13 research outputs found
La estructura del dominio de Colchicina como base para el diseño y síntesis de compuestos con propiedades antimitóticas y antivasculares
El desarrollo de redes de vasos sanguíneos que puedan aportar oxígeno y nutrienteses una de las características esenciales para el crecimiento de tumores sólidos. Dadala importancia de un adecuado flujo sanguíneo en el entorno tumoral para la expansióncelular y la metástasis tumoral, la búsqueda de compuestos capaces de inhibir dichavascularización centra grandes expectativas en el estudio actual de nuevas estrategiasantineoplásicas. Dentro de la terapia antivascular, los agentes interruptores de lavascularización tumoral (VDAs) ocupan un papel primordial debido a su mecanismo deacción, complementario a las terapias ya existentes. Los VDAs actúan directa yselectivamente sobre el endotelio tumoral, induciendo cambios morfológicos yfuncionales que provocan el descenso rápido y dramático del flujo sanguíneo en el senodel tumor, el cual acaba necrosándose. Dentro de los VDAs, los compuestos másestudiados se encuadran dentro del grupo de ligandos del sitio de colchicina en tubulina,que inhiben la polimerización de los microtúbulos celulares, actuando así como agentesantimitóticos.La acción antitumoral dual de los VDAs basados en colchicina (antivascular yantimitótico) explica el enorme potencial terapéutico de esta clase de compuestos. Entreestos VDAs cabe destacar la combretastatina A4 (CA-4), compuesto de referencia delque además existen varios derivados que actualmente se encuentran en fases clínicasavanzadas. Ahora bien, estos candidatos, junto a otros VDAs que también están siendoobjeto de investigación clínica, todavía presentan notables limitaciones que obstaculizanel desarrollo farmacéutico de los mismos, tales como la baja estabilidad química y/o lalimitada solubilidad. Por ello, el objetivo central de esta Tesis ha consistido en labúsqueda de nuevos VDAs ligandos del sitio de colchicina de mejor perfil farmacológico,que solventen los problemas de los compuestos desarrollados hasta el momento..
Protein-ligand complex for structure-based design: impact on the affinity and antitumor activity of new tubulin ligands
Resumen del trabajo presentado en el XVIII Congreso de la Sociedad Española de Química Terapéutica, celebrado en Salamanca (España), del 23 al 26 de enero de 2018Microtubules, made of ¿ß¿tubulin heterodimers, are the key components of the
cytoskeleton and play a crucial role in many cellular processes, such as cell motility,
morphogenesis and mitosis.[1] Interference with microtubule dynamics induces cell
cycle arrest during mitosis and triggers cell death. Compounds that interact with tubulin,
especially those binding at the colchicine domain, have been deeply investigated as
anticancer drugs due to their dual mechanism of action as antimitotics and as vascular
disrupting agents.[2,3] Our research group has recently described a new family of
colchicine¿domain binders, based on a cyclohexanedione skeleton, with potent
antiproliferative activity against tumor and endothelial cells.[4] Moreover, to gain
insight into the binding mode of these cyclohexanediones, we have determined the
crystal structure of ¿ß¿tubulin in complex with our hit compound (TUB075). Based on
this detailed information and by applying the affinity maps program cGRILL, a structurebased
synthesis of new cyclohexanedione derivatives has been accomplished with the
objective of improving their affinity for tubulin and their antitumor activity. Following
this approach, we have obtained new compounds with potent antiproliferative activity
against tumor and endothelial cells (IC50=8¿31 nM) and with the highest Kb value
reported for compounds binding at the colchicine site in tubulin. Additional studies have
shown that they arrest cell cycle at G2/M and disrupt a network of endothelial cells.
Moreover they keep antiproliferative activity against cell lines overexpressing P¿gp,
further supporting the potential of these compounds.The financial support
of the Spanish MINECO (SAF2012‐39760‐C02‐01 and SAF 2015‐64629‐C2‐1‐R), Comunidad de Madrid (BIPEDD2; ref
P2010/BMD‐2457) and the COST action CM1407 (to M J. P.P., S.L., M.O.S. and J.F.D.) is sincerely acknowledge
Antivascular and antitumor properties of the tubulin-binding chalcone TUB091
We investigated the microtubule-destabilizing, vascular-targeting, anti-tumor
and anti-metastatic activities of a new series of chalcones, whose prototype compound
is (E)-3-(3’’-amino-4’’-methoxyphenyl)-1-(5’-methoxy-3’,4’-methylendioxyphenyl)-
2-methylprop-2-en-1-one (TUB091). X-ray crystallography showed that these
chalcones bind to the colchicine site of tubulin and therefore prevent the curved-tostraight
structural transition of tubulin, which is required for microtubule formation.
