Pharmacological blockage of transforming growth factor-ß signalling by a Traf2- and Nck-interacting kinase inhibitor, NCB-0846.

BACKGROUND: Metastasis is the primary cause of death in cancer patients, and its management is still a major challenge. Epithelial to mesenchymal transition (EMT) has been implicated in the process of cancer metastasis, and its pharmacological interference holds therapeutic promise. METHODS: Traf2- and Nck-interacting kinase (TNIK) functions as a transcriptional coregulator of Wnt target genes. Given the convergence of Wnt and transforming growth factor-ß (TGFß) signalling, we examined the effects of a small-molecule TNIK inhibitor (named NCB-0846) on the TGFß1-induced EMT of lung cancer cells. RESULTS: NCB-0846 inhibited the TGFß1-induced EMT of A549 cells. This inhibition was associated with inhibition of Sma- and Mad-Related Protein-2/3 (SMAD2/3) phosphorylation and nuclear translocation. NCB-0846 abolished the lung metastasis of TGFß1-treated A549 cells injected into the tail veins of immunodeficient mice. The inhibition of EMT was mediated by suppression of the TGFß receptor type-I (TGFBR1) gene, at least partly through the induction of microRNAs targeting the TGFBR1 transcript [miR-320 (a, b and d) and miR-186]. CONCLUSIONS: NCB-0846 pharmacologically blocks the TGFß/SMAD signalling and EMT induction of lung cancer cells by transcriptionally downregulating TGFBRI expression, representing a potentially promising approach for prevention of metastasis in lung cancer patients.

Expression, Functional Characterization, and Preliminary Crystallization of the Cochaperone Prefoldin from the Thermophilic Fungus Chaetomium thermophilum.

Prefoldin is a hexameric molecular chaperone found in the cytosol of archaea and eukaryotes. Its hexameric complex is built from two related classes of subunits, and has the appearance of a jellyfish: Its body consists of a double ß-barrel assembly with six long tentacle-like coiled coils protruding from it. Using the tentacles, prefoldin captures an unfolded protein substrate and transfers it to a group II chaperonin. Based on structural information from archaeal prefoldins, mechanisms of substrate recognition and prefoldin-chaperonin cooperation have been investigated. In contrast, the structure and mechanisms of eukaryotic prefoldins remain unknown. In this study, we succeeded in obtaining recombinant prefoldin from a thermophilic fungus, Chaetomium thermophilum (CtPFD). The recombinant CtPFD could not protect citrate synthase from thermal aggregation. However, CtPFD formed a complex with actin from chicken muscle and tubulin from porcine brain, suggesting substrate specificity. We succeeded in observing the complex formation of CtPFD and the group II chaperonin of C. thermophilum (CtCCT) by atomic force microscopy and electron microscopy. These interaction kinetics were analyzed by surface plasmon resonance using Biacore. Finally, we have shown the transfer of actin from CtPFD to CtCCT. The study of the folding pathway formed by CtPFD and CtCCT should provide important information on mechanisms of the eukaryotic prefoldin⁻chaperonin system.

Discovery of AS-0141, a Potent and Selective Inhibitor of CDC7 Kinase for the Treatment of Solid Cancers.

CDC7, a serine-threonine kinase, plays conserved and important roles in regulation of DNA replication and has been recognized as a potential anticancer target. We report here the optimization of a series of furanone analogues starting from compound 1 with a focus on ADME properties suitable for clinical development. By replacing the 2-chlorobenzene moiety in 1 with various aliphatic groups, we identified compound 24 as a potent CDC7 inhibitor with excellent kinase selectivity and favorable oral bioavailability in multiple species. Oral administration of 24 demonstrated robust in vivo antitumor efficacy in a colorectal cancer xenograft model. Compound 24 (AS-0141) is currently in phase I clinical trials for the treatment of solid cancers.

Direct conversion of osteosarcoma to adipocytes by targeting TNIK.

Osteosarcoma (OS) is an aggressive mesenchymal tumor for which no molecularly targeted therapies are available. We have previously identified TRAF2- and NCK-interacting protein kinase (TNIK) as an essential factor for the transactivation of Wnt signal target genes and shown that its inhibition leads to eradication of colorectal cancer stem cells. The involvement of Wnt signaling in the pathogenesis of OS has been implicated. The aim of the present study was to examine the potential of TNIK as a therapeutic target in OS. RNA interference or pharmacological inhibition of TNIK suppressed the proliferation of OS cells. Transcriptome analysis suggested that a small-molecule inhibitor of TNIK upregulated the expression of genes involved in OS cell metabolism and downregulated transcription factors essential for maintaining the stem cell phenotype. Metabolome analysis revealed that this TNIK inhibitor redirected the metabolic network from carbon flux toward lipid accumulation in OS cells. Using in vitro and in vivo OS models, we confirmed that TNIK inhibition abrogated the OS stem cell phenotype, simultaneously driving conversion of OS cells to adipocyte-like cells through induction of PPARγ. In relation to potential therapeutic targeting in clinical practice, TNIK was confirmed to be in an active state in OS cell lines and clinical specimens. From these findings, we conclude that TNIK is applicable as a potential target for treatment of OS, affecting cell fate determination.

