Synthesis and evaluation of [99mTc]TcAMD3465 as a SPECT tracer for CXCR4 receptor imaging

Article abstract of DOI:10.1007/s10967-020-07532-8

CXCR4 plays an important role in a number of immunological-based diseases and cancers. The development of radiotracers targeting CXCR4 can provide a valuable tool for the diagnosis and monitoring of conditions involving deregulation of the receptor. The i

Full text of DOI:10.1007/s10967-020-07532-8

Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
https://doi.org/10.1007/s10967-020-07532-8
Synthesis and evaluation of [99mTc]TcAMD3465 as a SPECT tracer
for CXCR4 receptor imaging
Yitian Wu · Hong Zhu · Xiaojun Zhang · Peng Yu · Yuan Gui · Zhihong Xu · Jinming Zhang · Jiahe Tian1
1
2
1
1
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1
Received: 5 June 2020 / Accepted: 27 November 2020 / Published online: 4 January 2021
©
Akadémiai Kiadó, Budapest, Hungary 2021
Abstract
CXCR4 plays an important role in a number of immunological-based diseases and cancers. The development of radiotracers
targeting CXCR4 can provide a valuable tool for the diagnosis and monitoring of conditions involving deregulation of the
receptor. The incorporation of multiple radionuclides into small molecules, peptides, and CXCR4 ligands have been reported
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and characterized. In this study, a Tc labeled AMD3465 with high yields and radiochemical purity was prepared. In vitro
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and in vivo study of [ Tc]TcAMD3465 showed high stability and binding aꢀnity, with a hydrophilic log P value of − 2.67.
Biodistribution study was investigated using tissue and organ samples with a well-type Na(I) detector, high radioactivity accu-
mulation was observed in liver, spleen and bone, consistent with high CXCR4 expression in these organs. SPECT imaging
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was performed in H460 xenograft mouse model, [ Tc]TcAMD3465 showed comparable tumor uptake and a signiꢁcantly
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high tumor-to-background ratio, suggesting potential utility of [ Tc]TcAMD3465 as a CXCR4 receptor imaging agent.
Keywords Chemokine · CXCR4 · AMD3465 · 99mTc · Tumor imaging
Introduction
or molecules in health and disease. A lot of attempts have
been made to non-invasively image CXCR4 expressing
1
11
99m
The chemokine receptor (CXCR4) is a member of the
CXC-chemokine family belonging to a larger superfamily
of receptors known as G-protein coupled receptors (GPCRs).
CXCR4 is overexpressed in a range of human cancers
including breast, prostate, lung and colon cancer, as well as
multiple myeloma [1–4], it also plays a role in tumor metas-
tasis, providing an attractive target for cancer diagnosis and
treatment [5, 6].
tumor, such as using SPECT or PET/CT with In-, Tc-,
1
8
125
F-labeled peptides and I-labeled monoclonal antibod-
6
8
ies [7–10]. Ga-Pentixafor, a radiolabeled cyclic pentapep-
tide with high aꢀnity to CXCR4, has proven to be useful
in quantiꢁcation of CXCR4 [11]. A small molecule agent,
AMD3100, which was the ꢁrst non-peptide CXCR4 inhibi-
6
4
tor approved for clinical use, has been labeled with Cu,
6
7
99m
64
99m
Ga and
Tc [12–16]. [ Cu]CuAMD3100 and [ Tc]
Non-invasive imaging techniques can provide a better
understanding of the role of targeting biological tissues
TcAMD3100 have been evaluated in healthy mice and
the radioligands are accumulated in CXCR4 expressing
organs such as spleen and liver. However, AMD3100 has
6
4
a low aꢀnity for CXCR4 (651± 37nM), and Cu-labeled
AMD3100 showed a high non-speciꢁc liver uptake of >40%
[14]. A second-generation chelator, AMD3465 has been
demonstrated to have a higher aꢀnity, smaller molecular
weight and a monocyclam structure, as well as being ten-
