Development of Novel Anticancer Agents with a Scaffold of Tetrahydropyrido[4,3- d]pyrimidine-2,4-dione

Article abstract of DOI:10.1021/acsmedchemlett.8b00531

ONC201 is a small molecular anticancer agent currently in multiple Phase II clinical trials. Based on the pharmacophore of ONC201, a series of small molecular compounds with a core structure of tetrahydropyrido[4,3-d]pyrimidine-2,4-dione were designed and synthesized. Preliminary mechanism studies of these compounds indicated that they can inhibit the phosphorylation of AKT and ERK, induce the dephosphorylation of Foxo3a, and promote the expression of TRAIL and the enhancement of activating transcription factor 4 (ATF4) in PC-3 cells. Structure-activity relationship (SAR) studies indicated that modifications of the substituted groups on the core structure can significantly improve the cellular activities of these compounds. The most potent compounds are over 100 times more potent than ONC201 in inhibition of cell growth in a panel of different types of human cancer cell lines.

Full text of DOI:10.1021/acsmedchemlett.8b00531

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Letter
Development of novel anti-cancer agents with a
scaffold of tetrahydropyrido[4,3-d]pyrimidine-2,4-dione
Zonghui Ma, Ge Gao, Kunsen Fang, and Haiying Sun
ACS Med. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acsmedchemlett.8b00531 • Publication Date (Web): 16 Jan 2019
Downloaded from http://pubs.acs.org on January 17, 2019
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Development of novel anti-cancer agents with a scaffold of tetrahydropyrido[4,3-d]pyrimidine-
2,4-dione
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Zonghui Ma, Ge Gao, Kunsun Fang and Haiying Sun*
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Jiangsu Key Laboratory of Drug Design and Optimization, Department of Medicinal Chemistry, China Pharmaceutical
University, Nanjing 210009, China
KEYWORDS: TRAIL, AKT, ERK, Foxo3a, ATF4
ABSTRACT: ONC201 is a small molecular anti-cancer agent currently in multiple Phase II clinical trials. Based on the
pharmacophore of ONC201, a series of small molecular compounds with a core structure of tetrahydropyrido[4,3-d]pyrimidine-2,4-
dione were designed and synthesized. Preliminary mechanism studies of these compounds indicated that they can inhibit the
phosphorylation of AKT and ERK, induce the dephosphorylation of Foxo3a, and promote the expression of TRAIL and the
enhancement of activating transcription factor 4 (ATF4) in PC-3 cells. Structure-activity relationship (SAR) studies indicated that
modifications of the substituted groups on the core structure can significantly improve the cellular activity of these compound. The
most potent compounds are over 100 times more potent than ONC201 in inhibition of cell growth in a panel of different types of
human cancer cell lines.
Tumor necrosis factor related apoptosis-inducing ligand
(TRAIL) is tumor suppressor which induces apoptosis in a
wide range of human cancer cell lines by binding to and
activating pro-apoptotic death receptors 4 and 5 (DR4 and
DR5). TRAIL can potently induce apoptosis in cancer cells
while shows low toxicity to normal cells, therefore
recombinant TRAIL and TRAIL-agonist antibodies targeting
DR4 and DR5 have been evaluated in multiple clinical trials,
however these macro-biomolecules didn’t show sufficient
effects in these trials.1,2 The reasons for the failures of these
trials are not clear, but one hypothesis is that their poor
stability and bio-distribution may limit their usage as anti-
cancer agents.3 To overcome these drawbacks, Allen et al.