Functional analysis of the honeybee (Apis mellifera L.) salivary system using proteomics.

In insects, specific proteins and physiologically active molecules whose functions are related to their lifestyles are secreted from the salivary system. To investigate proteins/molecules related to the sociality of the European honeybee (Apis mellifera L.), we performed a proteomic analysis of the honeybee salivary system. The honeybee salivary system comprises two secretory glands: the postcerebral gland (PcG) and the thoracic gland (TG), both of which are connected to a common duct that opens in the mouthpart. Although most (31 out of 35) of the major proteins identified from the PcG and TG were housekeeping proteins, the spot intensities for aldolase and acetyl-CoA acyltransferase 2 were stronger in the PcG than in the TG in the 2-dimensional gel electrophoresis. Immunoblotting confirmed that the expression of these proteins was stronger in the PcG than in the TG, whereas expression was almost not detectable in the hypopharyngeal gland (HpG), suggesting that carbohydrate metabolism is enhanced in the honeybee PcG. In addition, imaginal disc growth factor 4 (IDGF4) was synthesized in the honeybee salivary system. Immunoblotting indicated IDGF4 expression was very strong in the PcG, moderate in the TG, and very weak in the HpG. A considerable amount of IDGF4 was detected in the royal jelly, while less was detected in honey, strongly suggesting that the honeybee salivary system secretes IDGF4 into the royal jelly and honey. The secreted IDGF4 might therefore affect growth and physiology of the other colony members.

Feasibility of Targeting Traf2-and-Nck-Interacting Kinase in Synovial Sarcoma.

BACKGROUND: The treatment of patients with metastatic synovial sarcoma is still challenging, and the development of new molecular therapeutics is desirable. Dysregulation of Wnt signaling has been implicated in synovial sarcoma. Traf2-and-Nck-interacting kinase (TNIK) is an essential transcriptional co-regulator of Wnt target genes. We examined the efficacy of a small interfering RNA (siRNA) to TNIK and a small-molecule TNIK inhibitor, NCB-0846, for synovial sarcoma. METHODS: The expression of TNIK was determined in 20 clinical samples of synovial sarcoma. The efficacy of NCB-0846 was evaluated in four synovial sarcoma cell lines and a mouse xenograft model. RESULTS: We found that synovial sarcoma cell lines with Wnt activation were highly dependent upon the expression of TNIK for proliferation and survival. NCB-0846 induced apoptotic cell death in synovial sarcoma cells through blocking of Wnt target genes including MYC, and oral administration of NCB-846 induced regression of xenografts established by inoculation of synovial sarcoma cells. DISCUSSION: It has become evident that activation of Wnt signaling is causatively involved in the pathogenesis of synovial sarcoma, but no molecular therapeutics targeting the pathway have been approved. This study revealed for the first time the therapeutic potential of TNIK inhibition in synovial sarcoma.

A Three-Compartment Pharmacokinetic Model to Predict the Interstitial Concentration of Talaporfin Sodium in the Myocardium for Photodynamic Therapy: A Method Combining Measured Fluorescence and Analysis of the Compartmental Origin of the Fluorescence.

To evaluate the effectiveness of photodynamic therapy occurring in the interstitial space of the myocardium, we estimated the interstitial concentration of talaporfin sodium in the canine myocardium by constructing a three-compartment pharmacokinetic model based on measured changes in talaporfin sodium plasma concentration and myocardial fluorescence. Differential rate equations of talaporfin sodium concentration in the plasma, interstitial space, and cell compartment were developed with individual compartment volume, concentration, and rate constants. Using measured volume ratios based on histological examinations, we defined that the myocardial fluorescence consisted of the linear addition of fluorescence generated from these three compartments. The rate constants were obtained by fitting to minimize the sum of the squared errors between the measured talaporfin sodium concentrations and the calculated concentrations divided by the number of data points using the conjugate gradient method in MATLAB. We confirmed that this fitting operation may be appropriate, because a coefficient of determination between the measured talaporfin sodium changes and the calculated concentrations using our equations was 0.99. Consequently, to estimate the interstitial concentration in the canine myocardium, we propose a three-compartment pharmacokinetic model construction methodology using measured changes in talaporfin sodium plasma concentration and changes in myocardial fluorescence.

Detection of betacyanin in red-tube spinach (Spinacia oleracea) and its biofortification by strategic hydroponics.

