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.

Discovery of AS-1763: A Potent, Selective, Noncovalent, and Orally Available Inhibitor of Bruton's Tyrosine Kinase.

Although Bruton's tyrosine kinase (BTK) has been recognized as a validated drug target for the treatment of B-cell malignances, the emergence of clinical resistance to the first-generation covalent BTK inhibitors is becoming a serious concern. As a part of our effort to develop noncovalent BTK inhibitors, a series of novel pyrrolopyrimidines was identified as noncovalent inhibitors of both the wild-type and C481S mutant BTKs. Subsequent lead optimization led to the identification of an orally available, potent, and selective BTK inhibitor 13f (AS-1763) as a next-generation noncovalent BTK inhibitor. With significant efficacies in vivo tumor xenograft models, AS-1763 has advanced to phase 1 clinical trials.

[In vivo activity of liposomal amphotericin B against Exophiala dermatitidis in a murine lethal infection model].

This study evaluated the in vivo activity of liposomal amphotericin B (L-AMB) and deoxycholate amphotericin B (D-AMB) in a murine model of disseminated infection caused by Exophiala dermatitidis. Cyclophosphamide-treated neutropenic ddY mice were inoculated intravenously with conidial suspensions of E. dermatitidis IFM 4827 or IFM 53409. The maximum tolerated doses of L-AMB and D-AMB were set at 10 mg/kg and 1 mg/kg, respectively. Four hours after infection, a single dose of L-AMB (0.3 to 10 mg/kg) or D-AMB (0.1 to 1 mg/kg) was administered intravenously. The efficacy of the antifungal treatment was assessed by the survival time over two weeks and the tissue fungal burdens 4 days after infection. L-AMB at a dose of > or =1 mg/kg significantly prolonged the survival time of mice infected with either strain compared with that of the control group. Percent survivals in the 10 mg/kg L-AMB-treated group (100% and 75%) were higher than those in the 1 mg/kg D-AMB-treated group (20% and 37.5%) in the IFM 4827 and IFM 53409 models, respectively. In the IFM 4827 model, 10 mg/kg L-AMB exhibited greater efficacy than 1 mg/kg D-AMB in terms of reducing the tissue fungal burdens (blood, lung, liver, spleen, and kidneys). These findings suggest that L-AMB was effective in the treatment of experimental disseminated E. dermatitidis infection, and the efficacy of L-AMB was superior to that of D-AMB.

Pleuromutilin derivatives having a purine ring. Part 3: synthesis and antibacterial activity of novel compounds possessing a piperazine ring spacer.

SAR studies on the water-soluble thioether pleuromutilin analogue 6, which has excellent in vitro and in vivo antibacterial activities, led to discovery of the novel pleuromutilin derivatives having a piperazine ring spacer. These derivatives displayed potent and well-balanced in vitro antibacterial activity against various drug-susceptible and -resistant Gram-positive bacteria. In particular, the promising pleuromutilin analogues 37 and 40 were found to exhibit strong in vivo efficacy against Staphylococcus aureus Smith.

Pleuromutilin derivatives having a purine ring. Part 2: influence of the central spacer on the antibacterial activity against Gram-positive pathogens.

Structural modification of the 4-piperidinethio moiety, as a spacer of the first pleuromutilin analogues 2A and 2B having a purine ring, led to discovery of the novel pleuromutilin derivatives 14B and 17B. These compounds with good solubility in water showed promising in vitro antibacterial activity against various Gram-positive bacteria including MRSA, PRSP, and VRE and have potent in vivo efficacy.

Water-soluble pleuromutilin derivative with excellent in vitro and in vivo antibacterial activity against gram-positive pathogens.

Although earlier pleuromutilin analogues showed potent in vitro antibacterial activity against some Gram-positive pathogens, their in vivo efficacy was low because of insufficient pharmacokinetic properties. We designed novel thioether pleuromutilin derivatives having a purine ring as a polar and water solubilizing group and identified a promising pleuromutilin analogue 6 with good solubility in water ( approximately 50 mg/mL). Compound 6 exhibited excellent in vitro and in vivo antibacterial activity against some Gram-positive strains, including drug-resistant pathogens.

Pleuromutilin derivatives having a purine ring. Part 1: new compounds with promising antibacterial activity against resistant Gram-positive pathogens.

In the course of our research aimed at the discovery of metabolic stable pleuromutilin derivatives with more potent antibacterial activity against Gram-positive pathogens than previous analogues, a series of compounds bearing a purine ring were prepared and evaluated. From SAR studies, we identified two promising compounds 85 and 87, which have excellent in vitro activity against a number of Gram-positive pathogens, including existing drug-resistant strains, and potent in vivo efficacy.

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.

Synthesis and structure-activity relationships of novel 7-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acids as antitumor agents. Part 2.

