JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Interim FDG PET/CT for predicting the outcome in patients with head and neck cancer.
Laryngoscope
PUBLISHED: 04-22-2014
Show Abstract
Hide Abstract
The study aimed to investigate the prognostic effects of interim (18) fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (PET/CT) during definitive radiotherapy (RT) or chemoradiotherapy (CRT) in patients with head and neck cancer.
Related JoVE Video
Discovery of SCH 900188: A Potent Hepatitis C Virus NS5B Polymerase Inhibitor Prodrug As a Development Candidate.
ACS Med Chem Lett
PUBLISHED: 03-13-2014
Show Abstract
Hide Abstract
Starting from indole-based hepatitis C virus (HCV) NS5B polymerase inhibitor lead compound 1, structure modifications were performed at multiple indole substituents to improve potency and pharmacokinetic (PK) properties. Bicyclic quinazolinone was found to be the best substituent at indole nitrogen, while 4,5-furanylindole was identified as the best core. Compound 11 demonstrated excellent potency. Its C2 N,N-dimethylaminoethyl ester prodrug 12 (SCH 900188) demonstrated significant improvement in PK and was selected as the development candidate.
Related JoVE Video
Sinugyrosanolide A, an unprecedented C-4 norcembranoid, from the Formosan soft coral Sinularia gyrosa.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-22-2014
Show Abstract
Hide Abstract
Chemical investigations on the acetone extract of the Formosan soft coral Sinularia gyrosa have obtained a novel C-4 norcembranoid possessing an unprecedented tricyclo[9.3.0.0(3,8)]tetradecane skeleton, namely sinugyrosanolide A. The NMR spectroscopic data of the novel norcembranoid were completely assigned by using a combination of 2D NMR experiments including (1)H-(1)H COSY, HSQC, HMBC, and NOESY. The cytotoxicities, anti-HCMV (human cytomegalovirus) endonuclease activities and antibacterial activities were evaluated in vitro. It showed moderate cytotoxicity against P-388 (mouse lymphocytic leukemia) cancer cell line with an EC50 of 11.8?M.
Related JoVE Video
Downregulation of a putative tumor suppressor BMP4 by SOX2 promotes growth of lung squamous cell carcinoma.
Int. J. Cancer
PUBLISHED: 01-13-2014
Show Abstract
Hide Abstract
SOX2 is a transcription factor essential for self-renewal and pluripotency of embryonic stem cells. Recently, SOX2 was found overexpressed in the majority of the lung squamous cell carcinoma (SQC), in which it acts as a lineage-survival oncogene. However, downstream targets/pathways of SOX2 in lung SQC cells remain to be identified. Here, we show that BMP4 is a downstream target of SOX2 in lung SQC. We found that SOX2-silencing-mediated inhibition of cell growth was accompanied by upregulation of BMP4 mRNA and its protein expression. Meta-analysis with 293 samples and qRT-PCR validation with 73 clinical samples revealed an inversely correlated relationship between levels of SOX2 and BMP4 mRNA, and significantly lower mRNA levels in tumor than in adjacent normal tissues. This was corroborated by immunohistochemistry analysis of 35 lung SQC samples showing lower BMP4 protein expression in tumor tissues. Cell-based experiments including siRNA transfection, growth assay and flow cytometry assay, further combined with a xenograft tumor model in mice, revealed that reactivation of BMP4 signaling could partially account for growth inhibition and cell cycle arrest in lung SQC cells upon silencing SOX2. Finally, chromatin immunoprecipitation analysis and luciferase reporter assay revealed that SOX2 could negatively regulate BMP4 promoter activity, possibly through binding to the promoter located in the first intron region of BMP4. Collectively, our findings suggest that BMP4 could act as a tumor suppressor and its downregulation by elevated SOX2 resulting in enhanced growth of lung SQC cells.
Related JoVE Video
IV. Discovery of CXCR3 antagonists substituted with heterocycles as amide surrogates: improved PK, hERG and metabolic profiles.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-03-2014
Show Abstract
Hide Abstract
The structure-human CXCR3 binding affinity relationship of a series of pyridyl/pyrazinyl-piperazinyl-piperidine derivatives were explored with a focus to improve PK, hERG and metabolic profiles. Several small heterocycles were identified as amide surrogates, which minimized many potential metabolite issues. During the course of SAR development, we have observed the additive effect of desirable functional groups to improve hERG and PK profiles which lead to the discovery of many clinically developable CXCR3 antagonists with excellent overall profile.
Related JoVE Video
Impact of body-mass factors on setup displacement in patients with head and neck cancer treated with radiotherapy using daily on-line image guidance.
Radiat Oncol
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
To determine the impact of body-mass factors (BMF) before radiotherapy and changes during radiotherapy on the magnitude of setup displacement in patients with head and neck cancer (HNC).
Related JoVE Video
Kelsoenethiol and dikelsoenyl ether, two unique kelsoane-type sesquiterpenes, from the Formosan soft coral Nephthea erecta.
Bioorg. Med. Chem. Lett.
PUBLISHED: 10-23-2013
Show Abstract
Hide Abstract
Two new kelsoane-type sesquiterpenes, namely kelsoenethiol (1) and dikelsoenyl ether (2), were obtained from the Formosan soft coral Nephthea erecta. Their structures were elucidated through extensive spectroscopic analyses, ESI orbitrap mass and quantum chemical calculations (QCC). The cytotoxicity against A-459 (human lung carcinoma), P-388 (mouse lymphocytic leukemia), and HT-29 (human colon adenocarcinoma) cancer cell lines of 1 and 2 was evaluated in vitro. Compound 1 showed cytotoxicity against P-388 and HT-29 cells with ED50s of 1.3 and 1.8?g/mL, respectively.
Related JoVE Video
Discovery of an irreversible HCV NS5B polymerase inhibitor.
Bioorg. Med. Chem. Lett.
PUBLISHED: 10-03-2013
Show Abstract
Hide Abstract
The discovery of lead compound 2e was described. Its covalent binding to HCV NS5B polymerase enzyme was investigated by X-ray analysis. The results of distribution, metabolism and pharmacokinetics were reported. Compound 2e was demonstrated to be potent (replicon GT-1b EC50=0.003?M), highly selective, and safe in in vitro and in vivo assays.
Related JoVE Video
Optimization of potency and pharmacokinetics of tricyclic indole derived inhibitors of HCV NS5B polymerase. Identification of ester prodrugs with improved oral pharmacokinetics.
Bioorg. Med. Chem.
PUBLISHED: 09-12-2013
Show Abstract
Hide Abstract
HCV infections are the leading causes for hepatocellular carcinoma and liver transplantation in the United States. Recent advances in drug discovery have identified direct acting antivirals which have significantly improved cure rates in patients. Current efforts are directed towards identification of novel direct acting antiviral targeting different mechanism of actions which could become part of all oral therapies. We recently disclosed the identification of a novel tricyclic indole derived inhibitors of HCV NS5B polymerase that bound to the enzyme close to the active site. In this manuscript we describe further optimization of potency and pharmacokinetics (PK) of these inhibitors to identify compounds in low nM potency against gt-1b. These analogs also demonstrate excellent PK in rats and monkeys when administered as a dimethyl ethyl amino ester prodrug.
Related JoVE Video
Radiotherapy for esophageal cancer using simultaneous integrated boost techniques: dosimetric comparison of helical TomoTherapy, Volumetric-modulated Arc Therapy (RapidArc) and dynamic intensity-modulated radiotherapy.
Technol. Cancer Res. Treat.
