Publications by authors named "Roberta Bortolozzi"

57 Publications

Concise synthesis and biological evaluation of 2-Aryl-3-Anilinobenzo[b]thiophene derivatives as potent apoptosis-inducing agents.

Bioorg Chem 2021 Jul 20;112:104919. Epub 2021 Apr 20.

Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy.

Many clinically used agents active in cancer chemotherapy exert their activity through the induction of cell death (apoptosis) by targeting microtubules, altering protein function or inhibiting DNA synthesis. The benzo[b]thiophene scaffold holds a pivotal place as a pharmacophore for the development of anticancer agents, and, in addition, this scaffold has many pharmacological activities. We have developed a flexible method for the construction of a new series of 2-aryl-3-(3,4,5-trimethoxyanilino)-6-methoxybenzo[b]thiophenes as potent antiproliferative agents, giving access to a wide range of substitution patterns at the 2-position of the 6-methoxybenzo[b]thiophene common intermediate. In the present study, all the synthesized compounds retained the 3-(3,4,5-trimethoxyanilino)-6-methoxybenzo[b]thiophene moiety, and the structure-activity relationship was examined by modification of the aryl group at its 2-position with electron-withdrawing (F) or electron-releasing (alkyl and alkoxy) groups. We found that small substituents, such as fluorine or methyl, could be placed in the para-position of the 2-phenyl ring, and these modifications only slightly reduced antiproliferative activity relative to the unsubstituted 2-phenyl analogue. Compounds 3a and 3b, bearing the phenyl and para-fluorophenyl at the 2-position of the 6-methoxybenzo[b]thiophene nucleus, respectively, exhibited the greatest antiproliferative activity among the tested compounds. The treatment of both Caco2 (not metastatic) and HCT-116 (metastatic) colon carcinoma cells with 3a or 3b triggered a significant induction of apoptosis as demonstrated by the increased expression of cleaved-poly(ADP-ribose) polymerase (PARP), receptor-interacting protein (RIP) and caspase-3 proteins. The same effect was not observed with non-transformed colon 841 CoN cells. A potential additional effect during mitosis for 3a in metastatic cells and for 3b in non-metastatic cells was also observed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bioorg.2021.104919DOI Listing
July 2021

Developing novel classes of protein kinase CK1δ inhibitors by fusing [1,2,4]triazole with different bicyclic heteroaromatic systems.

Eur J Med Chem 2021 Apr 2;216:113331. Epub 2021 Mar 2.

Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy. Electronic address:

Protein kinase CK1δ expression and activity is involved in different pathological situations that include neuroinflammatory and neurodegenerative diseases. For this reason, protein kinase CK1δ has become a possible therapeutic target for these conditions. 5,6-fused bicyclic heteroaromatic systems that resemble adenine of ATP represent optimal scaffolds for the development of a new class of ATP competitive CK1δ inhibitors. In particular, a new series of [1,2,4]triazolo[1,5-c]pyrimidines and [1,2,4]triazolo[1,5-a][1,3,5]triazines was developed. Some crucial interactors have been identified, such as the presence of a free amino group able to interact with the residues of the hinge region at the 5- and 7- positions of the [1,2,4]triazolo[1,5-c]pyrimidine and [1,2,4]triazolo[1,5-a][1,3,5]triazine scaffolds, respectively; or the presence of a 3-hydroxyphenyl or 3,5-dihydroxyphenyl moiety at the 2- position of both nuclei. Molecular modeling studies identified the key interactions involved in the inhibitor-protein recognition process that appropriately fit with the outlined structure-activity relationship. Considering the fact that the CK1 protein kinase is involved in various pathologies in particular of the central nervous system, the interest in the development of new inhibitors permeable to the blood-brain barrier represents today an important goal in the pharmaceutical field. The best potent compound of the series is the 5-(7-amino-5-(benzylamino)-[1,2,4]triazolo[1,5-a][1,3,5]triazin-2-yl)benzen-1,3-diol (compound 51, IC = 0.18 μM) that was predicted to have an intermediate ability to cross the membrane in our in vitro assay and represents an optimal starting point to both studies the therapeutic value of protein kinase CK1δ inhibition and to develop new more potent derivatives.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2021.113331DOI Listing
April 2021

A facile synthesis of diaryl pyrroles led to the discovery of potent colchicine site antimitotic agents.

Eur J Med Chem 2021 Mar 29;214:113229. Epub 2021 Jan 29.

Istituto di Ricerca Pediatrica (IRP), Corso Stati Uniti 4, 35128, Padova, Italy. Electronic address:

Three different series of cis-restricted analogues of combretastatin A-4 (CA-4), corresponding to thirty-nine molecules that contained a pyrrole nucleus interposed between the two aryl rings, were prepared by a palladium-mediated coupling approach and evaluated for their antiproliferative activity against six human cancer cell lines. In the two series of 1,2-diaryl pyrrole derivatives, results suggested that the presence of the 3',4',5'-trimethoxyphenyl moiety at the N-1 position of the pyrrole ring was more favorable for antiproliferative activity. In the series of 3,4-diarylpyrrole analogues, three compounds (11i-k) exhibited maximal antiproliferative activity, showing excellent antiproliferative activity against the CA-4 resistant HT-29 cells. Inhibition of tubulin polymerization of selected 1,2 pyrrole derivatives (9a, 9c, 9o and 10a) was similar to that observed with CA-4, while the isomeric 3,4-pyrrole analogues 11i-k were generally from 1.5- to 2-fold more active than CA-4. Compounds 11j and 11k were the only compounds that showed activity as inhibitors of colchicine binding comparable to that CA-4. Compound 11j had biological properties consistent with its intracellular target being tubulin. This compound was able to block the cell cycle in metaphase and to induce significant apoptosis at a concentration of 25 nM, following the mitochondrial pathway, with low toxicity for normal cells. More importantly, compound 11j exerted activity in vivo superior to that of CA-4P, being able to significantly reduce tumor growth in a syngeneic murine tumor model even at the lower dose tested (5.0 mg/kg).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2021.113229DOI Listing
March 2021

Synthesis, DNA-binding and antiproliferative properties of diarylquinolizinium derivatives.

