labelled peptides. Q. J. Nucl. Med., 2002, 46(3), 195-205.
[PMID: 12134136]

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Year: 2020
Published on: 19 June, 2020
Page: [1695 - 1703]
Pages: 9
DOI: 10.2174/1871520620666200619175352
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