PUBLISHED: 06-06-2013
Show Abstract
Hide Abstract
This study compared TomoTherapy (TM), with Volumetric-Modulated Arc Therapy (RapidArc, RA), and dynamic intensity-modulated radiotherapy (dIMRT) for locally advanced esophageal cancer (LAEC) with a simultaneous integrated boost (SIB) technique with regard to the target coverage and sparing of organs at risk (OARs). Twelve patients receiving four-dimensional computed tomography simulation were enrolled for dosimetric comparison. Gross tumor volume was contoured with the maximum intensity projection method. Using an SIB method, Planning target volume low (PTVL) and planning target volume high (PTVH) were prescribed as 54 Gy and 60 Gy, respectively, each administered in 30 fractions. We compared the results of statistical analysis for target coverage, homogeneity index (HI) and conformity index (CI) of PTVs, parameters of OARs and monitor unit (MU) were compared for analysis. The HI for PTVH varied significantly for the 3 techniques of TM, RA, and dIMRT (4.38 ± 0.86, 6.40 ± 0.86, and 6.11 ± 0.68, respectively; P , 0.001). The CI scores for PTVH also differed across TM, RA, and dIMRT (0.64 6 0.06, 0.53 6 0.06, and 0.59 ± 0.05, respectively; P < 0.001). The HI for PTVL showed a significant difference among TM, RA, and dIMRT (15.44 ± 0.88, 20.88 ± 1.03 and 18.65 ± 1.42, respectively; P < 0.001). The percentage of lung volume receiving 5 Gy (V5) and 20 Gy (V20) (for V5: TM 54.4 ± 8.0%; RA 67.5 ± 14.5%, P < 0.01; dIMRT 44.8 ± 8.2%; for V20: 13.6 6 3.3%, 12.2 ± 3.6%, 18.1 6 3.4%, P = 0.001, respectively). For RA, the lung V5 ? 65% was observed in 6 patients and the V10 ? 50 % in one patient. TM, RA and dIMRT provided comparable coverage of the target and sparing of OARs. TM demonstrated superior CI and HI for tumor coverage and lowered the specified dose parameters for lung. RA provided an advantage in terms of the lowest MU and V20 of the lung, but its higher lung V5 was of some concern about lung toxicity.
Related JoVE Video
Synthesis and SAR studies of benzimidazolone derivatives as histamine H3-receptor antagonists.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-09-2013
Show Abstract
Hide Abstract
A novel series of benzimidazolone-containing histamine H3-receptor antagonists were prepared and their structure-activity relationship was explored. These benzimidazolone analogs demonstrate potent H3-receptor binding affinities, no P450 enzyme inhibition, and strong H3 functional activity. Compound 1o exhibits the best overall profile with H3Ki=0.95nM and rat AUC=12.9?Mh.
Related JoVE Video
Discovery of novel tricyclic indole derived inhibitors of HCV NS5B RNA dependent RNA polymerase.
Bioorg. Med. Chem.
PUBLISHED: 01-03-2013
Show Abstract
Hide Abstract
The characterization of HCV genome has identified various vital functional proteins involved in the life cycle of hepatitis C virus. This has resulted in many novel enzymatic targets that are potential for development of therapeutic agents. The HCV RNA dependent RNA polymerase (HCV NS5B) is one such essential enzyme for HCV replication that has been well characterized and studied by various groups to develop novel therapies for hepatitis C. In this paper, we describe our efforts towards the identification and structure-activity relationship (SAR) of novel tricyclic indole derivatives that bind close to the palm site of the NS5B polymerase. X-ray crystal structure of an inhibitor bound to the polymerase is also described.
Related JoVE Video
Surface ?-enolase promotes extracellular matrix degradation and tumor metastasis and represents a new therapeutic target.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
In previous research, we found ?-enolase to be inversely correlated with progression-free and overall survival in lung cancer patients and detected ?-enolase on the surface of lung cancer cells. Based on these findings, we hypothesized that surface ?-enolase has a significant role in cancer metastasis and tested this hypothesis in the current study. We found that ?-enolase was co-immunoprecipitated with urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, and plasminogen in lung cancer cells and interacted with these proteins in a cell-free dot blotting assay, which can be interrupted by ?-enolase-specific antibody. ?-Enolase in lung cancer cells co-localized with these proteins and was present at the site of pericellular degradation of extracellular matrix components. Treatment with antibody against ?-enolase in vitro suppressed cell-associated plasminogen and matrix metalloproteinase activation, collagen and gelatin degradation, and cell invasion. Examination of the effect of treatment with shRNA plasmids revealed that down regulation of ?-enolase decreases extracellular matrix degradation by and the invasion capacity of lung cancer cells. Adoptive transfer of ?-enolase-specific antibody to mice resulted in accumulation of antibody in subcutaneous tumor and inhibited the formation of tumor metastasis in lung and bone. This study demonstrated that surface ?-enolase promotes extracellular matrix degradation and invasion of cancer cells and that targeting surface ?-enolase is a promising approach to suppress tumor metastasis.
Related JoVE Video
Selecting tyrosine kinase inhibitors for gastrointestinal stromal tumor with secondary KIT activation-loop domain mutations.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Advanced gastrointestinal stromal tumors (GIST), a KIT oncogene-driven tumor, on imatinib mesylate (IM) treatment may develop secondary KIT mutations to confer IM-resistant phenotype. Second-line sunitinib malate (SU) therapy is largely ineffective for IM-resistant GISTs with secondary exon 17 (activation-loop domain) mutations. We established an in vitro cell-based platform consisting of a series of COS-1 cells expressing KIT cDNA constructs encoding common primary±secondary mutations observed in GISTs, to compare the activity of several commercially available tyrosine kinase inhibitors on inhibiting the phosphorylation of mutant KIT proteins at their clinically achievable plasma steady-state concentration (Css). The inhibitory efficacies on KIT exon 11/17 mutants were further validated by growth inhibition assay on GIST48 cells, and underlying molecular-structure mechanisms were investigated by molecular modeling. Our results showed that SU more effectively inhibited mutant KIT with secondary exon 13 or 14 mutations than those with secondary exon 17 mutations, as clinically indicated. On contrary, at individual Css, nilotinib and sorafenib more profoundly inhibited the phosphorylation of KIT with secondary exon 17 mutations and the growth of GIST48 cells than IM, SU, and dasatinib. Molecular modeling analysis showed fragment deletion of exon 11 and point mutation on exon 17 would lead to a shift of KIT conformational equilibrium toward active form, for which nilotinib and sorafenib bound more stably than IM and SU. In current preclinical study, nilotinib and sorafenib are more active in IM-resistant GISTs with secondary exon 17 mutation than SU that deserve further clinical investigation.
Related JoVE Video
Novel substituted pyrimidines as HCV replication (replicase) inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 11-04-2011
Show Abstract
Hide Abstract
Compound 1 was identified as a HCV replication inhibitor from screening/early SAR triage. Potency improvement was achieved via modulation of substituent on the 5-azo linkage. Due to potential toxicological concern, the 5-azo linkage was replaced with 5-alkenyl or 5-alkynyl moiety. Analogs containing the 5-alkynyl linkage were found to be potent inhibitors of HCV replication. Further evaluation identified compounds 53 and 63 with good overall profile, in terms of replicon potency, selectivity and in vivo characteristics. Initial target engagement studies suggest that these novel carbanucleoside-like derivatives may inhibit the HCV replication complex (replicase).
Related JoVE Video
II. Novel HCV NS5B polymerase inhibitors: discovery of indole C2 acyl sulfonamides.
Bioorg. Med. Chem. Lett.
PUBLISHED: 08-31-2011
Show Abstract
Hide Abstract
Development of SAR at the C2 position of indole lead 1, a palm site inhibitor of HCV NS5B polymerase (NS5B IC(50)=0.053?M, replicon EC(50)=4.8?M), is described. Initial screening identified an acyl sulfonamide moiety as an isostere for the C2 carboxylic acid group. Further SAR investigation resulted in identification of acyl sufonamide analog 7q (NS5B IC(50)=0.039?M, replicon EC(50)=0.011?M) with >100-fold improved replicon activity.
