Acridin-3,6-dialkyldithiourea hydrochlorides as new photosensitizers for photodynamic therapy of mouse leukemia cells

Acridine as an Anti-Tumour Agent: A Critical Review

This review summarized the current breakthroughs in the chemistry of acridines as anti-cancer agents, including new structural and biologically active acridine attributes. Acridine derivatives are a class of compounds that are being extensively researched as potential anti-cancer drugs. Acridines are well-known for their high cytotoxic activity; however, their clinical application is restricted or even excluded as a result of side effects. The photocytotoxicity of propyl acridine acts against leukaemia cell lines, with C1748 being a promising anti-tumour drug against UDP-UGT's. CK0403 is reported in breast cancer treatment and is more potent than CK0402 against estrogen receptor-negative HER2. Acridine platinum (Pt) complexes have shown specificity on the evaluated DNA sequences; 9-anilinoacridine core, which intercalates DNA, and a methyl triazene DNA-methylating moiety were also studied. Acridine thiourea gold and acridinone derivatives act against cell lines such as MDA-MB-231, SK-BR-3, and MCF-7. Benzimidazole acridine compounds demonstrated cytotoxic activity against Dual Topo and PARP-1. Quinacrine, thiazacridine, and azacridine are reported as anti-cancer agents, which have been reported in the previous decade and were addressed in this review article.

Synthesis and Evaluation of Antiproliferative Activity, Topoisomerase IIα Inhibition, DNA Binding and Non-Clinical Toxicity of New Acridine-Thiosemicarbazone Derivatives

In this study, we report the synthesis of twenty new acridine–thiosemicarbazone derivatives and their antiproliferative activities. Mechanisms of action such as the inhibition of topoisomerase IIα and the interaction with DNA have been studied for some of the most active derivatives by means of both in silico and in vitro methods, and evaluations of the non-clinical toxicities (in vivo) in mice. In general, the compounds showed greater cytotoxicity against B16-F10 cells, with the highest potency for DL-08 (IC₅₀ = 14.79 µM). Derivatives DL-01 (77%), DL-07 (74%) and DL-08 (79%) showed interesting inhibition of topoisomerase IIα when compared to amsacrine, at 100 µM. In silico studies proposed the way of bonding of these compounds and a possible stereoelectronic reason for the absence of enzymatic activity for CL-07 and DL-06. Interactions with DNA presented different spectroscopic effects and indicate that the compound CL-07 has higher affinity for DNA (Kb = 4.75 × 10⁴ M⁻¹; Ksv = 2.6 × 10³ M⁻¹). In addition, compounds selected for non-clinical toxicity testing did not show serious signs of toxicity at the dose of 2000 mg/kg in mice; cytotoxic tests performed on leukemic cells (K-562) and its resistant form (K-562 Lucena 1) identified moderate potency for DL-01 and DL-08, with IC₅₀ between 11.45 and 17.32 µM.

Synthesis and evaluation of anticancer activity of new 9-acridinyl amino acid derivatives

A series of eleven 9-acridinyl amino acid derivatives were synthesized using a two-step procedure. Cytotoxicity was tested on the K562 and A549 cancer cell lines and normal diploid cell line MRC5 using the MTT assay. Compounds 6, 7, 8 and 9 were the most active, with IC₅₀ values comparable to or lower than that of chemotherapeutic agent amsacrine. 8 and 9 were especially effective in the A549 cell line (IC₅₀ ≈ 6 μM), which is of special interest since amsacrine is not sufficiently active in lung cancer patients. Cell cycle analysis revealed that 7 and 9 caused G2/M block, amsacrine caused arrest in the S phase, while 6 and 8 induced apoptotic cell death independently of the cell cycle regulation. In comparison to amsacrine, 6, 7, 8, and 9 showed similar inhibitory potential towards topoisomerase II, whereas only 7 showed DNA intercalation properties. In contrast to amsacrine, 6, 7, 8 and 9 showed a lack of toxicity towards unstimulated normal human leucocytes.

EtNBSe-PDT inhibited proliferation and induced autophagy of HNE-1 cells via downregulating the Wnt/β-catenin signaling pathway

BACKGROUND

Increasing evidence has suggested that autophagy may play a resistant role during photodynamic therapy (PDT). The Wnt/β-catenin pathway is tightly involved in cell proliferation and autophagy. In this study, we aimed to determine the influence of 5-Ethylamino-9-diethylaminobenzo[a]phenoselenazinium (EtNBSe) mediated PDT (EtNBSe-PDT) on autophagy, proliferation and Wnt/β-catenin pathway in human NPC cell line (HNE-1 cells), and further explore the underlying crosstalk between them.

METHODS

Cell viability and proliferation was evaluated by MTT assay. Autophagy and Wnt/β-catenin signaling pathway was analyzed by western blotting and immunofluorescence.

RESULTS

It was revealed that EtNBSe-PDT significantly impeded the viability and proliferation of HNE-1 cells. Meanwhile EtNBSe-PDT could notably induce autophagy in HNE-1 cells accompanied with the inhibition of Wnt/β-catenin pathway. The Wnt/β-catenin pathway activator Wnt agonist was found to partially counteract the inhibitory proliferation of HNE-1 cells and suppress the autophagy induced by EtNBSe-PDT. In addition, pretreatment with the autophagy inhibitor 3-methyladenine (3-MA) or Wnt agonist showed the potential in enhancing the cytotoxic effect of EtNBSe-PDT (cell survival from 50.71 ± 4.16% to 24.53 ± 4.27% and from 52.64 ± 3.54% to 35.74 ± 4.27% respectively).

CONCLUSION

Taken together, this study demonstrated that EtNBSe-PDT suppressed viability and proliferation, and induced autophagy of HNE-1 cells via downregulating the Wnt/β-catenin pathway. The autophagy further constituted the cytoprotective mechanisms involved in HNE-1 cells, which suggested that the combination of EtNBSe-PDT and autophagy inhibitors may be a promising strategy for the treatment of human NPC.

A review on acridinylthioureas and its derivatives: biological and cytotoxic activity

Acridines possess two characteristics that have led many researchers to consider the agents interesting targets for future development as potential farmacophores: the planar acridine skeleton, which is able to intercalate into DNA, and the intense fluorescence of the agents. This review offers a study of the multifunctional character of acridines and the synthesis of novel acridine derivatives, with particular focus being placed on isothiocyanates and their congeners, e.g. thioureas, isothioureas, quaternary ammonium salts and platinum/gold conjugates. The review provides an overview of the structure, spectral properties, DNA binding and biological activity of acridinylthiourea congeners. These acridinylthiourea derivatives display significant cytotoxic activities against different types of cancer cell lines at micromolar concentrations. Copyright © 2017 John Wiley & Sons, Ltd.

Recent developments in the synthesis and biological activity of acridine/acridone analogues

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