Parallel Synthesis and Cytotoxicity Evaluation of a Polyamine−Quinone Conjugates Library

Pioneering 4,11-Dioxo-4,11-dihydro-1H-anthra[2,3-d]imidazol-3-ium Compounds as Promising Survivin Inhibitors by Targeting ILF3/NF110 for Cancer Therapy

Survivin is a novel attractive target for cancer therapy; however, it is considered undruggable because it lacks enzymatic activities. Herein, we describe our efforts toward the discovery of a novel series of 4,11-dioxo-4,11-dihydro-1H-anthra[2,3-d]imidazol-3-ium derivatives as survivin inhibitors by targeting ILF3/NF110. Intensive structural modifications led us to identify a lead compound AQIM-I, which remarkably inhibited nonsmall cell lung cancer cells A549 with an IC50 value of 9 nM and solid tumor cell proliferation with more than 700-fold selectivity against human normal cells. Further biological studies revealed that compound AQIM-I significantly inhibited survivin expression and colony formation and induced ROS production, apoptosis, cell cycle arrest, DNA damage, and autophagy. Furthermore, the promoter-luciferase reporter assay showed that AQIM-I attenuated the survivin promoter activity enhanced by the overexpression of ILF3/NF110 in a concentration-dependent manner, and specific binding (KD = 163 nM) of AQIM-I to ILF3/NF110 was detected by surface plasmon resonance.

In Vitro and In Silico Study to Assess Toxic Mechanisms of Hybrid Molecules of Quinone-Benzocaine as Plastoquinone Analogues in Breast Cancer Cells

We managed to obtain three different series of 2,3-dimethyl-1,4-benzoquinones, named nonhalogenated and halogenated (brominated and chlorinated) PQ analogues, via the molecular hybridization strategy. Sixteen of eighteen hybrid molecules were selected by the National Cancer Institute (NCI) of Bethesda for their in vitro antiproliferative potential against the full NCI 60 cell line panel. The hybrid molecules (BrPQ5, CIPQ1, and CIPQ3) showed good growth inhibition at 10 μM concentration, particularly against breast cancer cell lines. As per the results obtained from in vitro antiproliferative evaluation, cytotoxic activities of the hybrid molecules (BrPQ5, CIPQ1, and CIPQ3) were evaluated with an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in T47D and MCF7 breast cancer and human umbilical vein endothelial (HUVEC) cells. Molecules exhibited cytotoxic activity, and especially, CIPQ1 showed remarkable cytotoxic activity and good selectivity on T47D and MCF7 cells. Furthermore, CIPQ1 could inhibit cell proliferation, cause apoptotic cell death and disturb the cell cycle in T47D and MCF7 cells. Additionally, CIPQ1 caused oxidative stress induction in both cells, more so in T47D. In vitro study results indicated that the anticancer activity of CIPQ1 was more prominent in T47D cells than in MCF7 cells. The compound CIPQ1 showed a prominent binding with JNK3 in silico. Thus, the obtained hybrid molecules via the molecular hybridization strategy of two important pharmacophores could be useful in the discovery of novel antiproliferative agents, and CIPQ1 could be considered a promising drug candidate.

On the Reaction of 2-Alkanoylnaphthohydroquinones with Hydroxylamine: Access to Cytotoxic 2-(Hydroxyamino)-1,4-naphthoquinone and Their 3-(Hydroxyimino)alkyl Analogous

Oximes are known for their anti-inflammatory, antimicrobial, antioxidant, and anticancer activities. Frequently, modification of biologically active carbonyl compounds into oximes leads to increased activity. The present study reports the reactivity of 2-alkanoylnaphthohydroquinones against hydroxylamine under aerial conditions. Results show that, depending on the structure of the hydroquinones, the reaction proceeds through two different chemical pathways to produce 2-(hydroxyamino)-1,4-naphthoquinone and their C-3 (hydroxyimino)alkyl derivatives. Both the formation of the quinoid compounds under aerial oxidation and C-C cleavage reactions of hemiaminal intermediates are discussed. In vitro screening of the substituted 1,4-naphthoquinones on a panel of cancer cells reveals moderate cytotoxic activities. Compound 19, 2-(hydroxyamino)-1,4-naphthoquinone, stands out by its anticancer potency against prostate cancer cells as shown by the lowest IC50 value (8.08 μM) and the best selectivity index (3.90).

Hybrid Molecules Containing Naphthoquinone and Quinolinedione Scaffolds as Antineoplastic Agents

In recent decades, molecular hybridization has proven to be an efficient tool for obtaining new synthetic molecules to treat different diseases. Based on the core idea of covalently combining at least two pharmacophore fragments present in different drugs and/or bioactive molecules, the new hybrids have shown advantages when compared with the compounds of origin. Hybridization could be successfully applied to anticancer drug discovery, where efforts are underway to develop novel therapeutics which are safer and more effective than those currently in use. Molecules presenting naphthoquinone moieties are involved in redox processes and in other molecular mechanisms affecting cancer cells. Naphthoquinones have been shown to inhibit cancer cell growth and are considered privileged structures and useful templates in the design of hybrids. The present work aims at summarizing the current knowledge on antitumor hybrids built using 1,4- and 1,2-naphthoquinone (present in natural compounds as lawsone, napabucasin, plumbagin, lapachol, α-lapachone, and β -lapachone), and the related quinolone- and isoquinolinedione scaffolds reported in the literature up to 2021. In detail, the design and synthetic approaches adopted to produce the reported compounds are highlighted, the structural fragments considered in hybridization and their biological activities are described, and the structure–activity relationships and the computational analyses applied are underlined.