fold more eꢂective as a CXCR4 antagonist than AMD3100
*
Jinming Zhang
zhangjm301@163.com
Hong Zhu
zh_zy@163.com
Yuan Gui
6
4
rabbitgy1981@163.com
[17, 18]. The suitability of Cu-labeled AMD3465 for
CXCR4 tumor imaging has been reported. However, sig-
niꢁcant (40%ID/g) accumulation of the labeled agent in liver
has also been observed [19]. The synthesis of another PET
1
2
3
Department of Nuclear Medicine, Chinese PLA General
Hospital, Beijing 100853, China
Department of Nuclear Medicine, Nanjing General Hospital
of Nanjing Command, Nanjing 21002, China
1
1
imaging agent N-[ C]methyl-AMD3465 has also been suc-
cessful, the tumor-to-muscle ratio was found to be 7.85 at
Huayi Isotopes, Changshu 215501, Jiangsu, China
Vol.:(0
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Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
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0 min after tracer injection, and CXCR4 expression in
19.9mmol) in CH CN (30mL) at 90°C was added K CO
3
3
2
tumors or other CXCR4 expressing tissues can be detected
(1.00g, 5.45mmol), followed by a solution of compound 1
99m
[
20]. Nevertheless, Tc is widely considered the best medi-
(2.4g, 4.8mmol) in CH CN (45mL) slowly within 1.5h. The
3
cal radionuclide due to its favorable physical properties and
reliable labeling technology, and SPECT imaging is more
available and aꢂordable compare to PET/CT. Therefore, the
reaction was kept at 90°C until completion. The solvent was
evaporated and the residue was puriꢁed by chromatogra-
phy on silica gel eluting with gradient MeOH/DCM to give
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development of a Tc-based agent for AMD3465 is highly
desirable and would have great potential for CXCR4 tumor
imaging.
compound 2 as a white solid in 49% yield (1.6g, 2.3mmol).
1
H NMR (300MHz, CDCl ) δ 7.31 (d, J=7.9Hz, 2H), 7.23
3
(d, J = 8.0 Hz, 2H), 4.48 (s, 2H), 3.52 (s, 2H), 3.20–3.50
(m, 12H), 2.62(br s, 2H), 2.38 (br s, 2H), 1.90 (br s, 2H),
1.55–1.75 (m, 2H), 1.30–1.50 (m, 27H); LC-MS: calculated
for C H BrN O 682.3, 684.3; found [M+H] 683.3, 685.3.
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Here, we report the synthesis and
Tc radiolabeling of
AMD3465 starting from cyclam, and the detail evaluation
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by in vitro and in vivo studies of [ Tc]TcAMD3465 as an
SPECT imaging agent for CXCR4.
33
55
4
6
Synthesis of tri‑tert‑butyl 11‑(4‑(((pyridin‑2‑ylmethyl)
amino)methyl)benzyl)‑1,4,8,11‑tetraazacyclotetra‑
decane‑1,4,8‑tricarboxylate (3)
Materials and methods
General
K CO (0.225 g, 1.62 mmol) was added to a solution of
2
3
2
-(aminomethyl)pyridine (0.465 g, 4.3 mmol) in CH CN
3
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Na TcO was provided by the China Institute of Atomic
(30mL). The suspension was heated to 80°C, and a solution
4
99
99m
Energy (CIAE). It was prepared by eluting from Mo/ Tc
of compound 2 (0.60g, 0.90mmol) in CH CN (20mL) was
3
generator in saline. All other chemicals were commercial
added slowly over 2h. The reaction was reꢃuxed for 40min,
1
analytical grade and used without further puriꢁcation. H-
concentrated and puriꢁed by chromatography on silica gel
NMR spectra were recorded in CDCl or DMSO-d on a
eluting with gradient MeOH/DCM to give compound 3 in
3
6
1
Bruker spectrometer operating at 300 MHz. Radio-TLC
was performed on BioScan-2000 radio-TLC using What-
man No.1 strips.
80% yield (0.5 g, 0.7 mmol). H NMR (300 MHz, CDCl )
3
δ 8.57 (d, 1H, J = 4.2 Hz), 7.66 (dt, 1H, J = 1.8,7.7 Hz),
7.16–7.35 (m, 6H), 3.99 (s,2H), 3.87 (s, 2H), 3.52 (s, 2H),
3
.20–3.42 (m, 12H), 2.60 (br s, 2H), 2.38 (br s, 2H), 1.90
Chemistry
(br s, 2H),1,0.67 (br s, 2H), 1.30–1.50 (m, 27H); LC-MS:
calculated for C H N O 710.47; found [M + H] 711.5,
3
9
62
6
6
Synthesis of tri‑tert‑butyl
[M+Na] 733.5.
