Discovery of indoline derivatives as anticancer agents via inhibition of tubulin polymerization.

Human esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers in human digestive system. It is necessary to discover novel antitumor agents for the treatment of esophageal cancers because of its poor prognosis. Indoline has been reported as an efficient anticancer fragment to design novel anticancer agents. In this work, indoline derivatives were designed, synthesized and explored their anticancer activity. Compound 9d, which exhibited potent antiproliferative activity with IC50 values of 1.84 µM (MGC-803 cells), 6.82 µM (A549 cells), 1.61 µM (Kyse30 cells), 1.49 µM (Kyse450 cells), 2.08 µM (Kyse510 cells) and 2.24 µM (EC-109 cells), respectively. The most active compound 9d was identified as a tubulin inhibitor targeting colchicine binding site with an IC50 value of 3.4 µM. Compound 9d could strongly suppress the tubulin polymerization in Kyse450 cells. The results of molecular docking also suggested compound 9d could tightly bind into the colchicine binding site of tubulin. Besides, compound 9d inhibited the growth of KYSE450 cells in a time and dose-dependent manner. All the results suggest that the indoline derivatives may be a class of novel tubulin inhibitors with potential anticancer activity, and which is worthy of further study.

WITHDRAWN: Discovery of indoline derivatives as anticancer agents via inhibition of tubulin polymerization.

Human esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers in human digestive system. It is necessary to discover novel antitumor agents for the treatment of esophageal cancers because of its poor prognosis. Indoline has been reported as an efficient anticancer fragment to design novel anticancer agents. In this work, indoline derivatives were designed, synthesized and explored their anticancer activity. Compound 9d, which exhibited potent antiproliferative activity with IC50 values of 1.84 µM (MGC-803 cells), 6.82 µM (A549 cells), 1.61 µM (Kyse30 cells), 1.49 µM (Kyse450 cells), 2.08 µM (Kyse510 cells) and 2.24 µM (EC-109 cells), respectively. The most active compound 9d was identified as a tubulin inhibitor targeting colchicine binding site with an IC50 value of 3.4 µM. Compound 9d could strongly suppress the tubulin polymerization in Kyse450 cells. The results of molecular docking also suggested compound 9d could tightly bind into the colchicine binding site of ß-tubulin. Besides, compound 9d inhibited the growth of KYSE450 cells in time and dose-dependent manners. All the results suggest that the indoline derivatives might be a class of novel tubulin inhibitors with potential anticancer activity and is worthy of further study.

Progress in the development of small molecular inhibitors of the Bruton's tyrosine kinase (BTK) as a promising cancer therapy.

Bruton tyrosine kinase (BTK) is a key kinase in the B cell antigen receptor signal transduction pathway, which is involved in the regulation of the proliferation, differentiation and apoptosis of B cells. BTK has become a significant target for the treatment of hematological malignancies and autoimmune diseases. Ibrutinib, the first-generation BTK inhibitor, has made a great contribution to the treatment of B cell malignant tumors, but there are still some problems such as resistance or miss target of site mutation. Therefore, there is an imperative need to develop novel BTK inhibitors to overcome these problems. Besides, proteolysis targeting chimera (PROTAC) technology has been successfully applied to the development of BTK degradation agents, which has opened a fresh way for the BTK targeted treatment. This paper reviews the biological function of BTK, the discovery and development of BTK targeted drugs as a promising cancer therapy. It mainly reviews the binding sites and structural characteristics of BTK, structure-activity relationships, activity and drug resistance of BTK inhibitors, as well as potential treatment strategies to overcome the resistance of BTK, which provides a reference for the rational design and development of new powerful BTK inhibitors.

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.

Drug Discovery Targeting Focal Adhesion Kinase (FAK) as a Promising Cancer Therapy.

