Synthesis and evaluation of novel N-3-benzimidazolephenylbisamide derivatives for antiproliferative and Hedgehog pathway inhibitory activity

Article abstract of DOI:10.1039/c5md00092k

A series of novel N-3-benzimidazolephenylbisamide derivatives bearing the 4-benzyloxyphenyl moiety were synthesized and evaluated for their antiproliferative activity against MGC803, HT29, MKN45 and SW620 cancer cell lines in vitro. The pharmacological data demonstrated that the majority of the target compounds exhibited higher efficacy against MGC803, HT29 and MKN45 cells, among which compound 7m displayed higher antiproliferative activity than vismodegib. Furthermore, compound 7m manifested better inhibition of the Hedgehog (Hh) signaling pathway in different Hh-related assays and may compete with boron-dipyrromethene (BODIPY)-cyclopamine for binding to the human smoothened (Smo) receptor. In addition, molecular docking studies suggested that compound 7m interacts very closely with the vismodegib docking pose through hydrogen bonds at the taladegib binding site of the Smo receptor.

Full text of DOI:10.1039/c5md00092k

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Synthesis and evaluation of novel N-3-
benzimidazolephenylbisamide derivatives for
antiproliferative and Hedgehog pathway inhibitory
activity†
Cite this: DOI: 10.1039/c5md00092k
Chiyu Sun,a Yangsheng Li,a Ailong Shi,a Jingzhou Zhang,a Yafei Li,a Mingming Zhao,a
a
b
c
a
a
*
*
Lijuan Zhang, Huachuan Zheng, Ying Meng, Huaiwei Ding and Hongrui Song
A series of novel N-3-benzimidazolephenylbisamide derivatives bearing the 4-benzyloxyphenyl moiety
were synthesized and evaluated for their antiproliferative activity against MGC803, HT29, MKN45 and
SW620 cancer cell lines in vitro. The pharmacological data demonstrated that the majority of the target
compounds exhibited higher efficacy against MGC803, HT29 and MKN45 cells, among which compound
7m displayed higher antiproliferative activity than vismodegib. Furthermore, compound 7m manifested
better inhibition of the Hedgehog (Hh) signaling pathway in different Hh-related assays and may compete
with boron-dipyrromethene (BODIPY)-cyclopamine for binding to the human smoothened (Smo) receptor.
In addition, molecular docking studies suggested that compound 7m interacts very closely with the
vismodegib docking pose through hydrogen bonds at the taladegib binding site of the Smo receptor.
Received 4th March 2015,
Accepted 17th April 2015
DOI: 10.1039/c5md00092k
www.rsc.org/medchemcomm
represents
therapy.
a promising approach for novel anticancer
1. Introduction
The Hedgehog (Hh) signaling pathway plays a significant role
in the initiation of cancer, cell growth, cell survival and
metastases.1–3 Activation of the Hh signaling pathway is initi-
ated by Hh ligands bound to its receptor Patched (Ptch),
which relieves its inhibition of the smoothened (Smo) recep-
tor and allows for downstream Hh signal transduction.4–6
Subsequently, active Smo trafficking into a primary cilium
transmits signals via a cytosolic complex of proteins, includ-
ing Suppressor of Fused (SuFu), and these signals trigger acti-
vation of glioma (Gli) zinc-finger transcription factors and aid
their translocation to the nucleus.7–9 This activation inten-
sifies the expression of specific genes that promotes cancer
cell proliferation and differentiation.10,11 Although Hh signal-
ing is silent in most adult tissues, ligand-dependent activa-
tion of Hh signaling has been described in a range of
tumors.12,13 Therefore, inhibition of aberrant Hh signaling
A majority of Hh pathway inhibitors block Hh signaling by
directly binding to the Smo receptor, slowing down tumor
growth in animal models.14,15 At present, there are seven Hh
pathway inhibitors under clinical development,16,17 among
which vismodegib (1) obtained marketing authorization in
the United States in 2012. However, recent evidence has
attested that the resistance was associated with Smo muta-
tion, Gli2 amplification or up-regulation of the phos-
phatidylinositol 3-kinase signaling pathway.18–20 There is still
an urgent need to investigate potent Hh inhibitors with dis-
tinct chemotypes.