1,4,8,11‑tetraazacyclotetradecane‑1,4,8‑tricarboxylate (1)
Synthesis of N‑(4‑((1,4,8,11‑tetraazacyclotetradecan‑1‑yl)
The reaction was conducted as previously described [22].
Brieꢃy, to a solution of cyclam (3.35g, 16.7mmol) in dichlo-
romethane (90 mL) was added di-tert-butyl dicarbonate
methyl)benzyl)‑1‑(pyridin‑2‑yl)methanamine (AMD3465)
12M HCl (10mL) was added slowly to a solution of com-
(
9.4g, 43.4mmol) in dichloromethane (60mL) slowly within
pound 3 (0.50g, 0.70mmol) in CH OH (15mL). The solu-
3
3
h at 0°C under nitrogen. The reaction was stirred at room
tion was stirred at room temperature for 10h. The methanol
was evaporated and the resulting solid was washed with
ether and ꢁltered to give AMD3465 as yellow solid in 89%
temperature for 12h. Solvent was evaporated, and the crude
product was puriꢁed by chromatography on silica gel eluting
with gradient MeOH/DCM to give compound 1 as a white
1
yield (0.37 g, 0.62 mmol). H NMR (300 MHz, DMSO) δ
1
solid in 45% yield (3.8 g, 7.6 mmol). H NMR (300 MHz,
11.9 (br s, 1H), 9.60–10.4 (m, 8H), 8.64 (d, J=4.2Hz, 1H),
7.92 (dt, J = 1.8,7.7 Hz, 1H), 7.60–7.68 (m, 4H), 7.56(d,
J = 7.9 Hz, 1H), 7.45–7.50 (m, 1H), 4.35 (br s, 2H), 4.32
(s, 2H), 4.28 (s, 2H), 3.42–3.58 (m, 8H), 3.20–3.38 (m,
8H), 2.08–2.30 (m, 4H); LC-MS: calculated for C H N
CDCl ) δ 3.20–3.45 (br, 12H), 2.79 (t, 2H, J=5.2Hz), 2.62
3
(
(
[
t, 2H, J=5.2Hz), 1.90 (br s, 2H), 1.70 (br s, 2H), 1.40–1.50
m, 27H); LC-MS: calculated for C H N O6 500.36; found
25
48
4
M+H] 501.4.
2
4
38
6
4
10.32;found [M+H] 411.4.
Synthesis of tri‑tert‑butyl 11‑(4‑(bromomethyl)
benzyl)‑1,4,8,11‑tetraazacyclotetradecane‑1,4,8‑tricarbox‑
ylate (2)
Radiochemistry
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The [ Tc]TcAMD3465 was prepared similarly to [ Tc]
TcAMD3100 [12]. Briefly, an AMD3465 solution was
The reaction was carried out according to reported proce-
dures [22]. To a heated solution of dibromoxylene (5.25 g
prepared by dissolving 0.1 mg AMD3465 in 0.5 mL H O
2
1
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Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
629
and the pH was adjusted to 7.0 using 1mol/L citrate solu-
of cells was counted and the IC values were determined by
5
0
tion. Then freshly prepared SnCl solution (300 µL; 1mg
nonlinear regression analysis using GraphPad Prism 5.0 and
reported as mean of triplicate measurements.
2
SnCl /1 mL H O) was added followed by 1850 MBq
2
2
9
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−
(
50mCi) of Na TcO . The mixture was kept at ambient
4
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temperature for 20 min to give [ Tc]TcAMD3465. For-
mation of the labeled compound was conꢁrmed by radio-
Tumor models
99m
TLC analysis. Approximately 2 µL [ Tc]TcAMD3564 was
spotted on Whatman No. 1 paper strips. The strips were
developed by two diꢂerent solvents: acetone and saline.
