WorldWideScience

Sample records for antimetabolites

  1. Malignant Pleural Mesothelioma Outcomes in the Era of Combined Platinum and Folate Antimetabolite Chemotherapy

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    Mathieu D. Saint-Pierre

    2015-01-01

    Full Text Available Introduction. Malignant pleural mesothelioma (MPM is associated with a poor prognosis. Palliative platinum-based chemotherapy may help to improve symptoms and prolong life. Since 2004, the platinum is commonly partnered with a folate antimetabolite. We performed a review investigating if survival had significantly changed before and after the arrival of folate antimetabolites in clinical practice. Methods. All MPM patients from January 1991 to June 2012 were identified. Data collected included age, gender, asbestos exposure, presenting signs/symptoms, performance status, histology, stage, bloodwork, treatment modalities including chemotherapy, and date of death or last follow-up. The primary endpoint was overall survival. Cox models were applied to determine variables associated with survival. Results. There were 245 patients identified. Median overall survival for all patients was 9.4 months. After multivariate analysis, performance status, stage, histology, leucocytosis, and thrombophilia remained independently associated with survival. Among all patients who received chemotherapy, there was no difference in overall survival between the periods before and after folate antimetabolite approval: 14.2 versus 13.2 months (P=0.35. Specifically receiving combined platinum-based/folate antimetabolite chemotherapy did not improve overall survival compared to all other chemotherapy regimens: 14.1 versus 13.6 months (P=0.97. Conclusions. In this review, we did not observe an incremental improvement in overall survival after folate antimetabolites became available.

  2. Sensitivity of gastric adenocarcinoma and normal cell lines against combined or conjugated antimetabolites.

    Science.gov (United States)

    Weinreich, Jürgen; Struller, Florian; Küper, Markus; Hack, Anita; Königsrainer, Alfred; Schott, Timm C

    2013-04-01

    The in-vitro growth inhibition of cancer and normal cell lines caused by mixed or covalently linked antimetabolites should clarify whether the conjugation of antimetabolites influences cell sensitivity and growth inhibition in a manner that differs from an equimolar mixture of the same antimetabolites or not. Growth inhibition of the human gastric adenocarcinoma cell lines 23132/87 and MKN-45 in comparison with normal gastric intestinal CCL-241 and the dermal fibroblast cell line NHDF was evaluated using CASY technology. The cell lines were incubated with an equimolar mixture of 5-fluoro-2'-deoxyuridine (5FdU)+3'-C-ethynylcytidine (ECyd) or the covalently linked duplex drug 5FdU(5'→5')ECyd. The drug and metabolites of the assays and medium were determined semiquantitatively using high-performance liquid chromatography. The sensitivity of cancer and nonmalignant cell lines was clearly different against the duplex drug. A measure of 0.65 µmol/l 5FdU(5'→5')ECyd, for example, reduced the growth of MKN-45 or 23132/87 gastric cancer cells from 100% on day 0 to about 50 or 20% on day 10, respectively. However, under the same conditions, the growth of the nonmalignant NHDF and CCL-241 cell lines was not markedly inhibited. The cytostatic activity of the duplex drug is based on the active metabolites in and outside the cell formed by the degradation of 5FdU(5'→5')ECyd. The sensitivity of cell lines against the duplex drug depended on its ability to metabolize the duplex drug. 5FdU(5'→5')ECyd should be more advantageous for specific and efficient polychemotherapy of gastric cancer than the corresponding equimolar mixture of 5FdU+ECyd or a standard combination regime of single drugs.

  3. Chemical and Metabolic Aspects of Antimetabolite Toxins Produced by Pseudomonas syringae Pathovars

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    Eva Arrebola

    2011-08-01

    Full Text Available Pseudomonas syringae is a phytopathogenic bacterium present in a wide variety of host plants where it causes diseases with economic impact. The symptoms produced by Pseudomonas syringae include chlorosis and necrosis of plant tissues, which are caused, in part, by antimetabolite toxins. This category of toxins, which includes tabtoxin, phaseolotoxin and mangotoxin, is produced by different pathovars of Pseudomonas syringae. These toxins are small peptidic molecules that target enzymes of amino acids’ biosynthetic pathways, inhibiting their activity and interfering in the general nitrogen metabolism. A general overview of the toxins’ chemistry, biosynthesis, activity, virulence and potential applications will be reviewed in this work.