As shown in Fig. 1, MRT-10 (2), which is identified by vir-
tual screening of commercial libraries, consists of a ligand-
based pharmacophore and displays antagonist potency in Hh
signaling inhibition assay. Besides, 2 is an attractive com-
pound with a balanced structure displaying two hydrophobic
zones at the terminal parts demarcated by a polar connector
to engage in H-bond interactions at the Smo receptor level.21
Moreover, the 4-benzyloxyphenyl moiety has been considered
as a privileged structure commonly occurring in anticancer
drugs such as lapatinib (3).22 In addition, glasdegib (4) bear-
ing the benzimidazole moiety is a potent Hh inhibitor under
phase II clinical development at Pfizer for the treatment of
leukemia and solid tumors,23 which is effective in low con-
centrations and inhibits both wild-type and oncogenic Smo.
Taladegib (5) is investigated in a phase I clinical trial for
a Key Laboratory of Structure-Based Drug Design and Discovery, Ministry of Edu-
cation, Shenyang Pharmaceutical University, Shenyang 110016, PR China.
E-mail: dinghuaiwei627@163.com, hongruisonghrs@126.com;
Fax: +86 24 23986443; Tel: +86 24 23986443
b The First Affiliated Hospital of Liaoning Medical University, Renmin Street,
Jinzhou 121001, PR China
c College of Pharmacy, Liaoning University of Traditional Chinese Medicine,
Dalian 116600, PR China
† Electronic supplementary information (ESI) available. See DOI: 10.1039/
c5md00092k
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Fig. 1 Structures of Hedgehog pathway inhibitors, lapatinib and the target compound.
patients with small cell lung cancer and brain cancer.24 In
contrast, Hh ligand-dependent abnormal activation has also
been reported in some gastrointestinal tumors,25 and their
cells, such as SW620,26 SW480,27 HT29,28,29 MGC803,30
MKN1 and MKN45,31 express Hh ligands and the down-
stream signaling components Ptch, Smo and Gli1. In 2013, C.
Wang and co-workers solved the co-crystal structure of 5 with
the Smo receptor and revealed its binding mode,32 which was
important for understanding the structure–activity relation-
ships (SARs) of chemically distinct Hh inhibitors.
benzimidazole moiety, and part
B
contains the
4-benzyloxyphenyl moiety. We envision that the merging of
these two bioactive parts with the flexible connector may
afford a compact structure with potential for antiproliferative
activity. Accordingly, we synthesize a series of novel N-3-
benzimidazolephenylbisamide derivatives as antiproliferative
agents and Hh inhibitors, in which the group at the 4-posi-
tion of the A-ring (part A) is methyl or chlorine and the
B-ring (part B) adds various substituents.
Inspired by the structural features of 2, we design the tar-
get compound (I) that contains the following three parts: A, B
and a connector. The connector between A and B, which
includes the acylthiourea or acylurea groups, is retained
because the amide bonds are likely to participate in hydrogen
bond interactions with the Smo receptor. Part A involves the
2. Results and discussion
2.1. Chemistry
Compounds 6a–o and 7a–o were synthesized according to the
routes33–35 outlined in Scheme 1. 2-Methyl-5-nitrobenzoic
acid or 2-chloro-5-nitrobenzoic acid was treated with oxalyl
Scheme 1 Reagents and conditions: (a) (1) (COCl)2, DMF cat, THF, 35 °C, 4 h and (2) 1,2-diaminobenzene, Et3N, THF, 0 °C–rt, 12 h; (b) glacial
acetic acid, 110 °C, reflux, 3 h; (c) SnCl2·2H2O, ethanol, HCl, 80 °C, reflux, 8 h; (d) substituted benzyl bromide, K2CO3, acetone, 80 °C, 5 h; (e)
NaOH, aqueous alcohol, 75 °C, reflux, 2 h; (f) (1) thionyl chloride, toluene, 72 °C, 6 h and (2) KSCN, 3a–b, acetonitrile, 80 °C, 5 h; (g) Na2CO3, H2O2,
aqueous acetone, rt, overnight.