Org Biomol Chem 2021 01 7;19(4):878-890. Epub 2021 Jan 7.

Department of Women's and Child's health, Oncohematology laboratory, University of Padova, Via Giustiniani 2, I-35128 Padova, Italy.

A series of ten 2,7- and 2,8-diarylquinolizinium derivatives was synthesized and their DNA-binding and cytotoxic properties were investigated. Except for one nitro-substituted derivative all tested diarylquinolizinium ions bind to DNA with sufficient affinity (2 × 10 M-2 × 10 M). It was shown with photometric, fluorimetric and polarimetric titrations as well as with flow-LD analysis that the ligands bind mainly by intercalation to duplex DNA, however, depending on the ligand-DNA ratio, groove binding and backbone association were also observed with some derivatives. The biological activity was further investigated with tests of cytotoxicity and antiproliferative properties towards non-tumor cells and selected cancer cells, along with cell cycle analysis and an annexin-V assay. Notably, substrates that carry donor-functionalities in the 4-position of the phenyl substituents revealed a strong, and in some cases selective, antiproliferative activity as quantified by the growth inhibition, GI, at very low micromolar and even submicromolar level both in leukemia and solid tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0ob02298eDOI Listing
January 2021

Insight on [1,3]thiazolo[4,5-e]isoindoles as tubulin polymerization inhibitors.

Eur J Med Chem 2021 Feb 24;212:113122. Epub 2020 Dec 24.

Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Archirafi 32, 90123, Palermo, Italy.

A series of [1,3]thiazolo[4,5-e]isoindoles has been synthesized through a versatile and high yielding multistep sequence. Evaluation of the antiproliferative activity of the new compounds on the full NCI human tumor cell line panel highlighted several compounds that are able to inhibit tumor cell proliferation at micromolar-submicromolar concentrations. The most active derivative 11g was found to cause cell cycle arrest at the G2/M phase and induce apoptosis in HeLa cells, following the mitochondrial pathway, making it a lead compound for the discovery of new antimitotic drugs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2020.113122DOI Listing
February 2021

Pyrrolo[2',3':3,4]cyclohepta[1,2-][1,2]oxazoles, a New Class of Antimitotic Agents Active against Multiple Malignant Cell Types.

J Med Chem 2020 10 11;63(20):12023-12042. Epub 2020 Oct 11.

Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123 Palermo, Italy.

A new class of pyrrolo[2',3':3,4]cyclohepta[1,2-][1,2]oxazoles was synthesized for the treatment of hyperproliferative pathologies, including neoplasms. The new compounds were screened in the 60 human cancer cell lines of the NCI drug screen and showed potent activity with GI values reaching the nanomolar level, with mean graph midpoints of 0.08-0.41 μM. All compounds were further tested on six lymphoma cell lines, and eight showed potent growth inhibitory effects with IC values lower than 500 nM. Mechanism of action studies showed the ability of the new [1,2]oxazoles to arrest cells in the G2/M phase in a concentration dependent manner and to induce apoptosis through the mitochondrial pathway. The most active compounds inhibited tubulin polymerization, with IC values of 1.9-8.2 μM, and appeared to bind to the colchicine site. The G2/M arrest was accompanied by apoptosis, mitochondrial depolarization, generation of reactive oxygen species, and PARP cleavage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.0c01315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901646PMC
October 2020

Ecdysteroid Derivatives that Reverse P-Glycoprotein-Mediated Drug Resistance.

J Nat Prod 2020 08 13;83(8):2434-2446. Epub 2020 Aug 13.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università degli Studi di Padova, Via Giustiniani 2, Padova, 35128, Italy.

The expression of multidrug resistance P-glycoprotein (P-gp) by cancer cells represents one of the major drawbacks to successful cancer therapy. Accordingly, the development of drugs that inhibit the activity of this transporter remains a major challenge in cancer drug discovery. In this context, several new ecdysteroid derivatives have been synthesized and evaluated as P-gp inhibitors. Two of them (compounds and ) were able to resensitize CEM and LoVo resistant cell lines to vinblastine and doxorubicin, respectively. Indeed, both compounds and increased the cellular accumulation of rhodamine 123 in cells expressing P-gp and stimulated basal P-glycoprotein-ATPase activity at a 1 μM concentration, demonstrating their interference with the transport of other substrates in a competitive mode. Moreover, in a medulloblastoma cell line (DAOY), compounds and reduced the side population representing cancer stem cells, which are characterized by a high expression of ABC drug transporters. Further, in DAOY cells, the same two compounds synergized with cisplatin and vincristine, two drugs used commonly in the therapy of medulloblastoma. Molecular docking studies on the homology-modeled structure of the human P-glycoprotein provided a rationale for the biological results, validating the binding mode within the receptor site, in accordance with lipophilicity data and observed structure-activity relationship information. Altogether, the present results endorse these derivatives as promising P-gp inhibitors, and they may serve as candidates to reverse drug resistance in cancer cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jnatprod.0c00334DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8009596PMC
August 2020

Design, synthesis, in vitro and in vivo biological evaluation of 2-amino-3-aroylbenzo[b]furan derivatives as highly potent tubulin polymerization inhibitors.

