1-Aryl-4,6-dihydropyrazolo[4,3-d][1]benzazepin-5(1H)-ones: a new class of antiproliferative agents with selectivity for human leukemia and breast cancer cell lines

Synthesis and biological evaluation of 1-phenyl-4,6-dihydrobenzo[b]pyrazolo[3,4-d]azepin-5(1H)-one/thiones as anticancer agents

Cancer is associated with uncontrolled cell proliferation invading adjoining tissues and organs. Despite the availability of several chemotherapeutic agents, the constant search for newer approaches and drugs is necessitated owing to the ever-growing challenge of resistance. Over the years, DNA has emerged as an important druggable therapeutic drug due to its role in critical cellular processes such as cell division and maintenance. Further, evading apoptosis stands out as a hallmark of cancer. Hence, designing new compounds that would target DNA and induce apoptosis plays an important role in cancer therapy. In the current work, we carried out the synthesis and anticancer evaluation of 1-aryl-4,6-dihydrobenzo[b]pyrazolo[3,4-d]azepin-5(1H)-ones/thiones (26 compounds) against selected human cancer cell lines. Among these, compounds 8ae, 8ad, 8cf, 10ad and Kenpaullone have shown good inhibitory properties against HeLa cells (IC₅₀ < 2 µM) with good selectivity over the non-cancerous human embryonic kidney (Hek293T) cells. In cell cycle analysis, the compounds 8ad and 8cf have exhibited G₂/M cell cycle arrest in HeLa cells. In addition, the compounds 8ad and 8cf induced apoptosis in a dose-dependent manner in the Annexin-V FITC staining assay. The DAPI staining clearly demonstrated the condensed and fragmented nuclei in 8ad, 8cf, 8ae and Kenpaullone-treated HeLa cells. In addition, these compounds strongly suppressed the healing after 48 h in in vitro cell migration assay. The DNA binding experiments indicated that compounds 8ae, 8cf, and 8ad as well as Kenpaullone interact with double-stranded DNA by binding in grooves which may interrupt the DNA replication and kill fast-growing cells. Molecular docking studies revealed the binding pose of 8ad and Kenpaullone at HT1 binding pocket of double-stranded DNA. Compounds 8ad and 8cf demonstrated moderate topo II inhibition which could be a possible reason for their anticancer properties. Compounds 8ad and 8cf may cause the topo II and DNA covalent complex, which leads to the inhibition of DNA replication and transcription. This eventually increases the DNA damage in cells and promotes cell apoptosis. With the above interesting biological profile, the new 1-aryl-2,6-dihydrobenzo[b]pyrazolo[3,4-d]azepin-5(4H)-one/thione derivatives have emerged as promising leads for the discovery of new anticancer agents.

Discovery of novel glycogen synthase kinase-3α inhibitors: Structure-based virtual screening, preliminary SAR and biological evaluation for treatment of acute myeloid leukemia

Glycogen synthase kinase 3α (GSK-3α) plays a constitutive role in various physiological processes and has been proved to be a therapeutic target for acute myeloid leukemia (AML). In this paper, by means of computer-aided drug design, we discovered a novel chemical series of GSK-3α inhibitors with an IC₅₀ value of 0.033-2.804 μM. The preliminary structure-activity relationship was concluded and, notably, the most potent and isoform-selective compound G28_14 was identified with IC₅₀ values of 33 nM and 218 nM against GSK-3α and -3β, respectively, exhibiting a nearly ten-fold isoform-selectivity. Further cell viability assays and colony formation assays revealed that G28_14 suppressed cell survival by impairing cell proliferation by up to 90% in two AML cell lines. Moreover, surface marker expression analysis demonstrated that G28_14 induced terminal differentiation with a high level of CD11b, CD11c, and CD14. Western immunoblotting showed that G28_14 isoform-selectively inhibited the phosphorylation of GSK-3α in-cell without activating Wnt/β-catenin signaling. In addition, to elucidate its structure-activity relationship, the binding mode of this chemical series was proposed using molecular docking and molecular dynamics simulations. Taken together, this chemical series is worth developing as differentiation therapies for the treatment of AML.

Polysubstituted 3-trifluoromethylpyrazoles: regioselective (3 + 2)-cycloaddition of trifluoroacetonitrile imines with enol ethers and functional group transformations

Non-catalysed addition of trifluoroacetonitrile imines to enol ethers provided fully regioselectively (3 + 2)-cycloadducts, which either spontaneously or via Brønsted acid-induced elimination of ROH molecules led to the formation of 3-trifluoromethylated pyrazoles. In the case of 2,3-dihydrofuran, the respective bicyclic intermediate was isolated and its structure was confirmed by X-ray analysis. Using the developed protocol the synthesis of a known antitumor compound SC-560 was performed in 45% yield. Subsequent functionalisations of selected 4-(ω-hydroxyalkyl)pyrazoles at C(5) through lithiation/addition, cross-coupling reactions or via intramolecular Pd-catalysed C-H arylations opened up an access to polysubstituted pyrazoles including unusual tricyclic systems comprising 7-membered rings (oxepane, thiepane and azepane) as the central unit.

TARGETgene: a tool for identification of potential therapeutic targets in cancer

The vast array of in silico resources and data of high throughput profiling currently available in life sciences research offer the possibility of aiding cancer gene and drug discovery process. Here we propose to take advantage of these resources to develop a tool, TARGETgene, for efficiently identifying mutation drivers, possible therapeutic targets, and drug candidates in cancer. The simple graphical user interface enables rapid, intuitive mapping and analysis at the systems level. Users can find, select, and explore identified target genes and compounds of interest (e.g., novel cancer genes and their enriched biological processes), and validate predictions using user-defined benchmark genes (e.g., target genes detected in RNAi screens) and curated cancer genes via TARGETgene. The high-level capabilities of TARGETgene are also demonstrated through two applications in this paper. The predictions in these two applications were then satisfactorily validated by several ways, including known cancer genes, results of RNAi screens, gene function annotations, and target genes of drugs that have been used or in clinical trial in cancer treatments. TARGETgene is freely available from the Biomedical Simulations Resource web site (http://bmsr.usc.edu/Software/TARGET/TARGET.html).