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chloride to yield the corresponding acyl chloride in anhy-
drous tetrahydrofuran, which condensed with 1,2-diamino-
benzene to afford amides 1a–b. Subsequently, these amides
were cyclized to benzimidazoles 2a–b under acidic condi-
tions. Reduction of the nitro compounds 2a–b in the pres-
ence of stannous chloride dihydrate, HCl and ethanol
afforded amino compounds 3a–b. Furthermore, methyl-
paraben was etherified with substituted benzyl bromide in
acetone to generate compounds 4a–l, which were hydrolyzed
to the key intermediates 5a–l in refluxing ethanol for 2 hours.
Carboxylic acids 5a–l reacted with thionyl chloride to produce
the corresponding acyl chloride, which then was treated with
KSCN and amino compounds 3a–b in anhydrous acetonitrile
to afford target compounds 6a–o. Additionally, 6a–o were fur-
ther converted to 7a–o via oxidative desulfurization. The
activity against human colorectal (SW620 and HT29) and
human gastric (MGC803 and MKN45) cancer cell lines by
using MTT assay with vismodegib (1) as the positive control
and MRT-10 (2) as the lead compound. The results expressed
as half maximal inhibitory concentration (IC50) values are
summarized in Table 1. The majority of the target com-
pounds exhibited higher efficacies against HT29, MGC803
and MKN45 cancer cells. We first explored the relationship
between the antiproliferative activities and some discrete var-
iations on phenyl ring B of the target compounds. The
unsubstituted compound 6a, which was the simplest com-
pound in this series of analogues, demonstrated low potency.
Likewise, the introduction of 3-chlorine (6b) and 3-fluorine
(6h) moieties was unsuccessful; nevertheless, addition of the
2-chlorine surrogate (6i) led to a slight increase in the anti-
proliferative activity. It was worth noting that compounds (6c,
6d, 6e and 6l, IC50 = 6.50 to 2.81 μM) with other mono-
electron-withdrawing groups (mono-EWGs) exhibited moder-
ate potencies against MGC803 cells. Addition of 2-fluorine
(6e) or 4-fluorine (6l) moieties had more significant impact
on the antiproliferative activity against HT29, MGC803 and
MKN45 cells as compared to 2. When double-EWGs (6k, R1 =
1
structures of 6a–o and 7a–o were confirmed by H NMR, 13C
NMR, ESI-MS and elemental analysis.
2.2. Biological evaluation
2.2.1. Antiproliferative activity assay. All the target com-
pounds 6a–o and 7a–o were evaluated for their antiproliferative
Table 1 In vitro cell growth inhibition by the target compounds, vismodegib (1) and MRT-10 (2)
IC50 (μmol L−1
)
SDa
Compd.
SW620
HT29
MGC803
MKN45
6a
6b
6c
6d
6e
6f
6g
6h
6i
6j
6k
6l
6m
6n
6o
7a
7b
7c
7d
7e
7f
7g
7h
7i
7j
7k
7l
7m
7n
7o
67.12 6.52
>100
72.36 9.68
15.37 1.41
6.44 0.24
>100
28.82 2.73
35.33 4.08
17.56 2.62
8.20 0.96
1.87 0.21
63.71 7.80
14.19 1.51
55.26 6.24
23.68 3.05
6.27 0.47
11.55 2.12
1.91 0.23
12.94 1.93
4.93 0.89
6.08 0.50
16.36 2.48
15.42 2.04
7.83 0.75
3.52 0.62
0.76 0.09
48.45 4.51
5.11 0.52
38.17 4.34
9.01 1.33
1.03 0.16
2.62 0.48
0.98 0.11
0.59 0.07
2.95 0.32
0.73 0.07
6.61 0.83
1.08 0.16
60.74 6.38
51.32 5.21
6.50 0.25
5.21 0.49
3.07 0.20
>100
57.79 5.41
43.28 4.36
10.21 2.07
6.05 0.45
2.42 0.21
>100
60.87 6.88
>100
4.98 0.58
>100
11.28 2.15
86.81 11.07
51.37 6.71
8.41 0.82
5.30 0.44
4.22 0.57
7.83 0.62
4.60 0.38
3.75 0.33
35.13 4.16
27.99 3.04
16.82 2.23
9.60 1.13
1.83 0.19
87.04 11.55
6.36 0.72
52.96 8.13
21.54 2.26
5.82 0.61
2.55 0.35
0.24 0.06
0.87 0.08
3.19 0.28
0.35 0.07
13.76 1.92
2.88 0.25
