Synthesis and biological evaluation of 4-phenyl-5-quinolinyl substituted isoxazole analogues as potent cytotoxic and tubulin polymerization inhibitors against ESCC.

The identification of chemically different inhibitors that target the colchicine site of tubulin is still of great value for cancer treatment. Combretastatin A-4(CA-4), a naturally occurring colchicine-site binder characterized by its structural simplicity and biological activity, has served as a structural blueprint for the development of novel analogues with improved safety and therapeutic efficacy. In this study, a library of forty-eight 4-phenyl-5-quinolinyl substituted triazole, pyrazole or isoxazole analouges of CA-4, were synthesized and evaluated for their cytotoxicity against Esophageal Squamous Cell Carcinoma (ESCC) cell lines. Compound C11, which features a 2-methyl substitution at the quinoline and carries an isoxazole ring, emerged as the most promising, with 48 h IC50s of less than 20 nmol/L against two ESCC cell lines. The findings from EBI competitive assay, CETA, and in vitro tubulin polymerization assay of C11 are consistent with those of the positive control colchicine, demonstrating the clear affinity of compound C11 to the colchicine binding site. The subsequent cellular-based mechanism studies revealed that C11 significantly inhibited ESCC cell proliferation, arrested cell cycle at the M phase, induced apoptosis, and impeded migration. Experiments conducted in vivo further confirmed that C11 effectively suppressed the growth of ESCC without showing any toxicity towards the selected animal species. Overall, our research suggests that the tubulin polymerization inhibitor incorporating quinoline and the isoxazole ring may deserve consideration for cancer therapy.

Discovery of novel tranylcypromine-based derivatives as LSD1 inhibitors for gastric cancer treatment.

As an important epigenetic regulator, histone lysine specific demethylase 1 (LSD1) has become an attractive target for the discovery of anticancer agents. In this work, a series of tranylcypromine-based derivatives were designed and synthesized. Among them, compound 12u exhibited the most potent inhibitory potency on LSD1 (IC50 = 25.3 nM), and also displayed good antiproliferative effects on MGC-803, KYSE450 and HCT-116 cells with IC50 values of 14.3, 22.8 and 16.3 µM, respectively. Further studies revealed that compound 12u could directly act on LSD1 and inhibit LSD1 in MGC-803 cells, thereby significantly increasing the expression levels of mono-/bi-methylation of H3K4 and H3K9. In addition, compound 12u could induce apoptosis and differentiation, inhibit migration and cell stemness in MGC-803 cells. All these findings suggested that compound 12u was an active tranylcypromine-based derivative as a LSD1 inhibitor that inhibited gastric cancer.

Discovery of N-aryl sulphonamide-quinazoline derivatives as anti-gastric cancer agents in vitro and in vivo via activating the Hippo signalling pathway.

Hippo signalling pathway plays a crucial role in tumorigenesis and cancer progression. In this work, we identified an N-aryl sulphonamide-quinazoline derivative, compound 9i as an anti-gastric cancer agent, which exhibited potent antiproliferative ability with IC50 values of 0.36 µM (MGC-803 cells), 0.70 µM (HCT-116 cells), 1.04 µM (PC-3 cells), and 0.81 µM (MCF-7 cells), respectively and inhibited YAP activity by the activation of p-LATS. Compound 9i was effective in suppressing MGC-803 xenograft tumour growth in nude mice without obvious toxicity and significantly down-regulated the expression of YAP in vivo. Compound 9i arrested cells in the G2/M phase, induced intrinsic apoptosis, and inhibited cell colony formation in MGC-803 and SGC-7901 cells. Therefore, compound 9i is to be reported as an anti-gastric cancer agent via activating the Hippo signalling pathway and might help foster a new strategy for the cancer treatment by activating the Hippo signalling pathway regulatory function to inhibit the activity of YAP.

Review of NEDDylation inhibition activity detection methods.

NEDDylation is a post-translational modification of a protein, which transfers Ubiquitin like protein NEDD8 (Neuronal Precursor Cell-expressed Developmentally Down-regulated Protein 8) to the lysine residue of the product through a three-stage enzymatic reaction, and widely regulates many biological processes, such as cell cycle signal transduction and immune recognition. In the past ten years, we have witnessed tremendous progress in the study of protein ubiquitination modification, from modification mechanisms to drug development. Which suggests that inhibition of NEDDylation is an effective way to inhibit tumor. A variety of biological detection methods have been developed during the development of the inhibitor. In this review, we briefly introduced the modification process and substrates of NEDDylation, and discussed detection methods of NEDDylation activity in detail. This review will provide an up-to-date and comprehensive review of the methods for detecting NEDDylation activity that will contribute to NEDDylation inhibitor development.