Related JoVE Video
III. Identification of novel CXCR3 chemokine receptor antagonists with a pyrazinyl-piperazinyl-piperidine scaffold.
Bioorg. Med. Chem. Lett.
PUBLISHED: 08-24-2011
Show Abstract
Hide Abstract
The SAR of a novel pyrazinyl-piperazinyl-piperidine scaffold with CXCR3 receptor antagonist activity was explored. Optimization of the DMPK profile and reduction of hERG inhibition is described. Compound 16e with single-digit CXCR3 affinity, good rat PK and hERG profiles has been identified as a lead for further study.
Related JoVE Video
Overexpression of ?-enolase correlates with poor survival in canine mammary carcinoma.
BMC Vet. Res.
PUBLISHED: 05-10-2011
Show Abstract
Hide Abstract
?-Enolase (ENO1) is a key glycolytic enzyme implicated in the development of many human cancers including breast cancer. Increased expression of ENO1 has recently been reported in estrogen (ER)-positive human breast cancer patients. The present study examined the expression of ENO1 and assessed its significance in canine mammary carcinoma.
Related JoVE Video
I. Novel HCV NS5B polymerase inhibitors: discovery of indole 2-carboxylic acids with C3-heterocycles.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-28-2011
Show Abstract
Hide Abstract
SAR development of indole-based palm site inhibitors of HCV NS5B polymerase exemplified by initial indole lead 1 (NS5B IC(50)=0.9 ?M, replicon EC(50)>100 ?M) is described. Structure-based drug design led to the incorporation of novel heterocyclic moieties at the indole C3-position which formed a bidentate interaction with the protein backbone. SAR development resulted in leads 7q (NS5B IC(50)=0.032 ?M, replicon EC(50)=1.4 ?M) and 7r (NS5B IC(50)=0.017 ?M, replicon EC(50)=0.3 ?M) with improved enzyme and replicon activity.
Related JoVE Video
2-(2-Aminothiazol-4-yl)pyrrolidine-based tartrate diamides as potent, selective and orally bioavailable TACE inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-03-2011
Show Abstract
Hide Abstract
TNF-? converting enzyme (TACE) inhibitors are promising agents to treat inflammatory disorders and cancer. We have investigated novel tartrate diamide TACE inhibitors where the tartrate core binds to zinc in a unique tridentate fashion. Incorporating (R)-2-(2-N-alkylaminothiazol-4-yl)pyrrolidines into the left hand side amide of the tartrate scaffold led to the discovery of potent and selective TACE inhibitors, some of which exhibited good rat oral bioavailability.
Related JoVE Video
II. SAR studies of pyridyl-piperazinyl-piperidine derivatives as CXCR3 chemokine antagonists.
Bioorg. Med. Chem. Lett.
PUBLISHED: 11-29-2010
Show Abstract
Hide Abstract
The structure-human CXCR3 binding affinity relationship of a series of pyridyl-piperazinyl-piperidine derivatives was explored. The optimization campaign highlighted the pronounced effect of 2-piperazine substitution on CXCR3 receptor affinity. Analog 18j, harboring a 2(S)-ethylpiperazine moiety, exhibited a human CXCR3 IC(50) of 0.2 nM.
Related JoVE Video
Utility of TL-201 SPECT in clarifying false-positive FDG-PET findings due to osteoradionecrosis in head and neck cancer.
Head Neck
PUBLISHED: 09-18-2010
Show Abstract
Hide Abstract
This study aimed to determine whether Tl-201 single photon emission CT (SPECT) is potentially useful in differentiating false-positive fluorodeoxyglucose positron emission tomography (FDG-PET) findings caused by osteoradionecrosis (ORN) from recurrent head and neck cancer after radiotherapy.
Related JoVE Video
MBP-1 is efficiently encoded by an alternative transcript of the ENO1 gene but post-translationally regulated by proteasome-dependent protein turnover.
FEBS J.
PUBLISHED: 09-16-2010
Show Abstract
Hide Abstract
The c-myc promoter-binding protein-1 (MBP-1) is a transcriptional suppressor of tumorigenesis and thought to be the product of alternative translation initiation of the ?-enolase (ENO1) transcript. In the present study, we cloned a 2552-bp novel cDNA with a putative coding sequence of MBP-1 and functionally examined its ability to encode the MBP-1 protein. Similarly to ENO1, the obtained MBP-1 was widely and differentially expressed in a variety of normal tissues and cancer cells. Experiments using MBP-1 promoter-driven luciferase reporter assays, biochemical cell fractionation followed by RT-PCR detection of the cytoplasmic mRNA, and transcription/translation-coupled reactions, consistently demonstrated that this novel transcript was alternatively transcribed from intron III of the ENO1 gene and was feasible for MBP-1 production. Hypoxia treatments significantly increased the transcriptional activation of the MBP-1 gene. Blocking the proteasomal degradation by MG132 stabilized the MBP-1 protein in cells. Compared with the translation efficiency for production of the MBP-1 protein, the MBP-1 transcript was 17.8 times more efficient than the ENO1 transcript. Thus, we suggest that this newly discovered transcript is a genuine template for the protein synthesis of MBP-1 in cells, and optimal expression of this gene in tumors may lead to effective clinical therapies for cancers.
Related JoVE Video
Novel TNF-? converting enzyme (TACE) inhibitors as potential treatment for inflammatory diseases.
Bioorg. Med. Chem. Lett.
PUBLISHED: 09-02-2010
Show Abstract
Hide Abstract
Our research on hydantoin based TNF-? converting enzyme (TACE) inhibitors has led to an acetylene containing series that demonstrates sub-nanomolar potency (K(i)) as well as excellent activity in human whole blood. These studies led to the discovery of highly potent TACE inhibitors with good DMPK profiles.
Related JoVE Video
Discovery of orally bioavailable imidazo[1,2-a]pyrazine-based Aurora kinase inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 07-30-2010
Show Abstract
Hide Abstract
We report a series of potent imidazo[1,2-a]pyrazine-based Aurora kinase inhibitors. Optimization of the solvent accessible 8-position led to improvements in both oral bioavailability and off-target kinase inhibition. Compound 25 demonstrates anti-tumor activity in an A2780 ovarian tumor xenograft model.
Related JoVE Video
Diagnostic detection of human lung cancer-associated antigen using a gold nanoparticle-based electrochemical immunosensor.
Anal. Chem.
PUBLISHED: 06-19-2010
Show Abstract
Hide Abstract
The development of rapid and sensitive methods for the detection of immunogenic tumor-associated antigen is important not only for understanding their roles in cancer immunology but also for the development of clinical diagnostics. Alpha-enolase (ENO1), a p48 molecule, is widely distributed in a variety of tissues, whereas gamma-enolase (ENO2) and beta-enolase (ENO3) are found exclusively in neuron/neuroendocrine and muscle tissues, respectively. Because ENO1 has been correlated with small cell lung cancer, nonsmall cell lung cancer, and head and neck cancer, it can be used as a potential diagnostic marker for lung cancer. In this study, we developed a simple, yet novel and sensitive, electrochemical sandwich immunosensor for the detection of ENO1; it operates through physisorption of anti-ENO1 monoclonal antibody on polyethylene glycol-modified disposable screen-printed electrode as the detection platform, with polyclonal secondary anti-ENO1-tagged, gold nanoparticle (AuNP) congregates as electrochemical signal probes. The immunorecognition of the sample ENO1 by the congregated AuNP@antibody occurred on the surface of the electrodes; the electrochemical signal from the bound AuNP congregates was obtained after oxidizing them in 0.1 M HCl at 1.2 V for 120 s, followed by the reduction of AuCl(4-) in square wave voltammetry (SWV) mode. The resulting sigmoidally shaped dose-response curves possessed a linear dynamic working range from 10(-8) to 10(-12) g/mL. This AuNP congregate-based assay provides an amplification approach for detecting ENO1 at trace levels, leading to a detection limit as low as 11.9 fg (equivalent to 5 microL of a 2.38 pg/mL solution).
