Induction of estrogen receptor ß-mediated autophagy sensitizes breast cancer cells to TAD1822-7, a novel biphenyl urea taspine derivative.

BACKGROUND: Female breast cancer has become the most commonly diagnosed cancer worldwide. As a tumor suppressor, estrogen receptor ß (ERß) can be potentially targeted for breast cancer therapy. METHODS AND RESULTS: TAD1822-7 was evaluated for ERß-mediated autophagy and cell death using cell proliferation assay, Annexin V/PI staining, immunofluorescence, western blotting, ERß siRNA, ERß plasmid transfection and hypoxia cell models. TAD1822-7 upregulated ERß causing cell death and induced mitochondrial dysfunction and autophagy companied with mitochondrial located ERß. Enhanced levels of microtubule associated protein1 light chain 3 (LC3)-II and p62/SQSTM1 (p62) indicated that TAD1822-7 blocked the late-stage autolysosome formation, leading to cell death. Mechanistically, TAD1822-7-induced cell death was mediated by phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathways. Moreover, TAD1822-7 modulated hypoxia inducible factor (HIF) functions and autophagy via the inhibition of HIF-1ß in the context of hypoxia-induced autophagy. ERß overexpression and ERß agonist showed similar effects, whereas ERß siRNA abrogated TAD1822-7-induced cell death, the inhibition of PI3K/AKT pathway and autophagy. The involvement of PI3K/AKT pathway and autophagy was also demonstrated in TAD1822-7-treated hypoxic breast cancer cells. CONCLUSIONS: These findings provide new insight into the mechanism underlying the inhibitory effects of TAD1822-7 via ERß-mediated pathways in breast cancer cells.

Molecular basis of human ATM kinase inhibition.

Human checkpoint kinase ataxia telangiectasia-mutated (ATM) plays a key role in initiation of the DNA damage response following DNA double-strand breaks. ATM inhibition is a promising approach in cancer therapy, but, so far, detailed insights into the binding modes of known ATM inhibitors have been hampered due to the lack of high-resolution ATM structures. Using cryo-EM, we have determined the structure of human ATM to an overall resolution sufficient to build a near-complete atomic model and identify two hitherto unknown zinc-binding motifs. We determined the structure of the kinase domain bound to ATPγS and to the ATM inhibitors KU-55933 and M4076 at 2.8 Å, 2.8 Å and 3.0 Å resolution, respectively. The mode of action and selectivity of the ATM inhibitors can be explained by structural comparison and provide a framework for structure-based drug design.

Cytotoxicity, metabolism, and isozyme mapping of the synthetic cannabinoids JWH-200, A-796260, and 5F-EMB-PINACA studied by means of in vitro systems.

Intake of synthetic cannabinoids (SC), one of the largest classes of new psychoactive substances, was reported to be associated with acute liver damage but information about their hepatotoxic potential is limited. The current study aimed to analyze the hepatotoxicity including the metabolism-related impact of JWH-200, A-796260, and 5F-EMB-PINACA in HepG2 cells allowing a tentative assessment of different SC subclasses. A formerly adopted high-content screening assay (HCSA) was optimized using a fully automated epifluorescence microscope. Metabolism-mediated effects in the HCSA were additionally investigated using the broad CYP inhibitor 1-aminobenzotriazole. Furthermore, phase I metabolites and isozymes involved were identified by in vitro assays and liquid chromatography-high-resolution tandem mass spectrometry. A strong cytotoxic potential was observed for the naphthoylindole SC JWH-200 and the tetramethylcyclopropanoylindole compound A-796260, whereas the indazole carboxamide SC 5F-EMB-PINACA showed moderate effects. Numerous metabolites, which can serve as analytical targets in urine screening procedures, were identified in pooled human liver microsomes. Most abundant metabolites of JWH-200 were formed by N-dealkylation, oxidative morpholine cleavage, and oxidative morpholine opening. In case of A-796260, most abundant metabolites included an oxidative morpholine cleavage, oxidative morpholine opening, hydroxylation, and dihydroxylation followed by dehydrogenation. Most abundant 5F-EMB-PINACA metabolites were generated by ester hydrolysis plus additional steps such as oxidative defluorination and hydroxylation. To conclude, the data showed that a hepatotoxicity of the investigated SC cannot be excluded, that metabolism seems to play a minor role in the observed effects, and that the extensive phase I metabolism is mediated by several isozymes making interaction unlikely.

