Novel 1,3,5-Triazinyl Aminobenzenesulfonamides Incorporating Aminoalcohol, Aminochalcone and Aminostilbene Structural Motifs as Potent Anti-VRE Agents, and Carbonic Anhydrases I, II, VII, IX, and XII Inhibitors

A series of 1,3,5-triazinyl aminobenzenesulfonamides substituted by aminoalcohol, aminostilbene, and aminochalcone structural motifs was synthesized as potential human carbonic anhydrase (hCA) inhibitors. The compounds were evaluated on their inhibition of tumor-associated hCA IX and hCA XII, hCA VII isoenzyme present in the brain, and physiologically important hCA I and hCA II. While the test compounds had only a negligible effect on physiologically important isoenzymes, many of the studied compounds significantly affected the hCA IX isoenzyme. Several compounds showed activity against hCA XII; (E)-4-{2-[(4-[(2,3-dihydroxypropyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (31) and (E)-4-{2-[(4-[(4-hydroxyphenyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (32) were the most effective inhibitors with KIs = 4.4 and 5.9 nM, respectively. In addition, the compounds were tested against vancomycin-resistant Enterococcus faecalis (VRE) isolates. (E)-4-[2-({4-[(4-cinnamoylphenyl)amino]-6-[(4-hydroxyphenyl)amino]-1,3,5-triazin-2-yl}amino)ethyl]benzenesulfonamide (21) (MIC = 26.33 µM) and derivative 32 (MIC range 13.80–55.20 µM) demonstrated the highest activity against all tested strains. The most active compounds were evaluated for their cytotoxicity against the Human Colorectal Tumor Cell Line (HCT116 p53 +/+). Only 4,4’-[(6-chloro-1,3,5-triazin-2,4-diyl)bis(iminomethylene)]dibenzenesulfonamide (7) and compound 32 demonstrated an IC50 of ca. 6.5 μM; otherwise, the other selected derivatives did not show toxicity at concentrations up to 50 µM. The molecular modeling and docking of active compounds into various hCA isoenzymes, including bacterial carbonic anhydrase, specifically α-CA present in VRE, was performed to try to outline a possible mechanism of selective anti-VRE activity.

Di-2-pyridylketone 4, 4-dimethyl-3-thiosemicarbazone effectively induces human colorectal carcinoma cell apoptosis via mTOR pathway

Background: To investigate the anticancer mechanisms of di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) in human colon cancer cells. Human colorectal carcinoma (HCC) is one of the most commonly diagnosed cancers in both males and females. Current studies have found that iron chelators can be used as novel anticancer drugs; however, the anticancer activity of iron chelators and their target genes in HCC has been rarely reported. Methods: Dp44mT was used to treat two colorectal tumor cell lines, SW480 and HT-29. The proapoptotic effects of different concentrations of Dp44mt were measured using flow cytometry and Hoechst 33258 staining. Ferric ammonium citrate (FAC) was used as an additional iron donor to inhibit the effects of Dp44mT. Apoptosis and DNA damage-related proteins were examined by Western blot analysis. Results: In this study, we found that the iron chelators Dp44mT could induce the apoptosis in two colorectal tumor cell lines SW480 and HT-29, upregulate the expression level of p-histone H2A.X, and inhibit the phosphorylation level of mTOR in a dose-dependent way. Those effects could be reversed by the additional iron donor FAC. Conclusion: These data indicate that iron depletion and/or the presence of iron can modulate the HCC apoptosis progression in vitro, which may be a potential target for future HCC therapy.

AM22 Inhibites the Proliferation of Colorectal Cancer by Targeting CBFB

Our previous studies have revealed the important roles of the non-seed regions of miRNAs in gene regulation, which provided a novel insight in the development of miRNA analogs for cancer therapy. Here, we altered each nucleotide in the non-seed region of miR-34a and obtained novel synthetic miRNA analogs. Among them, AM22 with a base alteration from G to C at the 17th nucleotide of miR-34a, showed extensive anti-proliferative activity against several colorectal tumor cell lines, and achieved effective inhibition of CBFB (core binding factor subunit β) expression. Subsequent investigations demonstrated that AM22 directly targeted CBFB by binding to its 3'-untranslated region (3'-UTR). Inhibition of CBFB showed obvious anti-proliferative activity on HCT-116 and SW620 cells. Furthermore, the anti-proliferative effects of AM22 on these cells were also measured in the xenograft mouse models. In conclusion, this study identified AM22 as a potential anti-tumor miRNA by targeting CBFB, and provided a new design approach for miRNA-based cancer treatment by changing the non-seed region of miRNA.