Eur J Med Chem 2020 Aug 12;200:112448. Epub 2020 May 12.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131, Padova, Italy. Electronic address:

A new class of inhibitors of tubulin polymerization based on the 2-amino-3-(3',4',5'-trimethoxybenzoyl)benzo[b]furan molecular scaffold was synthesized and evaluated for in vivo and in vitro biological activity. These derivatives were synthesized with different electron-releasing or electron-withdrawing substituents at one of the C-4 through C-7 positions. Methoxy substitution and location on the benzene part of the benzo[b]furan ring played an important role in affecting antiproliferative activity, with the greatest activity occurring with the methoxy group at the C-6 position, the least with the substituent at C-4. The same effect was also observed with ethoxy, methyl or bromine at the C-6 position of the benzo[b]furan skeleton, with the 6-ethoxy-2-amino-3-(3',4',5'-trimethoxybenzoyl)benzo[b]furan derivative 4f as the most promising compound of the series. This compound showed remarkable antiproliferative activity (IC: 5 pM) against the Daoy medulloblastoma cell line, and 4f was nearly devoid of toxicity on healthy human lymphocytes and astrocytes. The potent antiproliferative activity of 4f was derived from its inhibition of tubulin polymerization by binding to the colchicine site. The compound was also examined for in vivo activity, showing higher potency at 15 mg/kg compared with the reference compound combretastatin A-4 phosphate at 30 mg/kg against a syngeneic murine mammary tumor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2020.112448DOI Listing
August 2020

Design, synthesis and biological evaluation of 2-alkoxycarbonyl-3-anilinoindoles as a new class of potent inhibitors of tubulin polymerization.

Bioorg Chem 2020 04 18;97:103665. Epub 2020 Feb 18.

Rega Institute for Medical Research, KU Leuven, Laboratory of Virology and Chemotherapy, Leuven, Belgium.

A new class of inhibitors of tubulin polymerization based on the 2-alkoxycarbonyl-3-(3',4',5'-trimethoxyanilino)indole molecular skeleton was synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization and cell cycle effects. The results presented show that the methoxy substitution and location on the indole nucleus plays an important role in inhibition of cell growth, and the most favorable position for the substituent was at C-6. In addition, a small-size ester function (methoxy/ethoxycarbonyl) at the 2-position of the indole core was desirable. Also, analogues that were alkylated with methyl, ethyl or n-propyl groups or had a benzyl moiety on the N-1 indolic nitrogen retained activity equivalent to those observed in the parent N-1H analogues. The most promising compounds of the series were 2-methoxycarbonyl-3-(3',4'.5'-trimethoxyanilino)-5-methoxyindole 3f and 1-methyl-2-methoxycarbonyl-3-(3',4'.5'-trimethoxyanilino)-6-methoxy-indole 3w, both of which target tubulin at the colchicine site with antitubulin activities comparable to that of the reference compound combretastatin A-4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bioorg.2020.103665DOI Listing
April 2020

Design, synthesis and biological evaluation of novel vicinal diaryl-substituted 1H-Pyrazole analogues of combretastatin A-4 as highly potent tubulin polymerization inhibitors.

Eur J Med Chem 2019 Nov 1;181:111577. Epub 2019 Aug 1.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131, Padova, Italy; Istituto di Ricerca Pediatrica (IRP), Corso Stati Uniti 4, 35128, Padova, Italy. Electronic address:

A series of 3-(3',4',5'-trimethoxyphenyl)-4-substituted 1H-pyrazole and their related 3-aryl-4-(3',4',5'-trimethoxyphenyl)-1-H-pyrazole regioisomeric derivatives, prepared as cis-rigidified combretastatin A-4 (CA-4) analogues, were synthesized and evaluated for their in vitro antiproliferative against six different cancer cell lines and, for selected highly active compounds, inhibitory effects on tubulin polymerization, cell cycle effects and in vivo potency. We retained the 3',4',5'-trimethoxyphenyl moiety as ring A throughout the present investigation, and a structure-activity relationship (SAR) information was obtained by adding electron-withdrawing (OCF, CF) or electron-releasing (alkyl and alkoxy) groups on the second aryl ring, corresponding to the B-ring of CA-4, either at the 3- or 4-position of the pyrazole nucleus. In addition, the B-ring was replaced with a benzo[b]thien-2-yl moiety. For many of the compounds, their activity was greater than, or comparable with, that of CA-4. Maximal activity was observed with the two regioisomeric derivatives characterized by the presence of a 4-ethoxyphenyl and a 3',4',5'-trimethoxyphenyl group at the C-3 and C-4 positions, and vice versa, of the 1H-pyrazole ring. The data showed that the 3',4',5'-trimethoxyphenyl moiety can be moved from the 3- to the 4-position of the 1H-pyrazole ring without significantly affecting antiproliferative activity. The most active derivatives bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. In vivo experiments, on an orthotopic murine mammary tumor, revealed that 4c inhibited tumor growth even at low concentrations (5 mg/kg) compared to CA-4P (30 mg/kg).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2019.111577DOI Listing
November 2019

Evaluating the effects of fluorine on biological properties and metabolic stability of some antitubulin 3-substituted 7-phenyl-pyrroloquinolinones.

Eur J Med Chem 2019 Sep 3;178:297-314. Epub 2019 Jun 3.

Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Padova, Italy. Electronic address:

A small number of fluorinated 7-phenyl-pyrroloquinolinone (7-PPyQ) derivatives was synthesized in an attempt to improve the metabolic stability of 3N-ethyl-7-PPyQ and 3N-benzoyl-7-PPyQ. The possible impacts of the fluorine-hydrogen isosterism on both biological activity and metabolic stability were evaluated. Introduction of a fluorine atom in the 2 or 3 position of the 7-phenyl ring yielded the 7-PPyQ derivatives 12, 13 and 15, which showed potent cytotoxicity (low micromolar and sub-nanomolar GIs) both in human leukemic and solid tumor cell lines. None of them induced significant cell death in quiescent and proliferating human lymphocytes. Moreover, 12, 13 and 15 exhibited remarkable cytotoxic activity in the multidrug-resistant cell line CEM, suggesting that they are not substrates for P-glycoprotein. All compounds inhibited tubulin assembly and the binding of [H]colchicine to tubulin, with the best activity occurring with compound 15. Mechanistic studies carried out on compound 12 indicated that it caused (a) a strong G2/M arrest; (b) apoptosis in a time- and concentration-dependent manner; (c) a significant production of ROS (in good agreement with the observed mitochondrial depolarization); (d) caspase-3 and poly (ADP-ribose) polymerase activation; and (e) a decrease in the expression of anti-apoptotic proteins. In vivo experiments in a murine syngeneic tumor model demonstrated that compounds 12 and 15 significantly reduced tumor mass at doses four times lower than that required for the reference compound combretastatin A-4 phosphate. Neither monofluorination of the 7-phenyl ring of 3N-ethyl-7-PPyQ nor replacement of the benzoyl function of 3N-benzoyl-7-PPyQ with a 2-fluorobenzoyl moiety led to any improvement in the metabolic stability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2019.05.092DOI Listing
September 2019

Identification of novel indole derivatives acting as inhibitors of the Keap1-Nrf2 interaction.