Neuroimaging, Urinary, and Plasma Biomarkers of Treatment Response in Huntington's Disease: Preclinical Evidence with the p75NTR Ligand LM11A-31.

Huntington's disease (HD) is caused by an expansion of the CAG repeat in the huntingtin gene leading to preferential neurodegeneration of the striatum. Disease-modifying treatments are not yet available to HD patients and their development would be facilitated by translatable pharmacodynamic biomarkers. Multi-modal magnetic resonance imaging (MRI) and plasma cytokines have been suggested as disease onset/progression biomarkers, but their ability to detect treatment efficacy is understudied. This study used the R6/2 mouse model of HD to assess if structural neuroimaging and biofluid assays can detect treatment response using as a prototype the small molecule p75NTR ligand LM11A-31, shown previously to reduce HD phenotypes in these mice. LM11A-31 alleviated volume reductions in multiple brain regions, including striatum, of vehicle-treated R6/2 mice relative to wild-types (WTs), as assessed with in vivo MRI. LM11A-31 also normalized changes in diffusion tensor imaging (DTI) metrics and diminished increases in certain plasma cytokine levels, including tumor necrosis factor-alpha and interleukin-6, in R6/2 mice. Finally, R6/2-vehicle mice had increased urinary levels of the p75NTR extracellular domain (ecd), a cleavage product released with pro-apoptotic ligand binding that detects the progression of other neurodegenerative diseases; LM11A-31 reduced this increase. These results are the first to show that urinary p75NTR-ecd levels are elevated in an HD mouse model and can be used to detect therapeutic effects. These data also indicate that multi-modal MRI and plasma cytokine levels may be effective pharmacodynamic biomarkers and that using combinations of these markers would be a viable and powerful option for clinical trials.

Anti-NSCLC activity in vitro of Hsp90N inhibitor KW-2478 and complex crystal structure determination of Hsp90N-KW-2478.

KW-2478 is a promising anti-cancer lead compound targeting to the molecular chaperone heat shock protein 90 N (Hsp90N). Absence of complex crystal structure of Hsp90N-KW-2478, however, hampered further structure optimization of KW-2478 and understanding on the molecular interaction mechanism. Herein, a high-resolution complex crystal structure of Hsp90N-KW-2478 was determined by X-ray diffraction (XRD, resolution limit: 1.59 Å; PDB ID: 6LT8) and their molecular interaction was analyzed in detail, which suggested that KW-2478 perfectly bound in the N-terminal ATP-binding pocket of Hsp90 to disable its molecular chaperone function, therefore suppressed or killed cancer cells. The results from thermal shift assay (TSA, ΔTm, 18.82 ± 0.51 °C) and isothermal titration calorimetry (ITC, Kd, 7.30 ± 2.20 nM) suggested that there is an intense binding force and favorable thermodynamic changes during the process of KW-2478 binding with Hsp90N. Additionally, KW-2478 exhibited favorable anti-NSCLC activity in vitro, as it inhibited cell proliferation (IC50, 8.16 µM for A549; 14.29 µM for H1975) and migration, induced cell cycle arrest and promoted apoptosis. Thirty-six novel KW-2478 derivatives were designed, based on the complex crystal structure and molecular interaction analysis of Hsp90N-KW-2478 complex. Among them, twenty-two derivatives exhibited increased binding force with Hsp90N evaluated by molecular docking assay. The results would provide new guidance for anti-NSCLC new drug development based on the lead compound KW-2478.

Adaptive resistance to PI3Kα-selective inhibitor CYH33 is mediated by genomic and transcriptomic alterations in ESCC cells.