  4. An overview of the clinical pharmacology of N-phosphonacetyl-L-aspartate (PALA), a new antimetabolite.

    Science.gov (United States)

    Erlichman, C

    1980-01-01

    N-Phosphonacetyl-L-aspartic acid (PALA) is new synthetic antimetabolite which inhibits de novo pyrimidine biosynthesis. Its significant activity against Lewis lung carcinoma, B16 melanoma, and glioma 26 suggested that it might be useful in the treatment of human solid tumors. Phase I trials revealed that dose-limiting toxicity included skin reactions, diarrhea, and stomatitis. Pharmacologic studies demonstrated rapid renal excretion of more than 70% of the unmetabolized drug in 24 h. Peak plasma levels correlated with dose of PALA administered. Partial responses to PALA were seen in one patient with melanoma, one with chondrosarcoma, and one with colon carcinoma. The potential for PALA's use in combination chemotherapy, particularly with 5-fluorouracil, is discussed.

  5. Biosynthesis of the antimetabolite 6-thioguanine in Erwinia amylovora plays a key role in fire blight pathogenesis.

    Science.gov (United States)

    Coyne, Sébastien; Chizzali, Cornelia; Khalil, Mohammed N A; Litomska, Agnieszka; Richter, Klaus; Beerhues, Ludger; Hertweck, Christian

    2013-09-27

    Sulfur for fire: The molecular basis for the biosynthesis of the antimetabolite 6-thioguanine (6TG) was unveiled in Erwinia amylovora, the causative agent of fire blight. Bioinformatics, heterologous pathway reconstitution in E. coli, and mutational analyses indicate that the protein YcfA mediates guanine thionation in analogy to 2-thiouridylase. Assays in planta and in cell cultures reveal for the first time a crucial role of 6TG in fire blight pathogenesis.

  6. Structure and function of Neisseria gonorrhoeae MtrF illuminates a class of antimetabolite efflux pumps.

    Science.gov (United States)

    Su, Chih-Chia; Bolla, Jani Reddy; Kumar, Nitin; Radhakrishnan, Abhijith; Long, Feng; Delmar, Jared A; Chou, Tsung-Han; Rajashankar, Kanagalaghatta R; Shafer, William M; Yu, Edward W

    2015-04-07

    Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. N. gonorrhoeae MtrF is an integral membrane protein that belongs to the AbgT family of transporters for which no structural information is available. Here, we describe the crystal structure of MtrF, revealing a dimeric molecule with architecture distinct from all other families of transporters. MtrF is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins, posing a plausible pathway for substrate transport. A combination of the crystal structure and biochemical functional assays suggests that MtrF is an antibiotic efflux pump mediating bacterial resistance to sulfonamide antimetabolite drugs.

  7. Structure and Function of Neisseria gonorrhoeae MtrF Illuminates a Class of Antimetabolite Efflux Pumps

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    Chih-Chia Su

    2015-04-01

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. N. gonorrhoeae MtrF is an integral membrane protein that belongs to the AbgT family of transporters for which no structural information is available. Here, we describe the crystal structure of MtrF, revealing a dimeric molecule with architecture distinct from all other families of transporters. MtrF is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins, posing a plausible pathway for substrate transport. A combination of the crystal structure and biochemical functional assays suggests that MtrF is an antibiotic efflux pump mediating bacterial resistance to sulfonamide antimetabolite drugs.

  8. Effects of antimetabolites on adenovirus replication in sensitive and resistant human melanoma cell lines.

    Science.gov (United States)