Related JoVE Video
18F-FDG PET/CT-based gross tumor volume definition for radiotherapy in head and neck cancer: a correlation study between suitable uptake value threshold and tumor parameters.
Radiat Oncol
PUBLISHED: 06-14-2010
Show Abstract
Hide Abstract
To define a suitable threshold setting for gross tumor volume (GTV) when using 18Fluoro-deoxyglucose positron emission tomography and computed tomogram (PET/CT) for radiotherapy planning in head and neck cancer (HNC).
Related JoVE Video
Development of high-level carbapenem resistance in Klebsiella pneumoniae among patients with prolonged hospitalization and carbapenem exposure.
Microb. Drug Resist.
PUBLISHED: 06-06-2010
Show Abstract
Hide Abstract
An increasing incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections has been reported worldwide. The aim of this study was to investigate the mechanism underlying carbapenem resistance and its relationship to antibiotic exposure. Sixteen isolates with various carbapenem susceptibilities recovered from five patients between 2003 and 2006 were subjected to molecular study. The medical records of the patients were also reviewed. All of the patients were admitted for complicated respiratory illness, had a prolonged hospital stay, and were exposed to antibiotics. Carbapenems were prescribed before the emergence of the CRKP. Various combinations of extended-spectrum cephalosporinase genes belonging to the SHV, CTX-M, and AmpC groups were found among the isolates. Other carbapenem resistance-associated genes, such as bla(IMP), bla(VIM), bla(OXA), and bla(KPC), were not found. OmpK35 was not expressed in any of the isolates, and additional loss of OmpK36 was observed in all CRKP isolates. Two insertion elements, ISPa13 or IS5, were found inserted into OmpK36 in the isolates derived from three patients. These IS elements were also identified in their parental carbapenem-susceptible isolates, suggesting that an internal transposition into OmpK36 resulted in resistance. OmpK36 loss represents the major mechanism for the development of CRKP in extended-spectrum cephalosporinase-producing isolates. A prolonged hospital stay and recent carbapenem exposure may predispose patients to CRKP, impacting the clinical outcome.
Related JoVE Video
Clinical implications of the tumor volume reduction rate in head-and-neck cancer during definitive intensity-modulated radiotherapy for organ preservation.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 06-03-2010
Show Abstract
Hide Abstract
To investigate the prognostic value of the volume reduction rate (VRR) in patients with head-and-neck cancer treated with intensity-modulated radiotherapy (IMRT).
Related JoVE Video
Structure and activity relationships of tartrate-based TACE inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-29-2010
Show Abstract
Hide Abstract
The syntheses and structure-activity relationships of the tartrate-based TACE inhibitors are discussed. The optimization of both the prime and non-prime sites led to compounds with picomolar activity. Several analogs demonstrated good rat pharmacokinetics.
Related JoVE Video
Discovery of a series of potent, orally active ?,?-disubstituted piperidine NK(1) antagonists.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-21-2010
Show Abstract
Hide Abstract
Modification of prototype NK(1) antagonist 2 resulted in the synthesis of a series of simple amides 6 and retroamides 9. These compounds were shown to be potent and orally active NK(1) antagonists.
Related JoVE Video
Generation and characterization of anti-alpha-enolase single-chain antibodies in chicken.
Vet. Immunol. Immunopathol.
PUBLISHED: 04-20-2010
Show Abstract
Hide Abstract
It was previously reported that up-regulation of alpha-enolase protein was detected in 65% of patients with non-small cell lung cancers (NSCLC). Moreover, a high titer of anti-alpha-enolase antibodies was developed in a smaller proportion (7.4%) of these patients than in non-tumor-associated patients and healthy subjects. In the present study, we characterized polyclonal and single-chain variable fragment (scFv) anti-alpha-enolase antibodies from immunized chickens. The E. coli-derived recombinant alpha-enolase protein was purified to its high homogenicity as verified by SDS-PAGE. After the 4th immunization, a high titer of specific polyclonal anti-alpha-enolase antibodies was elicited in immunized chickens and specifically recognized the purified human alpha-enolase antigen as determined by Western blot and ELISA. The expressed heavy and light chain variable genes (VH and VL) were isolated from spleen B cells and amplified to construct phage antibody libraries containing scFv molecules. After four rounds of panning selection, the scFv antibodies of randomly chosen clones were expressed and their binding specificity to alpha-enolase protein was verified using competitive ELISA, flow cytometry and immunofluorescence staining. Nucleotide sequence analysis from 10 alpha-enolase binding clones showed that 3 (30%) clones used identical heavy and light genes for scFv antibody expression, as represented by EnL5. Notably, amino acid changes in complementarity-determining regions (CDRs) were more frequently observed than those in framework regions (FRs) in all clones, indicating a strong affinity selection through mutations. All together, it is believed that these polyclonal and scFv IgY antibodies may be helpful in the development of molecular diagnostic and therapeutic agents for lung cancers in the future.
Related JoVE Video
Anti-alpha-enolase autoantibodies are down-regulated in advanced cancer patients.
Jpn. J. Clin. Oncol.
PUBLISHED: 04-15-2010
Show Abstract
Hide Abstract
Elevation of serum autoantibodies to alpha-enolase (ENO1) is often seen in inflammation diseases. However, it is unclear whether the levels of serum ENO1 autoantibodies could be affected during tumor progression. Hence, we attempted to determine the relative serum ENO1 autoantibody levels in healthy individuals and various stages of patients with lung and breast cancers.
Related JoVE Video
Lack of the dose-rate effect of 192Ir source activity on pelvic control and late complications after high-dose-rate brachytherapy for cervical cancer.
J. Radiat. Res.
PUBLISHED: 03-27-2010
Show Abstract
Hide Abstract
This study aimed to assess the dose-rate effect of (192)Ir source activity on pelvic control and late complications following high-dose-rate intracavitary brachytherapy (HDRICB) for cervical cancer patients. Two hundred and twelve patients were enrolled in this study. They were treated with external beam radiotherapy to the pelvis, after which HDRICB was performed using (192)Ir remote after-loading at 1-week intervals for 4 or 5 sessions. Source activity was defined as the average of source activity in each HDRICB session. Dose-rate effect was analyzed after stratification of stage and biologically effective dose (BED). The 5-year pelvic relapse-free survival was 88% for all patients. Forty-two patients developed late rectal complications (13 grade 1, 23 grade 2, 6 grade 3-4). Twenty-seven patients had grade 2 and higher late bladder complications (14 grade 2, 13 grade 3-4). There was no dose-rate effect on pelvic control or complications when source activity was stratified. Multivariate analysis demonstrated a high risk of grade 2 and higher rectal sequelae in patients whose rectal BED >or= 110 Gy(3) (p = 0.039, hazard ratio 2.05). The high risk factors for grade 2 and higher bladder complications were a bladder BED >or= 100 Gy(3) (p = 0.03, hazard ratio 4.37). This study demonstrated no dose-rate effect of (192)Ir source in HDRICB for cervical cancer in terms of pelvic control or radiation injuries. Careful monitoring of the BED values for rectum and bladder is a scrutinizing factor for minimizing late sequelae.
Related JoVE Video
Biaryl substituted hydantoin compounds as TACE inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 03-18-2010
Show Abstract
Hide Abstract
We disclose further optimization of hydantoin TNF-alpha convertase enzyme (TACE) inhibitors. SAR with respect to the non-prime region of TACE active site was explored. A series of biaryl substituted hydantoin compounds was shown to have sub-nanomolar K(i), good rat PK, and good selectivity versus MMP-1, -2, -3, -7, -9, and -13.
Related JoVE Video
ENO1, a potential prognostic head and neck cancer marker, promotes transformation partly via chemokine CCL20 induction.