Accordingly, TUB091 inhibited cancer and endothelial cell growth, induced G2/M
phase arrest and apoptosis at 1-10 nM. In addition, TUB091 displayed vascular
disrupting effects in vitro and in the chicken chorioallantoic membrane (CAM) assay
at low nanomolar concentrations. A water-soluble L-Lys-L-Pro derivative of TUB091
(i.e. TUB099) showed potent antitumor activity in melanoma and breast cancer
xenograft models by causing rapid intratumoral vascular shutdown and massive
tumor necrosis. TUB099 also displayed anti-metastatic activity similar to that of
combretastatin A4-phosphate. Our data indicate that this novel class of chalcones
represents interesting lead molecules for the design of vascular disrupting agents
(VDAs). Moreover, we provide evidence that our prodrug approach may be valuable
for the development of anti-cancer drugs.M-DC thanks the Fondo Social Europeo (FSE) and
the JAE Predoc Programme for a predoctoral fellowship.
This work has received the Ramón Madroñero award for
young researchers (to M-DC and OB) in the XVII call
www.impactjournals.com/oncotarget 17 Oncotarget
sponsored by the Spanish Society of Medicinal Chemistry
(SEQT). This project has been supported by the Spanish
Ministerio de Economia y Competitividad (SAF2012-
39760-C02-01 to M-JC, M-JP-P, SV and E-MP; and
BIO2013-42984-R to JFD), Comunidad de Madrid
(BIPEDD2; ref. P2010/BMD-2457 to M-JC and J-FD),
the Swiss National Science Foundation (310030B_138659
and 31003A_166608; to MOS). The authors acknowledge
networking contribution by the COST Action CM1407
“Challenging organic syntheses inspired by nature - from
natural products chemistry to drug discovery” and COST
action CM1470.Peer reviewe
Blocking blood flow to solid tumors by destabilizing tubulin: An approach to targeting tumor growth
The unique characteristics of the tumor vasculature offer the possibility to selectively target tumor growth and vascularization using tubulin-destabilizing agents. Evidence accumulated with combretastatin A-4 (CA-4) and its prodrug CA-4P support the therapeutic value of compounds sharing this mechanism of action. However, the chemical instability and poor solubility of CA-4 demand alternative compounds that are able to surmount these limitations. This Perspective illustrates the different classes of compounds that behave similar to CA-4, analyzes their binding mode to αβ-tubulin according to recently available structural complexes, and includes described approaches to improve their delivery. In addition, dissecting the mechanism of action of CA-4 and analogues allows a closer insight into the advantages and drawbacks associated with these tubulin-destabilizing agents that behave as vascular disrupting agents (VDAs).status: publishe
Blocking Blood Flow to Solid Tumors by Destabilizing Tubulin : An Approach to Targeting Tumor Growth (Perspective)
The unique characteristics of the tumor
vasculature offer the possibility to selectively target tumor
growth and vascularization using tubulin-destabilizing agents.
Evidence accumulated with combretastatin A-4 (CA-4) and its
prodrug CA-4P support the therapeutic value of compounds
sharing this mechanism of action. However, the chemical
instability and poor solubility of CA-4 demand alternative
compounds that are able to surmount these limitations. This
Perspective illustrates the different classes of compounds that
behave similar to CA-4, analyzes their binding mode to αβ-
tubulin according to recently available structural complexes, and
includes described approaches to improve their delivery. In
addition, dissecting the mechanism of action of CA-4 and
analogues allows a closer insight into the advantages and
drawbacks associated with these tubulin-destabilizing agents that behave as vascular disrupting agents (VDAs).Due to the amount of original research articles and reviews on
this subject, we were unable to cite all of them; any omissions
were unintentional. Author’s research in this subject has been
financed by the Spanish Ministerio de Economıá y Competitividad
(SAF2012-39760-C02-01 and SAF2015-64629-C2-
1-R (MINECO-FEDER) to M.-J.P.-P. and E.-M.P.) and
Comunidad de Madrid (BIPEDD2; ref P2010/BMD-2457).