    Musk, P; Stowers, A; Parsons, P G

    1990-02-15

    Methotrexate (MTX), 6-thioguanine (6-TG) and cytosine arabinoside (ara-C) inhibited the replication of adenovirus (viral capacity) more in drug-sensitive than in resistant human melanoma cell lines. By comparison, inhibition of cellular DNA and RNA synthesis after short treatment periods (less than 48 hr) was not a good predictor of cellular sensitivity. MTX, an inhibitor of de novo nucleotide synthesis, was most effective when added to cells just before infection with virus and inhibited viral capacity at doses 10-1000-fold lower than those required to affect cell survival. The MTX-sensitive cell lines, members of a DNA repair deficient group sensitive also to killing by methylating agents (the Mer- phenotype), were not deficient in dihydrofolate reductase but exhibited DNA fragmentation after treatment with MTX for 48 hr. 6-TG and ara-C, inhibitors of purine and pyrimidine salvage, were most inhibitory to viral capacity when added greater than 36 hr before virus infection and were less effective than MTX (doses 5-7-fold and 4-24-fold higher than for cell survival respectively). No correlation was found between MTX sensitivity and sensitivity to 6-TG or ara-C. These results indicate that (i) inhibition of viral capacity is a more comprehensive test of antimetabolite cytotoxicity than inhibition of cellular DNA or RNA synthesis; (ii) the viral capacity assay correctly predicts cellular sensitivity to MTX, 6-TG and ara-C and therefore has potential for application to primary cultures of human tumours; and (iii) MTX-sensitive cell lines and adenovirus replication rely heavily on de novo nucleotide synthesis, which in Mer- cells appears to be linked to a DNA repair defect as yet undefined.

  9. Engineering Bacillus subtilis for the conversion of the antimetabolite 4-hydroxy-l-threonine to pyridoxine.

    Science.gov (United States)

    Commichau, Fabian M; Alzinger, Ariane; Sande, Rafael; Bretzel, Werner; Reuß, Daniel R; Dormeyer, Miriam; Chevreux, Bastien; Schuldes, Jörg; Daniel, Rolf; Akeroyd, Michiel; Wyss, Markus; Hohmann, Hans-Peter; Prágai, Zoltán

    2015-05-01

    Until now, pyridoxine (PN), the most commonly supplemented B6 vitamer for animals and humans, is chemically synthesized for commercial purposes. Thus, the development of a microbial fermentation process is of great interest for the biotech industry. Recently, we constructed a Bacillus subtilis strain that formed significant amounts of PN via a non-native deoxyxylulose 5'-phosphate-(DXP)-dependent vitamin B6 pathway. Here we report the optimization of the condensing reaction of this pathway that consists of the 4-hydroxy-l-threonine-phosphate dehydrogenase PdxA, the pyridoxine 5'-phosphate synthase PdxJ and the native DXP synthase, Dxs. To allow feeding of high amounts of 4-hydroxy-threonine (4-HO-Thr) that can be converted to PN by B. subtilis overexpressing PdxA and PdxJ, we first adapted the bacteria to tolerate the antimetabolite 4-HO-Thr. The adapted bacteria produced 28-34mg/l PN from 4-HO-Thr while the wild-type parent produced only 12mg/l PN. Moreover, by expressing different pdxA and pdxJ alleles in the adapted strain we identified a better combination of PdxA and PdxJ enzymes than reported previously, and the resulting strain produced 65mg/l PN. To further enhance productivity mutants were isolated that efficiently take up and convert deoxyxylulose (DX) to DXP, which is incorporated into PN. Although these mutants were very efficient to convert low amount of exogenous DX, at higher DX levels they performed only slightly better. The present study uncovered several enzymes with promiscuous activity and it revealed that host metabolic pathways compete with the heterologous pathway for 4-HO-Thr. Moreover, the study revealed that the B. subtilis genome is quite flexible with respect to adaptive mutations, a property, which is very important for strain engineering.

  10. Application of high-performance, thin-layer chromatography to quality control of antimetabolite analogue infusion bags.

    Science.gov (United States)

    Perello, L; Demirdjian, S; Dory, A; Bourget, P

    2001-01-01

    A global postproduction quality program was developed to secure chemotherapy infusion at the Gustave Roussy Institute. Despite rigorous procedures and computerized prescriptions, an analytical check was necessary to improve the quality of ready-to-use solutions of cytotoxic drugs in our Centralized Antineoplastics Reconstitution Unit. High-performance, thin-layer chromatography was selected as the analytical tool to assay 12 anticancer drugs. One of the analytical methods can separate 4 antimetabolite substances, i.e., fludarabine (FDB), cytarabine (CTB), gemcitabine (GTB), and fluorouracil (5 FU). For all infusion bags manufactured, up to 26 samples could be assayed per series using a double standard calibration (GTB and 5 FU).