initiated a campaign for searching small molecules which can
up-regulate the expression of TRAIL gene and enhance the
level of endogenous TRAIL by screening NCI chemical
library. Their effort led to the identification of a small
molecular compound ONC201 (also known as TIC10, Figure
1) as an inducer of the expression of TRAIL gene.4,5 ONC201
can inhibit cell growth and induce robust apoptosis in a broad
range of tumor cells, and the apoptosis induced by ONC201 is
p53 independent.5 Detail mechanism studies for ONC201 have
been performed and the results indicated that ONC201 exerts
its anti-cancer activity through two pathways, including both
TRAIL-dependent and –independent pathways.6-8 In the
TRAIL-dependent pathway, ONC201 induces dual-inhibition
of the phosphorylations of AKT and ERK, which leads to the
dephosphorylation of Foxo3a. Dephosphorylated Foxo3a then
translocates from the cytoplasm into the nucleus and binds to
the promoter of TRAIL gene to up-regulate the transcription
of TRAIL gene.6 In the TRAIL-independent pathway,
ONC201 can induce endoplasmic reticulum stress responses
(ER) or integrated stress responses ISR) which culminate at
the enhancement of activating transcription factor 4 (ATF4),
that leads to the expression of many ATF4 targeted genes.7,8 In
solid tumors ONC201 can function through both of the two
pathways, but in hematological malignancies it seems to act
only through the TRAIL-independent mechanism.6-8
In preclinical studies ONC201 exhibited excellent drug
properties, such as robust anti-proliferative and pro-apoptotic
effects, benign toxicity profile, optimum aqueous solubility,
favorable pharmacokinetic properties and oral bio-availability.
It also shows broad synergistic effects with approved and
investigational cancer therapies in many solid tumors and
hematological malignancies in preclinical model.9-11 Currently
ONC201 is being evaluated in multiple Phase II clinical
trials.12
Because of the promising anti-cancer activity of ONC201,
we are interested in the design of novel anti-cancer agents with
similar mechanism of functions as ONC201. In this paper, we
reported our design, synthesis and preliminary mechanism
studies of a class of tetrahydropyrido[4,3-d]pyrimidine-2,4-
diones using ONC201 as a lead compound.
O
O
R3
R2
O
N6
N2
N
N
N1
R1
N
N1
ONC-201
1
Figure 1. Design of analogues of ONC-201.
ONC201 has a unique tricyclic structure. Analyzing its
structure, we think that N1 in the five membered ring can
function as a hydrogen bond acceptor, while the ethylenyl
group in the five membered ring can provide hydrophobic
interaction. Based upon this analysis, we designed a class of
analogues of ONC201 with
a
core structure of
tetrahydropyrido[4,3-d]pyrimidine-2,4-dione (1, Figure 1), in
which N1 in ONC201 (Figure 1) is replaced with an oxygen
atom to maintain the ability as a hydrogen bond acceptor and a
small hydrophobic substitute group R1 is introduced to N1 in 1
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to mimic the hydrophobic effect of the ethylenyl group in the
note that the cells sensitive to ONC201 are also sensitive to
compounds 4 and 5, and the cells not sensitive to ONC201 are
also not sensitive to compounds 4 and 5, suggesting
compounds 4 and 5 have similar mechanism of function as
ONC201. Among all of the cell lines we have screened, PC3,
MDA-MB-468 and H3122 are the most sensitive solid tumor
cell lines, while MV4;11 is the most sensitive hematological
tumor cell line to these compounds
five membered ring in ONC201. R2 and R3 are the groups
mimicing the benzyl and 2-methylbenzyl groups respectively
in ONC201 (Figure 1).
1
2
3
4
5
6
7
8
Table 1. Cell growth inhibition of compounds 2-6 and
ONC201 in human breast cancer MDA-MB-231 cell.
O
N
N
Table 2. Cell growth inhibition of compounds 4, 5 and
ONC201 in a panel of human cancer cell lines.