J Enzyme Inhib Med Chem 2019 Dec;34(1):1152-1157

c Dipartimento di Salute della Donna e del Bambino , Università di Padova , Padua , Italy.

Nine indole derivatives () were tested as potential inhibitors of the Keap1-Nrf2 interaction. This class of compounds increases the intracellular levels of the transcription factor Nrf2 and the consequent expression of enzymes encoded by genes containing the antioxidant response element (ARE). In the ARE-luciferase reporter assay only - revealed to be remarkably more active than -butylhydroxyquinone (-BHQ), with standing out as the best performing compound. While and are weak acids, is an ampholyte prevailing as a zwitterion in neutral aqueous solutions. The ability of to significantly increase levels of Nrf2, NADPH:quinone oxidoreductase 1, and transketolase (TKT) gave further support to the hypothesis that these compounds act as inhibitors of the Keap1-Nrf2 interaction. Docking simulations allowed us to elucidate the nature of the putative interactions between and Keap1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/14756366.2019.1623209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567006PMC
December 2019

Synthesis, in vitro and in vivo biological evaluation of substituted 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones as new potent anticancer agents.

Eur J Med Chem 2019 Mar 26;166:514-530. Epub 2019 Jan 26.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35128, Padova, Italy. Electronic address:

A small library of 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones has been synthesized and screened according to protocols available at the National Cancer Institute (NCI). Some derivatives were potent antiproliferative agents, showing GI values in the nanomolar range. Remarkably, when most active compounds against leukemia cells were tested in human peripheral blood lymphocytes from healthy donors, were 100-200 times less cytotoxic. Some compounds, selected by the Biological Evaluation Committee of NCI, were examined to determine tubulin assembly inhibition. Furthermore, flow cytometric studies performed on HeLa, HT-29, and A549 cells, showed that compounds 14 and 25 caused a block in the G2/M phase. Interestingly, these derivatives induced apoptosis through the mitochondrial death pathway, causing in parallel significant activation of both caspase-3 and -9, PARP cleavage and down-regulation of the anti-apoptotic proteins Bcl-2 and Mcl-1. Finally, compound 25 was also tested in vivo in the murine BL6-B16 melanoma and E0771 breast cancer cells, causing in both cases a significant reduction in tumor volume.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2019.01.049DOI Listing
March 2019

Design, Synthesis, and Biological Evaluation of 6-Substituted Thieno[3,2- d]pyrimidine Analogues as Dual Epidermal Growth Factor Receptor Kinase and Microtubule Inhibitors.

J Med Chem 2019 02 18;62(3):1274-1290. Epub 2019 Jan 18.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia , Università di Padova , 35131 Padova , Italy.

The clinical evidence for the success of tyrosine kinase inhibitors in combination with microtubule-targeting agents prompted us to design and develop single agents that possess both epidermal growth factor receptor (EGFR) kinase and tubulin polymerization inhibitory properties. A series of 6-aryl/heteroaryl-4-(3',4',5'-trimethoxyanilino)thieno[3,2- d]pyrimidine derivatives were discovered as novel dual tubulin polymerization and EGFR kinase inhibitors. The 4-(3',4',5'-trimethoxyanilino)-6-( p-tolyl)thieno[3,2- d]pyrimidine derivative 6g was the most potent compound of the series as an antiproliferative agent, with half-maximal inhibitory concentration (IC) values in the single- or double-digit nanomolar range. Compound 6g bound to tubulin in the colchicine site and inhibited tubulin assembly with an IC value of 0.71 μM, and 6g inhibited EGFR activity with an IC value of 30 nM. Our data suggested that the excellent in vitro and in vivo profile of 6g may be derived from its dual inhibition of tubulin polymerization and EGFR kinase.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.8b01391DOI Listing
February 2019

Phytosterol and γ-Oryzanol Conjugates: Synthesis and Evaluation of their Antioxidant, Antiproliferative, and Anticholesterol Activities.

J Nat Prod 2018 10 17;81(10):2212-2221. Epub 2018 Oct 17.

Dipartimento di Chimica , Università degli Studi di Milano , Via Golgi 19 , 20133 , Milano , Italy.

Fifteen new multifunctional conjugates were designed and synthesized by chemically linking the steroidal framework of natural occurring γ-oryzanol and γ-oryzanol-derived phytosterols to a wide range of bioactive natural compounds (fatty acids, phenolic acids, amino acids, lipoic acid, retinoic acid, curcumin, and resveratrol). Starting from γ-oryzanol, which is the main component of rice bran oil, this study was aimed at assessing if the conjugation strategy might enhance some γ-oryzanol bioactivities. The antioxidant activity was evaluated through three different mechanisms, namely, DPPH-scavenging activity, metal-chelating activity, and β-carotene-bleaching inhibition. Measurement of the in vitro cell growth inhibitory effects on three different human cancer cellular lines was also carried out, and the potential hypocholesterolemic effect was studied. Compounds 10 and 15 displayed an improved antioxidant activity, with respect to that of γ-oryzanol. Compounds 2, 6, and 12 exerted an antiproliferative activity in the low micromolar range against HeLa and DAOY cells (GI < 10 μM). As for the claimed hypocholesterolemic effect of γ-oryzanol, none of the synthesized compounds inhibited the 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a key enzyme in cholesterol biosynthesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jnatprod.8b00465DOI Listing
October 2018

Choline Kinase Alpha Inhibition by EB-3D Triggers Cellular Senescence, Reduces Tumor Growth and Metastatic Dissemination in Breast Cancer.

Cancers (Basel) 2018 Oct 22;10(10). Epub 2018 Oct 22.