57.11 5.83
30.67 3.15
57.17 6.23
40.53 4.66
63.89 7.57
24.92 3.49
50.23 5.51
30.06 3.26
16.03 2.44
15.30 1.39
9.64 0.89
4.11 0.20
42.09 6.52
26.03 2.41
39.55 4.47
35.69 3.11
6.10 0.23
12.17 1.43
35.14 3.46
2.93 0.17
23.15 2.34
33.58 3.49
21.23 3.17
10.92 2.76
45.01 4.67
6.39 0.24
3.45 0.21
2.81 0.19
5.33 0.22
5.17 0.21
3.03 0.20
39.37 4.84
20.77 2.17
14.94 1.25
13.12 1.34
2.52 0.19
>100
4.25 0.21
44.78 4.49
19.46 2.57
6.08 0.22
2.74 0.18
0.16 0.06
0.12 0.05
3.86 0.21
0.061 0.01
8.62 0.26
2.39 0.17
MRT-10
Vismodegibb
a
Bold values show the IC50 values of target compounds lower than the values of the positive control. IC50: concentration of the compound
(μM) inducing 50% cell growth inhibition after 48 h of drug exposure, as determined by MTT assay. Each experiment was carried out in
b
triplicate. Used as a positive control.
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2,4-dichlorine, IC50 = 3.45 μM [MGC803], IC50 = 5.30 μM
[MKN45]) were introduced into ring B, the activity of this sub-
stituent was almost retained. However, the trend was not
sustained, as other disubstituted analogues (6j, 6f) were
either less potent or inactive. To further improve the activity
by altering the distribution of electrons in ring B, we incorpo-
rated the methyl group (6g, IC50 = 4.98 μM [MGC803]), but
this attempt was a failure.
Further investigations focusing on the effect of oxidation
of acylthiourea on the antiproliferative activity were
performed. It was found that oxidative products (e.g. 7e, 7g,
7k and 7l, IC50 = 0.76 μM, 5.11 μM, 2.62 μM and 0.98 μM
[HT29], IC50 = 1.83 μM, 6.36 μM, 2.55 μM and 0.24 μM
[MKN45]) significantly enhanced the antiproliferative activity,
confirming the beneficial impact of the acylurea fragment in
this connector. Strikingly, the 2-fluorine surrogates (e.g. 6e,
7e and 7m, IC50 = 6.44 μM, 4.11 μM and 2.93 μM [SW620],
IC50 = 2.42 μM, 1.83 μM and 0.87 μM [MKN45]) were found
to be effective against all four gastrointestinal cells. Although
alkaline phosphatase-positive osteoblasts (AP) induced by
Smo agonist SAG.39,40 The Gli–luc reporter assay and down-
regulation of AP assay can both effectively identify Hh inhibi-
tors. A fluorescence-based competitive displacement assay
was employed to substantiate that this series of compounds
was indeed Smo inhibitors in the Hh signaling pathway. In
this assay, displacement of boron-dipyrromethene (BODIPY)-
cyclopamine, a fluorescent derivative of cyclopamine, by the
synthesized compounds was evaluated in HEK293 cells over-
expressing human Smo.41,42
In the NIH3T3–Gli–luc reporter assay, compound 7m was
slightly less active as compared to the positive control
vismodegib (1), with IC50 values of 0.025 μM and 0.013 μM,
respectively. In addition, 7m, 7l, and 7o, showed higher
potency (IC50 = 0.025 μM, 0.037 μM and 0.032 μM) than 6e
(IC50 = 0.158 μM) and MRT-10 (2) (IC50 = 0.650 μM) in accor-
dance with regularity in the antiproliferative activity. Like-
wise, the biological potencies of 7m and 7o against C3H10T1/
2 cells were superior to the lead compound MRT-10 (2) as
well. The Hh inhibitory activities of these compounds may be
due to their interaction with Smo, since the two representa-
tive compounds, 7m and 7o, effectively displaced BODIPY-
cyclopamine in HEK293 cells over-expressing human Smo
(IC50 = 0.019 μM and 0.042 μM). Although the potency of 7m
was lower as compared to vismodegib (IC50 = 0.006 μM),
these data suggested that compound 7m was a promising Hh
inhibitor with a novel template.