N
R
O
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10
11
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13
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41
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45
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49
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Cell lines
ONC201
IC50 (μM)
4
5
MDA-MB-231
Compound
R
IC50 (μM)
IC50 (μM)
IC50 (μM)
Colo205
KYSE140
PC3
15.1±3.3
58.1±15.9
8.9±3.2
8.9±1.6
8.7±2.3
14.4±4.5
31.4±14.8
3.0±1.3
7.5±1.9
6.3±2.2
2.9±1.1
13.8±4.3
1.7±0.3
1.8±0.3
1.6±0.2
4.5±1.4
3.9±1.8
0.4±0.1
0.9±0.2
0.6±0.2
48.1±16.3
65.9±21.6
22.9±8.3
27.6±6.9
21.8±4.4
18.6±3.5
38.8±9.6
6.7±1.8
ONC201
14.6±3.2
32.0±5.6
1.9±0.8
2
3
4
5
6
H
Me
Et
2.0±0.7
MDA-MB-468
H3122
iPr
52.3±11.7
67.1±13.2
cyclopentyl
THP1
We at first designed and synthesized compounds 2-6 by
introducing different substituted groups to N1 of general
structure 1. In these five compounds the R2 and R3 groups in 1
were kept as benzyl groups. In our initial screen for the anti-
cancer cellular activities of ONC201, we have found that
ONC201 has modest anti-cancer cellular activity in MDA-
MB-231 cell line, therefore 2-6 were tested together with
ONC201 in this cell line for their abilities in inhibiting cell
growth and the results are shown in Table 1. ONC201 shows
an IC50 of 14.6 μM in this cell line, while compound 2 which
doesn’t have a substituted group on N1 shows an IC50 of 32.0
μM and is about 2-times less potent than ONC201.
Compounds 3 and 4 which contain a methyl or an ethyl group
on N1 show significantly improved cellular activity with IC50s
of 1.9 and 2.0 μM respectively and are about 7-times more
potent than ONC201, suggesting that a small hydrophobic
group at this position is critical to the cellular activity.
However, compounds 5 and 6 which have an isopropyl or a
cyclopentyl group on N1 respectively are 4- to 5-times less
potent than ONC201, indicating that the size of the substituted
group on N1 has critical influence to the cellular activity. To
reach potent cellular activity, R1 can only be a methyl or an
ethyl group, a larger hydrophobic group on N1 is detrimental.
RS4;11
MV4;11
Molm13
Molm14
28.9±7.4
15.3±3.9
In order to explore the mechanism of function of our
designed compounds, we performed preliminary mechanism
studies for compounds 4 and 5 in comparison with ONC201.
We at first evaluated these compounds for their ability in
promoting TRAIL expression and inducing the production of
SubG1 DNA in PC-3 and MDA-MB-468 cell lines, and the
results indicated that all of these three compounds can dose
dependently up-regulate TRAIL expression and enhance the
production of subG1 DNA (Figure 3). Consistent to their
cellular activities, compound 4 at 2.5 μM is more potent than
10 μM of ONC201 in promoting TRAIL expression and
increasing the production of subG1 DNA, while compound 5
is less potent than ONC201.
In order to find whether these compounds have similar
structure-activity relationship (SAR) in their anti-cancer
cellular activities in other cancer cell lines, we selected a more
potent compound 4 and a less potent compound 5 and
screened their anti-cancer cellular activities together with
ONC201 in a panel of different types of human cancer cell
lines and the results are reported in Table 2. ONC201 shows
IC50 values between 3-15 μM to most of the cancer cell lines
we have tested, but is less sensitive to KYSE140 and RS4;11
cell lines with IC50 values of 58.1 and 31.4 μM respectively. It
has been reported that ONC201 inhibits cell growth in most of
sensitive human cancer cell lines with IC50s between 1-10 μM,
thus our results are consistent to the reported results. Similar
to their activities to MDA-MB-231 cells, compound 5 is a few
fold less potent than ONC201 to all of these cell lines, while
compound 4 is 5-10 times more potent than ONC201. It is of
Figure 3. Compounds 4, 5 and ONC201 promote the expression
of TRAIL and the production of SubG1 DNA.