We have previously reported that a series of 7-substituted 6-fluoro-1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acids possess moderate cytotoxic activity. In a further attempt to find clinically useful antitumor agents, we investigated the structure-activity relationships (SARs) of a new series of compounds obtained by changing the C-6 position of the fluorine atom in addition to the C-5 and C-7 positions and evaluating their cytotoxic activity against several murine and human tumor cell lines. Our results showed that the 6-unsubstituted 1,8-naphthyridine structure had the most potent cytotoxic activity against murine P388 leukemia twice that of the 6-fluoro analogue. In addition, introduction of an amino group at the C-5 position did not have any substantial effect on the cytotoxic activity, while both the 5-chloro and 5-trifluoromethyl groups decreased the cytotoxic activity by 5- to 10-fold. Moreover, aminopyrrolidine derivatives at the C-7 position showed more potent cytotoxic activity than other amines or carbon derivatives. Among the 7-(3-aminopyrrolidinyl) derivatives, the trans-3-methoxy-4-methylaminopyrrolidinyl derivative (27l) was determined to have potent cytotoxic activity in both in vitro and in vivo assays and high water solubility. Finally, the (S,S)-isomer (AG-7352, 3) of 27l, with a cytotoxic activity against human tumor cell lines more potent than that of etoposide, was selected for further development.

Synthesis and structure-activity relationships of novel 7-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acids as antitumor agents. Part 1.

In an attempt to search for clinically useful antitumor agents, we have discovered that a series of 1,7-disubstituted-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acids possessed moderate cytotoxic activity. We investigated the structure-activity relationships in this series of compounds by changing N-1 and C-7 positions and the core ring structure itself and evaluated the synthesized compounds against several murine and human tumor cell lines. These modifications led us to the following findings. (1) The 2-thiazolyl group at the N-1 position of the naphthyridine structure is the best substituent for antitumor activity. (2) Regarding core ring structure, the naphthyridine derivative is the most active followed by pyridopyrimidine analogue. (3) At the C-7 position, aminopyrrolidine derivatives are more effective than other amines or thioether derivatives. Finally, the trans-3-amino-4-methoxypyrrolidinyl derivative (43j) and the 3-amino-3-methylpyrrolidinyl derivative (43f) as well as 3-aminopyrrolidinyl derivative (AT-3639, 1) were determined to be effective in in vitro and in vivo antitumor assays, and their activity was comparable to that of etoposide.

Voreloxin, formerly SNS-595, has potent activity against a broad panel of cancer cell lines and in vivo tumor models.

PURPOSE: Voreloxin, formerly known as SNS-595 or AG-7352, is a novel naphthyridine analog currently under investigation for the treatment of ovarian and hematologic malignancies. Voreloxin mechanism of action includes DNA intercalation and inhibition of topoisomerase II that causes selective DNA damage. In this study, we describe the anti-proliferative activity of voreloxin in a wide range of in vitro and in vivo models of human cancers. METHODS: The cytotoxicity of voreloxin in vitro was examined by MTT assay in 15 cell lines, including 4 drug-resistant lines. Activation of caspase in cell lines and tumors was evaluated by immunohistochemistry. Anti-tumor activity was assessed in 16 xenograft and 3 syngeneic tumor models in mice. Tumors were allowed to grow to approximately 150 mm(3) prior to treatment with voreloxin or comparator drugs. Activity of the anti-cancer agents was determined by calculating the inhibition rate (IR = [1 - (average tumor weight treated/average tumor weight control)] x 100%) and survival ratio (number surviving mice/number of mice per group at start of study) for each agent and dose and schedule tested. RESULTS: In vitro studies demonstrated voreloxin has broad anti-proliferative activity in 11 tumor cell lines, with IC(50) values ranging from 0.04 to 0.97 muM. Similar activity was observed in vitro in drug-resistant cell lines, including those that overexpress P-glycoprotein and have reduced topoisomerase levels. After a single intravenous dose, voreloxin concentrations in tumor were correlated with induction of the apoptosis marker caspase-3. The optimal dose and schedule was established using a KB nasopharyngeal carcinoma xenograft model. Administration of voreloxin at 20 mg/kg weekly for five doses effectively inhibited tumor growth (86%). Voreloxin demonstrated strong dose-dependent tumor growth inhibition (63-88%) in 10 of 11 solid tumor (breast, ovarian, colon, lung, gastric, and melanoma) xenograft models, 2 hematologic tumor xenograft models, 3 multidrug resistant tumor models and 3 murine syngeneic tumor models (Colon 26, Lewis Lung carcinoma, M5076 Ovarian Sarcoma). CONCLUSIONS: These data demonstrate that voreloxin is a broadly active anti-tumor agent in vitro and in vivo, with potent activity in aggressive and drug-resistant tumor models.

Synthesis and structure-activity relationships of 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines as novel antitumor agents.

In order to obtain clinically useful antitumor agent, we have designed and synthesized various 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines, and evaluated their cytotoxic activity. The series of novel 3-substituted derivatives synthesized in this study showed good antitumor activity against murine P388 leukemia. Particularly, the 3-formyl 1,8-naphthyridine displayed an antitumor activity equal to that of the 3-carboxy 1,8-naphthyridine against murine and human tumor cell lines as well as in vivo test for mouse leukemia. These results demonstrate that the carboxy group at the C-3 position of 1,8-naphthyridine ring is not essential for antitumor activity. In addition, the trend of cytotoxic activity for the 3-substituted 1,8-naphthyridines was different from that of antibacterial activity.