Animal experiments were conducted under a protocol
approved by the PLA Animal Care and Use Committee. All
work was performed in accordance with the terms of the
Animals (Scientiꢁc Procedures) Act 1986, Regulations of
Beijing Municipality on the administration of experimental
animals 2004, Guiding opinions on treating animals well
2006 and Guidelines for ethical review of laboratory ani-
mal welfare in Beijing. Providing a clean, comfortable and
safe living environment for experimental animals, and give
them enough feed and clean water. During the use of ani-
mals, panic and pain should be minimized. Female nude
mice obtained from Academy of Military Medical Sciences
at 6weeks of age were injected subcutaneously in the right
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With saline as the eluent, the hydrated
TcO impurities
2
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remained at the original point, while [ Tc]TcAMD3465
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−
and the free
TcO migrated to the solvent front. With
4
9
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acetone as the eluent, [ Tc]TcAMD3465 and the hydrated
9
9
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9m
TcO remained at the original point, while the free
2
−
TcO migrated with the solvent. When the solvent
4
reached the desired distance, the strips were taken out and
the radioactivity was scanned on AR2000.
Measurement of partition coeꢀcient
7
hind leg with 10 H460 lung adenocarcinoma cells. When
Octanol-water partition coefficient was determined by
the tumors reached 1.0cm in diameter, the mice were used
for SPECT imaging.
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measuring the distribution of [ Tc]TcAMD3465 in
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n-octanol and 0.01mol/L PB (pH 7.4). A sample of [ Tc]
TcAMD3465 (100 µL) was diluted with PB (900 µL), and
was mixed with n-octanol (1 mL). The mixture was vor-
texed for 5min, and then centrifuged at 4000rpm for 5min
to ensure separation of two layers. 10 µL aliquots were col-
lected from both layers and each radioactivity was counted
with counter respectively. Log P value was calculated
using Log P=log(CPM for octanol/CPM for water) and is
reported as the average of three independent experiments.
Biodistribution studies
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A dose of 3.7 MBq [ Tc]TcAMD3465 was injected
through the tail vein into ꢁve groups of normal NH mice
(20–22g, n=5/group). The mice were sacriꢁced at 30min,
60min, and 90min post injection and the organs of interest
(blood, heart, liver, spleen, lung, kidneys and others) were
dissected and weighed, the uptake of each organ was counted
by a well-type Na(I) detector and expressed as the percent-
age of injection dose per gram (%ID/g). All biodistribution
studies were carried out in compliance with the national laws
related to the conduct of animal experimentation.
In vitro stability study
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The in vitro stability of [ Tc]TcAMD3465 was studied
by measuring radiochemical purity (RCP) in 0.01 mol/L
NaH PO buꢂer (PB) and 1% BSA at diꢂerent time intervals
SPECT imaging
2
4
(
1, 2, 4, 8 and 24h) at room temperature using radio-TLC.
The SPECT imaging was performed in both normal NH
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In vitro receptor binding assays
mice and tumor bearing mice. [ Tc]TcAMD3465 was
injected to mice via the tail vein at a dose of 15MBq in
0.2 mL PBS. The mice were anesthetized with isoꢃurane/
The in vitro receptor binding assays were performed on
Jurkat-T cells to test the binding aꢀnity in homologous
competition as described elsewhere [13]. Brieꢃy, Jurkat-T
cells were harvested and seeded in 12-well plates at a den-
O . The whole body imaging was performed using Siemens
2
SPECT with pinhole collimator at 60min after injection.