  11. Effect of Moderate UVC Irradiation on Bovine Serum Albumin and Complex with Antimetabolite 5-Fluorouracil: Fluorescence Spectroscopic and Molecular Modelling Studies

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    Shanmugavel Chinnathambi

    2015-01-01

    Full Text Available The interaction of antimetabolite 5-fluorouracil (5FU with bovine serum albumin (BSA under UVC (253.7 nm irradiation was investigated in the present study using UV-Vis spectroscopy, steady state/time resolved fluorescence spectroscopic techniques. The stability of protein was found to be very strong when BSA gets bind to 5FU and moreover it is compared with the free BSA under UVC irradiation. From the fluorescence spectroscopic study, the stability of the complex was found to acquire 2-fold stronger than free protein. From the molecular modelling studies, we came to know the hydrogen bonds between BSA and antimetabolite 5FU are strong, up to 70.4 J/m2 under UVC irradiation.

  12. The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid inhibits growth of Erwinia amylovora and acts as a seed germination-arrest factor.

    Science.gov (United States)

    Lee, Xiaoyun; Azevedo, Mark D; Armstrong, Donald J; Banowetz, Gary M; Reimmann, Cornelia

    2013-02-01

    The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid (AMB) shares biological activities with 4-formylaminooxyvinylglycine, a related molecule produced by Pseudomonas fluorescens WH6. We found that culture filtrates of a P. aeruginosa strain overproducing AMB weakly interfered with seed germination of the grassy weed Poa annua and strongly inhibited growth of Erwinia amylovora, the causal agent of the devastating orchard crop disease known as fire blight. AMB was active against a 4-formylaminooxyvinylglycine-resistant isolate of E. amylovora, suggesting that the molecular targets of the two oxyvinylglycines in Erwinia do not, or not entirely, overlap. The AMB biosynthesis and transport genes were shown to be organized in two separate transcriptional units, ambA and ambBCDE, which were successfully expressed from IPTG-inducible tac promoters in the heterologous host P. fluorescens CHA0. Engineered AMB production enabled this model biocontrol strain to become inhibitory against E. amylovora and to weakly interfere with the germination of several graminaceous seeds. We conclude that AMB production requires no additional genes besides ambABCDE and we speculate that their expression in marketed fire blight biocontrol strains could potentially contribute to disease control.

  13. Antimalarial action of nitrobenzylthioinosine in combination with purine nucleoside antimetabolites.

    Science.gov (United States)

    Gero, A M; Scott, H V; O'Sullivan, W J; Christopherson, R I

    1989-04-01

    The infection of human erythrocytes by two strains of the human malarial parasite, Plasmodium falciparum (FCQ-27 or the multi-drug-resistant strain K-1), markedly changed the transport characteristics of the nucleosides, adenosine and tubercidin, compared to uninfected erythrocytes. A component of the transport of these nucleosides was insensitive to the classical mammalian nucleoside transport inhibitor nitrobenzylthioinosine (NBMPR). In vitro studies with tubercidin demonstrated ID50 values of 0.43 and 0.51 microM for FCQ-27 and K-1, respectively. In addition, the nucleoside transport inhibitors NBMPR, nitrobenzylthioguanosine (NBTGR), dilazep and dipyridamole also independently exhibited antimalarial activity in vitro. The combination of tubercidin and NBMPR or NBTGR in vitro demonstrated synergistic activity, whilst tubercidin together with dilazep or dipyridamole showed subadditive activity. Analysis by HPLC indicated that NBMPR could permeate the infected cell membrane and provided evidence for the catabolism of NBMPR in vitro, with subsequent alteration of the purine pool in the infected erythrocyte. These observations further indicated the possibility of the utilization of cytotoxic nucleosides against P. falciparum infection in conjunction with a nucleoside transport inhibitor to protect the host tissue.

  14. Challenges in implementing individualized medicine illustrated by antimetabolite therapy of childhood acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Nersting, Jacob; Borst, Louise; Schmiegelow, Kjeld

    2011-01-01

    of acceptable toxicity, an individualized therapeutic approach is indicated. The mapping of the human genome and technological developments in DNA sequencing, gene expression profiling, and proteomics have raised the expectations for implementing genotype-phenotype data into the clinical decision process...... illustrated by studies involving childhood acute lymphoblastic leukemia (ALL), where each patient may receive up to 13 different anticancer agents over a period of 2-3 years. The challenges include i) addressing important, but low-frequency outcomes, ii) difficulties in interpreting the impact of single drug...