Pediatric Hematooncology Laboratory, Department of Women's and Children's health, University of Padova, 35128 Padova, Italy.

Choline kinase (ChoK) is the first enzyme of the Kennedy pathway leading to the biosynthesis of phosphatidylcholine (PtdCho), the most abundant phospholipid in eukaryotic cell membranes. EB-3D is a novel choline kinase α1 (ChoKα1) inhibitor with potent antiproliferative activity against a panel of several cancer cell lines. ChoKα1 is particularly overexpressed and hyperactivated in aggressive breast cancer. By NMR analysis, we demonstrated that EB-3D is able to reduce the synthesis of phosphocholine, and using flow cytometry, immunoblotting, and q-RT-PCR as well as proliferation and invasion assays, we proved that EB-3D strongly impairs breast cancer cell proliferation, migration, and invasion. EB-3D induces senescence in breast cancer cell lines through the activation of the metabolic sensor AMPK and the subsequent dephosphorylation of mTORC1 downstream targets, such as p70S6K, S6 ribosomal protein, and 4E-BP1. Moreover, EB-3D strongly synergizes with drugs commonly used for breast cancer treatment. The antitumorigenic potential of EB-3D was evaluated in vivo in the syngeneic orthotopic E0771 mouse model of breast cancer, where it induces a significant reduction of the tumor mass at low doses. In addition, EB-3D showed an antimetastatic effect in experimental and spontaneous metastasis models. Altogether, our results indicate that EB-3D could be a promising new anticancer agent to improve aggressive breast cancer treatment protocols.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers10100391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6209942PMC
October 2018

Lead optimization-hit expansion of new asymmetrical pyridinium/quinolinium compounds as choline kinase α1 inhibitors.

Future Med Chem 2018 08 25;10(15):1769-1786. Epub 2018 Jul 25.

Department of Pharmaceutical & Organic Chemistry, Faculty of Pharmacy, University of Granada, 18010 Granada, Spain.

Aim: Choline kinase α inhibitors represent one of the newest classes of cytotoxic drugs for cancer treatment, since aberrant choline metabolism is a characteristic shared by many human cancers.

Results: Here, we present a new class of asymmetrical pyridinium/quinolinium derivatives developed and designed based on drug optimization.

Conclusion: Among all compounds described here, compound 8, bearing a 7-chloro-4N-methyl-p-chloroaniline quinolinium moiety, exhibited the greatest inhibitory activity at the enzyme (IC = 0.29 μM) and antiproliferative activity in cellular assays (GI = 0.29-0.92 μM). Specifically, compound 8 strongly induces a cell-cycle arrest in G1 phase, but it does not significantly induce apoptosis while causing senescence in the MDA-MB-231 cell line.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4155/fmc-2018-0059DOI Listing
August 2018

EB-3D a novel choline kinase inhibitor induces deregulation of the AMPK-mTOR pathway and apoptosis in leukemia T-cells.

Biochem Pharmacol 2018 09 11;155:213-223. Epub 2018 Jul 11.

Department of Woman's and Child's Health, Oncohematology Laboratory, University of Padova, 35128 Padova, Italy. Electronic address:

Choline kinase alpha 1 (ChoKα1) has recently become an interesting therapeutic target since its overexpression has been associated to tumorigenesis in many cancers. Nevertheless, little is known regarding hematological malignancies. In this manuscript, we investigated the effect of a novel and selective ChoKα inhibitor EB-3D in T acute lymphoblastic leukemia (T-ALL). The effect of EB-3D was evaluated in a panel of T-leukemia cell lines and ex-vivo primary cultures derived from pediatric T-ALL patients. We also evaluated in detail, using Reverse Phase Protein Array (RPPA), protein phosphorylation level changes in T-ALL cells upon treatment. The drug exhibits a potent antiproliferative activity in a panel of T-leukemia cell lines and primary cultures of pediatric patients. Moreover, the drug strongly induces apoptosis and more importantly it enhanced T-leukemia cell sensitivity to chemotherapeutic agents, such as dexamethasone and l-asparaginase. In addition, the compound induces an early activation of AMPK, the main regulator of cellular energy homeostasis, by its phosphorylation at residue T712 of catalytic subunit α, and thus repressing mTORC1 pathway, as shown by mTOR S2448 dephosphorylation. The inhibition of mTOR in turn affects the activity of several known downstream targets, such as 4E-BP1, p70S6K, S6 Ribosomal Protein and GSK3 that ultimately may lead to a reduction of protein synthesis and cell death. Taken together, our findings suggest that targeting ChoKα may be an interesting option for treating T-ALL and that EB-3D could represent a valuable therapeutic tool.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bcp.2018.07.004DOI Listing
September 2018

3-Aryl/Heteroaryl-5-amino-1-(3',4',5'-trimethoxybenzoyl)-1,2,4-triazoles as antimicrotubule agents. Design, synthesis, antiproliferative activity and inhibition of tubulin polymerization.

Bioorg Chem 2018 10 30;80:361-374. Epub 2018 Jun 30.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131 Padova, Italy. Electronic address:

Many natural and synthetic substances are known to interfere with the dynamic assembly of tubulin, preventing the formation of microtubules. In our search for potent and selective antitumor agents, a novel series of 1-(3',4',5'-trimethoxybenzoyl)-5-amino-1,2,4-triazoles were synthesized. The compounds had different heterocycles, including thiophene, furan or the three isomeric pyridines, and they possessed a phenyl ring bearing electron-releasing or electron-withdrawing substituents at the 3-position of the 5-amino-1,2,4-triazole system. Most of the twenty-two tested compounds showed moderate to potent antiproliferative activities against a panel of solid tumor and leukemic cell lines, with four (5j, 5k, 5o and 5p) showing strong antiproliferative activity (IC < 1 μM) against selected cancer cells. Among them, several molecules preferentially inhibited the proliferation of leukemic cell lines, showing IC values 2-100-fold lower for Jurkat and RS4;11 cells than those for the three lines derived from solid tumors (HeLa, HT-29 and MCF-7 cells). Compound 5k strongly inhibited tubulin assembly, with an IC value of 0.66 μM, half that obtained in simultaneous experiments with CA-4 (IC = 1.3 μM).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bioorg.2018.06.037DOI Listing
October 2018

AKR1C enzymes sustain therapy resistance in paediatric T-ALL.