In TRAIL dependent pathway, ONC201 can inhibit the
phosphorylation of AKT and ERK, which leads to the
dephsophorylation of Foxo3a, therefore we treated PC3 cells
with different concentrations of compounds 4, 5 and ONC201,
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and performed western blot analysis for these biomarkers
enlargement of the ring, but the most potent compound 11 in
which a cyclohexyl group is used to replace the phenyl ring is
still 7- to 9-times less potent than 4 in these two cell lines,
indicating that the phenyl ring is important to the cellular
activity.
1
2
3
4
5
6
7
8
(Figure 4). The results indicated that all of these three
compounds can dose dependently inhibit the phosphorylation
of ERK and AKT and reduce the phosphorylation of Foxo3a,
and compound 4 is more potent than ONC201 while 5 is less
potent than ONC201, therefore the ability of these compounds
in inducing the changes of these biomarkers is also consistent
to their cellular activity.
Table 3. Cell growth inhibition of compounds 7-25 in H3122
and MV4;11 cell lines.
O
R
It has been reported that in TRAIL independent pathway,
ONC201 can induce ER and ISR which culminate at the up-
regulation of ATF4, therefore we also performed western blot
analysis for ATF4, and the results indicated that all of these
three compounds can dose dependently induce the up-
regulation of ATF4, and again, compound 4 is more potent
than ONC201, while compound 5 is less potent than ONC201
(Figure 4). Our biological studies thus suggest that our
designed compounds have similar mechanism of functions as
ONC201.
N
N
9
N
O
10
11
12
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60
H3122
MV4;11
Compounds
R
IC50 (μM)
IC50 (μM)
ONC201
4
8.7±2.3
1.6±0.2
78.8±20.9
72.9±18.7
69.2±15.4
51.9±16.2
14.8±3.3
4.7±1.6
3.9±1.9
0.8±0.2
3.9±1.3
2.6±0.9
0.4±0.1
2.7±0.8
1.6±0.4
0.6±0.2
1.9±0.5
0.7±0.2
1.9±0.3
0.9±0.3
0.6±0.2
3.0±1.3
0.4±0.1
10.1±2.9
9.8±2.3
8.9±3.1
5.9±2.2
2.7±0.9
0.9±0.2
0.6±0.2
0.2±0.1
0.6±0.2
0.3±0.1
0.07±0.02
0.6±0.2
0.2±0.1
0.08±0.02
0.5±0.1
0.09±0.03
0.4±0.1
0.2±0.1
0.09±0.03
Bn
7
methyl
ethyl
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9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
F
F
F
Cl
Cl
Figure 4. Western blot analysis for compounds 4 and 5 in
comparison with ONC201 using human prostate cancer cell PC3.
Cell was treated for 24 hours.
Cl
Br
After confirming the mechanism of functions of our
designed compounds, we then designed and synthesized
compounds 7-25 (Table 3) to explore the substituted group on
N3 of the tetrahydropyrido[4,3-d]pyrimidine-2,4-dione core
structure for its influence to the cellular activity using
compound 4 as the lead compound. In these compounds the
substituted groups on N1 and N6 were kept as ethyl and benzyl
groups respectively. These compounds have been evaluated
for their anti-cancer cellular activities in two sensitive cell
lines H3122 and MV4;11 and the results are reported in Table
3. In these two cell lines, 4 shows IC50 values of 1.6 and 0.4
μM, respectively. Compounds 7 and 8, in which a methyl or
an ethyl group was used to replace the benzyl group on the N3
of compound 4 respectively are 45 times less potent than 4 in
inhibiting the cell growth of H3122 cell line and 25 times less
potent than 4 in inhibiting the cell growth of MV4;11 cell line,
suggesting that a larger hydrophobic group on N3 is critical for
the cellular activity. Replacement of the phenyl ring of the
benzyl group with an aliphatic ring (compounds 9-11)
significantly decreases the cellular activity. In these three
compounds, the anti-cancer cellular activity increases with the
Br
Br
OMe
OMe
CF3
Introduction of a halo atom to the ortho or meta position of
this phenyl ring doesn’t have significant influence to the
cellular activity. For example, compounds 12 and 13 which
have a fluoro atom on the ortho or meta position of the phenyl
ring respectively show comparable cellular activities in both of
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the two cell lines and are only 2-times less potent than
Table 4. Cell growth inhibition of compounds 26-40 in H3122
and MV4;11 cell lines.
