Synthesis of Bis-acridine Derivatives Exhibiting Anticancer and Anti-inflammatory Activity

Design, synthesis and high antitumor potential of new unsymmetrical bisacridine derivatives towards human solid tumors, specifically pancreatic cancers and their unique ability to stabilize DNA G-quadruplexes

New promising unsymmetrical bisacridine derivatives (UAs), have been developed. Three groups including 36 compounds were synthesized by the condensation of 4-nitro or 4-methylacridinone, imidazoacridinone and triazoloacridinone derivatives with 1-nitroacridine compounds linked with an aminoalkyl chain. Cytotoxicity screening revealed the high potency of these compounds against several tumor cell lines. Particularly, imidazoacridinone-1-nitroacridine dimers strongly inhibited pancreatic Panc-1, Mia-Pa-Ca-2, Capan-2 and prostate cancer DU-145 cell growth. The studied compounds showed very strong antitumor activity (T/C> 300%) against Walker 256 rat adenocarcinoma. The selected 26 UAs were tested against 12 human tumor xenografts in nude mice, including colon, breast, prostate and pancreatic cancers. The studies on the molecular mechanism of action demonstrated that these unsymmetrical dimers significantly responded to the presence of G-quadruplex not to dsDNA. Structure-activity relationships for UAs potency to G-quadruplex stabilization indicated that thermal stability of this drug-G-quadruplex complex depended not only on the structure of heterocyclic rings, but also on the properties of dialkylamino chains of the ring linkers. In conclusion, the presented studies identified the new group of effective antitumor agents against solid human tumors, particularly pancreatic Panc-1, BxPC-3 and Mia-Pa-Ca-2 and strongly indicated their distinctive interactions with DNA. In contrast to monomers, G-quadruplex not dsDNA is proposed to be the first molecular target for these compounds.

Intercalating Electron Dyes for TEM Visualization of DNA at the Single-Molecule Level

Staining compounds containing heavy elements (electron dyes) can facilitate the visualization of DNA and related biomolecules by using TEM. However, research into the synthesis and utilization of alternative electron dyes has been limited. Here, we report the synthesis of a novel DNA intercalator molecule, bis-acridine uranyl (BAU). NMR spectroscopy and MS confirmed the validity of the synthetic strategy and gel electrophoresis verified the binding of BAU to DNA. For TEM imaging of DNA, two-dimensional DNA origami nanostructures were used as a robust microscopy test object. By using scanning transmission electron microscopy (STEM) imaging, which is favored over conventional wide-field TEM for improved contrast, and therefore, quantitative image analysis, it is found that the synthesized BAU intercalator can render DNA visible, even at the single-molecule scale. For comparison, other staining compounds with a purported affinity towards DNA, such as dichloroplatinum, cisplatin, osmium tetroxide, and uranyl acetate, have been evaluated. The STEM contrast is discussed in terms of the DNA-dye association constants, number of dye molecules bound per base pair, and the electron-scattering capacity of the metal-containing ligands. These findings pave the way for the future development of electron dyes with specific DNA-binding motifs for high-resolution TEM imaging.

Novel multi-substituted benzyl acridone derivatives as survivin inhibitors for hepatocellular carcinoma treatment

Sorafenib was the only small-molecule drug approved by FDA for treatment of the advanced hepatocellular carcinoma (HCC). Recent study indicated that YM155 was a promising agent for HCC cells with high survivin expression, however, the antitumor activity needs to be further improved. Based on molecular docking and rational design method, a series of multi-substituted benzyl acridone derivatives were designed and synthesized. MTT assay indicated that some of the synthesized compounds displayed better antiproliferative activity against HepG2 cells than YM155. Later study indicated that the representive compound 8u may directly interact with survivin protein and induce HepG2 cells apoptosis, which is different from YM155. In addition, ADME property was predicted in silico, and it performed well. Moreover, in vivo preliminary experiments showed that 8u may be a good lead compound in the treatment of HCC.