FAK is a nonreceptor intracellular tyrosine kinase which plays an important biological function. Many studies have found that FAK is overexpressed in many human cancer cell lines, which promotes tumor cell growth by controlling cell adhesion, migration, proliferation, and survival. Therefore, targeting FAK is considered to be a promising cancer therapy with small molecules. Many FAK inhibitors have been reported as anticancer agents with various mechanisms. Currently, six FAK inhibitors, including GSK-2256098 (Phase I), VS-6063 (Phase II), CEP-37440 (Phase I), VS-6062 (Phase I), VS-4718 (Phase I), and BI-853520 (Phase I) are undergoing clinical trials in different phases. Up to now, there have been many novel FAK inhibitors with anticancer activity reported by different research groups. In addition, FAK degraders have been successfully developed through "proteolysis targeting chimera" (PROTAC) technology, opening up a new way for FAK-targeted therapy. In this paper, the structure and biological function of FAK are reviewed, and we summarize the design, chemical types, and activity of FAK inhibitors according to the development of FAK drugs, which provided the reference for the discovery of new anticancer agents.

Discovery of Novel Diarylamide N-Containing Heterocyclic Derivatives as New Tubulin Polymerization Inhibitors with Anti-Cancer Activity.

Tubulin has been regarded as an attractive and successful molecular target in cancer therapy and drug discovery. Vicinal diaryl is a simple scaffold found in many colchicine site tubulin inhibitors, which is also an important pharmacophoric point of tubulin binding and anti-cancer activity. As the continuation of our research work on colchicine binding site tubulin inhibitors, we designed and synthesized a series of diarylamide N-containing heterocyclic derivatives by the combination of vicinal diaryl core and N-containing heterocyclic skeletons into one hybrid though proper linkers. Among of these compounds, compound 15b containing a 5-methoxyindole group exhibited the most potent inhibitory activity against the tested three human cancer cell lines (MGC-803, PC-3 and EC-109) with IC50 values of 1.56 µM, 3.56 µM and 14.5 µM, respectively. Besides, the SARs of these compounds were preliminarily studied and summarized. The most active compound 15b produced the inhibition of tubulin polymerization in a dose-dependent manner and caused microtubule network disruption in MGC-803 cells. Therefore, compound 15b was identified as a novel tubulin polymerization inhibitor targeting the colchicine binding site. In addition, the results of molecular docking also suggested compound 15b could tightly bind into the colchicine binding site of ß-tubulin.

Design, Synthesis, and Anticancer Activity Studies of Novel Quinoline-Chalcone Derivatives.

The chalcone and quinoline scaffolds are frequently utilized to design novel anticancer agents. As the continuation of our work on effective anticancer agents, we assumed that linking chalcone fragment to the quinoline scaffold through the principle of molecular hybridization strategy could produce novel compounds with potential anticancer activity. Therefore, quinoline-chalcone derivatives were designed and synthesized, and we explored their antiproliferative activity against MGC-803, HCT-116, and MCF-7 cells. Among these compounds, compound 12e exhibited a most excellent inhibitory potency against MGC-803, HCT-116, and MCF-7 cells with IC50 values of 1.38, 5.34, and 5.21 µM, respectively. The structure-activity relationship of quinoline-chalcone derivatives was preliminarily explored in this report. Further mechanism studies suggested that compound 12e inhibited MGC-803 cells in a dose-dependent manner and the cell colony formation activity of MGC-803 cells, arrested MGC-803 cells at the G2/M phase and significantly upregulated the levels of apoptosis-related proteins (Caspase3/9 and cleaved-PARP) in MGC-803 cells. In addition, compound 12e could significantly induce ROS generation, and was dependent on ROS production to exert inhibitory effects on gastric cancer cells. Taken together, all the results suggested that directly linking chalcone fragment to the quinoline scaffold could produce novel anticancer molecules, and compound 12e might be a valuable lead compound for the development of anticancer agents.

Synthesis and Biological Evaluation of Amino Chalcone Derivatives as Antiproliferative Agents.