1
compound 4. Compounds 18 and 19 which have a bromo atom
on the ortho or meta position respectively are slightly more
potent than 12 and 13, suggesting that a larger halo atom on
these two position is more favorable to the cellular activity.
Different from the orhto and meta substitutions, introduction
of a halo atom to the para position of this phenyl ring can
improve the cellular activity by 2-5 fold (compounds 14, 17
and 20 vs 4). Compound 17 which has a chloro atom on the
para positon of this phenyl ring shows IC50 values of 0.4 and
0.07 μM to H3122 and MV4;11 cell lines respectively and is
the most potent compound in this series. We have also tried
introduction of other hydrophobic groups, such as methoxyl,
methyl and trifluoromethyl groups (21-25) to different
positions of the phenyl ring and found the same trend.
Interestingly, it seems that the position for introducing the
substituted group but not the substituted group itself has more
significant influence to the cellular activity. If these groups
were introduced to the para position, the cellular activity can
be improved, but if the groups were introduced to the ortho or
meta position, the cellular activity was not dramatically
influenced.
2
3
4
5
6
7
8
9
H3122
MV4;11
Compounds
R
IC50 (μM)
IC50 (μM)
ONC201
4
8.7±2.3
1.6±0.2
84.3±27.9
79.6±24.6
54.7±18.8
22.5±5.9
17.3±4.6
0.4±0.1
3.0±1.3
0.4±0.1
19.4±4.6
18.8±3.9
13.2±3.3
3.8±0.9
Bn
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
26
methyl
ethyl
27
28
29
F
30
1.6±0.3
F
We then explored the substituted group on N6 for its
influence to the anti-cancer cellular activity by designing and
synthesizing compounds 26-40. In these compounds the
substituted groups on N1 and N3 were kept as ethyl and benzyl
groups respectively, while various hydrophobic groups were
used to replace the benzyl group on N6 of compound 4. These
compounds were also evaluated for their abilities in inhibiting
cell growth in H3122 and MV4;11 cell lines and the results are
reported in Table 4. Similar to the modifications of the
substituted group on N3, replacement of the benzyl group on
N6 of compound 4 with small hydrophobic groups, such as
methyl, ethyl or cyclopropylmethyl significantly decreases the
cellular activities (compounds 26-28 vs 4) by more than 30
fold. Replacement of the benzyl group with a phenyethyl
group (compound 29) also decreases the cellular activities by
more than 10 fold, indicating that this benzyl group is also
critical for the cellular activity. We then tried introduction of a
halo atom to different positions of the phenyl ring. For this
phenyl ring, introduction of a F, Cl or Br atom to the ortho
position dramatically decreases the cellular activity by 4-20
fold (30, 33 and 36 vs 4), indicating that a substituted group on
the ortho position is detrimental to the cellular activity.
Introduction of a halo atom to the para position doesn’t have
significant influence to the cellular activity (32, 35 and 38 vs
4), but compounds 31, 34 and 37 which have a F, Cl and Br at
the meta position of the phenyl ring have 3-20 times more
potent cellular activities in these two cell lines than 4.
Compound 34 shows IC50 values of 0.3 and 0.02 μM in
inhibiting the cell growth in these two cell lines and is the
most potent compound in this series. We have also tried
introduction of a methoxy group to the meta and para positions
of the phenyl ring and found meta substituted compound 39 is
slightly more potent than 4 while para substituted compound
40 is about 8 times less potent than 4. These results also
suggested that the meta substituted compound has more potent
cellular activity, but 39 is 4 and 10 times less potent than 34 in
inhibiting the cell growth of H3122 and MV4;11 cell lines
respectively, indicating that a larger group at the meta position
is not favorable.