Eur. J. Cancer
PUBLISHED: 03-10-2010
Show Abstract
Hide Abstract
The success of using glycolytic inhibitors for cancer treatment depends on studying the individual role of frequently deregulated glycolytic genes in cancer. This report aims to study the prognostic implication, and determine the cellular role and action mechanism of glycolytic ENO1 overexpression in head and neck cancer. The relationship of ENO1 mRNA expression in 44-pair clinical specimens with patient clinicopathologic characteristics was analysed by semi-quantitative RT-PCR, Kaplan-Meier survival curve and Cox model analyses. Following ectopic ENO1 expression or knockdown, we studied the proliferative, migratory, invasive, colony-forming and tumourigenic abilities of ENO1-genetically altered cells. DNA microarray analysis was used to identify downstream targets responsible for the ENO1 action in the cells. The expression of ENO1 mRNA was increased in 68% of tumour (T) specimens when compared to their normal (N) counterparts, and positively associated with clinical progression (p<0.05). High ENO1 expression (T/N2) was frequently observed in the patients with large primary tumours, late clinical stages or advanced neck metastasis. Moreover, high ENO1 patients had significantly poorer clinical outcomes than low expressers (T/N<2). Ectopic ENO1 expression stimulated cell transformation, invasion and tongue tumour formation. ENO1 knockdown abrogated the stimulation. Suppression of ENO1-induced proinflammatory CCL20 chemokine expression significantly attenuated its stimulatory effects on cell transformation and invasion. A concordant expression of ENO1 and CCL20 was validated both in ENO1-expressing cells and in clinical specimens. Together, we demonstrate a prognostic role of ENO1 overexpression in head and neck cancer and ENO1-mediated promotion of cell transformation and invasion partly via induced CCL20 expression.
Related JoVE Video
Discovery and SAR of hydantoin TACE inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-28-2010
Show Abstract
Hide Abstract
We disclose inhibitors of TNF-alpha converting enzyme (TACE) designed around a hydantoin zinc binding moiety. Crystal structures of inhibitors bound to TACE revealed monodentate coordination of the hydantoin to the zinc. SAR, X-ray, and modeling designs are described. To our knowledge, these are the first reported X-ray structures of TACE with a hydantoin zinc ligand.
Related JoVE Video
Discovery of potent sulfonamide P4-capped ketoamide second generation inhibitors of hepatitis C virus NS3 serine protease with favorable pharmacokinetic profiles in preclinical species.
Bioorg. Med. Chem.
PUBLISHED: 01-14-2010
Show Abstract
Hide Abstract
Hepatitis is a disease characterized by inflammation of the liver, usually producing swelling and, in many cases, permanent damage to liver tissues. Viral hepatitis C (HCV), a small (+)-RNA virus, infects chronically 3% of the worlds population. Boceprevir, SCH 503034, (1) our first generation HCV inhibitor, has already established proof-of- concept and is currently in late stage (phase III) clinical trials. In view of the positive data from our first generation compound, further work aimed at optimizing its overall profile was undertaken. Herein, we report that extension of our earlier inhibitor to the P(4) pocket by introducing a new sulfonamide moiety and optimization of the P1/P(1) capping led to the discovery of a novel series of inhibitors of the HCV NS3 serine protease. Optimization of the P(1) residue significantly improved potency and selectivity. The combination of optimal moieties led to the discovery of compound 47 which, in addition to being a potent inhibitor of HCV subgenomic RNA replication, was also found to have good PK profile in rat, dog and monkey.
Related JoVE Video
On the tuning of electric conductance of extended metal atom chains via axial ligands for [Ru3(mu3-dpa)4(X)2](0/+) (X = NCS-, CN-).
Chem. Commun. (Camb.)
PUBLISHED: 01-08-2010
Show Abstract
Hide Abstract
The influence of a pi-acid cyanide axial ligand on the metal-metal interactions of [Ru(3)(mu(3)-dpa)(4)(X)(2)](0/+) (X = NCS(-), CN(-)) is manifested by the measurements of single-molecule conductance coupled with in situ electrochemical control.
Related JoVE Video
Non-aromatic A-ring replacement in the triaryl bis-sulfone CB2 receptor inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 10-06-2009
Show Abstract
Hide Abstract
The triaryl bis-sulfone 1 was modified by converting the aryl A-ring to a piperidine ring. The piperidine ring was further elaborated to a spirocyclopropyl piperidine moiety. The effect on CB2 binding potency, rat calcium channel affinity, and CYP 2C9 inhibition is described.
Related JoVE Video
The discovery of novel tartrate-based TNF-alpha converting enzyme (TACE) inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 10-05-2009
Show Abstract
Hide Abstract
A novel series of TNF-alpha convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMPs. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.
Related JoVE Video
Investigating expression profiles of VEGF-Flk, and Angpt1 during development of gas glands in Japanese eel (Anguilla japonica).
Comp. Biochem. Physiol., Part A Mol. Integr. Physiol.
PUBLISHED: 09-01-2009
Show Abstract
Hide Abstract
Angiogenesis is a highly regulated physiological process in animals. Angiopoietin-1 (Angpt1) induces the signaling pathways related to vessel maturation in late phase of angiogenesis, which recruits pericyte supplements to make compact interaction with vessel tubes. There are only few data showing Angpt1 functions in fish. By using degenerate primers, partial sequence (812 bp) of Angpt1 was cloned from Anguilla japonica, and deduced amino acids showed 80% similarity to those of zebrafish. Physiological functions of cloned eel Angpt1 were studied by in vitro and in vivo manipulations with gas glands (rete mirabile) taken as the tested target tissues. RT-PCR and immunofluorescent staining techniques were performed to examine the expression patterns of Angpt1 as well as VEGF-Flk. Experimental data showed that, in vitro, bFGF, PPAR beta agonist, and estradiol affected Angpt1 expression; while cobalt ions, a VEGF expression-inducer, did not affect Angpt1 expression. In vivo, expression levels of Angpt1 increased with body growth. Furthermore, Angpt1 expressions increased significantly in the late stage of gas glands in the stimulated eel. Successive expression patterns on VEGF-Flk, and Angpt1 on different development stages of gas glands were observed. Our results suggest that the original function of angiopoietin-1 on angiogenesis is conserved during evolution.
Related JoVE Video
Mechanical stretch induces endothelial nitric oxide synthase gene expression in neonatal rat cardiomyocytes.
Clin. Exp. Pharmacol. Physiol.
PUBLISHED: 08-14-2009
Show Abstract
Hide Abstract
1. Mechanical stretch leads to cardiac hypertrophy and may ultimately cause heart failure. However, the effect of mechanical stretch on gene induction in cardiomyocytes remains to be determined. 2. In the present study, we compared transcript profiles of mechanically stretched neonatal rat cardiomyocytes with those of unstretched cells using cDNA microarrays. The microarrays contained probes for 480 known genes, including those involved in signal transduction, cell cycle regulation, the cytoskeleton and cell motility. Eighteen genes, including the eNOS gene, were identified as having significantly differential expression in response to mechanical stretch in cardiomyocytes. 3. Northern and western blot analysis further quantified the expression of the eNOS gene. Mechanical stretch increased constitutive NOS activity and nitric oxide (NO) production. The NO donor s-nitroso-N-acetylpenicillamine (SNAP) inhibited mechanical stretch-stimulated protein synthesis, as measured by [3H]-leucine uptake. In addition, cardiomyocytes were infected with adenoviral vectors encoding cDNA for eNOS (Ad-eNOS) and a phosphoglycerate kinase (PGK) empty vector (Ad-PGK). In contrast with Ad-PGK-infected cells, in cardiomyocytes infected with Ad-eNOS, there was increased calcium-dependent NOS activity and nitrite production. Cardiomyocytes infected with Ad-eNOS exhibited diminished mechanical stretch-stimulated protein synthesis. In contrast, in eNOS-knockdown cells, the increased eNOS protein levels and NOS activity induced by mechanical stretch were abolished, but protein synthesis was enhanced. 4. The results of the present study indicate that eNOS gene expression is induced by mechanical stretch, leading to increased constitutive NOS activity and NO production, which may be a negative regulator in cardiomyocyte hypertrophy.