  15. Influence of methylene tetrahydrofolate reductase polymorphisms and coadministration of antimetabolites on toxicity after high dose methotrexate

    DEFF Research Database (Denmark)

    Niekerk, P.B. van Kooten; Schmiegelow, K.; Schroeder, H.

    2008-01-01

    BACKGROUND AND OBJECTIVE: Through interruption of maintenance treatment with 6-mercaptopurine (6MP), toxicity after high-dose methotrexate (HDMTX) may compromise the efficiency of the treatment of children with acute lymphocytic leukaemia (ALL). We investigated the influence of polymorphisms......-intensity co-treatment (6MP 75 mg/m(2)/d + MTX 20 mg/m(2)/wk) was found associated with increased odds of haematological toxicity (OR's: 3.47-7.88; P's: fever (OR = 2.2; P = 0.004) and interruption maintenance treatment (OR = 15.9; P ....006-0.027), fever (OR = 2.65; P = 0.037) and interruption of maintenance treatment (OR = 3.04; P = 0.032). No convincing associations were found between the MTHFR C677T or A1298C polymorphisms and toxicity. CONCLUSION: Our findings demonstrate that toxicity after HDMTX is influenced by coadministrated...

  16. Challenges in implementing individualized medicine illustrated by antimetabolite therapy of childhood acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Nersting, Jacob; Borst, Louise; Schmiegelow, Kjeld

    2011-01-01

    of acceptable toxicity, an individualized therapeutic approach is indicated. The mapping of the human genome and technological developments in DNA sequencing, gene expression profiling, and proteomics have raised the expectations for implementing genotype-phenotype data into the clinical decision process......, but also multiplied the complex interaction of genetic and other laboratory parameters that can be used for therapy adjustments. Thus, with the advances in the laboratory techniques, post laboratory issues have become major obstacles for treatment individualization. Many of these challenges have been...... or single gene response data that often vary across treatment protocols, iii) combining disease and host genomics with outcome variations, and iv) physicians' reluctance in implementing potentially useful genotype and phenotype data into clinical practice, since unjustified downward or upward dose...

  17. Inhibition of lettuce seed germination and seedling growth by antimetabolites of nucleic acids, and reversal by nucleic acid precursors and gibberellic acid.

    Science.gov (United States)

    Khan, A A

    1966-03-01

    Germination of White Paris lettuce seeds is inhibited by 2-thiouracil up to 24 hours. This inhibition is reversed by RNA precursors only. Seedling growth of lettuce is inhibited by 2-thiouracil and 5-fluorouracil; and white the effect of 2-thiouracil is counteracted by RNA precursors, inhibition due to 5-fluorouracil is not reversed significantly by any nucleic acid precursors. Possibly 2-thiouracil controls germination and seedling growth by interfering with RNA synthesis, while the effect of 5-fluorouracil is non-specific.In the presence of gibberellic acid, 5-fluorouracil and 2-thiouracil are relatively ineffective in causing inhibition of hypocotyl growth. Mechanism of gibberellic acid action remains obscure.

  18. Drug: D01784 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ] L ANTINEOPLASTIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BC Pyrimidine analogue...BC04] D01784 Carmofur (JP16/INN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogues Carmofur

  19. Drug: D07472 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available PLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid analogues L01BA04 Pemetrexed...Pemetrexed (INN) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogues Pemetrexed [ATC:L01BA04

  20. Drug: D03046 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available STIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BC Pyrimidine analogue...46 Cytarabine ocfosphate hydrate (JAN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogue

  1. Experimente ueber den Einflusse von Metaboliten und Antimetaboliten am Modell von Trichomonas Vaginalis. VI. (Experiments on the Influence of Metabolites and Antimetabolites on the Model of Trichomonas Vaginalis. VI. Communication: Effect of Vitamins and Vitamin-Like Substances),

    Science.gov (United States)

