Jinhong Feng

Development of tetrahydroisoquinoline-based hydroxamic acid derivatives: potent histone deacetylase inhibitors with marked in vitro and in vivo antitumor activities.

Inhibition of histone deacetylase (HDAC) results in growth arrest, differentiation, and apoptosis in nearly all tumor cell lines, promoting HDACs as promising targets for antitumor therapy. In our previous study we developed a novel series of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives as HDAC inhibitors (HDACi), among which compound 7d exhibited promising HDAC8 inhibitory and antiproliferative activities. Herein, we report the design and development of a new class of tetrahydroisoquinoline-bearing hydroxamic acid analogues as potential HDACi and anticancer agents. In vitro biological evaluation of these compounds showed improved HDAC8 inhibition (compounds 31a and 31b exhibited mid-nM IC(50) values against HDAC8) and potent growth inhibition in multiple tumor cell lines. Most importantly, compounds 25e, 34a, and 34b exhibited excellent in vivo anticancer activities in a human breast carcinoma (MDA-MB-231) xenograft model compared with suberoylanilide hydroxamic acid (SAHA), an approved HDACi. Collectively, our results indicate that tetrahydroisoquinoline bearing a hydroxamic acid is an excellent template to develop novel HDACi as potential anticancer agents.

Design, synthesis and preliminary activity assay of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives as novel Histone deacetylases (HDACs) inhibitors.

Histone deacetylases (HDACs) are enzymes involved in tumor genesis and development. Herein, we report a novel series of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives as HDACs inhibitors. The preliminary biological screening showed that most of our compounds exhibited potent inhibitory activity against HDACs. Within this series, five compounds, 13a (IC(50)=0.58+/-0.10 microM), 7d (IC(50)=1.00+/-0.16 microM), 8l (IC(50)=1.06+/-0.14 microM), 7i (IC(50)=1.17+/-0.19 microM) and 7a (IC(50)=1.29+/-0.15 microM) possessed better HDACs inhibitory activity than Vorinostat (IC(50)=1.48+/-0.20 microM). So these five compounds could be used as novel lead compounds for further design of HDACs inhibitors. The anti-proliferative activities of a few compounds and the structure-activity relationships are also briefly discussed.

Discovery of a tetrahydroisoquinoline-based hydroxamic acid derivative (ZYJ-34c) as histone deacetylase inhibitor with potent oral antitumor activities.

Histone deacetylase (HDAC) has emerged as an attractive target for the development of antitumor agents during the past decade. Previously tetrahydroisoquinoline-bearing hydroxamic acid analogue, ZYJ-25e (1), was identified and validated as a potent histone deacetylase inhibitor (HDACi) with marked in vitro and in vivo antitumor potency. In the present study, further modification of 1 led to another more potent, orally active HDACi, ZYJ-34c (4). Compared to FDA-approved drug suberoylanilide hydroxamic acid (SAHA), compound 4 exhibited higher in vivo antitumor potency in a human breast carcinoma (MDA-MB-231) xenograft model and in a mouse hepatoma-22 (H22) pulmonary metastasis model and similar in vivo antitumor potency in a human colon tumor (HCT116) xenograft model.

Design, synthesis and biological evaluation of tyrosine-based hydroxamic acid analogs as novel histone deacetylases (HDACs) inhibitors.

Histone deacetylases (HDACs) are a promising target for treating cancer and some other disorders. Herein, based on the structure of our previously reported tetrahydroisoquinoline-based hydroxamic acids, a novel series of tyrosine-based hydroxamic acid derivatives was designed and synthesized as HDACs inhibitors. Compared with tetrahydroisoquinoline-based hydroxamic acids, tyrosine-based hydroxamic acid derivatives exhibited more potent HDAC8 inhibitory activity. However, the antiproliferative activities and HeLa cell nuclear extract inhibition of several selected tyrosine-based hydroxamic acids were moderate.

Design, synthesis and primary activity assay of tripeptidomimetics as histone deacetylase inhibitors with linear linker and branched cap group.

A novel series of tripeptidomimetics with spiro ring containing sulfur atoms as cap group and linear carbochain as linker was designed and synthesized as HDACs inhibitors. Several compounds possessed more potent HDAC8 inhibitory activity than clinically used drug SAHA, although their HDAC1 inhibitory activities and anti-proliferative activities against human breast cancer cell lines (MCF-7, MDA-MB-231) and prostate cancer cell line (PC-3) were not satisfactory. Among them, compounds 11l and 11k showed excellent potency against HDAC8 (IC(50) values were 0.021 ± 0.004 μM and 0.035 ± 0.007 μM, respectively, whereas SAHA was 0.70 ± 0.12 μM), and good selectivity over HDAC1. Up to now, few hydroxamic acid derivatives with linear linker were reported to possess HDAC8 selectivity over HDAC1.