Antitumor Activity of Fucus vesiculosus-Derived Phlorotannins through Activation of Apoptotic Signals in Gastric and Colorectal Tumor Cell Lines

Seaweeds are one of the largest producers of biomass in the marine environment and a source of multiple bioactive metabolites with valuable health benefits. Among these, phlorotannins have been widely recognized for their promising bioactive properties. The potential antitumor capacity of Fucus vesiculosus-derived phlorotannins remains, however, poorly explored, especially in gastrointestinal tract-related tumors. Therefore, this work aimed to evaluate the cytotoxic properties and possible mechanisms by which F. vesiculosus crude extract (CRD), phlorotannin-rich extract (EtOAc), and further phlorotannin-purified fractions (F1–F9) trigger cell death on different tumor cell lines of the gastrointestinal tract, using flow cytometry. The results indicate that F. vesiculosus samples exert specific cytotoxicity against tumor cell lines without affecting the viability of normal cells. Moreover, it was found that, among the nine different phlorotannin fractions tested, F5 was the most active against both Caco-2 colorectal and MKN-28 gastric cancer cells, inducing death via activation of both apoptosis and necrosis. The UHPLC-MS analysis of this fraction revealed, among others, the presence of a compound tentatively identified as eckstolonol and another as fucofurodiphlorethol, which could be mainly responsible for the promising cytotoxic effects observed in this sample. Overall, the results herein reported contribute to a better understanding of the mechanisms behind the antitumor properties of F. vesiculosus phlorotannin-rich extracts.

A novel 3-dimensional (3D) microfluidics device to model the tumor microenvironment (TME).

704 Background: In vitro models of cancer have led to significant therapeutic advances. Despite the widespread use of in vitro tissue culture, the ability to directly evaluate human biology is limited by the inability to model the complex, 3D nature of the TME. We introduce a novel, microfluidic-based system of 3D human micro-tumors perfused with a network of human micro-vessels which could overcome the shortcomings of current in vitro systems. Methods: The micro-device was created by casting polydimethylsiloxane (PDMS) onto master molds, which are then bonded to a flat PDMS sheet using air plasma. Normal human lung fibroblasts (NHLF) and GFP labelled endothelial colony forming cell derived endothelial cells (EC-FCECs) were loaded in a fibrin gel at a 1:2 ratio into the central tissue chamber. Media was introduced through the microfluidic lines. The vascular network was developed with complete EGM2 media under nominal interstitial flow. Colorectal tumor cell lines labelled with mCherry were loaded to the side chambers on the seventh day after NHLF and EC loading. Bevacizumab or TGF- β were added on the second day after tumor cell loading. Results: Micro-vessels formed in the central chamber in 5-7 days after loading. The vessels were perfused with 70KDa fluorescent (red) dextran, and displayed intact vessel wall barrier. A suspension of a colorectal tumor cell line was loaded into the device side chambers, next to a fully developed vasculature. The tumor cells drove angiogenesis into the side chambers, and at the same time tumor began to migrate into the central chamber and within the vessel lumen. The angiogenesis induced by tumor cells can be pharmacologically inhibited, and the migration/ intravasation of tumor cells can be stimulated by TGF-β. Conclusions: Our novel micro-device system can be used as a functional in vitro system that can model the tumor micro-environment. This system has the advantage over current in vitro and in vivo systems in that it is high-throughput, rapid, cost-effective, and recreates many features of the 3D TME. We are currently expanding the platform to incorporate immune cells and designing a completely autologous system to test cancer immunotherapeutics.