5
sity of 10 cells per well. After 24h, the cells were washed
two times with 0.5 mL PBS. The cells were treated with
unlabeled AMD3465 solution at the ꢁnal concentration of
Results
−
6
9
−3
1
0
to 10 M, following by incubation with 100 nmol/L
Chemistry and radiolabeling
9m
of [ Tc]TcAMD3465. Cells were incubated in 1000 µL
binding buꢂer (PBS containing 5 nM MgCl , 1nM CaCl ,
AMD3465 was synthesized by a four-step reaction sequence
starting from cyclam (Scheme 1). The intermediates and
2
2
0
.25% BSA) at 37°C for 1 h. After incubation, cells were
1
washed twice with 0.5mL cold binding buꢂer. The uptake
the target compound were characterized by H-NMR and
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Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
Scheme 1 Synthesis of AMD3465 and 99mTc-AMD3465
mass spectrometry, with the results conforming to expected
In vitro receptor binding assays
99m
chemical structures. AMD3465 was labeled with Na TcO
4
by reduction with stannous chloride. For thin layer chroma-
Jurkat-T cell line expresses high level of CXCR4 and was
used in a homologous binding assay to determine the aꢀn-
tography (TLC) analysis, a two-eluent system (acetone and
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99m
saline) similar to that for [ Tc]TcAMD3100 was used. It
ity of [ Tc]TcAMD3465 to CXCR4 receptor. The results
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99m
was found that the radiochemical purities (RCP) of [ Tc]
TcAMD3465 were greater than 99% (Fig. 1), and the spe-
ciꢁc activity was > 37 GBq/µmol. The radiolabeled com-
pound was used directly for in vitro and in vivo studies.
are shown in Fig. 2. The IC value of [ Tc]TcAMD3465
5
0
was 72.2± 1.4µM, indicating a higher aꢀnity than that of
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[
Tc]TcAMD3100 (97± 3.4µM) (results not shown). In
the literature, Hartimath S.V reported IC of 92± 5µM for
5
0
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[
Tc]TcAMD3100 [13].
1
. Synthesis of AMD3465 and [99mTc]TcAMD3465.
Biodistribution studies
Measurement of partition co‑eꢀcient
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The biodistribution of [ Tc]TcAMD3465 in normal NH
mice was evaluated at 30, 60min after injection (Fig. 3). In
general, immune tissues such as the blood, kidney, bone,
spleen, and liver showed relative high levels of radioactiv-
ity at all time points. The accumulation of radioactivity in
heart, muscle, lung, and stomach were relatively low. Very
low levels of radioactivity were demonstrated in brain, con-
The partition co-efficient (log P) value of [99mTc]
TcAMD3465 was determined to be − 2.67, similar to the log
6
4
P of − 2.71 reported for [ Cu]CuAMD3465 [19], suggest-
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ing a hydrophilic nature of the radiotracers. Thus, [ Tc]
TcAMD3465 is expected to behave similarly to the hydro-
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philic [ Tc]TcAMD3100 as a suitable agent for tumor
imaging without crossing the blood brain barrier (BBB).
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ꢁrming to the anticipated low BBB penetration of [ Tc]
TcAMD3465 due to its high hydrophilicity.
In vitro stability study
SPECT imaging
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Tc-AMD3465 was found to be stable (>99% radiochemi-
cal purity) in PBS (pH 7.4) and 1% BSA for 24h at room
SPECT image obtained in normal NH mice 60 min after
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99m
99m
temperature, similar to [ Tc]TcAMD3100. It is believed
injection of [ Tc]TcAMD3465 is shown in Fig. 4a. [ Tc]
TcAMD3465 was excreted from kidneys and bladder. Liver
and femur uptake of the tracer was detectably high. No accu-
mulation of radioactivity was observed in healthy brain,
9
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that the stabilization of
Tc in AMD3100 and AMD3465
is attributed to the common cyclam structure. The stability
was suꢀcient to further biodistribution and imaging studies.
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Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
631
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because of the existence of an intact blood-brain barrier and
the high hydrophilicity of the radio agent.
the preparation of [ Tc]TcAMD3465 using previously
optimized procedures for AMD-3100, provided high purity
radiocompounds suitable for in vitro and in vivo charac-
terization without further puriꢁcation. It appears that the
pyridyl methylamine group in AMD3465 exerted simi-
lar hydrophilicity to the cyclam moiety and the measured
A plane projection image from SPECT at 60 min of a
mouse bearing a H460 tumor on the right front leg after
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intravenous injection of 15 MBq [ Tc]TcAMD3465 is
shown in Fig. 4b. The tumor was clearly visible and showed
high contrast to the contralateral muscles. The results were
consistent with the known overexpression of CXCR4 in
H460 cells [21]. High uptake was also seen in the liver, con-
sistent with the biodistribution results of the present study
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logP of [ Tc]TcAMD3465 was nearly identical to that
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64
of [ Tc]TcAMD3100 and [ Cu]Cu-AMD3465 [19], but
1
1
more lower than N-[ C]methyl-AMD3465 [20].