Phosphoinositide-3 kinase alpha-specific inhibitors (PI3Kαi) displayed promising potential for the treatment of esophageal squamous cell carcinoma (ESCC) with frequent activation in PI3K signaling. However, acquired resistance is likely to develop and limit the efficacy of PI3Kαi like other targeted therapies. To identify genomic adaptation to PI3Kαi, we applied whole-genome sequencing and detected gene mutation and amplification in four lines of ESCC cells established with adapted resistance to a novel PI3Kαi CYH33. Particularly, HRASG12S mutation was found in KYSE180C cells. Overexpression of HRASG12S in ESCC parental cells rendered resistance to CYH33. By contrast, down-regulation of HRASG12S restored the sensitivity of KYSE180C1 cells to CYH33, and combination of CYH33 and MEK162 displayed synergistic effect against KYSE180C1 cells and xenografts. Furthermore, elevated mTORC1, mitogen-activated protein kinase (MAPK), and c-Myc signaling pathways were found in resistant cells by RNA sequencing and combination of CYH33 and RAD001, MEK162, or OTX015 overcame the resistance to CYH33, which was accompanied with enhanced inhibition on S6, extracellular signal-regulated kinase 1 (ERK), or c-Myc, respectively. Overall, we characterized the adaptations to PI3Kαi in ESCC cells and identified combinatorial regimens that may circumvent resistance.

4-(Difluoromethyl)-5-(4-((3R,5S)-3,5-dimethylmorpholino)-6-((R)-3-methylmorpholino)-1,3,5-triazin-2-yl)pyridin-2-amine (PQR626), a Potent, Orally Available, and Brain-Penetrant mTOR Inhibitor for the Treatment of Neurological Disorders.

The mechanistic target of rapamycin (mTOR) pathway is hyperactivated in cancer and neurological disorders. Rapalogs and mTOR kinase inhibitors (TORKi) have recently been applied to alleviate epileptic seizures in tuberous sclerosis complex (TSC). Herein, we describe a pharmacophore exploration to identify a highly potent, selective, brain penetrant TORKi. An extensive investigation of the morpholine ring engaging the mTOR solvent exposed region led to the discovery of PQR626 (8). 8 displayed excellent brain penetration and was well-tolerated in mice. In mice with a conditionally inactivated Tsc1 gene in glia, 8 significantly reduced the loss of Tsc1-induced mortality at 50 mg/kg p.o. twice a day. 8 overcomes the metabolic liabilities of PQR620 (52), the first-in-class brain penetrant TORKi showing efficacy in a TSC mouse model. The improved stability in human hepatocytes, excellent brain penetration, and efficacy in Tsc1GFAPCKO mice qualify 8 as a potential therapeutic candidate for the treatment of neurological disorders.

Development of a Highly Specific Anti-drug Antibody Assay in Support of a Nanoparticle-based Therapeutic.

PEGylated biotherapeutics can elicit anti-PEG (polyethylene glycol) immune responses in patients treated with this category of drugs. While anti-PEG antibody assays for this class of biotherapeutics have become a common element of the clinical immunogenicity testing strategy, the overall antibody incidence induced by the nanoparticle (NP) delivery system (such as ACCURINS®) has not been fully studied to date. To support the immunogenicity assessment of one of Pfizer's NP-based therapeutics, consisting of gedatolisib (GEDA) encapsulated in ACCURINS® (GEDA-NP), we developed an anti-GEDA-NP antibody (ADA) assay on the MSD platform for the detection of GEDA-NP induced ADA in human serum. The focus of our strategy was on developing a clinically relevant ADA assay and systematically addressing assay interference through rigorous assay optimization. Our efforts led to a fit-for-purpose assay for the detection of anti-GEDA-NP ADA in serum samples obtained from breast cancer patients. Results from method qualification indicated robust assay performance, as highlighted by inter and intra-assay precision within 25% CV for all controls, and reproducible response profiles across multiple runs during the assessment of assay cut points with breast cancer samples. The assay sensitivity was between 4.3 ng/mL and 123 ng/mL for surrogate positive controls of IgG and IgM isotypes, respectively. Additionally, assay interference from nonspecific matrix proteins and circulating drug was addressed, which ensured accurate assessment of ADA incidence that can be attributed to GEDA-NP.

Synthesis and exploration of 2-morpholino-4-phenylthiazol-5-yl acrylamide derivatives for their effects against carbonic anhydrase I, II, IX and XII isoforms as a non-sulfonamide class of inhibitors.