the appendages with
a
bulky substituent such as
trifluoromethyl (7c and 7d, IC50 = 7.83 μM and 3.52 μM) were
effective in suppressing the proliferation of HT29 cells, their
IC50 values were not satisfactory. We then focused on the
A-ring (part A). Compounds 6m–o and 7m–o were chlorine
surrogates. Upon comparing 6n with 6j, it was found
that the methyl surrogates that were replaced with chlorine
were well tolerated, and the same conclusion was made
upon comparing 6o with 6k, as well as 7l with 7o. Moreover,
compounds 7m and 7o (e.g. IC50 = 0.12 μM and 0.061
μM [MGC803]) displayed superior activities to 1. Taken
together, these findings indicate that the combination of the
4-IJ2-fluorobenzyloxy)phenyl moiety with the acylurea frag-
ment is the most favourable modification for the anti-
proliferative activity of this series of analogues.
2.2.2. Hedgehog signalling pathway inhibition. J. Taipale
and co-workers36 had substantiated that NIH3T3 cells provide
a faithful and physiologically meaningful model for analysis
of the Hh signalling pathway through screening of several
responsive fibroblast cell lines. As shown in Table 2, the four
selected compounds were tested for Hh signaling inhibition
by using a luciferase reporter in NIH3T3 cells carrying a sta-
bly transfected Gli–reporter construct (Gli–luc reporter cell
line).37,38 They were also evaluated for inhibition of differen-
tiation of mesenchymal pluripotent C3H10T1/2 cells into
2.3. Molecular modelling
The mutation of Smo largely occurred in the Asp473 residue,
and this mutation provided resistance to vismodegib (1)
(pink) and disrupted the ability of 1 to bind Smo and sup-
press the Hh signalling pathway.19 Nevertheless, the disrup-
tion of a local structure, as chemoresistance mutations did,
could not abolish ligand binding if it either bypassed the
Asp473 residue or had a larger contacting surface and more
binding sub-sites.43 In the binding models shown in Fig. 2A,
the side chain of Asp473 directly interacted with 1 (3.5 Å
between the oxygen atom from carbonyl and the Asp473 resi-
due) in the ligand binding cavity, whereas its interaction with
taladegib (5) (blue) was much weaker as revealed by a longer
distance (4.0 Å and 4.2 Å between two nitrogen atoms from
the phthalazine core and the Asp473 residue). This made 5
Table 2 Hedgehog pathway inhibition of compounds 7l, 7m, 7o, 6e, vismodegib (1) and MRT-10 (2)
a
a
Compd.
NIH3T3–Gli–luc IC50 (μM)
C3H10T1/2 IC50 (μM)
hSMO–BCB IC50b (μM)
7l
7m
7o
6e
0.037
0.025
0.032
0.158
0.650
0.013
—
—
0.063
0.049
—
0.868
0.017
0.019
0.042
—
0.281
0.006
MRT-10
Vismodegibc
a
b
The values are an average of triplicate separate determinations. Inhibition of BODIPY-cyclopamine fluorescence signaling in the competitive
c
displacement experiment using HEK293 cells over-expressing human Smo. Data are expressed from a single IC50 determination. Used as a
positive control.
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Fig. 2 (A) The conformation of vismodegib (1) (pink) and taladegib (5) (blue) in the ligand binding pocket (PDB code: 4KJV); (B) predicted model
of compound 7m (purple) and MRT-10 (2) (yellow) binding with the Smo receptor, overlapping with that of 1; (C) docking conformation of com-
pound 7m (purple) at the binding site of the Smo receptor. Surrounding amino acid side chains were displayed as light grey sticks. The dashed
green lines represent hydrogen bonds, and the distance between ligands and proteins is less than 2.8 Å. The red solid lines denote the distance
between the Asp473 residue and the disrupted groups.
insensitive to drug-resistance mutation. As shown in Fig. 2B,
the binding orientations of compound 7m (purple) and MRT-
10 (2) (yellow) overlapped with each other and with that of 1.