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The in vitro stability of [ Tc]TcAMD3465 was evalu-
ated in pH 7.4 buꢂer and 1% BSA, and no detectable dis-
sociation of technetium from the complex was observed on
64
as well as that for [ Cu]CuAMD3465, which was evaluated
as a PET tracer for CXCR4 imaging and showed signiꢁcant
accumulation in the liver.
Discussion
The chelation properties of cyclam-based small molecule
CXCR4 antagonists, such as AMD3100 and AMD3465,
have been utilized for the preparation of radiopharmaceu-
ticals as imaging agents that can be used for diagnosis
and post-treatment monitoring of CXCR4 positive tumors.
While AMD3100 is approved for stem cell mobilization
in patients with lymphoma and multiple myeloma, and
the preparation and evaluation of AMD3100 radiolabeled
6
4
67
99m
with Cu, Ga and
Tc have been reported, a more
potent and selective radioimaging agent that can provide
improved speciꢁcity and sensitivity is in need. In this
regard, AMD3465, a monocyclam structure agent, rep-
resents a propelling candidate due to its superior aꢀnity
to CXCR4 compared to AMD3100. In the present study,
Fig. 2 In vitro homologous AMD3465 displacement assay with
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[
Tc]TcAMD3465
Fig. 1 Radio-TLC chromatograms in a acetone, b saline
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3

632
Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
9
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The SPECT imaging study of [ Tc]TcAMD3465 was
conducted in an H460 lung cancer xenograft mouse model.
The clear visualization of the CXCR4 expressing tumor
demonstrated potential utility of this new radiotracer,
although the signiꢁcant accumulation of radioactivity
in the liver and bladder in both tumor-bearing mice and
controls would limit its application in these organs. Also,
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the in vivo speciꢁcity of [ Tc]TcAMD3465 for CXCR4
remains unclear, and can only be further characterized
by additional studies such as blocking experiments and
kinetic imaging studies using additional tumor models.
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64
[
Tc]TcAMD3465 exhibited advantages over [ Cu]
1
1
CuAMD3465 and N-[ C]methyl-AMD3465. First, the
9
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64
11
obtention of
Tc is easier than Cu and C, and SPECT
Fig. 3 Biodistribution of [99mTc]TcAMD3465 in organs of NH mice
imaging is more available and aꢂordable compare to PET/
CT. Next, the radiolabeling technology is mature. Last, the
injected with 3.7MBq radiotracer
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physical properties of
Tc is favorable, the half-life time
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of
Tc(6h) is more appropriate for imaging, while longer
6
4
half-time of Cu(13h) will result more radiation burden to
11
patients and the shorter half-time of C(20min) will limit the
use in hospitals without cyclotron. So, for institution without
99m
a cyclotron or even without a PET/CT, [ Tc]TcAMD3465
could be an attractive SPECT tracer for imaging of CXCR4
expression tumors.
Conclusions
AMD3465 was synthesized and successfully labeled with
9
9m
Tc with high labeling yield and good in vitro stability.
Homologous CXCR4 binding assays showed IC value of
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50
Fig. 4 a Normal NH mice imaging with [ Tc]TcAMD3465; b
99m
9
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72.2± 1.4µM for [ Tc]TcAMD3465, compared to IC of
50
H460 tumor-bearing mice imaging with [ Tc]TcAMD3465
9
9m
99m
9
7± 3.4µM for [ Tc]TcAMD3100. [ Tc]TcAMD3465
showed high aꢀnity for organs with high CXCR4 expression.
In the H460 cell xenograft model, the tumor was clearly vis-
radio TLC at room temperature for 24h, suggesting limited
metal translocation from the complex to plasma proteins.
99m
9
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ible after injection of [ Tc]TcAMD3465. The results suggest
As expected, [ Tc]TcAMD3465 displayed a higher
binding aꢀnity for CXCR4 in Jurkat-T cells compare to
99m
that [ Tc]TcAMD3465 could be useful for the imaging of
CXCR4 receptor expressing tumors.
