Anti-Cancer Effects of Artesunate in Human 3D Tumor Models of Different Complexity

The anti-malaria drug Artesunate (ART) shows strong anti-cancer effects in vitro; however, it shows only marginal treatment results in clinical cancer studies. In this study, ART was tested in preclinical 3D cancer models of increasing complexity using clinically relevant peak plasma concentrations to obtain further information for translation into clinical use. ART reduced cell viability in HCT-116 and HT-29 derived cancer spheroids (p < 0.001). HCT-116 spheroids responded dose-dependently, while HT-29 spheroids were affected more strongly by ART than by cytostatics (p < 0.001). HCT-116 spheroids were chemo-sensitized by ART (p < 0.001). In patient-derived cancer spheroids (PDCS), ART led to inhibition of cell viability in 84.62% of the 39 samples tested, with a mean inhibitory effect of 13.87%. Viability reduction of ART was 2-fold weaker than cytostatic monotherapies (p = 0.028). Meanwhile, tumor-stimulation of up to 16.30% was observed in six (15.38%) PDCS-models. In 15 PDCS samples, ART modulated chemotherapies in combined testing, eight of which showed chemo-stimulation (maximum of 36.90%) and seven chemo-inhibition (up to 16.95%). These results demonstrate that ART's anti-cancer efficacy depends on the complexity of the tumor model used. This emphasizes that cancer treatment with ART should be evaluated before treatment of the individual patient to ensure its benefits and prevent unwanted effects.

Antitumor agents 7. Synthesis, antiproliferative activity and molecular modeling of new l-lysine-conjugated pyridophenoxazinones as potent DNA-binding ligands and topoisomerase IIα inhibitors

A series of l-lysine-conjugated pyridophenoxazinones 2-5 and 2'-5' were designed and synthesized for developing compounds with multimodal anticancer potentialities. All compounds inhibited the proliferation of a panel of human liquid and solid neoplastic cell lines. 2 and 5 were the most active compounds with IC₅₀ values in the submicromolar range. UV-vis, ¹H NMR, unwinding, and docking experiments demonstrated that they intercalate between the middle 5'-GC-3' base pairs with the carboxamide side chain lying into major groove. Charge-transfer contribution to the complex stability, evaluated by ab initio calculations, was found to correlate with cytotoxicity. Relaxation and cleavage assays showed that 2 and 5 selectively target Topo IIα over Topo IIβ and stimulate the formation of covalent Topo II-DNA complexes, functioning as poisons. Moreover, compound 5 induced DNA damage and arrested MCF-7 cells at the G2/M phase. Altogether, the work provides interesting structure-activity relationships in the pyridophenoxazinone-l-lysine conjugate series and identifies 5 as a promising candidate for further in vivo evaluation.

Three-Component Approach to Pyridine-Stabilized Ketenimines for the Synthesis of Diverse Heterocycles

Ketenimines are versatile synthetic intermediates capable of performing novel transformations in organic synthesis. They are normally generated in situ due to their inherent instability and high level of reactivity. Herein, we report pyridine-stabilized ketenimine zwitterionic salts, which are prepared through click chemistry from readily accessible alkynes and sulfonyl azides. To demonstrate their synonymous reactivity to ketenimines, these salts have been utilized in a cascade sequence to access highly functionalized quinolines including the core structures of an antiprotozoal agent and the potent topoisomerase inhibitor Tas-103.

An overview of recent advances in duplex DNA recognition by small molecules

As the carrier of genetic information, the DNA double helix interacts with many natural ligands during the cell cycle, and is amenable to such intervention in diseases such as cancer biogenesis. Proteins bind DNA in a site-specific manner, not only distinguishing between the geometry of the major and minor grooves, but also by making close contacts with individual bases within the local helix architecture. Over the last four decades, much research has been reported on the development of small non-natural ligands as therapeutics to either block, or in some cases, mimic a DNA–protein interaction of interest. This review presents the latest findings in the pursuit of novel synthetic DNA binders. This article provides recent coverage of major strategies (such as groove recognition, intercalation and cross-linking) adopted in the duplex DNA recognition by small molecules, with an emphasis on major works of the past few years.