Related JoVE Video
Increased expression of enolase alpha in human breast cancer confers tamoxifen resistance in human breast cancer cells.
Breast Cancer Res. Treat.
PUBLISHED: 06-13-2009
Show Abstract
Hide Abstract
Enolase-alpha (ENO-1) is a key glycolytic enzyme that has been used as a diagnostic marker to identify human lung cancers. To investigate the role of ENO-1 in breast cancer diagnosis and therapy, the mRNA levels of ENO-1 in 244 tumor and normal paired tissue samples and 20 laser capture-microdissected cell clusters were examined by quantitative real-time PCR analysis. Increased ENO-1 mRNA expression was preferentially detected in estrogen receptor-positive (ER+) tumors (tumor/normal ratio >90-fold) when compared to ER-negative (tumor/normal ratio >20-fold) tumor tissues. The data presented here demonstrate that those patients whose tumors highly expressed ENO-1 had a poor prognosis with greater tumor size (>2 cm, *P = .017), poor nodal status (N > 3, *P = .018), and a shorter disease-free interval (<==1 year, *P < .009). We also found that higher-expressing ENO-1 tumors confer longer distance relapse (tumor/normal ratio = 82.8-92.4-fold) when compared to locoregional relapse (tumor/normal ratio = 43.4-fold) in postsurgical 4-hydroxy-tamoxifen (4-OHT)-treated ER+ patients (*P = .014). These data imply that changes in tumor ENO-1 levels are related to clinical 4-OHT therapeutic outcome. In vitro studies demonstrated that decreasing ENO-1 expression using small interfering RNA (siRNA) significantly augmented 4-OHT (100 nM)-induced cytotoxicity in tamoxifen-resistant (Tam-R) breast cancer cells. These results suggest that downregulation of ENO-1 could be utilized as a novel pharmacological approach for overcoming 4-OHT resistance in breast cancer therapy.
Related JoVE Video
Geometrical sparing factors for the rectum and bladder in the prediction of grade 2 and higher complications after high-dose-rate brachytherapy for cervical cancer.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 04-20-2009
Show Abstract
Hide Abstract
This study aimed to assess the predictive values of geometrical sparing factors for the rectum and bladder in high-dose-rate intracavitary brachytherapy (HDRICB) for Grade 2 and higher late sequelae in patients with cervical cancer.
Related JoVE Video
Potent aza-peptide derived inhibitors of HCV NS3 protease.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-09-2009
Show Abstract
Hide Abstract
Chronic hepatitis C infection is the primary cause for cirrhosis of the liver and hepatocellular carcinoma leading to liver failure and transplantation. The etiological agent hepatitis C virus produces a single positive strand RNA that is processed further with the help of NS3 serine protease to produce mature virus. Inhibition of this protease can potentially be used to develop drugs for HCV infections. Boceprevir is a ketoamide derived novel inhibitor of HCV NS3 protease that has been progressed to clinical trials and proven to be efficacious in humans. Herein, we report our efforts in identifying an aza-peptide derivative as a potential second generation compound, that lacks electrophilic ketoamide group and are potent in enzyme and replicon assay.
Related JoVE Video
Conditioning vaccination site with irradiated MIP-3alpha-transfected tumor cells enhances efficacy of dendritic cell-based cancer vaccine.
J. Immunother.
PUBLISHED: 04-04-2009
Show Abstract
Hide Abstract
Macrophage inflammation protein-3alpha (MIP-3alpha) is a chemokine expressed in inflamed tissue and capable of inducing migration of immature dendritic cells (DCs) or Langerhans cells. We postulated that conditioning vaccination sites with MIP-3alpha might enhance the efficacy of subsequently administered DC-based cancer vaccines. Our results demonstrate that subcutaneously injection of irradiated tumor cells expressing MIP-3alpha induces substantial cell infiltration to the injection site. Vaccination of irradiated tumor cells expressing MIP-3alpha followed by DCs pulsed with irradiated tumor cells can effectively suppress tumor growth in animals, which is significantly better than vaccination with irradiated MIP-3alpha-producing tumor cells or DCs pulsed with tumor cells alone. The protective effect was most evident when the MIP-3alpha-producing tumor cells and DC-based vaccines were injected at the same site. These results support the notion that this combination vaccination strategy might generate a more effective immune response to suppress the growth of tumor cells in animals.
Related JoVE Video
Outcomes and cost-effectiveness of gamma knife radiosurgery and whole brain radiotherapy for multiple metastatic brain tumors.
J Clin Neurosci
PUBLISHED: 03-09-2009
Show Abstract
Hide Abstract
We aimed to analyze the outcomes and cost-effectiveness of gamma knife radiosurgery (GKRS) and whole brain radiotherapy (WBRT) for multiple metastatic brain tumors. Over a period of 5 years, 156 patients with multiple metastatic brain tumors were enrolled and freely assigned by the referring doctors to either gamma knife radiosurgery (GKRS, Group A, n=56), or to whole brain radiotherapy (WBRT, Group B, n=100). The follow-up time was set at 1200 days (3.3 years) post-treatment. The number of tumors, patient age, extent of systemic disease and Karnofsky performance scale (KPS) score, were recorded and recursive partitioning analysis used. The outcomes analyzed were: mortality, survival time, neurological complications, post-treatment KPS score, quality-adjusted life years (QALY), and cost-effectiveness. A paired t-test was used for statistical analysis. Mortality rates for patients receiving GKRS and WBRT were 81.1% and 93.0%, respectively (p=0.05). The mortality rate was lower for GKRS (74.4%) than for WBRT (97.1%) in patients with initial KPS70 (p=0.02). The mortality rate was also significantly lower for GKRS (78.9%) than WBRT (95.5%) in patients with 2-5 tumors (p<0.05). Post-treatment KPS score (mean+/-standard deviation [s.d.] was higher for patients receiving GKRS (73.8+/-13.2) than for those receiving WBRT (45.5+/-26.0), p<0.01. The median survival time for GKRS and WBRT was 9.5 months and 8.3 months, respectively, p=0.72. The mean (+/- s.d.) QALY was 0.76+/-0.23 for GKRS and 0.59+/-0.18 for WBRT, respectively (p<0.05). The cost-effectiveness per unit of QALY was better for the GKRS treatment (US$10,381/QALY) than in the WBRT treatment (US$17,622/QALY), p<0.05. The cost-effectiveness per KPS score was also higher for the GKRS treatment (US$139/KPS score) than for WBRT (US$229/KPS score), p<0.01. Thus, the mortality rate for multiple metastatic brain tumors treated by GKRS is significantly better with a good initial KPS score and when the tumor number is 2-5. GKRS results in a better post-treatment KPS score, QALY, and higher cost-effectiveness than WBRT for treating multiple metastatic brain tumors.
Related JoVE Video
Prognostic impact of tumor volume in patients with stage III-IVA hypopharyngeal cancer without bulky lymph nodes treated with definitive concurrent chemoradiotherapy.
Head Neck
PUBLISHED: 03-05-2009
Show Abstract
Hide Abstract
To investigate the prognostic value of volumetric analysis in patients with stage III-IVA hypopharyngeal cancer treated with concurrent chemoradiotherapy (CCRT).
Related JoVE Video
Discovery and structure-activity relationship of P1-P3 ketoamide derived macrocyclic inhibitors of hepatitis C virus NS3 protease.
