Considerable attention has focused on the health-promoting effects of red wine and its nonflavonoid polyphenol compound resveratrol. However, the underlying molecular mechanisms and molecular target(s) of red wine or other potentially active ingredients in red wine remain unknown. Here, we report that red wine extract (RWE) or the red wine flavonoid quercetin inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced transformation of JB6 promotion-sensitive mouse skin epidermal (JB6 P+) cells. The activation of activator protein-1 and nuclear factor-KB induced by TPA was dose dependently inhibited by RWE or quercetin treatment. Western blot and kinase assay data revealed that RWE or quercetin inhibited mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK) 1 and Raf1 kinase activities and subsequently attenuated TPAinduced phosphorylation of ERK/p90 ribosomal S6 kinase. Although either RWE or quercetin suppressed Raf1 kinase activity, they were more effective in inhibiting MEK1 activity. Importantly, quercetin exerted stronger inhibitory effects than PD098059, a well-known pharmacologic inhibitor of MEK. Resveratrol did not affect either MEK1 or Raf1 kinase activity. Pull-down assays revealed that RWE or quercetin (but not resveratrol) bound with either MEK1 or Raf1. RWE or quercetin also dose dependently suppressed JB6 P+ cell transformation induced by epidermal growth factor or H-Ras, both of which are involved in the activation of MEK/ ERK signaling. Docking data suggested that quercetin, but not resveratrol, formed a hydrogen bond with the backbone amide group of Ser 212 , which is the key interaction for stabilizing the inactive conformation of the activation loop of MEK1. [Cancer Res 2008;68(3):946-55]

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Abstract[6]-Gingerol, a natural component of ginger, exhibits antiinflammatory and antitumorigenic activities. Despite its potential efficacy in cancer, the mechanism by which [6]-gingerol exerts its chemopreventive effects remains elusive. The leukotriene A 4 hydrolase (LTA 4 H) protein is regarded as a relevant target for cancer therapy. Our in silico prediction using a reverse-docking approach revealed that LTA 4 H might be a potential target of

Our previous findings indicated that RSK2 plays a critical role in proliferation and cell transformation induced by tumor promoters, such as epidermal growth factor or 12-O-tetradecanoylphorbol-13-acetate, and that kaempferol, a natural compound found in edible plants, selectively inhibits RSK2 activity. However, the molecular mechanism for RSK2 activation is unclear. Herein, we provide evidence showing that NH 2 -terminal kinase domain (NTD) activation of RSK2 is required for the activation of the extracellular signalregulated kinase-mediated COOH-terminal kinase domain (CTD). We also found that the NTD plays a key role in substrate phosphorylation and that kaempferol binds with the NTD but not the CTD in both the active and inactive forms. Homology modeling of the RSK2 NH 2 -terminal domain and small-molecule docking, validated by mutagenesis experiments, clearly showed that Val 82 and Lys 100 are critical amino acids for kaempferol binding and RSK2 activity. Furthermore, immunohistofluorescence and Western blot results indicated that the RSK2 protein level is markedly higher in cancer cell lines as well as cancer tissues compared with nonmalignant cell lines or normal tissues. In addition, kaempferol inhibited proliferation of malignant human cancer cell lines, including A431, SK-MEL-5 and SK-MEL-28, and HCT-116. These results indicate that targeting RSK2 with natural compounds, such as kaempferol, might be a good strategy for chemopreventive or chemotherapeutic application. [Cancer Res 2009;69(10):4398-406]

The anticancer effects of red wine have attracted considerable attention. Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a well-known polyphenolic compound of red wine with cancer chemopreventive activity. However, the basis for this activity is unclear. We studied leukotriene A4 hydrolase (LTA4H) as a relevant target in pancreatic cancer. LTA4H knockdown limited the formation of leukotriene B4 (LTB4), the enzymatic product of LTA4H, and suppressed anchorage-independent growth of pancreatic cancer cells. An in silico shape similarity algorithm predicted that LTA4H might be a potential target of resveratrol. In support of this idea, we found that resveratrol directly bound to LTA4H in vitro and in cells and suppressed proliferation and anchorage-independent growth of pancreatic cancer by inhibiting LTB4 production and expression of the LTB4 receptor 1 (BLT1). Notably, resveratrol exerted relatively stronger inhibitory effects than bestatin, an established inhibitor of LTA4H activity, and the inhibitory effects of resveratrol were reduced in cells where LTA4H was suppressed by shRNA-mediated knockdown. Importantly, resveratrol inhibited tumor formation in a xenograft mouse model of human pancreatic cancer by inhibiting LTA4H activity. Our findings identify LTA4H as a functionally important target for mediating the anticancer properties of resveratrol.

