Huixiong Chen

Synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK inhibitors with anti-angiogenic activity.

We report herein the synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK (focal adhesion kinase) inhibitors and the evaluation of their anti-angiogenic activity on HUVEC cells. Generally, the effects of these compounds on endothelial cells could be correlated with their kinase inhibitory activity. The most efficient compounds displayed inhibition of viability against HUVEC cells in the micromolar range, as observed with TAE-226, which was designed by Novartis Pharma AG. X-ray crystallographic analysis of the co-crystal structure for compound 34 revealed that the mode of interaction with the FAK kinase domain is highly similar to that observed in the complex of TAE-226.

Development of Binding Assays for the SH2 Domain of Grb7 and Grb2 Using Fluorescence Polarization

Adaptor proteins Grb7 and Grb2 have been implicated as being 2 potential therapeutic targets in several human cancers, especially those that overexpress ErbB2. These 2 proteins contain both a SH2 domain (Src homology 2) that binds to phosphorylated tyrosine residues contained within ErbB2 and other specific protein targets. Two assays based on enzyme-linked immunosorbent assay and fluorescence polarization methods have been developed and validated to find and rank inhibitors for both proteins binding to the pY1139. Fluorescence polarization assays allowed the authors to determine quickly and reproducibly affinities of peptides from low nanomolar to high micromolar range and to compare them directly for Grb7 and Grb2. As a result, the assays have identified a known peptidomimetic Grb2 SH2 inhibitor (mAZ-pTyr-(αMe)pTyr-Asn-NH2) that exhibits the most potent affinity for the Grb7 SH2 domain described to date. (Journal of Biomolecular Screening 2008:112-119)

Inhibition of both focal adhesion kinase and fibroblast growth factor receptor 2 pathways induces anti-tumor and anti-angiogenic activities

FAK and FGFR2 signaling pathways play important roles in cancer development, progression and tumor angiogenesis. PHM16 is a novel ATP competitive inhibitor of FAK and FGFR2. To evaluate the therapeutic efficacy of this agent, we examined its anti-angiogenic effect in HUVEC and its anti-tumor effect in different cancer cell lines. We showed PHM16 inhibited endothelial cell viability, adherence and tube formation along with the added ability to induce endothelial cell apoptosis. This compound significantly delayed tumor cell growth. Together, these data showed that inhibition of both FAK and FGFR2 signaling pathways can enhance anti-tumor and anti-angiogenic activities.

Synthesis of carbazole derivatives containing chalcone analogs as non-intercalative topoisomerase II catalytic inhibitors and apoptosis inducers

Novel topoisomerase II (Topo II) inhibitors have gained considerable interest for the development of anticancer agents. In this study, a series of carbazole derivatives containing chalcone analogs (CDCAs) were synthesized and investigated for their Topo II inhibition and cytotoxic activities. The results from Topo II mediated DNA relaxation assay showed that CDCAs could significantly inhibit the activity of Topo II, and the structure-activity relationship indicated the halogen substituent in phenyl ring play an important role in the activity. Further mechanism studies revealed that CDCAs function as non-intercalative Topo II catalytic inhibitors. Moreover, some CDCAs showed micromolar cytotoxic activities. The most potent compound 3h exhibited notable growth inhibition against four human cancer cell lines. Flow cytometric analysis revealed that compounds 3d and 3h arrested the HL-60 cells in sub G1 phase by induction of apoptosis. It was further confirmed by Annexin-V-FITC binding assay. Western blot analysis revealed that compound 3h induces apoptosis likely through the activation of caspase proteins.

Restoration of TRAIL-induced apoptosis in resistant human pancreatic cancer cells by a novel FAK inhibitor, PH11

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) emerges as one of the most-promising experimental cancer therapeutic drugs and is currently being tested in clinical trials. However, both intrinsic and acquired resistance of human cancer cells to TRAIL-induced apoptosis poses a huge problem in establishing clinically efficient TRAIL therapies. To assess the regulation of TRAIL-resistance in human pancreatic cancer cells, we studied the TRAIL resistant pancreatic cell line PANC-1. We show that treatment with PH11, a novel Focal Adhesion Kinase (FAK) inhibitor in association with TRAIL rapidly induces apoptosis in TRAIL-resistant PANC-1 cells, but not in normal human fibroblast cells. To explain sensitization, we showed that PH11 restores TRAIL apoptotic pathway in PANC-1 cells through down-regulation of c-FLIP via inhibition of FAK and the phosphatidylinositol-3 kinase (PI3K)/AKT pathways. These findings suggest that this combined treatment may offer an attractive therapeutic strategy for safely and efficiently treating pancreatic cancer.

Synthesis of novel 1,2,4-triazine scaffold as FAK inhibitors with antitumor activity

A series of 1,3,5-triazinic inhibitors of focal adhesion kinase (FAK) has recently been shown to exert antiangiogenic activity against HUVEC cells and anticancer efficacy against several cancer cell lines. In this report, we designed and synthesized a series of new compounds containing a 1,2,4-triazine core as novel scaffold for FAK inhibitors. These compounds displayed 10-7M IC50 values, and the best one showed IC50 value of 0.23μM against FAK enzymatic activity. Among them, several inhibitors potently inhibited the proliferation of glioblastoma (U-87MG) and colon (HCT-116) cancer cell lines. Docking of compound 10 into the active site of the FAK kinase was performed to explore its potential binding mode.