    A number of substances (folic acid, axerophtol, tokopherol and others) stimulate the growth of Trichomonas vaginalis and, therefore, are very well...group of vitamins (thiamine, lactoflavin, pyridoxine and others) are without recognizeable effect upon the growth of Trichomonas vaginalis . The third...inhibiting effect upon the growth of Trichomonas vaginalis . Further investigations with these substances within a combined inhibition system seem to be important. (Modified author abstract)

  2. Drug: D08603 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available neoplastic, antimetabolite Same as: C07648 ATC code: L01BB03 Guanine [CPD:C00242] analogue Genomic biomarker...AGENTS L01B ANTIMETABOLITES L01BB Purine analogues L01BB03 Tioguanine D08603 Tioguanine (INN) Antineoplastic...s [BR:br08308] Antimetabolites Purine analogues Tioguanine [ATC:L01BB03] D08603 Tioguanine (INN) CAS: 154-42

  3. Drug: D03665 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available gif Antineoplastic ATC code: L01BC08 Cytidine [CPD:C00475] analogue DNA methyltransferase inhibitor [HSA:178...INEOPLASTIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BC Pyrimidine analogue...itabine [ATC:L01BC08] D03665 Decitabine (USAN/INN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogue

  4. Drug: D02115 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid analogues L01BA01 Methotrexate D02115 Methotr...1BA01 L04AX03] D02115 Methotrexate sodium Antineoplastics [BR:br08308] Antimetabolites Folic acid analogue

  5. Drug: D01064 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid analogues L01BA03 Raltitrexed D01064...JAN/USAN/INN) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogues Raltitrexed [ATC:L01BA03] D0

  6. Drug: D05589 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available PLASTIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid analogue...exate [ATC:L01BA05] D05589 Pralatrexate (USAN/INN) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogue

  7. Drug: D06503 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available N) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogues Pemetrexed [...cation [BR:br08303] L ANTINEOPLASTIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid anal...ogues L01BA04 Pemetrexed D06503 Pemetrexed sodium hydrat

  8. Drug: D03828 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available NTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETABOLITES L01BA Folic acid analogues L01...7] Pemetrexed [ATC:L01BA04] D03828 Pemetrexed disodium (USAN) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogue

  9. Drug: D02131 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available nations D02131 Tegafur - uracil mixt Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogues Tegaf...3 Therapeutic category of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplast...ics 422 Antimetabolites 4229 Others D02131 Tegafur - uracil mixt Anatomical Therape

  10. Drug: D00584 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available A:1806] Genomic biomarker: DPYD [HSA:1806] map07041 Antineoplastics - antimetabolic agents map00983 Drug met...nts affecting cellular function 42 Antineoplastics 422 Antimetabolites 4223 Fluorouracils D00584 Fluorouraci... Fluorouracil (JP16/USP/INN) Antineoplastics [BR:br08308] Antimetabolites Pyrimid

  11. Drug: D00161 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available B02 Genomic biomarker: TPMT [HSA:7172] map07041 Antineoplastics - antimetabolic agents map07046 Immunosuppre...ng cellular function 42 Antineoplastics 422 Antimetabolites 4221 Mercaptopurines D00161 Mercaptopurine hydra...P drug classification [BR:br08302] Antineoplastics Antimetabolites Mercaptopurine D00161 Mercaptopurine hydr...ptopurine D00161 Mercaptopurine hydrate (JP16); Mercaptopurine (USP) Antineoplastics [BR:br08308] Antimetabo

  12. Drug: D03637 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available tive DNA polymerase inhibitor [EC:2.7.7.7] map07041 Antineoplastics - antimetabolic agents map07046 Immunosu...BC01] D03637 Cytarabine hydrochloride (USAN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogu

  13. Drug: D01309 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 00240(7298) Pyrimidine metabolism hsa00670(7298) One carbon pool by folate map07041 Antineoplastics...rugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics 422 Antimetabolites 4223

  14. Drug: D04197 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ] hsa00240(7298) Pyrimidine metabolism hsa00670(7298) One carbon pool by folate map07041 Antineoplastics - a...04197 Floxuridine (USP/INN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogues Floxuridine D0

  15. Drug: D05134 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 4 Agents affecting cellular function 42 Antineoplastics 422 Antimetabolites 4229 Others D05134 Nelarabine (J...S L01BB Purine analogues L01BB07 Nelarabine D05134 Nelarabine (JAN/USAN/INN); Nelzarabine (USAN) Antineoplastics