9
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[
Tc]TcAMD3100, albeit not as dramatic as metal free
ligands. This is likely due to the signiꢁcant impact of
the Tc complexation to the binding aꢀnity of the parent
compounds towards CXCR4, which is presumably highly
dependent on the interaction between the cyclam and the
receptor protein. In the presence of Tc, the availability of
protonated tetraaza-functionality of the cyclam for hydro-
gen bonding or electrostatic interactions with target pro-
teins can diminish dramatically.
Acknowledgements The authors are very grateful to the National
Natural Science Foundation of China (81071170) and Beijing Natural
Science Foundation (7122162) for ꢁnancial support.
Author contributions J.Z. and J.T. conceived and designed the experi-
ments; Y.W., X.Z. and Y.G. performed the experiments; Y.W., H.Z. and
P.Y. analyzed the data; Z.X. provided reagents/materials/analysis tools;
Y.W. wrote the paper.
The signiꢁcant uptake of kidney, bone, spleen, and
liver is consistent with high expression of CXCR4 in these
organs, similar to the biodistribution results observed
Compliance with ethical standards
Conflict of interest The authors declare no conꢃict of interest. The
founding sponsors had no role in the design of the study; in the col-
lection, analyses, or interpretation of data; in the writing of the manu-
script, and in the decision to publish the results.
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for [ Tc]TcAMD3100. However, the accumulation of
9
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[
Tc]TcAMD3465 in liver (< 1%ID/g) was much lower
6
4
11
than that of [ Cu]CuAMD3465(40%ID/g) and N-[ C]
methyl-AMD3465 [19, 20], .
1
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Journal of Radioanalytical and Nuclear Chemistry (2021) 327:627–633
633
target radiopharmaceutical for tumor imaging. Chin Chem Lett
References
2
1:461–463
1
1
1
3. Hartimath SV, Domanska UM, Walenkamp AM, Rudi AJOD,
1
.
Redjal N, Chan JA, Segal RA, Kung AL (2006) CXCR4 inhibition
synergizes with cytotoxic chemotherapy in gliomas. Clin Cancer
Res 12:6765–6771
99m
de Vries EF (2013) [ Tc]O2-AMD3100 as a SPECT tracer for
CXCR4 receptor imaging. Nucl Med Biol 40:507–517
4. Jacobson O, Weiss ID, Szajek L, Farber JM, Kiesewetter DO
2
3
.
.
Balkwill F (2004) The signiꢁcance of cancer cell expression of
the chemokine receptor CXCR4. Semin Cancer Biol 14:171–179
Tanaka T, Bai Z, Srinoulprasert Y, Yang BG, Hayasaka H, Miya-
saka M (2005) Chemokines in tumor progression and metastasis.
Cancer Sci 96:317–322
6
4
(
2009) Cu-AMD3100—a novel imaging agent for targeting
chemokine receptor CXCR4. Bioorg Med Chem 17:1486–1493
5. Nimmagadda S, Pullambhatla M, Stone K, Green G, Bhujwalla
ZM, Pomper MG (2010) Molecular imaging of CXCR4 recep-
6
4
tor expression in human cancer xenografts with Cu-AMD3100
positron emission tomography. Cancer Res 70:3935–3944
4
5
6
.
.
.