Betacyanins have been reported as water-soluble, nitrogenous pigments found in the order Caryophyllales, and they are known for powerful natural antioxidant. The biofortification of secondary metabolites such as anthocyanins and betacyanins has recently been performed in food crops by metabolic engineering through genetic modification. However, the distribution of genetically modified foods is strictly regulated. Therefore, we aimed to develop a new method for biofortifying natural antioxidants, betacyanins, without genetic modification. We first detected the presence of betacyanins in red-tube spinach (Spinacia oleracea) through ultraviolet-visible spectroscopy and mass spectrometry. We then hydroponically cultivated plants in the presence of three candidate compounds for betacyanin biofortification: dopamine, Ca2+, and sucrose. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and antioxidant activity analyses showed that sucrose was most successful in biofortifying betacyanins, and reverse transcription polymerase chain reaction (RT-PCR) indicated that several genes involved in betacyanin biosynthesis were induced by sucrose. Therefore, strategic hydroponics represents a new approach for cultivating betacyanin-enriched vegetables.

Identification of proteins whose expression is up- or down-regulated in the mushroom bodies in the honeybee brain using proteomics.

To identify protein(s) with different expression patterns in the mushroom bodies (MBs) in the honeybee brain, we compared the protein profiles of MBs and optic lobes (OLs) using proteomics. Two-dimensional gel electrophoresis revealed that five and three spots were selectively expressed in the MBs or OLs, respectively. Liquid chromatography tandem mass spectrometry analysis identified juvenile hormone diol kinase and glyceraldehyde-3-phosphate dehydrogenase as MB- and OL-selective proteins, respectively. In situ hybridization revealed that jhdk expression was upregulated in MB neuron subsets, whereas gapdh expression was downregulated, indicating that MBs have a distinct gene and protein expression profile in the honeybee brain.

Discovery of novel furanone derivatives as potent Cdc7 kinase inhibitors.

Cdc7 is a serine-threonine kinase and plays a conserved and important role in DNA replication, and it has been recognized as a potential anticancer target. Herein, we report the design, synthesis and structure-activity relationship of novel furanone derivatives as Cdc7 kinase inhibitors. Compound 13 was identified as a strong inhibitor of Cdc7 with an IC50 value of 0.6 nM in the presence of 1 mM ATP and showed excellent kinase selectivity. In addition, it exhibited slow off-rate characteristics, which may offer advantages over known Cdc7 inhibitors in its potential to yield prolonged inhibitory effects in vivo. Compound 13 potently inhibited Cdc7 activity in cancer cells, and effectively induced cell death.

Asymmetry in the function and dynamics of the cytosolic group II chaperonin CCT/TRiC.

The eukaryotic group II chaperonin, the chaperonin-containing t-complex polypeptide 1 (CCT), plays an important role in cytosolic proteostasis. It has been estimated that as much as 10% of cytosolic proteins interact with CCT during their folding process. CCT is composed of 8 different paralogous subunits. Due to its complicated structure, molecular and biochemical investigations of CCT have been difficult. In this study, we constructed an expression system for CCT from a thermophilic fungus, Chaetomium thermophilum (CtCCT), by using E. coli as a host. As expected, we obtained recombinant CtCCT with a relatively high yield, and it exhibited fairly high thermal stability. We showed the advantages of the overproduction system by characterizing CtCCT variants containing ATPase-deficient subunits. For diffracted X-ray tracking experiment, we removed all surface exposed cysteine residues, and added cysteine residues at the tip of helical protrusions of selected two subunits. Gold nanocrystals were attached onto CtCCTs via gold-thiol bonds and applied for the analysis by diffracted X-ray tracking. Irrespective of the locations of cysteines, it was shown that ATP binding induces tilting motion followed by rotational motion in the CtCCT molecule, like the archaeal group II chaperonins. When gold nanocrystals were attached onto two subunits in the high ATPase activity hemisphere, the CtCCT complex exhibited a fairly rapid response to the motion. In contrast, the response of CtCCT, which had gold nanocrystals attached to the low-activity hemisphere, was slow. These results clearly support the possibility that ATP-dependent conformational change starts with the high-affinity hemisphere and progresses to the low-affinity hemisphere.

TNIK inhibition abrogates colorectal cancer stemness.

Canonical Wnt/ß-catenin signalling is essential for maintaining intestinal stem cells, and its constitutive activation has been implicated in colorectal carcinogenesis. We and others have previously identified Traf2- and Nck-interacting kinase (TNIK) as an essential regulatory component of the T-cell factor-4 and ß-catenin transcriptional complex. Consistent with this, Tnik-deficient mice are resistant to azoxymethane-induced colon tumorigenesis, and Tnik(-/-)/Apc(min/+) mutant mice develop significantly fewer intestinal tumours. Here we report the first orally available small-molecule TNIK inhibitor, NCB-0846, having anti-Wnt activity. X-ray co-crystal structure analysis reveals that NCB-0846 binds to TNIK in an inactive conformation, and this binding mode seems to be essential for Wnt inhibition. NCB-0846 suppresses Wnt-driven intestinal tumorigenesis in Apc(min/+) mice and the sphere- and tumour-forming activities of colorectal cancer cells. TNIK is required for the tumour-initiating function of colorectal cancer stem cells. Its inhibition is a promising therapeutic approach.