S.L. and M.-J.P.-P. acknowledge networking contribution by
COST Action CM1407 “Challenging organic synthesis inspired
by nature-from natural products chemistry to drug discovery”.
M.-D.C. thanks the Fondo Social Europeo (FSE) and the JAE
Predoc Programme for a predoctoral fellowship.Peer reviewe
Conformational mimetics of the α-methyl chalcone TUB091 binding tubulin: Design, synthesis and antiproliferative activity
Based on the conformation of the α-methyl chalcone TUB091 in its complex with tubulin, a series of conformational mimetics have been designed and synthesized where the methyl group of the chalcone has been fused to phenyl ring B resulting in 1,2,3,4-tetrahydronaphthalen-2-yl aryl ketones. Among the synthesized compounds, the 5-amino-6-methoxy derivative, with a similar substitution pattern to that of TUB091, showed antiproliferative activity around 20 nM against tumor and endothelial cells. Tubulin binding experiments confirmed its binding to tubulin at the colchicine site with a Kb of 2.4 × 10 M resulting in the inhibition of the in vitro assembly of purified tubulin. Moreover, based on the recently reported complex of combretastatin A4 (CA4) with tubulin, a comparative analysis of the binding mode of CA4 and the α-methyl chalcone to tubulin has been performed.This project has been supported by MINECO (SAF2012-39760-
C02-01) and MINECO/FEDER (SAF2015-64629-C2-1-R), and to M.-
J.P.-P., E.-M.P. E. Q. and M. J. C. and MINECO/FEDER BFU2016-
75319-R to J.F.D. The authors acknowledge networking contribution
by the COST Action CM1407 “Challenging organic syntheses
inspired by nature - from natural products chemistry to drug discovery”
(to M-J. P.-P. S.L. and J.-F.D.) We also would like to
acknowledge Eef Meyen and Lizette Van Berckelaer for excellent
technical assistance.Peer Reviewe
Antiviral activity of [1,2,3]triazolo[4,5- d ]pyrimidin-7(6 H )-ones against chikungunya virus targeting the viral capping nsP1
International audienceChikungunya virus (CHIKV) is a re-emerging alphavirus transmitted to humans by Aedes mosquitoes. Since 2005, CHIKV has been spreading worldwide resulting in epidemics in Africa, the Indian Ocean islands, Asia and more recently in the Americas. CHIKV is thus considered as a global health concern. There is no specific vaccine or drug available for the treatment of this incapacitating viral infection. We previously identified 3-aryl-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones as selective inhibitors of CHIKV replication and proposed the viral capping enzyme nsP1 as a target. This work describes the synthesis of novel series of related compounds carrying at the aryl moiety a methylketone and related oximes combined with an ethyl or an ethyl-mimic at 5-position of the triazolopyrimidinone. These compounds have shown antiviral activity against different CHIKV isolates in the very low μM range based on both virus yield reduction and virus-induced cell-killing inhibition assays. Moreover, these antivirals inhibit the in vitro guanylylation of alphavirus nsP1, as determined by Western blot using an anti-cap antibody. Thus, the data obtained seem to indicate that the anti-CHIKV activity might be related to the inhibition of this crucial step in the viral RNA capping machinery
High-affinity ligands of the colchicine domain in tubulin based on a structure-guided design
Microtubule-targeting agents that bind at the colchicine-site of tubulin are of particular interest in
antitumoral therapy due to their dual mechanism of action as antimitotics and vascular disrupting
agents. Cyclohexanediones derivatives have been described as a new family of colchicine-domain
binders with an association constant to tubulin similar to that of colchicine. Here, the highresolution
structures of tubulin in complex with cyclohexanediones TUB015 and TUB075 were
solved by X-ray crystallography. A detailed analysis of the tubulin-TUB075 interaction by means of
computational affinity maps allowed the identification of two additional regions at the binding site
that were addressed with the design and synthesis of a new series of cyclohexanediones with a distal
2-substituted benzofurane. These new compounds showed potent antiproliferative activity with IC50
values in the nM range, arrested cell cycle progression at the G2/M phase and induced apoptosis at sub
μM concentrations. Moreover, they caused the destruction of a preformed vascular network in vitro
and inhibited the migration of endothelial cells at non-toxic concentrations. Finally, these compounds