Design, synthesis and biological evaluation of pazopanib derivatives as antitumor agents.

A novel series of pazopanib derivatives were designed, synthesized, and evaluated for their inhibitory activity against a series of kinases including VEGFR‐2, EGFR, AKT1, ALK1, and ABL1. The anti‐angiogenic activities ex vivo of some compounds were also investigated. Compounds P2d and P2e demonstrated outstanding inhibitory activity against VEGFR‐2 and ABL1 and higher anti‐angiogenic activity compared with Pazopanib, the reference standard. These two compounds (P2d and P2e) could be used as novel lead compounds for further development of anticancer agents.

3D-QSAR study of pyrrolidine derivatives as matrix metalloproteinase-2 inhibitors

In order to develop potent inhibitors of matrix metalloproteinase-2(MMP-2) as anticancer agents, a three-dimensional quantitative structure–activity relationship (3D-QSAR) model was established by using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. This study correlates the MMP-2 inhibitory activities of 67 pyrrolidine derivatives to steric, electrostatic, hydrophobic, and hydrogen-bond donor and acceptor fields. After using two different molecular alignments, both CoMFA and CoMSIA models resulted in good statistical predictions, a case in point being their high q2 values of between 0.757 and 0.843. The CoMFA and CoMSIA models established herein will be helpful in understanding the structure–activity relationship of pyrrolidine derivatives as well as in the design of novel derivatives with enhanced MMP-2 inhibitory activity.

Design, synthesis and preliminary evaluation of α-sulfonyl γ-(glycinyl-amino)proline peptidomimetics as matrix metalloproteinase inhibitors

A series of novel α-sulfonyl γ-(glycinyl-amino)proline peptidomimetic derivatives were designed, synthesized and assayed for their activities against matrix metalloproteinase-2 (MMP-2), aminopeptidase N (APN)/CD13 and HDACs. The results indicated that all the compounds exhibited highly selective inhibition against MMP-2 as compared with APN and HDACs. The antiproliferative activities of some compounds against SKOV3, HL60 and A549 cells were also investigated. Comparing with the control LY52, compound 12u, with excellent activity both in the enzymatic inhibition assay and cell-based assay, could be used as lead compound for the further development of MMP inhibitors.

Discovery of N-hydroxy-4-(3-phenylpropanamido)benzamide derivative 5j, a novel histone deacetylase inhibitor, as a potential therapeutic agent for human breast cancer

A novel series of N-hydroxy-4-(3-phenylpropanamido)benzamide (HPPB) derivatives comprising N-hydroxybenzamide group as zinc-chelating moiety were designed, synthesized and evaluated as histone deacetylases inhibitors. The thiophene substituted derivative 5j exhibited the best HDAC inhibition activity among these compounds. The present study was designed to evaluate the efficacy of 5j as a candidate compound for cancer therapy. Our results indicated that 5j exhibited better HDAC1, 8 and hela nuclear extract inhibition activities than SAHA, and good antiproliferative activities against a broad spectrum of human cancer cell lines especially for breast cancer. 5j induced cell cycle arrest at G2/M phase, and eventual apoptosis possibly by modulating p21, caspase-3 and Bcl-xL on MDA-MB-231 cells. In addition, 5j down regulated the active form of MMP2, and inhibited the invasion of MDA-MB-231 cell lines. Moreover, 5j significantly delayed the growth of MDA-MB-231 xenografts in mice after 3 weeks of peritoneal injection. In summary, our results suggest that 5j might have therapeutic potential for the treatment of human breast cancer.

A novel aminopeptidase N inhibitor developed by virtual screening approach.

A virtual screening was performed to discover novel lead structures as potent aminopeptidase N(APN) inhibitors. A commercial database containing about 1,60,000 molecules in SPECS was filtered by rule of five, zinc binding groups, pharmacophore models and binding pattern analysis. At last, 24 molecules were selected for enzyme inhibition assay and compound 2 exhibited the inhibition constant (K(i)) of 2.79±0.32 μM against APN compared with Bestatin (K(i)= 3.37±0.24 μM). Our results indicated that compound 2 exhibited good antiproliferative activities against a broad spectrum of human cancer cell lines, and induced cell cycle arrest at G1 phase and eventual apoptosis. Moreover, compound 2 can inhibit the invasion of MDA-MB-231 cells. In summary, our results suggest that compound 2, a potent APN inhibitor, is worthy of further development.