Novel series of 2-morpholino-4-phenylthiazol-5-yl acrylamide derivatives (8a-s) have been synthesized and explored as a non-sulfonamide class of carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The newly synthesized molecules were evaluated for their CA inhibitory potency against four isoforms: the cytosolic isozyme hCA I, II as well as trans-membrane tumor associated isoform hCA IX and hCA XII taking acetazolamide (AAZ) as standard drug. The results revealed that most of the compounds showed good activity against hCA II, IX, and XII whereas none of them were active against hCA I (Ki >100 µM). It is observed that the physiologically most important cytosolic isoform hCA II was inhibited by these molecules in the range of Ki 9.3-77.7 µM. It is also found the both the transmembrane isoforms hCA IX and XII were also inhibited with Kis ranging between 54.7-96.7 µM and 4.6-8.8 µM, respectively. The binding modes of the active compounds within the catalytic pockets of hCA II, IX and XII were evaluated by docking studies. This new non-sulfonamide class of selective inhibitors of hCA II, IX and XII over the hCA I isoform may be used for further understanding the physiological roles of some of these isoforms in various pathologies.

(S)-4-(Difluoromethyl)-5-(4-(3-methylmorpholino)-6-morpholino-1,3,5-triazin-2-yl)pyridin-2-amine (PQR530), a Potent, Orally Bioavailable, and Brain-Penetrable Dual Inhibitor of Class I PI3K and mTOR Kinase.

The phosphoinositide 3-kinase (PI3K)/mechanistic target of rapamycin (mTOR) pathway is frequently overactivated in cancer, and drives cell growth, proliferation, survival, and metastasis. Here, we report a structure-activity relationship study, which led to the discovery of a drug-like adenosine 5'-triphosphate-site PI3K/mTOR kinase inhibitor: (S)-4-(difluoromethyl)-5-(4-(3-methylmorpholino)-6-morpholino-1,3,5-triazin-2-yl)pyridin-2-amine (PQR530, compound 6), which qualifies as a clinical candidate due to its potency and specificity for PI3K and mTOR kinases, and its pharmacokinetic properties, including brain penetration. Compound 6 showed excellent selectivity over a wide panel of kinases and an excellent selectivity against unrelated receptor enzymes and ion channels. Moreover, compound 6 prevented cell growth in a cancer cell line panel. The preclinical in vivo characterization of compound 6 in an OVCAR-3 xenograft model demonstrated good oral bioavailability, excellent brain penetration, and efficacy. Initial toxicity studies in rats and dogs qualify 6 for further development as a therapeutic agent in oncology.

CoMFA, CoMSIA, Topomer CoMFA, HQSAR, molecular docking and molecular dynamics simulations study of triazine morpholino derivatives as mTOR inhibitors for the treatment of breast cancer.

mTOR has become a promising target for many types of cancer like breast, lung and renal cell carcinoma. CoMFA, CoMSIA, Topomer CoMFA and HQSAR were performed on the series of 39 triazine morpholino derivatives. CoMFA analysis showed q2 value of 0.735, r2cv value of 0.722 and r2pred value of 0.769. CoMSIA analysis (SEHD) showed q2 value of 0.761, r2cv value of 0.775 and r2pred value of 0.651. Topomer CoMFA analysis showed q2 value of 0.693, r2 (conventional correlation coefficient) value of 0.940 and r2pred value of 0.720. HQSAR analysis showed q2,r2and r2pred values of 0.694, 0.920 and 0.750, respectively. HQSAR analysis with the combination of atomic number (A), bond type (B) and atomic connections showed q2 and r2 values of 0.655 and 0.891, respectively. Contour maps from all studies provided significant insights. Molecular docking studies with molecular dynamics simulations were carried out on the highly potent compound 36. Furthermore, four acridine derivatives were designed and docking results of these designed compounds showed the same interactions as that of the standard PI-103 which proved the efficiency of 3D-QSAR and MD/MS study. In future, this study might be useful prior to synthesis for the designing of novel mTOR inhibitors.

KHC-4 inhibits ß-catenin expression in prostate cancer cells.