Identification of a new class of WNT1 inhibitor: Cancer cells migration, G-quadruplex stabilization and target validation

Developing the Wnt pathway inhibitors has been considered as a therapeutic approach for cancers and other Wnt-related diseases. Previously we found that the G-rich sequence of WNT1 promoter is capable of forming G-quadruplex structure and stabilizing agents for Wnt1-mediated signaling pathway. Using a established cell-based drug screen system that enabled the evaluation of WNT1 expression activity in a G-quadruplex structure dependent manner, we evaluated a series of 6-substituted 9-chloro-11H-indeno[1,2-c]quinolin-11-one derivatives that potentially inhibit the Wnt1-mediated signaling pathway. The most potent compound SJ26 showed repression of WNT1 activity in a G-quadruplex structure-dependent manner. Moreover, compound SJ26 inhibited the WNT1-mediated downstream signaling pathway and suppressed migration activity of cancer cells. Thus, we have identified a tetracyclic azafluorenone, SJ26, that is capable of binding to G-quadruplex DNA structure, repressing WNT1 expression, and inhibiting cell migration.

Prospective cohort study using the breast cancer spheroid model as a predictor for response to neoadjuvant therapy--the SpheroNEO study

Background

Aim of this prospective study was to predict response to neoadjuvant therapy in breast cancer patients using an in vitro breast cancer spheroid model.

Methods

Three-dimensional spheroids were directly generated from fresh breast tumor biopsies of 78 patients eligible for neoadjuvant therapy. Cell survival was measured after in vitro exposure to the equivalent therapeutic agents in the breast cancer spheroid model. Treatment results in vitro were correlated with pathological complete response (pCR, i.e. ypT0 ypN0) determined at surgery.

Results

A mean cell survival of 21.8 % was found in the breast cancer spheroid model for 22 patients with pCR versus 63.8 % in 56 patients without pCR (P = .001). The area under the receiver operator characteristic curve to predict pCR was 0.86 (95 % CI: 0.77 to 0.96) for cell survival in vitro compared to 0.80 (95 % CI: 0.70 to 0.90) for a combined model of conventional factors (hormone- and HER2 receptor, and age). A cutoff at 35 % cell survival for the spheroid model was proposed. Out of the 32 patients with values below this threshold, 21 patients (65.6 %) and one patient (2.2 %) with a cell survival greater than 35 % achieved pCR respectively; (sensitivity 95.5 % (95 % CI: 0.86 to 1.00); specificity 80.4 % (95 % CI: 0.70 to 0.91)). Extent of residual disease positively correlated with increased cell survival (P = .021).

Conclusion

The breast cancer spheroid model proved to be a highly sensitive and specific predictor for pCR after neoadjuvant chemotherapy in breast cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1491-7) contains supplementary material, which is available to authorized users.

Impact of the spheroid model complexity on drug response

Pharmaceutical investigators are searching for preclinical models closely resembling the original cancer and predicting clinical outcome. This study compares drug response of three in vitro 3D-drug screening models with different complexity. Tumor cell line spheroids were generated from the cell lines Caco-2, DLD-1, COLO 205, HT-29 and HCT-116, and treated with clinically relevant combination therapies, namely 5-FU/oxaliplatin (FO), 5-FU/irinotecan (FI) and the molecular drugs Cetuximab, Trastuzumab, Vorinostat and Everolimus. Treatment results were compared with spheroids originated from tumor cell lines (Caco-2, DLD-1) co-cultured with stromal cells (PBMCs, cancer-associated fibroblasts of colorectal origin) and spheroids directly prepared from colon cancer tissues. Different microenvironment compositions altered the tumor cell line spheroid response patterns. Adding PBMCs increased resistance to FO treatment by 10-15% in Caco-2 and DLD-1 spheroids but decreased resistance to FI by 16% in DLD-1 spheroids. Fibroblast co-cultures decreased resistance to FI in Caco-2 spheroids by 38% but had no impact on FO. Treatment of colon cancer tissue spheroids revealed three distinct response pattern subgroups not detectable in 3D cell lines models. The cancer tissue spheroid model mimics both tumor characteristics and the stromal microenvironment and therefore is an invaluable screening model for pharmaceutical drug development.