31
0.04±0.01
0.5±0.2
F
32
3.1±0.8
Cl
33
21.9±2.7
0.3±0.1
3.3±0.9
Cl
34
0.02±0.01
0.6±0.2
Cl
35
4.1±0.9
Br
36
32.5±11.7
0.6±0.1
3.9±1.1
Br
37
0.07±0.02
0.3±0.1
Br
38
3.0±0.9
OMe
39
1.2±0.3
0.2±0.1
OMe
40
11.9±4.7
1.6±0.3
O
N
R
N
N
O
Combining the SAR information obtained from
optimizations of the substituted groups on the two phenyl
rings we designed compounds 41-49 in which two halo atoms
were introduced to the meta position of the phenyl ring in the
benzyl group on N6 and the para position of the phenyl ring in
the benzyl group on N3, respectively. These compounds have
also been evaluated for their anti-cancer cellular activities in
H3122 and MV4,11 cell lines and the results are reported in
Table 5. All of these compounds show more potent or
comparable cellular activities as the corresponding compounds
in which only one of the two benzyl groups on N3 and N6
contains halo atom substitution at corresponding position. For
example, compounds 41-43 which contain a para fluoro
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substituted benzyl group on N3 and a meta fluoro, chloro or
Corresponding Authors
1
2
3
4
5
6
7
8
bromo substituted benzyl group on N6 respectively shows IC50
values of 24, 21 and 55 nM in inhibiting the cell growth of
MV4,11 cell line and are 4-8 times more potent than 14 in
which only the benzyl group on N3 has a para fluoro
substitution (Table 3). These three compounds are also
slightly more potent than their corresponding compounds 31,
34 and 37 which contain a benzyl group on N3 and a fluoro,
chloro or bromo substituted benzyl group on N6 respectively.
Compounds 43, 46 and 49 which contain a meta bromo
substituted benzyl group on N3 show slightly less potent
cellular activities than other compounds in this series,
indicating that a larger substituted group at the meta position
of this phenyl ring is not favorable to the cellular activity,
consistent to the SAR found from the optimization of the
benzyl group on N3 (Table 4).
* E-mail: haiyings1969@cpu.edu.cn
Author Contributions
All authors have given approval to the final version of the
manuscript.
Funding Sources
Financial support is from National Natural Science Foundation of
China 81473079, the Program for Specially Appointed Professor
of Jiangsu Province to H.S., the Program for Jiangsu Province
Innovative Research Team and Personnel, the Funding of Double
First-rate Discipline Innovation Teams (CPU2018GY05 and
CPU2018GF05)
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49
50
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60
Notes
The authors declare no competing financial interest.
Table 5. Cell growth inhibition of compounds 41-49 in H3122
and MV4;11 cell lines.
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(4) Allen, J. E.; Krigsfeld, G.; Mayes, P. A.; Patel, L.; Dicker, D.
T.; Patel, A. S.; Dolloff, N. G.; Messaris, E.; Scata, K. A.; Wang, W.
Dual inactivation of Akt and ERK by TIC10 signals Foxo3a nuclear
translocation, TRAIL gene induction, and potent antitumor effects.
Sci. Transl. Med. 2013, 5, 171ra17.
(5) Allen, J. E.; Krigsfeld, G.; Patel, L.; Mayes, P. A.; Dicker, D.
T.; Wu, G. S.; El-Deiry, W. S. Identification of TRAIL-inducing
compounds highlights small molecule ONC201/TIC10 as a unique
anti-cancer agent that activates the TRAIL pathway. Mol. Cancer
2015, 14, 99.