KHC-4 is a 2-phenyl-4-quinolone analogue that exhibits anticancer activity. Aberrant activation of ß-catenin signaling contributes to prostate cancer development and progression. Therefore, targeting ß-catenin expression could be a useful approach to treating prostate cancer. We found that KHC-4 can inhibit ß-catenin expression and its signaling pathway in DU145 prostate cancer cells. Treatment with KHC-4 decreased total ß-catenin expression and concomitantly decreased ß-catenin levels in both the cytoplasm and nucleus of cells. KHC-4 treatment also inhibited ß-catenin expression and that of its target proteins, PI3K, AKT, GSK3ß and TBX3. We monitored the stability of ß-catenin with the proteasomal inhibitor, MG132, in DU145 cells and found that MG132 reversed KHC-4-induced proteasomal ß-catenin degradation. We verified CDK1/ß-catenin expression in KHC-4 treated DU145 cells. We found that roscovitine treatment reversed cell proliferation by arresting the cell cycle at the G2/M phase and ß-catenin expression caused by KHC-4 treatment. We suggest that KHC-4 inhibits ß-catenin signaling in DU145 prostate cancer cells.

Buparlisib is a novel inhibitor of daunorubicin reduction mediated by aldo-keto reductase 1C3.

Buparlisib is a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor and is currently under clinical evaluation for the treatment of different cancers. Because PI3K signalling is related to cell proliferation and resistance to chemotherapy, new therapeutic approaches are focused on combining PI3K inhibitors with other anti-cancer therapeutics. Carbonyl-reducing enzymes catalyse metabolic detoxification of anthracyclines and reduce their cytotoxicity. In the present work, the effects of buparlisib were tested on six human recombinant carbonyl-reducing enzymes: AKR1A1, AKR1B1, AKR1B10, AKR1C3, and AKR7A2 from the aldo-keto reductase superfamily and CBR1 from the short-chain dehydrogenase/reductase superfamily, all of which participate in the metabolism of daunorubicin. Buparlisib exhibited the strongest inhibitory effect on recombinant AKR1C3, with a half-maximal inhibitory concentration (IC50) of 9.5 µM. Its inhibition constant Ki was found to be 14.0 µM, and the inhibition data best fitted a mixed-type mode with α = 0.6. The same extent of inhibition was observed at the cellular level in the human colorectal carcinoma HCT 116 cell line transfected with a plasmid encoding the AKR1C3 transcript (IC50 = 7.9 µM). Furthermore, we performed an analysis of flexible docking between buparlisib and AKR1C3 and found that buparlisib probably occupies a part of the binding site for a cofactor most likely via the trifluoromethyl group of buparlisib interacting with catalytic residue Tyr55. In conclusion, our results show a novel PI3K-independent effect of buparlisib that may improve therapeutic efficacy and safety of daunorubicin by preventing its metabolism by AKR1C3.

Regulating ferroportin-1 and transferrin receptor-1 expression: A novel function of hydrogen sulfide.

Hydrogen sulfide (H2 S) has a significant effect on the regulation of interleukin-6 (IL-6) and signal transducer and activator of transcription 3 (STAT3) activities, while IL-6 directly regulates hepcidin expression via STAT3. We therefore hypothesized that H 2 S has a role in body iron homeostasis by regulating the expression of iron transport proteins via the IL-6/STAT3/Hepcidin pathway. Here, we investigated the effects of two H 2 S donors sodium hydrosulfide and GYY4137 on the expression of ferroportin-1 (Fpn1), transferrin receptor-1 (TfR1), hepcidin, IL-6 and pSTAT3 in the spleen of mice in vivo and peritoneal macrophage in vitro. We also examined the effects of H 2 S on serum iron, transferrin saturation, and ferritin light chain contents in the spleen, and on nitrite content, nuclear factor erythroid 2-related factor-2 (Nrf2) and iron regulatory protein 1 (IRP1) in the macrophages. We demonstrated that H 2 S regulates the expression of TfR1 and Fpn1 in the spleen in vivo and in peritoneal macrophages in vitro predominantly via the IL-6/pSTAT3/hepcidin pathway, under the conditions of inflammation induced by lipopolysaccharides. We also provide evidence that under uninflamed conditions, the regulation of Fpn1 and TfR1 expression by H 2 S, both in vivo and in vitro, are mediated by the nitric oxide (NO)/Nrf2 and iron regulatory protein/iron responsive element pathways, respectively, which are independent of IL-6/pSTAT3/hepcidin signals. These findings show that H 2 S is a key player in iron homeostasis under not only the inflamed conditions but also uninflamed conditions.