Moreover, 1 bound with Smo by hydrogen bonds that
involved the carbonyl moiety interacting with residue Arg400
and the nitrogen atom of pyridine forming a hydrogen bond
with residue Tyr394. As evident in Fig. 2C, the hydrogen bond
acceptor groups of compound 7m included a nitrogen atom
present in the imidazole ring, two oxygen atoms of the car-
bonyl group in the connector, and a fluorine atom of the phe-
nyl ring in part B, which formed four hydrogen bonds with
Smo protein residues Tyr394, Arg400, Asn219 and Lys395,
respectively. Compound 7m had two more binding sites and
weaker interaction with residue Asp473 (longer distance of
3.8 Å) as compared to 1. Computational modelling analysis
further supported the results of inhibition of the Hh signal-
ing pathway; compound 7m does bind to the taladegib bind-
ing site of the Smo receptor, and its docking pose is
extremely similar to that of 1.
a binding mode very similar to that of vismodegib. According
to the obtained results, 7m was identified as a promising
candidate and further structural optimization studies are cur-
rently in progress and will be reported in due course.
Experimental section
Synthetic protocols for all compounds, analytical data, and
procedures and methods for in vitro assays are available in
the ESI.†
Acknowledgements
This work was supported by the Program for Innovative
Research Team of the Ministry of Education of the People's
Republic of China and the Program for Liaoning Innovative
Research Team in University.
References
1 M. Neeraj, P. Chandanamali and F. Naoaki, J. Med. Chem.,
2009, 52, 3829–3845.
3. Conclusions
In summary,
a
series of novel and distinct N-3-
2 M. K. Hadden, Expert Opin. Ther. Pat., 2013, 23, 345–361.
3 O. Hideya and K. Mitsuo, Cancer Sci., 2011, 102, 1756–1760.
4 K. L. Ayers and P. P. Therond, Trends Cell Biol., 2010, 20,
287–298.
5 P. D. M. Marina and H. Matthias, Nat. Rev. Cancer, 2003, 3,
903–911.
6 S. Ahn and A. L. Joyner, Nature, 2005, 437, 894–897.
7 R. Martial, H. Lucile, F. Helene and R. Didier, Trends
Pharmacol. Sci., 2014, 35, 237–246.
8 S. X. Atwood, M. Li, A. Lee, J. Y. Tang and A. E. Oro, Nature,
2013, 494, 484–488.
9 Y. Wang, A. C. Arvanites, L. Davidow, J. Blanchard, K. Lam,
J. W. Yoo, S. Coy, L. L. Rubin and A. P. McMahon, ACS
Chem. Biol., 2012, 7, 1040–1048.
10 S. Coni, P. Infante and A. Gulino, Biochem. Pharmacol.,
2013, 85, 623–628.
benzimidazolephenylbisamide analogues were synthesized
and characterized. Furthermore, four human gastrointestinal
cancer cell lines were used to evaluate their antiproliferative
activity; the majority of analogues exhibited higher potency
against MGC803, HT29 and MKN45 cells. In particular, com-
pounds 7l, 7m and 7o exhibited enhanced activity as com-
pared to vismodegib against these cells. The analysis of SARs
indicated that compounds with 2-fluorine or 4-fluorine
groups on phenyl ring B were more potent than those with
other substituents. In addition, the acylurea fragment in the
connector was essential to improve the potency, and the
introduction of chlorine into phenyl ring A led to a slight
improvement in activity. Compound 7m exhibited greater
potency in different Hh assays, suggesting that it acts
through inhibition of the Hh signaling pathway. Molecular
simulations of the docking of 7m to the Smo receptor showed
that 7m binds to the taladegib site of the Smo receptor with
11 R. Martial, H. Lucile, F. Helene and R. Didier, Trends
Pharmacol. Sci., 2014, 35, 237–246.
This journal is © The Royal Society of Chemistry 2015
Med. Chem. Commun.

