Synthesis and bioevaluation of N-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-b]pyridin-3-amines as tubulin polymerization inhibitors with anti-angiogenic effects.

A new series of N-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-b]pyridin-3-amine derivatives as tubulin polymerization inhibitors were synthesized, and evaluated for the anti-proliferative activities. A structure-activity relationship study revealed that the free amino moiety of 1H-pyrazolo[3,4-b]pyridin-3-amine played an essential role in the anti-proliferative activities. Especially, compound 15c displayed the strongest anti-proliferation against MCF-7 cells with IC50 value of 0.067 ± 0.003 µM, and high selectivity over the normal human embryonic lung WI-38 cells with IC50 value of 23.41 ± 1.53 µM. Further mechanistic studies revealed that 15c showed strong anti-tubulin polymerization activity, changed the morphology of tubulin, and arrested the cell cycle at the G2/M transition in MCF-7 cells. Molecular docking analysis suggested that 15c well occupied the colchicine-binding pocket of tubulin. Additionally, 15c demonstrated anti-angiogenic activities with blocking the migration, invasion and tube formation, disrupting the newly formed tube, and regulating both MMP-9 and TIMP-1 in HUVEC cells. In summary, our results highlight that compound 15c is a potential antitumor compound that are worthy of further development.

The synthesis and anti-tumour properties of novel 4-substituted phthalazinones as Aurora B kinase inhibitors.

A series of novel 4-substituted phthalazinones as Aurora B kinase inhibitors was synthesized and evaluated the anti-proliferative activities against A549, HCT116, MCF-7 and HepG2 cells. 1-(4-(2-((4-Oxo-3,4-dihydrophthalazin-1-yl)amino)ethyl) phenyl)-3-(3-(trifluoromethyl)phenyl)urea (17b) exhibited the most potent anti-proliferative activity against HCT116 cells with IC50 value of 4.35 ± 1.21 µM, as well as the moderate Aurora B inhibitory activity with the IC50 value of 142 nM. Furthermore, 17b inhibited the phosphorylation of Aurora B on Thr232, leading to cell cycle arrest in the G2/M phase by down-regulating the expression of CyclinB1 and Cdc2 proteins, and apoptosis by up-regulating the expression of BAD and Bax proteins in HCT116 cells. In addition, a docking study revealed that 17b could form key hydrogen bonds with Ala173, Glu171 and Glu177 in Aurora B. All the results reveal that 17b is worthy of further development as an Aurora B kinase inhibitor.

Synthesis, biological evaluation and molecular modeling study of 2-amino-3,5-disubstituted-pyrazines as Aurora kinases inhibitors.

Serine/threonine protein kinases Aurora A, B, and C play essential roles in cell mitosis and cytokinesis, and a number of Aurora kinase inhibitors have been evaluated in the clinic. Herein we report the synthesis and their antiproliferation of 3,5-disubstituted-2-aminopyrazines as kinases inhibitors. Amongst, 4-((3-amino-6- (3,5-dimethylisoxazol-4-yl)pyrazin-2-yl)oxy)-N-(3-chlorophenyl) benzamide (12Aj) exhibited the strongest antiproliferative activities against U38, HeLa, HepG2 and LoVo cells with IC50 values were 11.5 ± 3.2, 1.34 ± 0.23, 7.30 ± 1.56 and 1.64 ± 0.48 µM, as well as inhibited Aurora A and B with the IC50 values were 90 and 152 nM, respectively. Molecular docking studies indicated that 12Aj appeared to form stable hydrogen bonds with either Aurora A or Aurora B. Furthermore, 12Aj arrested HeLa cell cycle in G2/M phase by regulating protein levels of cyclinB1 and cdc2. In addition, the bioinformatics prediction further revealed that 12Aj possessed good drug likeness using SwissADME. These results suggested that 12Aj was worthy of future development of potent anticancer agents as pan-Aurora kinases.

Discovery of novel 2,4-disubstituted pyrimidines as Aurora kinase inhibitors.

In order to explore novel Aurora kinase inhibitors, a series of novel 2,4-disubstituted pyrimidines were designed, synthesized and evaluated their in vitro anti-proliferative activities against a panel of cancerous cell lines (A549, HCT-116 and MCF-7). Among them, compound 12a showed the moderate to high anti-proliferative activities against A549 (IC50 = 12.05 ± 0.45 µM), HCT-116 (IC50 = 1.31 ± 0.41 µM) and MCF-7 (IC50 = 20.53 ± 6.13 µM) cells, as well as the Aurora A and Aurora B inhibitory activities with the IC50 values of 309 nM and 293 nM, respectively. Furthermore, compound 12a induced apoptosis by upregulated the pro-apoptotic proteins Bax and decreased the anti-apoptotic protein Bcl-xl in HCT-116 cells. Moreover, the molecular docking study showed that compound 12a had good binding modes with Aurora A and Aurora B and the bioinformatics prediction discovered that compound 12a exhibited good drug likeness using SwissADME. Taken together, these results indicated that 12a may be a potential anticancer compound that was worthy of further development as Aurora kinase inhibitor.

Synthesis and biological evaluation of 1-(benzofuran-3-yl)-4-(3,4,5-trimethoxyphenyl)-1H-1,2,3-triazole derivatives as tubulin polymerization inhibitors.

The key functions of microtubules and the mitotic spindle in cell division make them attractive targets for cancer therapy. In this study, a series of 1-(benzofuran-3-yl)-4-(3,4,5-trimethoxyphenyl)-1H-1,2,3-triazole derivatives was synthesized, and their antiproliferative activities against HCT116, HeLa, HepG2, and A549 cells were evaluated. 6-Methoxy-N-phenyl-3-(4-(3,4,5-trimethoxyphenyl)-1H-1,2,3-triazol-1-yl)benzofuran-2-carboxamide (17g) exhibited the strongest antiproliferative activities, with IC50 values ranging from 0.57 to 5.7 µM. Mechanistic studies showed that 17g inhibited tubulin polymerization, leading to the disruption of mitotic spindle formation, cell cycle arrest in the G2/M phase, and apoptosis of A549 cells. A docking study indicated that 17g was a good molecular fit at the colchicine binding site of tubulin. These results showed that 17g is a potential anticancer compound that is worthy of further development as a tubulin polymerization inhibitor.

Novel conjugates of podophyllotoxin and coumarin: Synthesis, cytotoxicities, cell cycle arrest, binding CT DNA and inhibition of Topo IIß.

A series of conjugates of podophyllotoxin and coumarin were prepared using the click reaction, and their cytotoxicities against A549, HepG2, HeLa, and LoVo cells were evaluated. Among them, compound 14e exhibited the strongest cytotoxicities against these cancer cells with IC50 values of 4.9-17.5 µM. Furthermore, 14e disrupted microtubules and induced cell cycle arrest at G1 phase by regulating P21 and Cyclin D1 in LoVo cells. In addition, 14e bond CT DNA and selectively inhibited Topo IIß over Topo IIα. Molecular docking model showed that 14e appeared to form stable hydrogen bonds with several DNA bases and residue Gln778. Taken together, these conjugates have the potential to be developed as anti-tumor drugs.