Abstract
Early detection of primary melanoma tumors is essential because there is no effective treatment for metastatic melanoma. Several linear and cyclic radiolabeled α-melanocyte stimulating hormone (α-MSH) analogs have been proposed to target the melanocortin type 1 receptor (MC1R) overexpressed in melanoma. The compact structure of a rhenium-cyclized α-MSH analog (Re-CCMSH) significantly enhanced its in vivo tumor uptake and retention. Melanotan II (MT-II), a cyclic lactam analog of α-MSH (Ac-Nle-cyclo[Asp-His-dPhe-Arg-Trp-Lys]-NH2]), is a very potent and stable agonist peptide largely used in the characterization of melanocortin receptors. Taking advantage of the superior biological features associated with the MT-II cyclic peptide, we assessed the effect of lactam-based cyclization on the tumor-seeking properties of α-MSH analogs by comparing the pharmacokinetics profile of the 99mTc-labeled cyclic peptide βAla-Nle-cyclo[Asp-His-d-Phe-Arg-Trp-Lys]-NH2 with that of the linear analog βAla-Nle-Asp-His-dPhe-Arg-Trp-Lys-NH2 in melanoma-bearing mice. We have synthesized and coupled the linear and cyclic peptides to a bifunctional chelator containing a pyrazolyl-diamine backbone (pz) through the amino group of βAla, and the resulting pz–peptide conjugates were reacted with the fac-[99mTc(CO)3]+ moiety. The 99mTc(CO)3-labeled conjugates were obtained in high yield, high specific activity, and high radiochemical purity. The cyclic 99mTc(CO)3-labeled conjugate presents a remarkable internalization (87.1% of receptor-bound tracer and 50.5% of total applied activity, after 6 h at 37 °C) and cellular retention (only 24.7% released from the cells after 5 h) in murine melanoma B16F1 cells. A significant tumor uptake and retention was obtained in melanoma-bearing C57BL6 mice for the cyclic radioconjugate [9.26 ± 0.83 and 11.31 ± 1.83% ID/g at 1 and 4 h after injection, respectively]. The linear 99mTc(CO)3-pz–peptide presented lower values for both cellular internalization and tumor uptake. Receptor blocking studies with the potent (Nle4,dPhe7)-αMSH agonist demonstrated the specificity of the radioconjugates to MC1R (74.8 and 44.5% reduction of tumor uptake at 4 h after injection for cyclic and linear radioconjugates, respectively).
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Abbreviations
- αMSH:
-
α-Melanocyte stimulating hormone
- Boc:
-
tert-Butoxycarbonyl
- BSA:
-
Bovine serum albumin
- DMEM:
-
Dulbecco’s modified Eagle’s medium
- DOTA:
-
1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid
- ESI-MS:
-
Electrospray ionization mass spectrometry
- 18F-FDG:
-
Fluoro-2-deoxyglucose
- Fmoc:
-
9-Fluorenylmethoxycarbonyl
- HPLC:
-
High-performance liquid chromatography
- ID:
-
Injected dose
- MC1R:
-
Melanocortin type 1 receptor
- MEM:
-
Modified Eagle’s medium
- MT-II:
-
Melanotan II
- NAPamide:
-
[Ac–Nle4,Asp5,dPhe7]–αMSH4–11
- NDP-MSH:
-
(Nle4,dPhe7)-αMSH
- PBS:
-
Phosphate-bufered saline
- pz:
-
Tridentate ligand containing a pyrazolyl-diamine backbone
- RP:
-
Reversed phase
- TBTU:
-
O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate
- TFA:
-
Trifluoroacetic acid
- TLC:
-
Thin-layer chromatography
References
Carlson JA, Slominski A, Linette GP, Mihm MC, Ross JS (2003) Expert Rev Mol Diagn 3:303–330
Mijnhout GS, Hoekstra OS, Tulder MW, Teule GJ, Deville WL (2001) Cancer 91:1530–1542
Dimitrakopoulou-Strauss A, Strauss LG, Burger C (2001) J Nucl Med 42:248–256
Ghanem GE, Comunale G, Libert A, Vercammen-Grandjean A, Lejeune FJ (1988) Int J Cancer 41:248–255
Siegrist W, Solca F, Stutz S, Giuffre L, Carrel S, Girard J, Eberle AN (1989) Cancer Res 49:6352–6358
Siegrist W, Stutz S, Eberle AN (1994) Cancer Res 54:2604–2610
Eberle AN, Froidevaux S (2003) J Mol Recognit 16:248–254
Froidevaux S, Calame-Christe M, Shuhmacker J, Tanner H, Saffrich R, Henze M, Eberle AN (2004) J Nucl Med 45:116–123
Cheng Z, Xiong Z, Subbarayan M, Chen X, Gambhir SS (2007) Bioconjug Chem 18:765–772