  16. THE EFFECTS OF GAMMA-INTERFERON COMBINED WITH 5-FLUOROURACIL OR 5-FLUORO-2'-DEOXYURIDINE ON PROLIFERATION AND ANTIGEN EXPRESSION IN A PANEL OF HUMAN COLORECTAL-CANCER CELL-LINES

    NARCIS (Netherlands)

    MAAS, IWHM; BOVEN, E; PINEDO, HM; SCHLUPER, HMM; Haisma, Hidde

    1991-01-01

    Gamma-Interferon (IFN-gamma) and the antimetabolites 5-fluorouracil (5-FU) and S-fluoro-2'-deoxyuridine (FUdR) were investigated as individual agents and in combination for their in vitro antiproliferative capacity and for their effect on the expression of HLA class-I antigen, carcinoembryonic antig

  17. The Pseudomonas aeruginosa oxyvinylglycine L-2-amino-4-methoxy-trans-3-butenoic acid inhibits growth of Erwinia amylovora and acts as a weak seed germination-arrest factor

    Science.gov (United States)

    The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid (AMB) is demonstrated to share biological activities with 4-formylaminooxyvinylglycine, a related molecule produced by Pseudomonas fluorescens WH6. We found that culture filtrates of a P. aeruginosa strain overproduc...

  18. Modulators of Response to Tumor Necrosis-related Apoptosis Inducing Ligand (TRAIL) Therapy in Ovarian Cancer

    Science.gov (United States)

    2011-05-01

    shifted its movement on the gel, suggesting an interaction and supporting previously reported data . -------#1------- --------#2...anthracycline (doxorubicin), a proteosome inhibitor (MG132), DNA damaging agents (UV, temozolomide ) and an antimetabolite (5-fluorouracil). Similarly...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources

  19. Modern technologies of refractory glaucoma treatment. Review

    Directory of Open Access Journals (Sweden)

    A. Yu. Rascheskov

    2014-07-01

    Full Text Available this article presents a review of available literature concerning basic directions of refractory glaucoma treatment. the surgical management of refractory glaucoma is presented by two main groups of surgical techniques: filtering surgery (including surgery with the use of antimetabolites and implants and cyclodestructive procederes. types of glaucoma drainages are described, modern valve drainage system is presented.

  20. Drug: D01155 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 0240(6240) Pyrimidine metabolism hsa00480(6240) Glutathione metabolism map07041 Antineoplastics... cellular function 42 Antineoplastics 422 Antimetabolites 4224 Cytosines D01155 Gemcitabine hydrochloride (J...807] Gemcitabine [ATC:L01BC05] D01155 Gemcitabine hydrochloride (JAN/USAN) Antineoplastics [BR:br08308] Anti

  1. Drug: D01370 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D01370.gif Antineoplastic [DS:H00006] Therapeutic category: 4291 ATC code: L01BB04 map07041 Antineoplastics... - antimetabolic agents Therapeutic category of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics...D01370 Cladribine (JAN/USAN/INN) Antineoplastics [BR:br08308] Antimetabolites Pur

  2. Drug: D07974 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available HSA:1806] Genomic biomarker: DPYD [HSA:1806] map07041 Antineoplastics - antimetabolic agents Anatomical Ther...stics [BR:br08308] Antimetabolites Pyrimidine analogues Fluorouracil [ATC:L01BC02] ...late synthase [HSA:7298] [KO:K00560] Fluorouracil [ATC:L01BC02] D07974 Fluorouracil sodium salt Antineopla

  3. Drug: D04931 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 3], SLC28A3 [HSA:64078], SLC29A1 [HSA:2030], SLC29A2 [HSA:3177] Genomic biomarker: TPMT [HSA:7172] map07041 Antineoplastics... classification [BR:br08302] Antineoplastics Antimetabolites Mercaptopurine D04931 Mercaptopurine (INN) Immu...nological Agents Immune Suppressants 6-Mercaptopurine D04931 Mercaptopurine (INN) Antineoplastics [BR:br0830