displayed high affinity for tubulin as substantiated by a Kb value of 2.87 × 108 M−1 which, to the best
of our knowledge, represents the highest binding constant measured to date for a colchicine-domain
ligand.This project has been supported by the Spanish Ministerio de Economía y Competitividad (SAF2015–64629-
C2-1-R to EMP, MJPP. and MJC and SAF2015-64629-C2-2 to F.G.), by the Swiss National Science Foundation
(31003A_166608, to MOS) and COST action CM1407 (to MJPP, SL, AP, MS, and JFD). We acknowledge
Lizette Van Berckelaer, Eef Meyen and Sam Noppen for excellent technical assistance. We thank V. Olieric and
M. Wang for excellent technical assistance with the collection of X-ray data at beamline X06SA of the Swiss
Light Source (Paul Scherrer Institut, Villigen PSI, Switzerland). We thank José Fernando Escolar for his help
with electron microscopy. We thank ganadería Fernando Díaz for calf brains for tubulin purification. This
work was supported in part by grants BFU2016-75319-R (AEI/FEDER, UE) (JFD.) JFD. is a member of the CIB
Intramural Program “Molecular Machines for Better Life” (MACBET). We also thank SEQT for the “Ramón
Madroñero Award” to O.B.Peer Reviewe
Antiviral activity of [1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones against chikungunya virus targeting the viral capping nsP1
Chikungunya virus (CHIKV) is a re-emerging alphavirus transmitted to humans by Aedes mosquitoes. Since 2005, CHIKV has been spreading worldwide resulting in epidemics in Africa, the Indian Ocean islands, Asia and more recently in the Americas. CHIKV is thus considered as a global health concern. There is no specific vaccine or drug available for the treatment of this incapacitating viral infection. We previously identified 3-aryl-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones as selective inhibitors of CHIKV replication and proposed the viral capping enzyme nsP1 as a target. This work describes the synthesis of novel series of related compounds carrying at the aryl moiety a methylketone and related oximes combined with an ethyl or an ethyl-mimic at 5-position of the triazolopyrimidinone. These compounds have shown antiviral activity against different CHIKV isolates in the very low μM range based on both virus yield reduction and virus-induced cell-killing inhibition assays. Moreover, these antivirals inhibit the in vitro guanylylation of alphavirus nsP1, as determined by Western blot using an anti-cap antibody. Thus, the data obtained seem to indicate that the anti-CHIKV activity might be related to the inhibition of this crucial step in the viral RNA capping machinery.A. G. has received a JAE-predoctoral fellowship financed by the
CSIC and the FSE (Fondo Social Europeo).We thank Caroline Collard
and Kim Donckers for their excellent technical assistance in the
acquisition of the antiviral data. This work has been supported by
grants of the MINECO/FEDER (SAF2015-64629-C2-1-R), BIPEDD-2-
CM (S2010/BMD-2457) and by EU F7 projects SILVER and EUVIRNA
(grant numbers 260644 and 264286, respectively).Peer Reviewe
Antiviral activity of [1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones against chikungunya virus targeting the viral capping nsP1
Chikungunya virus (CHIKV) is a re-emerging alphavirus transmitted to humans by Aedes mosquitoes. Since 2005, CHIKV has been spreading worldwide resulting in epidemics in Africa, the Indian Ocean islands, Asia and more recently in the Americas. CHIKV is thus considered as a global health concern. There is no specific vaccine or drug available for the treatment of this incapacitating viral infection. We previously identified 3-aryl-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones as selective inhibitors of CHIKV replication and proposed the viral capping enzyme nsP1 as a target. This work describes the synthesis of novel series of related compounds carrying at the aryl moiety a methylketone and related oximes combined with an ethyl or an ethyl-mimic at 5-position of the triazolopyrimidinone. These compounds have shown antiviral activity against different CHIKV isolates in the very low μM range based on both virus yield reduction and virus-induced cell-killing inhibition assays. Moreover, these antivirals inhibit the in vitro guanylyl-transfer activity of alphavirus nsP1, as determined by Western blot using an anti-cap antibody. Thus, the data obtained seem to indicate that the anti-CHIKV activity might be related to the inhibition of this crucial step in the viral RNA capping machinery.status: publishe