Kim J, Takeuchi H, Lam ST, Turner RR, Wang HJ, Kuo C, Fos-
hag L, Bilchik AJ, Hoon DS (2005) Chemokine receptor CXCR4
expression in colorectal cancer patients increases the risk for
recurrence and for poor survival. J Clin Oncol 23:2744–2753
Xiang Z, Zeng Z, Tang Z, Fan J, Zhuang P, Liang Y, Tan YS, He J
1
1
1
6. Aghanejad A, Jalilian AR, Fazaeli Y, Alirezapoor B, Pouladi
M, Beiki D, Maus S, Khalaj A (2013) Synthesis and evalua-
6
7
tion of Ga-AMD3100: a novel imaging agent for targeting the
chemokine receptor CXCR4. Sci Pharm 82:29–42
(
2009) Chemokine receptor CXCR4 expression in hepatocellular
7. Hatse S, Princen K, Declercq E, Rosenkilde MM, Schwartz TW,
Hernandez-Abad PE, Skerlj RT, Bridger GJ, Schols D (2005)
AMD3465, a monomacrocyclic CXCR4 antagonist and potent
HIV entry inhibitor. Biochem Pharmacol 70:752–761
carcinoma patients increases the risk of bone metastases and poor
survival. BMC Cancer 9:176
Ling X, Spaeth E, Chen Y, Shi Y, Zhang W, Schober W, Hail
N Jr, Konopleva M, Andreeꢂ M (2013) The CXCR4 antagonist
AMD3465 regulates oncogenic signaling and invasiveness in vitro
and prevents breast cancer growth and metastasis in vivo. PLoS
One 8:e58426
8. Bodart V, Anastassov V, Darkes MC, Idzan SR, Labrecque J, Lau
G, Mosi RM, Neꢂ KS, Nelson KL, Ruzek MC, Patel K, San-
tucci Z, Scarborough R, Wong RS, Bridger GJ, Macfarland RT,
Fricker SP (2009) Pharmacology of AMD3465: a small molecule
antagonist of the chemokine receptor CXCR4. Biochem Pharma-
col 78:993–1000
7
8
9
.
.
.
Misra P, Lebeche D, Ly H, Schwarzkopf M, Diaz G, Hajjar
RJ, Schecter AD, Frangioni JV (2008) Quantitation of CXCR4
9
9m
expression in myocardial infarction using
Tc-labeled SDF-
1
2
9. DeSilva RA, Peyre K, Pullambhatla M, Fox JJ, Pomper MG, Nim-
magadda S (2011) Imaging CXCR4 expression in human cancer
1
alpha. J Nucl Med 49:963–969
Hanaoka H, Mukai T, Tamamura H, Mori T, Ishino S, Ogawa
K, Iida Y, Doi R, Fujii N, Saji H (2006) Development of a
6
4
xenografts: evaluation of monocyclam Cu-AMD3465. J Nucl
Med 52:986–993
1
11
In-labeled peptide derivative targeting a chemokine receptor,
0. Hartimath SV, Waarde AV, Dierckx RAJO, Vries EFJ (2014) Eval-
uation of N [11C]Methyl-AMD3465 as a PET tracer for imaging
of CXCR4 receptor expression in a C6 glioma tumor model. Mol
Pharm 11:3810
CXCR4, for imaging tumors. Nucl Med Biol 33:489–494
Jacobson O, Weiss ID, Kiesewetter DO, Farber JM, Chen X
1
8
(
2010) PET of tumor CXCR4 expression with 4- F-T140. J Nucl
Med 51:1796–1804
2
2
1. Liang CY, Liu HF1, Liu X, Zhou NK, Zhang JM, Guo J (2011)
Expression of CXCR4 protein and mRNA in diꢂerent lung cancer
cell lines. J Chin PLA Postgrad Med Sch 32:757–759
2. Gui Y, Xu ZH, Zhang XJ, Zhang SW, Liu J, Tian JH, Zhang JM
1
1
0. Boulais PE, Dulude D, Cabana J, Heveker N, Escher E, Lavi-
gne P, Leduc R (2009) Photolabeling identiꢁes transmembrane
domain 4 of CXCR4 as a T140 binding site. Biochem Pharmacol
7
8:1382–1390
(
2013) Synthesis of AMD3100 for antagonist of CXCR4 and
1. Lapa C, Lückerath K, Kleinlein I, Monoranu CM, Linsenmann T,
Kessler AF, Rudelius M, Kropf S, Buck AK, Ernestus RI, Wester
99m
labeled with
Tc. Isotopes 26:158–162
6
8
HJ, Löhr M, Herrmann K (2016) Ga-pentixafor-PET/CT for
imaging of chemokine receptor 4 expression in glioblastoma.
Theranostics 6:428–434
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jurisdictional claims in published maps and institutional aꢀliations.
1
2. Zhang JM, Tian JH, Li TR, Guo HY, Shen L (2010)
9
9m
Tc-AMD3100:
a novel potential receptor-based
1
3