J. Med. Chem.
PUBLISHED: 02-24-2009
Show Abstract
Hide Abstract
Hepatitis C virus (HCV) infection is the major cause of chronic liver disease, leading to cirrhosis and hepatocellular carcinoma, and affects more than 200 million people worldwide. Although combination therapy of interferon-alpha and ribavirin is reasonably successful in treating majority of genotypes, its efficacy against the predominant genotype (genotype 1) is moderate at best, with only about 40% of the patients showing sustained virological response. Herein, the SAR leading to the discovery of a series of ketoamide derived P(1)-P(3) macrocyclic inhibitors that are more potent than the first generation clinical candidate, boceprevir (1, Sch 503034), is discussed. The optimization of these macrocyclic inhibitors identified a P(3) imide capped analogue 52 that was 20 times more potent than 1 and demonstrated good oral pharmacokinetics in rats. X-ray structure of 52 bound to NS3 protease and biological data are also discussed.
Related JoVE Video
Reduction of monocyte chemoattractant protein-1 and interleukin-8 levels by ticlopidine in TNF-alpha stimulated human umbilical vein endothelial cells.
J. Biomed. Biotechnol.
PUBLISHED: 02-09-2009
Show Abstract
Hide Abstract
Atherosclerosis and its associated complications represent major causes of morbidity and mortality in the industrialized or Western countries. Monocyte chemoattractant protein-1 (MCP-1) is critical for the initiating and developing of atherosclerotic lesions. Interleukin-8 (IL-8), a CXC chemokine, stimulates neutrophil chemotaxis. Ticlopidine is one of the antiplatelet drugs used to prevent thrombus formation relevant to the pathophysiology of atherothrombosis. In this study, we found that ticlopidine dose-dependently decreased the mRNA and protein levels of TNF-alpha-stimulated MCP-1, IL-8, and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs). Ticlopidine declined U937 cells adhesion and chemotaxis as compared to TNF-alpha stimulated alone. Furthermore, the inhibitory effects were neither due to decreased HUVEC viability, nor through NF-kB inhibition. These results suggest that ticlopidine decreased TNF-alpha induced MCP-1, IL-8, and VCAM-1 levels in HUVECs, and monocyte adhesion. Therefore, the data provide additional therapeutic machinery of ticlopidine in treatment and prevention of atherosclerosis.
Related JoVE Video
Second-generation highly potent and selective inhibitors of the hepatitis C virus NS3 serine protease.
J. Med. Chem.
PUBLISHED: 02-07-2009
Show Abstract
Hide Abstract
The hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The moderate efficacy along with side effects of the current pegylated interferon and ribavirin combination therapy underscores the need for more effective and safer new treatment. In an effort to improve upon our current clinical candidate, Boceprevir (SCH 503034), extensive SAR studies were performed on the P3 capping moieties. This led to the discovery of tert-leucinol derived cyclic imides as a potent series of novel P3 capping groups. Thus, the introduction of these imide caps improved the cell-based replicon EC(90) by more than 10-fold. A number of imides with various substitutions, ring sizes, bicyclic systems, and heterocyclic rings were explored. The 4,4-dimethyl substituted glutarimide emerged as the best cap as exemplified in compound 21 (K(i)* = 4 nM, EC(90) = 40 nM). Systematic optimization of different positions (P, P3, and P1) of the inhibitor resulted in the identification of the lead compound 46, which had an excellent potency (K(i)* = 4 nM, EC(90) = 30 nM) and good pharmacokinetic profile (22% and 35% bioavailability in rats and dogs, respectively). X-ray structure of inhibitor 46 bound to the enzyme revealed that there was an additional hydrogen bonding interaction between one of the imide carbonyls and Cys159.
Related JoVE Video
Discovery of novel spirocyclopropyl hydroxamate and carboxylate compounds as TACE inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-29-2009
Show Abstract
Hide Abstract
We have discovered nanomolar inhibitors of TNF-alpha convertase (TACE) comprised of a novel spirocyclic scaffold and either a carboxylate or hydroxamate zinc binding moiety. X-ray crystal structures and computer models of selected compounds binding to TACE explain the observed SAR. We report the first TACE X-ray crystal structure for an inhibitor with a carboxylate zinc ligand.
Related JoVE Video
Clusterin silencing in human lung adenocarcinoma cells induces a mesenchymal-to-epithelial transition through modulating the ERK/Slug pathway.
Cell. Signal.
PUBLISHED: 01-03-2009
Show Abstract
Hide Abstract
The ubiquitously expressed glycoprotein Clusterin (CLU) is implicated in diverse cellular processes, yet its genuine molecular function remains undefined. CLU expression has been associated with various human malignancies, yet the mechanisms by which CLU promotes cancer progression and metastasis are not elucidated. In this study, using human lung adenocarcinoma cell lines as a model, we explored the involvement of CLU in modulating invasiveness of cancer cells. We discovered that CLU levels positively correlated with the degree of invasiveness in human lung adenocarcinoma cell lines. The observation that CLU-rich cells displayed a spindle-shape morphology while those with low CLU levels were cuboidal in shape prompted us to investigate if CLU modulates epithelial-to-mesenchymal transitions (EMT). CLU silencing by siRNA in a highly invasive, CLU-rich lung adenocarcinoma cell line induced a mesenchymal-to-epithelial transition (MET) evidenced by the spindle-to-cuboidal morphological change, increased E-cadherin expression, and decreased fibronectin expression. Compared with the vector-transfected cells, CLU-knocked-down (CLUi) cells showed reduced migration and invasion in vitro, as well as decreased metastatic potential in experimental metastasis. Re-expression of CLU in CLUi cells reversed the MET and restored the mesenchymal and invasive phenotypes. We found that Slug, a zinc-finger-containing transcriptional repressor of E-cadherin, was downregulated in CLUi cells. We also discovered that levels of activated ERK correlated with those of CLU and Slug. Taken together, our data suggest that CLU may regulate EMT and aggressive behaviour of human lung adenocarcinoma cells through modulating ERK signalling and Slug expression.
Related JoVE Video
Autophagy is involved in endogenous and NVP-AUY922-induced KIT degradation in gastrointestinal stromal tumors.
Autophagy
Show Abstract
Hide Abstract
Gastrointestinal stromal tumor (GIST) is a prototype of mutant KIT oncogene-driven tumor. Prolonged tyrosine kinase inhibitor (TKI) treatment may result in a resistant phenotype through acquired secondary KIT mutation. Heat shock protein 90 (HSP90AA1) is a chaperone protein responsible for protein maturation and stability, and KIT is a known client protein of HSP90AA1. Inhibition of HSP90AA1 has been shown to destabilize KIT protein by enhancing its degradation via the proteasome-dependent pathway. In this study, we demonstrated that NVP-AUY922 (AUY922), a new class of HSP90AA1 inhibitor, is effective in inhibiting the growth of GIST cells expressing mutant KIT protein, the imatinib-sensitive GIST882 and imatinib-resistant GIST48 cells. The growth inhibition was accompanied with a sustained reduction of both total and phosphorylated KIT proteins and the induction of apoptosis in both cell lines. Surprisingly, AUY922-induced KIT reduction could be partially reversed by pharmacological inhibition of either autophagy or proteasome degradation pathway. The blockade of autophagy alone led to the accumulation of the KIT protein, highlighting the role of autophagy in endogenous KIT turnover. The involvement of autophagy in endogenous and AUY922-induced KIT protein turnover was further confirmed by the colocalization of KIT with MAP1LC3B-, acridine orange- or SQSTM1-labeled autophagosome, and by the accumulation of KIT in GIST cells by silencing either BECN1 or ATG5 to disrupt autophagosome activity. Therefore, the results not only highlight the potential application of AUY922 for the treatment of KIT-expressing GISTs, but also provide the first evidence for the involvement of autophagy in endogenous and HSP90AA1 inhibitor-induced KIT degradation.
Related JoVE Video
Synthesis and SAR of pyridothiazole substituted pyrimidine derived HCV replication inhibitors.
Bioorg. Med. Chem. Lett.