Br J Cancer 2018 04 8;118(7):985-994. Epub 2018 Mar 8.

Istituto di Ricerca paediatrica Città della Speranza-IRP, corso Stati Uniti 4, Padova, 35127, Italy.

Background: Despite chemotherapy intensification, a subgroup of high-risk paediatric T-cell acute lymphoblastic leukemia (T-ALL) patients still experience treatment failure. In this context, we hypothesised that therapy resistance in T-ALL might involve aldo-keto reductase 1C (AKR1C) enzymes as previously reported for solid tumors.

Methods: Expression of NRF2-AKR1C signaling components has been analysed in paediatric T-ALL samples endowed with different treatment outcomes as well as in patient-derived xenografts of T-ALL. The effects of AKR1C enzyme modulation has been investigated in T-ALL cell lines and primary cultures by combining AKR1C inhibition, overexpression, and gene silencing approaches.

Results: We show that T-ALL cells overexpress AKR1C1-3 enzymes in therapy-resistant patients. We report that AKR1C1-3 enzymes play a role in the response to vincristine (VCR) treatment, also ex vivo in patient-derived xenografts. Moreover, we demonstrate that the modulation of AKR1C1-3 levels is sufficient to sensitise T-ALL cells to VCR. Finally, we show that T-ALL chemotherapeutics induce overactivation of AKR1C enzymes independent of therapy resistance, thus establishing a potential resistance loop during T-ALL combination treatment.

Conclusions: Here, we demonstrate that expression and activity of AKR1C enzymes correlate with response to chemotherapeutics in T-ALL, posing AKR1C1-3 as potential targets for combination treatments during T-ALL therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41416-018-0014-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931104PMC
April 2018

Ribociclib, a Cdk4/Cdk6 kinase inhibitor, enhances glucocorticoid sensitivity in B-acute lymphoblastic leukemia (B-All).

Biochem Pharmacol 2018 07 3;153:230-241. Epub 2018 Feb 3.

Department of Woman's and Child's Heath, Oncohematology Lab, University of Padova, Italy. Electronic address:

Dysregulation of the cyclin D1-CDK4/CDK6 complex is frequently observed in almost all human cancer and contributes to aberrant cell proliferation and consequent tumorigenesis. Although many reports described the importance of CDK4/CDK6 in different set of human tumors, only few studies have been performed on leukemia. By gene expression analysis performed in a cohort of childhood patients affected by B-acute lymphoblastic leukemia (B-ALL) we found that both CDK4 and CDK6 are highly expressed. Moreover, reverse phase protein array (RPPA) analysis showed that cyclin D1 levels are higher in patients undergoing relapse. Starting from these considerations, we evaluated the effect of dual inhibition of CDK4/CDK6 in B-ALL and if this inhibition could enhance cytotoxic killing of leukemia cells after combination treatment with dexamethasone. We treated B-ALL cell lines with ribociclib, a highly specific CDK4/6 inhibitor. As expected, treatment with ribociclib induced growth inhibition of B-ALL cell lines, accompanied by strong cell cycle arrest in G1 phase, along with a dose-dependent decrease in phosphorylated retinoblastoma protein. Ribociclib exposure strongly synergizes with dexamethasone in SEM and RCH-ACV, two dexamethasone-resistant cell lines, along with a strong decrease in proliferation and a significant increase in apoptotic cell death. These results were also confirmed on primary cultures derived from bone marrow of pediatric patients affected by B-ALL. Immunoblot analysis showed a significant increase in glucocorticoid receptor (GR) along with some of its target genes, after combined treatment with ribociclib and dexamethasone. Altogether our findings support the concept that pharmacologic inhibition of CDK4/CDK6 may represent a useful therapeutic strategy to control cell proliferation in B-ALL and provide new insight in understanding potential mechanism of glucocorticoid resistance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bcp.2018.01.050DOI Listing
July 2018

Targeting tubulin polymerization by novel 7-aryl-pyrroloquinolinones: Synthesis, biological activity and SARs.

Eur J Med Chem 2018 Jan 20;143:244-258. Epub 2017 Nov 20.

Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy. Electronic address:

Earlier studies had confirmed that the 7-phenylpyrroloquinolinone (7-PPyQ) nucleus was an important scaffold for new chemotherapeutic drugs targeting microtubules. For wide-ranging SARs, a series of derivatives were synthesized through a robust procedure. For comparison with the reference 3-ethyl-7-PPyQ 31, the angular geometry and substituents at the 3 and 7 positions were varied to explore interactions inside the colchicine site of tubulin. Of the new compounds synthesized, potent cytotoxicity (low and sub-nanomolar GI values) was observed with 21 and 24, both more potent than 31, in both leukemic and solid tumor cell lines. Neither compound 21 nor 24 induced significant cell death in normal human lymphocytes, suggesting that the compounds may be selectively active against cancer cells. In particular, 24 was a potent inducer of apoptosis in the A549 and HeLa cell lines. With both compounds, induction of apoptosis was associated with dissipation of the mitochondrial transmembrane potential and production of reactive oxygen species, indicating that cells treated with the compounds followed the intrinsic pathway of apoptosis. Moreover, immunoblot analysis revealed that compound 24 even at 50 nM reduced the expression of anti-apoptotic proteins such as Bcl-2 and Mcl-1. Finally, molecular docking studies of the newly synthesized compounds demonstrate that active pyrroloquinolinone derivatives strongly bind in the colchicine site of β-tubulin.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2017.11.038DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5798451PMC
January 2018

Glucocorticoid resistance is reverted by LCK inhibition in pediatric T-cell acute lymphoblastic leukemia.

Blood 2017 12 3;130(25):2750-2761. Epub 2017 Nov 3.

Department of Woman's and Child's Health and.