Glabridin, an isoflavan from licorice root, ameliorates imiquimod-induced psoriasis-like inflammation of BALB/c mice

ABSTRACT In this paper, we investigate the effect of glabridin (Glab) on psoriasis. We observed that Glab significantly suppressed the levels of nitric oxide (NO), NF‐&kgr;B subunit p65, interleukin (IL)‐6, and IL‐1&bgr; in lipopolysaccharide (LPS)‐stimulated HaCaT cells. In addition, Glab treatment reduced the expression of IL‐17A, IL‐22, and IL‐23 in TNF‐&agr;‐stimulated‐HaCaT cells. These findings prompted us to test whether Glab could be used to treat psoriasis in vivo. The effects of Glab on PASI scores, histopathological changes, oxidative/anti‐oxidative indexes and pro‐inflammatory cytokines in IMQ‐induced mice were investigated. The results indicated that Glab could reduce the PASI scores and ameliorate the deteriorating histopathology. Interestingly, RT‐PCR revealed that Glab significantly decreased the mRNA expression of p65, IL‐6, IL‐1&bgr;, IL‐17A, IL‐22, and IL‐23. These results were confirmed by Western blot analysis and immunohistochemistry staining. In conclusion, our present study revealed that Glab had beneficial effects on psoriasis, and the underlying mechanism may be associated with the downregulation of pro‐inflammatory cytokines and the improvement of antioxidant status. Hence, Glab is a promising candidate molecule for development of effective psoriasis therapies. HIGHLIGHTSGlabridin exhibits potent anti‐psoriasis effects on IMQ‐induced mice.Glabridin displays anti‐psoriasis activity through downregulated proinflammatory cytokines and mediators.Glabridin shows anti‐psoriasis activity by improving the antioxidant status.

Synthesis and biological evaluation of novel carbazole-rhodanine conjugates as topoisomerase II inhibitors

In this study, a series of carbazole-rhodanine conjugates was synthesized and evaluated for their Topoisomerase II inhibition potency as well as cytotoxicity against a panel of four human cancer cell lines. Among these thirteen compounds, 3a, 3b, 3g, and 3h possessed Topoisomerase II inhibition potency at 20 μM. Mechanism study revealed that these compounds may function as Topo II catalytic inhibitors. It was found that the electron-withdrawing groups on the phenyl ring of compounds played an important role on enhancing both enzyme inhibition and cytotoxicity.

Aromatic-turmerone ameliorates imiquimod-induced psoriasis-like inflammation of BALB/c mice

ABSTRACT Psoriasis is a usual immune‐mediated inflammatory skin disease with undefined pathogenesis. Aromatic‐turmerone (ATM) is a mainly constituent of essential oil from Curcuma longa L. It has been shown to exhibit strong anti‐oxidant, anti‐tumor activities and anti‐inflammatory effects. In this study, we investigated the effects of ATM on imiquimod (IMQ)‐induced psoriasis‐like BALB/c mice and its molecular mechanisms for anti‐inflammatory effect. ATM showed inhibition of the transfer of CD8+ T cells in epidermis, and reduced expression of NF‐&kgr;B and COX‐2 as well as phosphorylation of p38 MAPK. It also decreased the level of TNF‐&agr; and IL‐6, and down‐regulates IL‐17 IL‐22 and IL‐23 mRNA synthesis. Notably, we demonstrated that topically applied ATM alleviated skin inflammation in IMQ‐induced mice. These results indicate that ATM, a natural active compound exhibits anti‐inflammatory activity and is a promising candidate molecule to treat inflammatory skin diseases, such as psoriasis. Graphical abstract Figure. No Caption available. HighlightsAromatic‐turmerone inhibited of the transfer of CD8+ T cells in epidermis.Aromatic‐turmerone reduced expression of NF‐&kgr;B and COX‐2 as well as phosphorylation of p38 MAPK.Aromatic‐turmerone decreased the level of TNF‐&agr; and IL‐6 in full‐thickness skin.Aromatic‐turmerone down‐regulated IL‐17 IL‐22 and IL‐23 mRNA synthesis in full‐thickness skin.Aromatic‐turmerone alleviated skin inflammation and improves psoriatic lesions in IMQ‐induced mice.

Structure-Based Design, Synthesis, and Characterization of the First Irreversible Inhibitor of Focal Adhesion Kinase

Focal Adhesion Kinase signaling pathway and its functions have been involved in the development and aggressiveness of tumor malignancy, it then presents a promising cancer therapeutic target. Several reversible FAK inhibitors have been developed and are being conducted in clinical trials. On the other hand, irreversible covalent inhibitors would bring many desirable pharmacological features including high potency and increased duration of action. Herein we report the structure-guided development of the first highly potent and irreversible inhibitor of the FAK kinase. This inhibitor showed a very potent decrease of autophosphorylation of FAK in squamous cell carcinoma. A cocrystal structure of the FAK kinase domain in complex with this compound revealed the inhibitor binding mode within the ATP binding site and confirmed the covalent linkage between the targeted Cys427 of the protein and the inhibitor.