Show Abstract
Hide Abstract
Introduction of a nitrogen atom into the benzene ring of a previously identified HCV replication (replicase) benzothiazole inhibitor 1, resulted in the discovery of the more potent pyridothiazole analogues 3. The potency and PK properties of the compounds were attenuated by the introductions of various functionalities at the R(1), R(2) or R(3) positions of the molecule (compound 3). Inhibitors 38 and 44 displayed excellent potency, selectivity (GAPDH/MTS CC(50)), PK parameters in all species studied, and cross genotype activity.
Related JoVE Video
The clinical application of 4D 18F-FDG PET/CT on gross tumor volume delineation for radiotherapy planning in esophageal squamous cell cancer.
J. Radiat. Res.
Show Abstract
Hide Abstract
A combination of four-dimensional computed tomography with (18)F-fluorodeoxyglucose positron emission tomography (4D CT-FDG PET) was used to delineate gross tumor volume (GTV) in esophageal cancer (EC). Eighteen patients with EC were prospectively enrolled. Using 4D images taken during the respiratory cycle, the average CT image phase was fused with the average FDG PET phase in order to analyze the optimal standardized uptake values (SUV) or threshold. PET-based GTV (GTV(PET)) was determined with eight different threshold methods using the auto-contouring function on the PET workstation. The difference in volume ratio (VR) and conformality index (CI) between GTV(PET) and CT-based GTV (GTV(CT)) was investigated. The image sets via automatic co-registrations of 4D CT-FDG PET were available for 12 patients with 13 GTV(CT) values. The decision coefficient (R(2)) of tumor length difference at the threshold levels of SUV 2.5, SUV 20% and SUV 25% were 0.79, 0.65 and 0.54, respectively. The mean volume of GTV(CT) was 29.41 ± 19.14 ml. The mean VR ranged from 0.30 to 1.48. The optimal VR of 0.98, close to 1, was at SUV 20% or SUV 2.5. The mean CI ranged from 0.28 to 0.58. The best CI was at SUV 20% (0.58) or SUV 2.5 (0.57). The auto-contouring function of the SUV threshold has the potential to assist in contouring the GTV. The SUV threshold setting of SUV 20% or SUV 2.5 achieves the optimal correlation of tumor length, VR, and CI using 4D-PET/CT images.
Related JoVE Video
Pyridofuran substituted pyrimidine derivatives as HCV replication (replicase) inhibitors.
Bioorg. Med. Chem. Lett.
Show Abstract
Hide Abstract
Introduction of nitrogen atom into the benzene ring of a previously identified HCV replication (replicase) benzofuran inhibitor 2, resulted in the discovery of the more potent pyridofuran analogue 5. Subsequent introduction of small alkyl and alkoxy ligands into the pyridine ring resulted in further improvements in replicon potency. Replacement of the 4-chloro moiety on the pyrimidine core with a methyl group, and concomitant monoalkylation of the C-2 amino moiety resulted in the identification of several inhibitors with desirable characteristics. Inhibitor 41, from the monosubstituted pyridofuran and inhibitor 50 from the disubstituted series displayed excellent potency, selectivity (GAPDH/MTS CC(50)) and PK parameters in all species studied, while the selectivity in the thymidine incorporation assay (DNA·CC(50)) was low.
Related JoVE Video
Pretreatment maximal standardized uptake value of the primary tumor predicts outcome to radiotherapy in patients with pharyngeal cancer.
J. Radiat. Res.
Show Abstract
Hide Abstract
This study aimed to investigate whether the combination of clinical information, tumor volume and pretreatment SUVmax at the primary tumors might improve the prognostic stratification in pharyngeal cancer (PC) patients treated with radiotherapy (RT). Sixty-two patients with PC (35 oropharynx; 27 hypopharynx) treated with RT were enrolled in this retrospective analysis. All patients received pretreatment FDG- PET or PET/CT. The primary tumor relapse-free survival (PRFS) was calculated according to different variables. The median values of the SUVmax for the primary tumors (SUVp-max) and the gross tumor volume (GTVp) were used to divide patients into two groups. Independent prognosticators were identified by the Cox regression analysis. In this study, the median SUVp-max and GTVp was 11 and 15.5 ml. Patients having tumors with SUVp-max > 11 had a significantly inferior 2-year PRFS (41% vs. 75%, p = 0.003) compared with patients having lower uptake tumors. Multivariate analysis of the PRFS showed two prognostic factors: SUVp-max > 11 (p = 0.04, hazard ratio = 2.67) and GTVp > 15.5 ml (p = 0.03, hazard ratio = 2.88). For patients with a GTVp less than 15.5 ml, there was a more significant impact of SUVmax-p on their PRFS compared to that for those with large ones. We disclosed a higher pretreatment SUVp-max is a predictor for primary recurrence in PC patients treated with RT, particularly for those with smaller tumor volumes. Patients with a large tumor volume or a higher SUVp-max should be considered for requiring more aggressive treatment approaches.
Related JoVE Video
Use of pretreatment metabolic tumour volumes to predict the outcome of pharyngeal cancer treated by definitive radiotherapy.
Eur. J. Nucl. Med. Mol. Imaging
Show Abstract
Hide Abstract
The aim of the study was to investigate the predictive role of pretreatment metabolic volume (MTV) in pharyngeal cancer (PC) patients treated with definitive (chemo) radiotherapy.
Related JoVE Video
5-Benzothiazole substituted pyrimidine derivatives as HCV replication (replicase) inhibitors.
Bioorg. Med. Chem. Lett.
Show Abstract
Hide Abstract
Based on a previously identified HCV replication (replicase) inhibitor 1, SAR efforts were conducted around the pyrimidine core to improve the potency and pharmacokinetic profile of the inhibitors. A benzothiazole moiety was found to be the optimal substituent at the pyrimidine 5-position. Due to potential reactivity concern, the 4-chloro residue was replaced by a methyl group with some loss in potency and enhanced rat in vivo profile. Extensive investigations at the C-2 position resulted in identification of compound 16 that demonstrated very good replicon potency, selectivity and rodent plasma/target organ concentration. Inhibitor 16 also demonstrated good plasma levels and oral bioavailability in dogs, while monkey exposure was rather low. Chemistry optimization towards a practical route to install the benzothiazole moiety resulted in an efficient direct C-H arylation protocol.
Related JoVE Video
Discovery of oxazole-based PDE4 inhibitors with picomolar potency.
Bioorg. Med. Chem. Lett.
Show Abstract
Hide Abstract
Optimization of oxazole-based PDE4 inhibitors has led to the discovery of a series of quinolyl oxazoles, with 4-benzylcarboxamide and 5-?-aminoethyl groups which exhibit picomolar potency against PDE4. Selectivity profiles and in vivo biological activity are also reported.
Related JoVE Video
A novel class of highly potent irreversible hepatitis C virus NS5B polymerase inhibitors.
J. Med. Chem.
Show Abstract
Hide Abstract
Starting from indole-based C-3 pyridone HCV NS5B polymerase inhibitor 2, structure-activity relationship (SAR) investigations of the indole N-1 benzyl moiety were performed. This study led to the discovery of irreversible inhibitors with p-fluoro-sulfone- or p-fluoro-nitro-substituted N-1 benzyl groups which achieved breakthrough replicon assay potency (EC(50) = 1 nM). The formation of a covalent bond with adjacent cysteine-366 thiol was was proved by mass spectroscopy and X-ray crystal structure studies. The C-5 ethyl C-2 carboxylic acid derivative 47 had an excellent oral area-under-the-curve (AUC) of 18 ?M·h (10 mg/kg). Its oral exposure in monkeys and dogs was also very good. The NMR ALARM assay, mass spectroscopy experiments, in vitro counter screening, and toxicology assays demonstrated that the covalent bond formation between compound 47 and the protein was highly selective and specific. The overall excellent profile of 47 made it an interesting candidate for further investigation.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.