Metal complexes of a pro-vitamin K3 analog phthiocol (2-hydroxy-3-methylnaphthalene-1,4-dione): synthesis, characterization, and anticancer activity

Anticancer activity of geometrical isomers of phthiocol complexes are evaluated against MCF-7 and A549 cell lines.

The lead optimization of the polyamine conjugate of flavonoid with a naphthalene motif: Synthesis and biological evaluation

Polyamine conjugated flavonoid with a naphthalene moiety (ZYY14) displayed excellent therapeutic activity against hepatocellular carcinoma. In this study, three different series of novel flavonoid-polyamine conjugates were designed and screened against tumor cell lines. The structure-activity relationship study demonstrated the importance of the naphthalene moiety (as the B-ring), the basic side chains in the A-ring, and the methoxy group linked to the C-ring. The optimized compound 9b displayed better antitumor potency in vitro and in vivo than the lead compound ZYY14. Fluorescent assays revealed that 9b could enter cancer cells via polyamine transporter (PAT) and locate in mitochondria and endoplasmic reticulum. Compound 9b and ZYY14 demonstrated similar apoptotic mechanism in the cytotoxicity studies and stimulated the expression of apoptosis-related proteins, such as p-p38, p-JNK, p53 and Bax. In addition, 9b can initiate autophagy which inhibited the occurrence of apoptosis. Thus, 9b can be used as a valuable lead for the future development of antitumor agents.

Copper-catalyzed three-component synthesis of aminonaphthoquinone-sulfonylamidine conjugates and in vitro evaluation of their antiproliferative activity

A series of aminonaphthoquinone-sulfonylamidine conjugates were synthesized via a copper-catalyzed three-component reaction of N-propargyl aminonaphthoquinone, sulfonyl azides and various amines. Majority of the compounds exhibited promising antiproliferative potential when evaluated against a panel of four cancer cell lines. Docking experiments of representative compounds indicated that the conjugates can occupy the ATP-binding pocket of topoisomerase-II enzyme.

Naphthoquinone-based chalcone hybrids and derivatives: synthesis and potent activity against cancer cell lines

Naphthoquinone-based chalcone hybrids were synthesized and evaluated for their cytotoxic activity against four cancer cell lines and PBMC. Some of the hybrids exhibited promising anticancer activity with IC₅₀ values < 1 μM.

Synthesis and evaluation of 2-heteroaryl and 2,3-diheteroaryl-1,4-naphthoquinones that potently induce apoptosis in cancer cells

This article describes the preparation of 2-heteroaryl and 600 dpi in TIF format)??>2,3-diheteroaryl-1,4-naphthoquinones by an environmentally benign short synthetic route with the goal of finding 1,4-naphthoquinone derivatives that induce apoptosis in cancer cells.

tert-ButylN-{3-[(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-yl)amino]propyl}carbamate

In the title compound, C₁₈H₂₁ClN₂O₄, the mol­ecular sytructure is stabilized by two intra­molecular N—H⋯O hydrogen bonds. In the crystal, mol­ecules are linked by pairs of C—H⋯O hydrogen bonds, forming inversion dimers with graph-set motif R₂²(10). N—H⋯O hydrogen bonds further link the dimers into C(10) chains along [010].

Mononaphthalimide spermidine conjugate induces cell proliferation inhibition and apoptosis in HeLa cells

Developing polyamine-drug conjugates that are capable of specific entry to tumor cells is attractive in improving chemotherapeutic efficacy. Currently, the exact cytotoxic mechanism of these conjugates is not well known. Here, our research revealed the effect of a mononaphthalimide-spermidine (MNISpd) conjugate on the growth and survival of HeLa cells and possible mechanisms. In characterizing the mechanism of MNISpd cytotoxicity, inhibition of proliferation is observed in the 0.5-6 μM range and there is evidence of apoptosis at equal or greater than 6 μM, but with less toxicity on HELF cell. The lower concentrations of MNISpd induced a cell cycle arrest correlated with enhanced p21 expression and decreased cdc2 but not Cdk2 expression. MNISpd-induced apoptosis was correlated with caspase-3 activation, decreased XIAP expression and a loss of mitochondrial membrane potential. Apoptosis but not cell cycle arrest was susceptible to N-acetyl-L-cysteine (NAC) treatment. It is proposed that MNISpd-induced apoptosis in HeLa cells is related to oxidative stress and that at lower exposure concentrations effects on cell proliferation predominate while at higher concentrations apoptosis develops.