View Article Online
Concise Article
MedChemComm
12 A. Pimentel, M. Velez, L. J. Barahona, R. Swords and L.
Lekakis, Future Oncol., 2013, 9, 681–697.
27 T. Mazumdar, J. DeVecchio, T. Shi, J. Jones, A. Agyeman and
J. A. Houghton, Cancer Res., 2011, 71, 1092–1102.
13 J. M. Ruch and E. J. Kim, Drugs, 2013, 73, 613–623.
14 S. Peukert and K. Miller-Moslin, ChemMedChem, 2010, 5,
500–512.
15 T. N. Trinh, E. A. McLaughlin, C. P. Gordon and A.
McCluskey, MedChemComm, 2014, 5, 117–133.
16 S. E. Gould, J. A. Low, J. C. Marsters Jr, K. Robarge, L. L.
Rubin, F. J. D. Sauvage, D. P. Sutherlin, H. Wong and R. L.
Yauch, Expert Opin. Drug Discovery, 2014, 9, 969–984.
17 A. E. Proctor, L. A. Thompson and C. L. Bryant, Ann.
Pharmacother., 2014, 48, 99–106.
18 G. J. P. Dijkgraaf, B. Alicke, L. Weinmann, T. Januario, K.
West, Z. Modrusan, D. Burdick, R. Goldsmith, K. Robarge,
D. Sutherlin, S. J. Scales, S. E. Gould, R. L. Yauch and F. J.
de Sauvage, Cancer Res., 2011, 71, 435–444.
19 R. L. Yauch, G. J. Dijkgraaf, B. Alicke, T. Januario, C. P. Ahn,
T. Holcomb, K. Pujara, J. Stinson, C. A. Callahan, T. Tang,
J. F. Bazan, Z. Kan, S. Seshagiri, C. L. Hann, S. E. Gould, J. A.
Low, C. M. Rudin and F. J. de Sauvage, Science, 2009, 326,
572–574.
20 S. Buonamici, J. Williams, M. Morrissey, A. Wang, R. Guo, A.
Vattay, K. Hsiao, J. Yuan, J. Green, B. Ospina, Q. Yu, L.
Ostrom, P. Fordjour, D. L. Anderson, J. E. Monahan, J. F.
Kelleher, S. Peukert, S. Pan, X. Wu, S. M. Maira, C. Garcia-
Echeverria, K. J. Briggs, D. N. Watkins, Y. M. Yao, C.
Lengauer, M. Warmuth, W. R. Sellers and M. Dorsch, Sci.
Transl. Med., 2010, 51, 51ra70.
21 S. Antonio, F. Hélène, R. Hermine, T. Elisabeth, S. Angèle,
M. André, M. Fabrizio, T. Maurizio and R. Martial, J. Med.
Chem., 2012, 55, 1559–1571.
22 K. G. Petrov, Y. M. Zhang, M. Carter, G. S. Cockerill, S.
Dickerson, C. A. Gauthier, Y. Guo, R. A. D. Mook, W.
Rusnak, A. L. Walker, E. R. Wood and K. E. Lackey, Bioorg.
Med. Chem. Lett., 2006, 16, 4686–4691.
28 D. Qualtrough, A. Buda, W. Gaffield, A. C. Williams and
C. P. Araskeva, Int. J. Cancer, 2004, 110, 831–837.
29 F. Varnat, A. Duquet, M. C. Malerba, M. Zbinden, C. Mas, P.
Gervaz and A. R. Altaba, EMBO Mol. Med., 2009, 1, 338–351.
30 Z. Rong, C. Fang, D. Zhu and S. Liu, Zhonghua Shiyan Waike
Zazhi, 2007, 24, 531–533.
31 M. Ohta, K. Tateishi, F. Kanai, H. Watabe, S. Kondo, B.
Guleng, Y. Tanaka, Y. Asaoka, A. Jazag, J. Imamura, H. Ijichi,
T. Ikenoue, M. Sata, M. Miyagishi, K. Taira, M. Tada, T.
Kawabe and M. Omata, Cancer Res., 2005, 65, 10822–10829.
32 C. Wang, H. X. Wu, V. Katritch, G. W. Han, X. P. Huang, W.
Liu, F. Y. Siu, B. L. Roth, V. Cherezov and R. C. Stevens,
Nature, 2013, 497, 338–343.