Intranasal Surface-Modified Mosapride Citrate-Loaded Nanostructured Lipid Carriers (MOS-SMNLCs) for Treatment of Reflux Diseases: In vitro Optimization, Pharmacodynamics, and Pharmacokinetic Studies.

Gastroesophageal reflux disease (GERD) is an esophageal injury occurred when the stomach contents reflux abnormally into the esophagus. GERD complications include esophageal adenocarcinoma. Mosapride (MOS) is a safe prokinetic agent potentially used to treat GERD. Yet, its low solubility and bioavailability due to extensive first-pass metabolism limits its applications. This study aimed to formulate MOS nanostructured lipid carriers (MOS-NLCs) via the intranasal route to improve its bioavailability. Melt-emulsification low temperature-solidification technique using 23 full factorial design was adopted to formulate MOS-NLCs. Eight formulae were prepared and assessed in terms of entrapment efficiency (%EE), particle size, and in vitro release. Glycerol addition significantly reduced the particle sizes and improved %EE and %drug released. Surface modification using chitosan was applied. The optimized MOS surface-modified nanostructured lipid carriers (MOS-SMNLCs-F7)(stearic acid, 4% glycerol, 0.5% LuterolF127, 0.5% chitosan) showed low particle size 413.8 nm ± 11.46 nm and high %EE 90.19% ± 0.06% and a threefold increase in permeation of MOS with respect to the drug suspension. MOS-SMNLCs (F7) was also evaluated for its bioavailability compared with drug suspension and commercial product. Statistical analysis revealed a significant increase in gastric emptying rate to be 21.54 ± 1.88 contractions/min compared with10.02 ± 0.62 contractions/min and 8.9 ± 0.72 contractions/min for drug suspension and oral marketed product respectively. Pharmacokinetic studies showed 2.44-fold rise in bioavailability as compared to MOS suspension and 4.54-fold as compared to the oral marketed product. In vitro/in vivo studies proven to level A correlation between in vitro permeation through sheep nasal mucosa and in vivo absorption. Therefore, MOS-SMNLCs could be considered a step forward towards enhancing the clinical efficacy of Mosapride.

Activation of the Gi protein-RHOA axis by non-canonical Hedgehog signaling is independent of primary cilia.

Primary cilia are solitary organelles that emanate from the plasma membrane during growth arrest in almost all mammalian cells. The canonical Hedgehog (HH) pathway requires trafficking of the G protein-coupled receptor SMOOTHENED (SMO) and the GLI transcription factors to the primary cilium upon binding of a HH ligand to PATCHED1. However, it is unknown if activation of the small GTPase RHOA by SMO coupling to heterotrimeric Gi proteins, a form of non-canonical HH signaling, requires localization of SMO in the primary cilium. In this study, we compared RHOA and Gi protein stimulation by activation of SMO or sphingosine 1-phosphate receptor (S1P) receptors in WT and KIF3A-deficient mouse embryonic fibroblasts that lack primary cilia. We found that activation of SMO in response to Sonic HH (SHH) or purmorphamine (PUR), a small molecule agonist of SMO, stimulates Gi proteins and RHOA independently of the presence of primary cilia, similar to the effects of S1P. However, while S1P induced a fast activation of AKT that is sensitive to the Gi inhibitor pertussis toxin, HH pathway activators did not significantly activate AKT, suggesting that RHOA activation is not downstream of AKT. Our findings demonstrate that early events in some forms of non-canonical HH signaling occur in extraciliary membranes, which might be particularly relevant for actively-cycling cells, for some cancers characterized by loss of primary cilia, and in ciliopathies.