Polyamine conjugation of curcumin analogues toward the discovery of mitochondria-directed neuroprotective agents

Mitochondria-directed antioxidants 2-5 were designed by conjugating curcumin congeners with different polyamine motifs as vehicle tools. The conjugates emerged as efficient antioxidants in mitochondria and fibroblasts and also exerted a protecting role through heme oxygenase-1 activation. Notably, the insertion of a polyamine function into the curcumin-like moiety allowed an efficient intracellular uptake and mitochondria targeting. It also resulted in a significant decrease in the cytotoxicity effects. 2-5 are therefore promising molecules for neuroprotectant lead discovery.

Conjugation of substituted naphthalimides to polyamines as cytotoxic agents targeting the Akt/mTOR signal pathway

Though several naphthalimide derivatives have exhibited antitumor activity in clinical trials, some issues such as toxicity prompted further structural modifications on the naphthalimide backbone. A series of naphthalimides conjugated with polyamines were synthesized to harness the polyamine transporter (PAT) for drug delivery, which was beneficial for the tumor cell selectivity. Bioevaluation in human hepatoma HepG2 cells treated with alpha-difluoromethylornithine (DFMO) or spermidine (Spd), human hepatoma Bel-7402 and normal QSG-7701 hepatocyte confirmed the PAT recognition and cell selectivity. In addition, the novel naphthalimide polyamine conjugate kills cells via apoptosis, and the Akt/mTOR signal pathway was first identified as the upstream cellular target through the apoptotic mechanism research. The presence of DFMO or Spd only either elevated or attenuated the cell apoptosis, but did not change the signal pathway. Collectively, the proper polyamine recognition element (i.e., homospermidine) mediated effective drug delivery via the PAT, and helped the proper cytotoxic goods (i.e., diverse naphthalimides) exert antitumor properties.

Preclinical activity of F14512, designed to target tumors expressing an active polyamine transport system

We have exploited the polyamine transport system (PTS) to deliver selectively a spermine-drug conjugate, F14512 to cancer cells. This study was aimed to define F14512 anticancer efficacy against tumor models and to investigate whether fluorophor-labeled polyamine probes could be used to identify tumors expressing a highly active PTS and that might be sensitive to F14512 treatments. Eighteen tumor models were used to assess F14512 antitumor activity. Cellular uptake of spermine-based fluorescent probes was measured by flow cytometry in cells sampled from tumor xenografts by needle biopsy. The accumulation of the fluorescent probe within B16 tumors in vivo was assessed using infrared fluorescence imaging. This study has provided evidence of a major antitumor activity for F14512. Significant responses were obtained in 67% of the tumor models evaluated, with a high level of activity recorded in 33% of the responsive models. Complete tumor regressions were observed after i.v., i.p. or oral administrations of F14512 and its antitumor activity was demonstrated over a range of 2-5 dose levels, providing evidence of its good tolerance. The level of cellular fluorescence emitted by the fluorescent probes was higher in cells sampled from tumors sensitive to F14512 treatments than from F14512-refractory tumors. We suggest that these probes could be used to identify tumors expressing a highly active PTS and guide the selection of patients that might be treated with F14512. These results emphasize the preclinical interest of this novel molecule and support its further clinical development.

Spermidinyl-CoA-based HAT inhibitors block DNA repair and provide cancer-specific chemo- and radiosensitization

Acetyl group turnover on specific lysine epsilon-amino groups of the core chromosomal histones regulates DNA accessibility function, and the acetylating and deacetylating enzymes that govern the turnover provide important targets for the development of anti-cancer drugs. Histone deacetylase (HDAC) inhibitors have been developed and evaluated extensively in clinical trials, while the development of inhibitors of histone acetyltransferase (HAT) has proceeded more slowly. Here we have examined the cellular effects of an S-substituted coenzyme A (CoA) inhibitor of histone acetylation, consisting of spermidine (Spd) linked to the S-terminus of CoA through a thioglycolic acid linkage (adduct abbreviated as Spd-CoA), as well as the effects of a truncated Spd-CoA derivative lacking the negatively charged portion of the CoA moiety. While exposure of cancer cells to Spd-CoA has little effect on cell viability, it causes a rapid inhibition of histone acetylation that correlates with a transient arrest of DNA synthesis, a transient delay in S-phase progression, and an inhibition of nucleotide excision repair and DNA double strand break repair. These effects correlate with increased cellular sensitivity to the DNA-targeted chemotherapeutic drugs, cisplatin (Platinol()) and 5-fluorouracil, to the DNA damaging drug, camptothecin, and to UV-C irradiation. The sensitization effects of Spd-CoA are not observed in normal cells due to a barrier to uptake. The truncated Spd-CoA derivative displays similar but enhanced chemosensitization effects, suggesting that further modifications of the Spd-CoA structure could further improve potency. The results demonstrate that Spd-CoA and its truncated version are efficiently and selectively internalized into cancer cells, and suggest that the resulting inhibition of acetylation-dependent DNA repair enhances cellular sensitivity to DNA damage. These and related inhibitors of histone acetylation could therefore constitute a novel class of potent therapy sensitizers applicable to a broad range of conventional cancer treatments.