Modular o-quinone catalyst system for dehydrogenation of tetrahydroquinolines under ambient conditions

Quinolines are common pharmacophores present in numerous FDA-approved pharmaceuticals and other bioactive compounds. Here, we report the design and development of new o-quinone-based catalysts for the oxidative dehydrogenation of tetrahydroquinolines to afford quinolines. Use of a Co(salophen) cocatalyst allows the reaction to proceed efficiently with ambient air at room temperature. The utility of the catalytic method is demonstrated in the preparation of a number of medicinally relevant quinolines.

A review on anticancer potential of bioactive heterocycle quinoline

The advent of Camptothecin added a new dimension in the field anticancer drug development containing quinoline motif. Quinoline scaffold plays an important role in anticancer drug development as their derivatives have shown excellent results through different mechanism of action such as growth inhibitors by cell cycle arrest, apoptosis, inhibition of angiogenesis, disruption of cell migration, and modulation of nuclear receptor responsiveness. The anti-cancer potential of several of these derivatives have been demonstrated on various cancer cell lines. In this review we have compiled and discussed specifically the anticancer potential of quinoline derivatives, which could provide a low-height flying bird's eye view of the quinoline derived compounds to a medicinal chemist for a comprehensive and target oriented information for development of clinically viable anticancer drugs.

Anticancer potency of cytotoxic drugs after exposure to high-intensity focused ultrasound in the presence of microbubbles and hematoporphyrin

Chemotherapy is undertaken perioperatively to improve the efficacy of high-intensity focused ultrasound (HIFU) for solid tumors. HIFU at a sufficient intensity for tissue ablation has recently been applied for drug delivery; ultrasonic cavitation plays an important part in HIFU and drug delivery. Hematoporphyrin and microbubbles are adjuncts because they aid cavitation. The effect of HIFU (1.0 MHz; 12,999 W/cm(2) in continuous waves), in the presence of hematoporphyrin and/or microbubbles, on the anticancer potency of 5-fluorouracil, cisplatin, paclitaxel, mitomycin C or adriamycin, was investigated. Insonated adriamycin resulted in a lower death rate of human cancer cells HO-8910 (45.85 ± 2.65% vs 34.84 ± 1.21%, p < 0.05), which was exacerbated when employing hematoporphyrin (34.84 ± 1.21% vs 23.09 ± 7.82%, p < 0.05) or hematoporphyrin combined with microbubbles (34.84 ± 1.21% vs. 8.79 ± 3.69%, p < 0.05); the therapeutic activity was not affected when adding microbubbles alone. High-performance liquid chromatography detected a smaller peak area after subjecting adriamycin to HIFU with the use of hematoporphyrin alone or combined with microbubbles. The other drugs were not affected. Hematoporphyrin, microbubbles and adriamycin increased the throughput of hydroxyl radicals resulting from cavitation as determined by iodine and methylene blue assays. These data suggested that the anticancer activity of a drug may be decreased by HIFU exposure (particularly in the presence of hematoporphyrin and microbubbles). Cavitation produced reactive species that attacked drug molecules, thereby decreasing their antitumor potency; this process was enhanced if the drug itself generated free radicals under insonation.

Dual inhibition: a novel promising pharmacological approach for different disease conditions

To overcome the problems associated with polypharmacy, which include medication non compliance, adverse drug reactions, drug-drug interactions and increased pill-burden, various strategies, such as sustained-release drugs and fixed-dose combination regimens (polypills), have been developed. Out of these, a novel and very much promising approach is the use of dual-action drugs. Amongst the dual-action drugs, there is a class of compounds known as dual inhibitors, which possess the dual inhibitory activity. The most common examples of dual inhibitors are rivastigmine, ladostigil, asenapine, phenserine, amitriptyline, clomipramine, doxepin and desipramine. This review article focuses on the conventional drugs used in different diseases which possess dual inhibition activity as well as those which are still in the preclinical/clinical phase.

Ethyl 2-amino-4-(3-chloro-phen-yl)-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxyl-ate

The title mol­ecule, C₂₂H₁₆ClNO₅, was obtained by the reaction of (E)-ethyl 3-(3-chloro­phen­yl)-2-cyano­acrylate and 2-hydroxy­naphthalene-1,4-dione catalysed by triethylamine in ethanol. In the crystal structure, the chlorobenzene ring makes a dihedral angle of 88.63 (4)° with the fused ring system. The six-membered ring formed by an intra­molecular N—H⋯O hydrogen bond is almost planar. The crystal packing is stabilized by N—H⋯O hydrogen bonds.