(6) Prabhu, V.V.; Allen, J. E.; Dicker, D. T; El-Deiry, W. S. Small-
molecule ONC201/TIC10 targets chemotherapy-resistant colorectal
cancer stem-like cells in an Akt/Foxo3a/ TRAIL-dependent manner.
Cancer Res. 2015, 75, 1423-1432.
(7) Kline, C. L. B.; Heuvel, A. P. J. V. D.; Allen, J. E.; Prabhu, V.
V.; Dicker, D. T.; Eldeiry, W. S. ONC201 kills solid tumor cells by
triggering an integrated stress response dependent on ATF4 activation
by specific eIF2α kinases. Sci. Signal. 2016, 9, ra18.
(8) Ishizawa, J.; Kojima, K.; Chachad, D.; Ruvolo, P.; Ruvolo, V.;
Jacamo, R. O.; Borthakur, G.; Mu, H.; Zeng, Z.; Tabe, Y. ATF4
induction through an atypical integrated stress response to ONC201
triggers p53-independent apoptosis in hematological malignancies.
Sci. Signal. 2016, 9, ra17.
(9) Talekar, M. K.; Allen, J. E.; Dicker, D. T.; El-Deiry, W. S.
ONC201 induces cell death in pediatric non-Hodgkin's lymphoma
cells. Cell cycle 2015, 14, 2422-2428.
(10) Allen, J. E.; Prabhu, V. V.; Talekar, M.; Ap, V. D. H.; Lim,
B.; Dicker, D. T.; Fritz, J. L.; Beck, A.; Eldeiry, W. S. Genetic and
Pharmacological Screens Converge in Identifying FLIP, BCL2, and
IAP Proteins as Key Regulators of Sensitivity to the TRAIL-Inducing
Anticancer Agent ONC201/TIC10. Cancer Res. 2015, 75, 1668.
(11) Jin, Z. Z.; Wang, W.; Fang, D. L.; Jin, Y. J. mTOR inhibition
sensitizes ONC201-induced anti-colorectal cancer cell activity.
Biochem. Biophys. Res. Commun. 2016, 478, 1515-1520.
(12) Allen, J. E.; Kline, C. L. B.; Prabhu, V. V.; Wagner, J.;
Ishizawa, J.; Madhukar, N.; Lev, A.; Baumeister, M.; Zhou, L.; Lulla,
A. J. O. Discovery and clinical introduction of first-in-class
imipridone ONC201. Oncotarget, 2016, 7, 74380-74392.
O
R1
N
N
N
O
R2
Compounds
R1
R2
H3122
MV4,11
IC50 (nM) IC50 (nM)
134±29
158±35
326±49
217±31
147±32
386±53
223±59
139±41
379±39
24±6
21±4
55±7
33±7
23±6
59±16
39±13
21±5
62±17
41
42
43
44
45
46
47
48
49
F
F
Cl
Br
F
F
F
Cl
Cl
Cl
Br
Br
Br
Cl
Br
F
Cl
Br
In summary, a series of tetrahydropyrido[4,3-d]pyrimidine-
2,4-diones have been designed and synthesized as analogues
of a clinical lead ONC201. Preliminary mechanism studies
indicated that these compounds have similar mechanism of
functions as ONC201. These compounds potently inhibit cell
growth in a panel of human cancer cell lines and modifications
of the substituted groups on the core structure can dramatically
improve the cellular activities. Therefore, these compounds
represent a class of novel anti-cancer agents worthy of further
studies. More detailed SAR studies and investigations to
identify the protein targets of these compounds is proceeding.
ASSOCIATED CONTENT
Supporting Information
The experimental details for the synthesis of the designed
compounds, assays for cell growth inhibition, western blot
analysis of the biomarkers, the detection of TRAIL concentration,
the detection of SubG1 DNA
Supporting Information for analogues of ONC201.pdf
The Supporting Information is available free of charge on the
ACS Publications website.
AUTHOR INFORMATION
5
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