Pediatric T-acute lymphoblastic leukemia (T-ALL) patients often display resistance to glucocorticoid (GC) treatment. These patients, classified as prednisone poor responders (PPR), have poorer outcome than do the other pediatric T-ALL patients receiving a high-risk adapted therapy. Because glucocorticoids are administered to ALL patients during all the different phases of therapy, GC resistance represents an important challenge to improving the outcome for these patients. Mechanisms underlying resistance are not yet fully unraveled; thus our research focused on the identification of deregulated signaling pathways to point out new targeted approaches. We first identified, by reverse-phase protein arrays, the lymphocyte cell-specific protein-tyrosine kinase (LCK) as aberrantly activated in PPR patients. We showed that LCK inhibitors, such as dasatinib, bosutinib, nintedanib, and WH-4-023, are able to induce cell death in GC-resistant T-ALL cells, and remarkably, cotreatment with dexamethasone is able to reverse GC resistance, even at therapeutic drug concentrations. This was confirmed by specific gene silencing and ex vivo combined treatment of cells from PPR patient-derived xenografts. Moreover, we observed that LCK hyperactivation in PPR patients upregulates the calcineurin/nuclear factor of activated T cells signaling triggering to interleukin-4 () overexpression. GC-sensitive cells cultured with IL-4 display an increased resistance to dexamethasone, whereas the inhibition of IL-4 signaling could increase GC-induced apoptosis in resistant cells. Treatment with dexamethasone and dasatinib also impaired engraftment of leukemia cells in vivo. Our results suggest a quickly actionable approach to supporting conventional therapies and overcoming GC resistance in pediatric T-ALL patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood-2017-05-784603DOI Listing
December 2017

Design, synthesis and biological evaluation of 3-substituted-2-oxindole hybrid derivatives as novel anticancer agents.

Eur J Med Chem 2017 Jul 13;134:258-270. Epub 2017 Apr 13.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131 Padova, Italy. Electronic address:

The 2-oxindole nucleus is the central core to develop new anticancer agents and its substitution at the 3-position can effect antitumor activity. Utilizing a pharmacophore hybridization approach, a novel series of antiproliferative agents was obtained by the modification of the structure of 3-substituted-2-oxindole pharmacophore by the attachment of the α-bromoacryloyl moiety, acting as a Michael acceptor, at the 5-position of 2-oxindole framework. The impact of the substituent at the 3-position of 2-oxindole core on the potency and selectivity against a panel of seven different cancer cell lines was examined. We found that these hybrid molecules displayed potent antiproliferative activity against a panel of four cancer cell lines, with one-to double digit nanomolar 50% inhibitory concentrations (IC). A distinctive selective antiproliferative activity was obtained towards CCRF-CEM and RS4; 11 leukemic cell lines. In order to study the possible mechanism of action, we observed that the two most active compounds namely 3(E) and 6(Z) strongly induce apoptosis that follow the mitochondrial pathway. Interestingly a decrease of intracellular reduced glutathione content (GSH) and reactive oxygen species (ROS) production was detected in treated cells compared with controls suggesting that these effects may be involved in their mechanism of action.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2017.03.089DOI Listing
July 2017

Synthesis and Biological Evaluation of 2-Methyl-4,5-Disubstituted Oxazoles as a Novel Class of Highly Potent Antitubulin Agents.

Sci Rep 2017 04 13;7:46356. Epub 2017 Apr 13.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131 Padova, Italy.

Antimitotic agents that interfere with microtubule formation are one of the major classes of cytotoxic drugs for cancer treatment. Multiple 2-methyl-4-(3',4',5'-trimethoxyphenyl)-5-substituted oxazoles and their related 4-substituted-5-(3',4',5'-trimethoxyphenyl) regioisomeric derivatives designed as cis-constrained combretastatin A-4 (CA-4) analogues were synthesized and evaluated for their antiproliferative activity in vitro against a panel of cancer cell lines and, for selected highly active compounds, interaction with tubulin, cell cycle effects and in vivo potency. Both these series of compounds were characterized by the presence of a common 3',4',5'-trimethoxyphenyl ring at either the C-4 or C-5 position of the 2-methyloxazole ring. Compounds 4g and 4i, bearing a m-fluoro-p-methoxyphenyl or p-ethoxyphenyl moiety at the 5-position of 2-methyloxazole nucleus, respectively, exhibited the greatest antiproliferative activity, with IC values of 0.35-4.6 nM (4g) and 0.5-20.2 nM (4i), which are similar to those obtained with CA-4. These compounds bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. Furthermore, 4i strongly induced apoptosis that follows the mitochondrial pathway. In vivo, 4i in a mouse syngeneic model demonstrated high antitumor activity which significantly reduced the tumor mass at doses ten times lower than that required for CA-4P, suggesting that 4i warrants further evaluation as a potential anticancer drug.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep46356DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390315PMC
April 2017

Synthesis, structure-activity relationships and biological evaluation of 7-phenyl-pyrroloquinolinone 3-amide derivatives as potent antimitotic agents.

Eur J Med Chem 2017 Feb 21;127:643-660. Epub 2016 Oct 21.

Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Padova, Italy. Electronic address:

A small library of 7-pyrrolo[3,2-f]quinolinones was obtained by introducing benzoyl, sulfonyl and carbamoyl side chains at the 3-N position, and their cytotoxicity against a panel of leukemic and solid tumor cell lines was evaluated. Most of them showed high antiproliferative activity with GIs ranging from micro-to sub-nanomolar values, and these values correlated well with the inhibitory activities of the compounds against tubulin polymerization. Based on a recently proposed colchicine bind site inhibitors (CBSIs) pharmacophore, the interactions of the novel 7-PPyQs at the colchicine domain were rationalized. The most active compounds (4a and 4b) did not induce significant cell death in normal human lymphocytes, suggesting that the compounds may be selective against cancer cells. In particular, 4a was a potent inducer of apoptosis in both the HeLa and Jurkat cell lines. On the other hand, the sulfonyl derivative 4b exhibited a lower potency in comparison with 4a. With both compounds, induction of apoptosis was associated with dissipation of the mitochondrial transmembrane potential and production of reactive oxygen species, suggesting that cells treated with the compounds followed the intrinsic pathway of apoptosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2016.10.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5431288PMC
February 2017

The Novel Antitubulin Agent TR-764 Strongly Reduces Tumor Vasculature and Inhibits HIF-1α Activation.