Chen J-Q, Cheng Z, Owen NK, Hoffman TJ, Miao Y, Jurisson SS, Quinn TP (2001) J Nucl Med 42:1847–1855
Cheng Z, Chen J, Miao Y, Owen NK, Quinn TP, Jurisson SS (2002) J Med Chem 45:3048–3056
Miao Y, Owen NK, Whitener D, Gallazzi F, Hoffman TJ, Quinn TP (2002) Int J Cancer 101:480–487
Miao Y, Whitener D, Feng W, Owen NK, Chen J, Quinn TP (2003) Bioconjug Chem 14:1177–1184
Miao Y, Hoffman TJ, Quinn TP (2005) Nucl Med Biol 32:485–493
Wei L, Butcher C, Miao Y, Gallazzi F, Quinn TP, Welch MJ, Lewis JS (2007) J Nucl Med 48:64–72
Giblin MF, Wang N, Hoffman TJ, Jurisson SS, Quinn TP (1998) Proc Natl Acad Sci USA 95:12814–12818
Chen J-Q, Chen Z, Hoffman TJ, Jurisson SS, Quinn TP (2000) Cancer Res 60:5649–5658
Miao Y, Benwell K, Quinn TP (2007) J Nucl Med 48:73–80
Froidevaux S, Calame-Christe M, Tanner H, Sumanovski L, Eberle AN (2002) J Nucl Med 43:1699–1706
Raposinho PD, Correia JDG, Alves S, Botelho MF, Santos AC, Santos I (2008) Nucl Med Biol 35:91–99
Miao Y, Owen NK, Fisher DR, Hoffman TJ, Quinn TP (2005) J Nucl Med 46:121–129
Miao Y, Hylarides M, Fisher DR, Shelton T, Moore H, Wester DW, Fritzberg AR, Winkelmann CT, Hoffman TJ, Quinn TP (2005) Clin Cancer Res 11:5616–5621
McQuade P, Miao Y, Yoo J, Quinn TP, Welch MJ, Lewis JS (2005) J Med Chem 48:2985–2992
Garcia-Borrón JC, Sánchez-Laorden BL, Jiménez-Cervantes C (2005) Pigment Cell Res 18:393–410
Holder JR, Haskell-Luevano C (2004) Med Res Rev 24:325–56
Alberto R, Pak JK, Staveren DV, Mundwiler S, Benny P (2004) Biopolymers 76:324–333
Alberto R (2005) Top Curr Chem 252:1–44
Schibli R, Schubiger AP (2002) Eur J Nucl Med 29:1529–1542
Santos I, Paulo A, Correia JDG (2005) Top Curr Chem 252:45–84
Banerjee SR, Maresca KP, Francesconi L, Valliant J, Babich JW, Zubieta J (2005) Nucl Med Biol 32:1–20
Alves S, Paulo A, Correia JDG, Domingos Â, Santos I (2002) J Chem Soc Dalton Trans 24:4714–4719
Alves S, Paulo A, Correia JDG, Gano L, Smith CJ, Hoffman TJ, Santos I (2005) Bioconjug Chem 16:438–449
Alves S, Correia JDG, Santos I, Veerendra B, Sieckman GL, Hoffman TJ, Rold T, Retzloff L, McCrate J, Prasanphanich A, Smith CJ (2006) Nucl Med Biol 33:625–634
Alves S, Correia JDG, Gano L, Rold TL, Prasanphanich A, Haubner R, Rupprich M, Alberto R, Decristoforo C, Santos I, Smith CJ (2007) Bioconjug Chem 18:530–537
Fields GB, Noble RL (1990) Int J Pept Protein Res 35:161–214
Knorr R, Trzeciak A, Bannwarth W, Gillessend D (1989) Tetrahedron Lett 30:1927–1930
Lloyd-Williams P, Albericio F, Giralt E (1997) Chemical approaches to the synthesis of peptides and proteins. CRC, Boca Raton
Chhabra SR, Hothi B, Evans D J, White PD, Bycroft BW, Chan WC (1998) Tetrahedron Lett 39:1603–1606
Chan WC, Bycroft BW, Evans DJ, White P D (1995) J Chem Soc Chem Commun 21:2209–2210
Díaz-Mochón J, Bialy L, Bradley M (2004) Org Lett 6:1127–1129
Troutner DE, Volkert WA, Hoffman TJ, Holmes RA (1984) Int J Appl Radiat Isot 35:10467–10470
Behr TM, Goldenberg DM, Becker W (1998) Eur J Nucl Med 25:201–212
Rolleman EJ, Valkema R, de Jong M, Kooij PPM, Krenning ER (2003) Eur J Nucl Med 30:9–15
Miao Y, Fisher DR, Quinn TP (2007) Nucl Med Biol 33:723–733
de Jong M, Barone R, Krenning E, Bernard B, Melis M, Visser T, Gekle M, Willnow TE, Walrand S, Jamar F, Pauwels S (2005) J Nucl Med 46:1696–1700
Verroust PJ, Christensen EI (2002) Nephrol Dial Transplant 17:1867–1871
Acknowledgments
Mallinckrodt-Tyco Inc. is acknowledged for financial support and for providing IsoLink® kits. C.X. thanks Fundação para a Ciência e Tecnologia (FCT) for a PhD grant (SFRH/BD/16680/2004). P.G. thanks FCT for pluriannual funding to the CIQ(UP) research unit.
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Raposinho, P.D., Xavier, C., Correia, J.D.G. et al. Melanoma targeting with α-melanocyte stimulating hormone analogs labeled with fac-[99mTc(CO)3]+: effect of cyclization on tumor-seeking properties. J Biol Inorg Chem 13, 449–459 (2008). https://doi.org/10.1007/s00775-007-0338-3
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DOI: https://doi.org/10.1007/s00775-007-0338-3