Exenatide ameliorates hepatic steatosis and attenuates fat mass and FTO gene expression through PI3K signaling pathway in nonalcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a common disease associated with metabolic syndrome and can lead to life-threatening complications like hepatic carcinoma and cirrhosis. Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist antidiabetic drug, has the capacity to overcome insulin resistance and attenuate hepatic steatosis but the specific underlying mechanism is unclear. This study was designed to investigate the underlying molecular mechanisms of exenatide therapy on NAFLD. We used in vivo and in vitro techniques to investigate the protective effects of exenatide on fatty liver via fat mass and obesity associated gene (FTO) in a high-fat (HF) diet-induced NAFLD animal model and related cell culture model. Exenatide significantly decreased body weight, serum glucose, insulin, insulin resistance, serum free fatty acid, triglyceride, total cholesterol, low-density lipoprotein, aspartate aminotransferase, and alanine aminotransferase levels in HF-induced obese rabbits. Histological analysis showed that exenatide significantly reversed HF-induced lipid accumulation and inflammatory changes accompanied by decreased FTO mRNA and protein expression, which were abrogated by PI3K inhibitor LY294002. This study indicated that pharmacological interventions with GLP-1 may represent a promising therapeutic strategy for NAFLD.

Discovery of Novel Dual Mechanism of Action Src Signaling and Tubulin Polymerization Inhibitors (KX2-391 and KX2-361).

The discovery of potent, peptide site directed, tyrosine kinase inhibitors has remained an elusive goal. Herein we describe the discovery of two such clinical candidates that inhibit the tyrosine kinase Src. Compound 1 is a phase 3 clinical trial candidate that is likely to provide a first in class topical treatment for actinic keratosis (AK) with good efficacy and dramatically less toxicity compared to existing standard therapy. Compound 2 is a phase 1 clinical trial candidate that is likely to provide a first in class treatment of malignant glioblastoma and induces 30% long-term complete tumor remission in animal models. The discovery strategy for these compounds iteratively utilized molecular modeling, along with the synthesis and testing of increasingly elaborated proof of concept compounds, until the final clinical candidates were arrived at. This was followed with mechanism of action (MOA) studies that revealed tubulin polymerization inhibition as the second MOA.

Identification of the First Diketomorpholine Biosynthetic Pathway Using FAC-MS Technology.

Filamentous fungi are prolific producers of secondary metabolites with drug-like properties, and their genome sequences have revealed an untapped wealth of potential therapeutic leads. To better access these secondary metabolites and characterize their biosynthetic gene clusters, we applied a new platform for screening and heterologous expression of intact gene clusters that uses fungal artificial chromosomes and metabolomic scoring (FAC-MS). We leverage FAC-MS technology to identify the biosynthetic machinery responsible for production of acu-dioxomorpholine, a metabolite produced by the fungus, Aspergilllus aculeatus. The acu-dioxomorpholine nonribosomal peptide synthetase features a new type of condensation domain (designated CR) proposed to use a noncanonical arginine active site for ester bond formation. Using stable isotope labeling and MS, we determine that a phenyllactate monomer deriving from phenylalanine is incorporated into the diketomorpholine scaffold. Acu-dioxomorpholine is highly related to orphan inhibitors of P-glycoprotein targets in multidrug-resistant cancers, and identification of the biosynthetic pathway for this compound class enables genome mining for additional derivatives.

Probing cytochrome P450 bioactivation and fluorescent properties with morpholinyl-tethered anthraquinones.

Structural features from the anticancer prodrug nemorubicin (MMDX) and the DNA-binding molecule DRAQ5™ were used to prepare anthraquinone-based compounds, which were assessed for their potential to interrogate cytochrome P450 (CYP) functional activity and localisation. 1,4-disubstituted anthraquinone 8 was shown to be 5-fold more potent in EJ138 bladder cancer cells after CYP1A2 bioactivation. In contrast, 1,5-bis((2-morpholinoethyl)amino) substituted anthraquinone 10 was not CYP-bioactivated but was shown to be fluorescent and subsequently photo-activated by a light pulse (at a bandwidth 532-587 nm), resulting in punctuated foci accumulation in the cytoplasm. It also showed low toxicity in human osteosarcoma cells. These combined properties provide an interesting prospective approach for opto-tagging single or a sub-population of cells and seeking their location without the need for continuous monitoring.