Sci Rep 2016 06 13;6:27886. Epub 2016 Jun 13.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia pediatrica, Università di Padova, 35128 Padova, Italy.

Tubulin binding agents (TBAs) are commonly used in cancer therapy as antimitotics. It has been described that TBAs, like combretastatin A-4 (CA-4), present also antivascular activity and among its derivatives we identified TR-764 as a new inhibitor of tubulin polymerization, based on the 2-(alkoxycarbonyl)-3-(3',4',5'-trimethoxyanilino)benzo[b]thiophene molecular skeleton. The antiangiogenic activity of TR-764 (1-10 nM) was tested in vitro on human umbilical endothelial cells (HUVECs), and in vivo, on the chick embryo chorioallantoic membrane (CAM) and two murine tumor models. TR-764 binding to tubulin triggers cytoskeleton rearrangement without affecting cell cycle and viability. It leads to capillary tube disruption, increased cell permeability, and cell motility reduction. Moreover it disrupts adherens junctions and focal adhesions, through mechanisms involving VE-cadherin/β-catenin and FAK/Src. Importantly, TR-764 is active in hypoxic conditions significantly reducing HIF-1α. In vivo TR-764 (1-100 pmol/egg) remarkably blocks the bFGF proangiogenic activity on CAM and shows a stronger reduction of tumor mass and microvascular density both in murine syngeneic and xenograft tumor models, compared to the lead compound CA-4P. Altogether, our results indicate that TR-764 is a novel TBA with strong potential as both antivascular and antitumor molecule that could improve the common anticancer therapies, by overcoming hypoxia-induced resistance mechanisms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep27886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4904223PMC
June 2016

Vascular disrupting activity of combretastatin analogues.

Vascul Pharmacol 2016 08 25;83:78-89. Epub 2016 May 25.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131 Padova, Italy. Electronic address:

Tubulin binding agents (TBAs) are drugs commonly used in cancer therapy as antimitotics. In the last years it has been described that TBAs, like combretastatin A-4 (CA-4), present also vascular disrupting activity and among its derivatives we identified three analogues endowed with potent microtubule depolymerizing activity, higher than that of the lead compound. In this paper we have investigated the anti-vascular activity of these derivatives. We tested the anti-angiogenic effects in human umbilical endothelial cells (HUVEC) and in vivo in chick chorioallantoic membrane assay (CAM), and in a syngeneic tumor mouse model. The three molecules, compound 1: 1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-1,2,4-triazole; compound 2: (1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-tetrazole, compound-3 (4-amino-2-p-tolylaminothiazol-5-yl)-(3,4,5-trimethoxyphenyl)-methanone) showed a moderate effect on the growth of HUVEC cells at concentrations below 200nM. At lower concentrations (5-20nM), in particular compound 2, they induced inhibition of capillary tube formation, inhibition of endothelial cell migration and affected endothelial cell morphology as demonstrated by the alteration of the microfilaments network. Moreover, they also increased permeability of HUVEC cells in a time dependent manner. In addition, compounds 1 and 3, as well as the reference compound CA-4, inhibited VEGF-induced phosphorylation of VE-cadherin and in addition compound 3 prevented the VEGF-induced phosphorylation of FAK. In CAM assay, both compounds 2 and 3 efficiently counteracted the strong angiogenic response induced by bFGF, even at the lowest concentration used (1pmol/egg). Moreover in a syngenic mouse model, compounds 1-3 after a single i.p. injection (30mg/kg), showed a stronger reduction of microvascular density. Altogether our results identified these derivatives as potential new vascular disrupting agents candidates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vph.2016.05.006DOI Listing
August 2016

Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3',4',5'-Trimethoxyphenyl)-2-Aryl-1H-Imidazole.

Sci Rep 2016 05 24;6:26602. Epub 2016 May 24.

Dipartimento di Salute della Donna e del Bambino, Laboratorio di Oncoematologia, Università di Padova, 35131 Padova, Italy.

A novel series of tubulin polymerization inhibitors, based on the 1-(3',4',5'-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3'-chloro-4'-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep26602DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4877593PMC
May 2016

Design, synthesis, crystallization and biological evaluation of new symmetrical biscationic compounds as selective inhibitors of human Choline Kinase α1 (ChoKα1).

Sci Rep 2016 Mar 31;6:23793. Epub 2016 Mar 31.

Departamento de Química Farmacéutica y Orgánica, Facultad de Farmacia, Campus de Cartuja, 18071 Granada (Spain).

A novel family of compounds derivative of 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bispyridinium or -bisquinolinium bromide (10a-l) containing a pair of oxygen atoms in the spacer of the linker between the biscationic moieties, were synthesized and evaluated as inhibitors of choline kinase against a panel of cancer-cell lines. The most promising compounds in this series were 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))bis(4-(dimethylamino)pyridinium) bromide (10a) and 1,1'-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bis(7-chloro-4-(pyrrolidin-1-yl)quinolinium) bromide (10l), which inhibit human choline kinase (ChoKα1) with IC50 of 1.0 and 0.92 μM, respectively, in a range similar to that of the previously reported biscationic compounds MN58b and RSM932A. Our compounds show greater antiproliferative activities than do the reference compounds, with unprecedented values of GI50 in the nanomolar range for several of the cancer-cell lines assayed, and more importantly they present low toxicity in non-tumoral cell lines, suggesting a cancer-cell-selective antiproliferative activity. Docking studies predict that the compounds interact with the choline-binding site in agreement with the binding mode of most previously reported biscationic compounds. Moreover, the crystal structure of ChoKα1 with compound 10a reveals that this compound binds to the choline-binding site and mimics HC-3 binding mode as never before.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep23793DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4814829PMC
March 2016