Chalcone is a common scaffold found in many biologically active compounds. The chalcone scaffold was also frequently utilized to design novel anticancer agents with potent biological efficacy. Aiming to continue the research of effective chalcone derivatives to treat cancers with potent anticancer activity, fourteen amino chalcone derivatives were designed and synthesized. The antiproliferative activity of amino chalcone derivatives was studied in vitro and 5-Fu as a control group. Some of the compounds showed moderate to good activity against three human cancer cells (MGC-803, HCT-116 and MCF-7 cells) and compound 13e displayed the best antiproliferative activity against MGC-803 cells, HCT-116 cells and MCF-7 cells with IC50 values of 1.52 µM (MGC-803), 1.83 µM (HCT-116) and 2.54 µM (MCF-7), respectively which was more potent than the positive control (5-Fu). Further mechanism studies were explored. The results of cell colony formatting assay suggested compound 10e inhibited the colony formation of MGC-803 cells. DAPI fluorescent staining and flow cytometry assay showed compound 13e induced MGC-803 cells apoptosis. Western blotting experiment indicated compound 13e induced cell apoptosis via the extrinsic/intrinsic apoptosis pathway in MGC-803 cells. Therefore, compound 13e might be a valuable lead compound as antiproliferative agents and amino chalcone derivatives worth further effort to improve amino chalcone derivatives' potency.

A novel aromatic amide derivative SY-65 co-targeted tubulin and histone deacetylase 1 with potent anticancer activity in vitro and in vivo.

Given the essential role of Epigenetic regulation in many biological processes, targeted epigenetic drugs have been gradually applied to the treatment of tumors. Histone deacetylases (HDACs) are a class of epigenetic enzymes, which play key roles in chromosome structural modification and gene expression regulation. Targeted microtubules drugs have achieved great success in clinical application for decades. Development of novel agents with multitargeting capabilities specially dual-target has become a popular research field for the treatment of human cancers, which may provide synergistic anticancer effects. Here, we reported a novel aromatic amide derivative SY-65 co-targeted tubulin and histone deacetylase 1 with potent anticancer activity in vitro and in vivo. Compound SY-65 was identified as a dual inhibitor of tubulin/HDAC1 (IC50 = 3.64 and 0.529 µM, respectively) with excellent antiproliferative activity against MGC-803, HCT-116, KYSE-450, HGC-27, SGC-7901 and MKN-45 cells. Especially, compound SY-65 exhibited potent antiproliferative activity against MGC-803, HGC-27 and SGC-7901 cells with IC50 values <55 nM, which was better than that of Colchicine, MS-275 and SAHA. Compound SY-65 effectively inhibited tubulin polymerization and bound to the colchicine binding site of tubulin, as well as inhibited HDAC1 activity both intra/extracellularly. Molecular docking results suggested there were the well-defined binding modes of compound SY-65 in HDAC1 and tubulin. In addition, compound SY-65 inhibited colony formation, interfered with the cell cycle distribution, induced cell cycle arrest at the G2/M phase and apoptosis in MGC-803 and HGC-27 cells. Compound SY-65 also exhibited a good tumor inhibitory effect in vivo without obvious toxicity. Therefore, compound SY-65 could be developed as a novel tubulin/HDAC1 candidate inhibitor for future cancer therapeutics.

Discovery of 1,2,4-triazine dithiocarbamate derivatives as NEDDylation agonists to inhibit gastric cancers.

NEDDylation process regulates multiple physiological functions and signaling pathways, which are still in an equilibrium that favors the survival and proliferation of tumor cells. Unlike inhibitors, NEDDylation agonists are rarely studied. In this work, novel 1,2,4-triazine-dithiocarbamate derivatives were synthesized and evaluated for antiproliferative activity against MGC-803, PC-3 and EC-109 cells. Among them, compound K3 displayed the most potent activity MGC-803, PC-3 and EC-109 cells with IC50 values of 2.35, 5.71 and 10.1 µM, respectively, which were more potent than 5-FU. Further cellular mechanisms suggested that compound K3 inhibited the cell viability, induced proliferation inhibition, arrested cell cycle at G2/M phase and induced cell apoptosis in MGC-803 and HGC-27 cells. Importantly, compound K3 could interact with NAE1 to promote the NEDDylation of MGC-803 and HGC-27 cells. The promotion of NEDDylation resulted in the degradation of c-IAP and YAP/TAZ, which leads to the induction of cell apoptosis and inhibition of proliferation in MGC-803 and HGC-27 cells. Therefore, as a NEDDylation agonist, compound K3 could effectively inhibit gastric cancer cells. Here, we reported NEDDylation promotion induced by compound K3, which could inhibit the cancer cell lines MGC-803 and HGC-27 and induce the cancer cell apoptosis via prompting the degradation of c-IAP and YAP/TAZ.