33 A. M. DeBerardinis, D. J. Madden, U. Banerjee, V. Sail, D. S.
Raccuia, D. D. Carlo, S. M. Lemieux, A. Meares and M. K.
Hadden, J. Med. Chem., 2014, 57, 3724–3736.
34 P. Thanigaimalai, T. A. L. Hoang, K. C. Lee, S. C. Bang, V. K.
Sharma, C. Y. Yun, E. Roh, B. Y. Hwang, Y. Kim and S. H.
Jung, Bioorg. Med. Chem. Lett., 2010, 20, 2991–2993.
35 U. D. Pete, C. M. Zade, J. D. Bhosale, S. G. Tupe, P. M.
Chaudhary, A. G. Dikundwar and R. S. Bendre, Bioorg. Med.
Chem. Lett., 2012, 22, 5550–5554.
36 J. Taipale, J. K. Chen, M. K. Cooper, B. L. Wang, R. K. Mann,
L. Milenkovic, M. P. Scott and P. A. Beachy, Nature,
2000, 406, 1005–1009.
37 J. K. Chen, J. Taipale, K. E. Young, T. Maiti and P. A. Beachy,
Proc. Natl. Acad. Sci. U. S. A., 2002, 99, 14071–14076.
38 M. H. Xin, L. D. Zhang, F. Tang, C. X. Tu, J. Wen, X. G.
Zhao, Z. Y. Liu, L. F. Cheng and H. Shen, Bioorg. Med.
Chem., 2014, 22, 1429–1440.
39 B. Yang, A. W. Hird, D. J. Russell, B. P. Fauber, L. A. Dakin,
X. L. Zheng, Q. B. Su, R. Godin, P. Brassil, E. Devereaux and
J. W. Janetka, Bioorg. Med. Chem. Lett., 2012, 22, 4907–4911.
40 S. Pathi, S. Pagan-Westphal, D. P. Baker, E. A. Garber, P.
Rayhorn, D. Bumcrot, C. J. Tabin, R. B. Pepinsky and K. P.
Williams, Mech. Dev., 2001, 106, 107–117.
23 M. J. Munchhof, Q. Li, A. Shavnya, G. V. Borzillo, T. L.
Boyden, C. S. Jones, S. D. LaGreca, L. Martinez-Alsina, N. I.
Patel, K. Pelletier, L. A. Reiter, M. D. Robbins and G. T.
Tkalcevic, ACS Med. Chem. Lett., 2012, 3, 106–111.
24 J. Bendell, G. Weiss, J. Infante, R. Ramanathan, S. Jones, R.
Korn, H. Burris, L. Brail, E. Jones and D. Von Hoff, Eur. J.
Cancer, 2012, 48(supplement 6), 182–182.
25 D. M. Berman, S. S. Karhadkar, A. Maitra, D. R. Montes,
M. R. Gerstenblith, K. Briggs, A. R. Parker, Y. Shimada, J. R.
Eshleman, D. N. Watkins and P. A. Beachy, Nature,
2003, 425, 846–851.
41 H. Ma, W. Lu, Z. Sun, L. Luo, D. Geng, Z. Yang, E. Li, J.
Zheng, M. Wang, H. Zhang, S. Yang and X. Zhang, Eur. J.
Med. Chem., 2015, 89, 721–732.
42 M. Fabrizio, F. Helene, R. Hermine, G. Tatiana, T. Elisabeth,
S. Angele, M. Andre, S. Antonio, T. Maurizio and R. Martial,
Mol. Pharmacol., 2010, 78, 658–665.
43 C. Wang, H. Wu, T. Evron, E. Vardy, G. W. Han, X. Huang,
S. J. Hufeisen, T. J. Mangano, D. J. Urban, V. Katritch, V.
Cherezov, M. G. Caron, B. L. Roth and R. C. Stevens, Nat.
Commun., 2014, 5, 4355–4365.
26 W. Ou, K. Sun, C. Wu, S. Lei and X. Zhang, Zhongguo
Xiandai Yixue Zazhi, 2013, 23, 25–30.
Med. Chem. Commun.
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