Computer-aided drug design plays a vital role in drug discovery and development and has become an indispensable tool in the pharmaceutical industry. Computational medicinal chemists can take advantage of all kinds of software and resources in the computer-aided drug design field for the purposes of discovering and optimizing biologically active compounds. This article reviews software and other resources related to computer-aided drug design approaches, putting particular emphasis on structure-based drug design, ligand-based drug design, chemical databases and chemoinformatics tools.

For thousands of years, tea has been the most widely consumed beverage in the world after water. Historically, tea has been credited with various beneficial health effects, including medicinal efficacy in the prevention and treatment of numerous diseases. Thus, longevity and good health have often been associated with the habit of drinking tea (1). Four major polyphenolic catechins are found in green tea and include (Ϫ)-epicatechin (EC), 3 (Ϫ)-epicatechin 3-gallate (ECG), (Ϫ)-epigallocatechin (EGC), and (Ϫ)-epigallocatechin 3-gallate (EGCG). A cup of green tea may contain 100 -200 mg of EGCG (2). Several investigators have reported that green tea exerts cancer preventive activity at a variety of organ sites, including skin, lung, oral cavity, esophagus, stomach, small intestine, colon, pancreas, and mammary gland (1, 3, 4). However, the mechanisms explaining the cancer preventive activity of tea and tea polyphenols are still not clearly understood.The -associated 70-kDa protein (ZAP-70) is a Syk (spleen tyrosine kinase) family tyrosine kinase, which is associated with the subunit of the T cell receptor (TCR). The ZAP-70 protein is primarily expressed in T cells and natural killer cells and plays an essential role in signaling through the T cell antigen receptor (5). The TCRs are associated with tyrosine phosphorylation of multiple proteins resulting in activation of various signaling pathways causing alterations in gene expression, increased T cell proliferation, and secretion of cytokines (6). CD3 (cluster of differentiation 3) stimulation of the T cell antigen receptor plays a role in tyrosine phosphorylation of a number of cellular substrates. An important substrate of ZAP-70 is the TCR chain, which can mediate the transduction of extracellular stimuli into cellular effector functions (7,8). ZAP-70 plays a critical role in cell surface expression of T cell antigen receptor-CD3 complex signaling during the early stages of T cell development and differentiation (9 -13). The ZAP-70 tyrosine kinase is reported to play a critical role in T cell activation and the immune response, and therefore might be a logical target for immunomodulatory therapies (5). Crespo et al. (14) observed that among B cell and T cell lymphoproliferative disorders, a high level of ZAP-70 expression is found in T cell proliferative diseases, acute lymphoblastic leukemia, and a subgroup of chronic lymphocytic leukemia (CLL) (15,16). These * This work was supported, in whole or in part, by National Institutes of Health Grants CA81064, CA77646, CA111536, and CA120388. This work was also supported by The Hormel Foundation. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

NEK6 (NIMA-related kinase 6) is a homologue of the Aspergillus nidulans protein NIMA (never in mitosis, gene A). We demonstrate that overexpression of NEK6 induces anchorageindependent transformation of JB6 Cl41 mouse epidermal cells. Tissue arrays and Western immunoblot analysis show that NEK6 is overexpressed in malignant tissues and several cancer cell lines. Our data also show that NEK6 interacts with STAT3, an oncogenic transcription factor, and phosphorylates STAT3 on Ser 727 , which is important for transcriptional activation. Additional studies using NEK6 mutants suggested that the phosphorylation on both Ser 206 and Thr 210 of NEK6 is critical for STAT3 phosphorylation and anchorage-independent transformation of mouse epidermal cells. Notably, knockdown of NEK6 decreased colony formation and STAT3 Ser 727 phosphorylation. Based on our findings, the most likely mechanism that can account for this biological effect involves the activation of STAT3 through the phosphorylation on Ser 727 . Because of the critical role that STAT3 plays in mediating oncogenesis, the stimulatory effects of NEK6 on STAT3 and cell transformation suggest that this family of serine/threonine kinases might represent a novel chemotherapeutic target.