  4. Drug: D07966 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available derivative DNA synthesis inhibitor map07041 Antineoplastics - antimetabolic agents Anatomical Therapeutic Ch...abine (INN) USP drug classification [BR:br08302] Antineoplastics Antineoplastics, Other Fludarabine D07966 F...ludarabine (INN) Antineoplastics [BR:br08308] Antimetabolites Purine analogues Fl

  5. Drug: D06109 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D06109.gif Antineoplastic [DS:H00001 H00002] ATC code: L01BB03 Genomic biomarker: TPMT [HSA:7172] map07041 Antineoplastics...OLITES L01BB Purine analogues L01BB03 Tioguanine D06109 Thioguanine (USP) USP drug classification [BR:br08302] Antineoplastics... Antimetabolites Thioguanine D06109 Thioguanine (USP) Antineoplastics [BR:br08308] Antimet

  6. Drug: D03021 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 1786+1788+1789+29947) Cysteine and methionine metabolism map07041 Antineoplastics... - antimetabolic agents Therapeutic category of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics...L01BC07] D03021 Azacitidine (JAN/USAN/INN) Antineoplastics [BR:br08308] Antimetabolites Pyrimidine analogues

  7. Drug: D01223 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available pool by folate Enzyme: CYP2C9 [HSA:1559] Genomic biomarker: DPYD [HSA:1806] map07041 Antineoplastics...drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics 422 Antimetabolites 4223...hase [HSA:7298] [KO:K00560] Capecitabine [ATC:L01BC06] D01223 Capecitabine (JAN/USAN/INN) Antineoplastics [B

  8. Identifying anti-growth factors for human cancer cell lines through genome-scale metabolic modeling

    DEFF Research Database (Denmark)

    Ghaffari, Pouyan; Mardinoglu, Adil; Asplund, Anna

    2015-01-01

    Human cancer cell lines are used as important model systems to study molecular mechanisms associated with tumor growth, hereunder how genomic and biological heterogeneity found in primary tumors affect cellular phenotypes. We reconstructed Genome scale metabolic models (GEMs) for eleven cell lines...... based on RNA-Seq data and validated the functionality of these models with data from metabolite profiling. We used cell line-specific GEMs to analyze the differences in the metabolism of cancer cell lines, and to explore the heterogeneous expression of the metabolic subsystems. Furthermore, we predicted...... antimetabolites using two cell lines with different phenotypic origins, and found that it is effective in inhibiting the growth of these cell lines. Using immunohistochemistry, we also showed high or moderate expression levels of proteins targeted by the validated antimetabolite. Identified anti-growth factors...

  9. ACTA-EVER lecture 2007 - The retinal pigment epithelium: friend or foe?

    DEFF Research Database (Denmark)

    La Cour, Morten

    2008-01-01

    far. We report on a drug delivery system under development where a prodrug of the antimetabolite 5-fluoro-uracil (5-FU) is suspended in the silicone oil used as a surgical device in the treatment of proliferative vitreoretinopathy (PVR). The theoretical advantage of this approach is that it allows...... for long contact times between therapeutic, and non-toxic, concentrations of 5-FU and the RPE Udgivelsesdato: 2008/9...

  10. Glucose-mediated control of ghrelin release from primary cultures of gastric mucosal cells

    OpenAIRE

    Sakata, Ichiro; Park, Won-Mee; Walker, Angela K.; Piper, Paul K.; Chuang, Jen-Chieh; Osborne-Lawrence, Sherri; Zigman, Jeffrey M.

    2012-01-01

    The peptide hormone ghrelin is released from a distinct group of gastrointestinal cells in response to caloric restriction, whereas its levels fall after eating. The mechanisms by which ghrelin secretion is regulated remain largely unknown. Here, we have used primary cultures of mouse gastric mucosal cells to investigate ghrelin secretion, with an emphasis on the role of glucose. Ghrelin secretion from these cells upon exposure to different d-glucose concentrations, the glucose antimetabolite...

  11. Drug: D00142 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available xate [ATC:L01BA01 L04AX03] D00142 Methotrexate (JP16/USP/INN) Antineoplastics [BR:br08308] Antimetabolites Folic acid analogue...OLITES L01BA Folic acid analogues L01BA01 Methotrexate D00142 Methotrexate (JP16/USP/INN) L04 IMMUNOSUPPRESS...ification [BR:br08303] L ANTINEOPLASTIC AND IMMUNOMODULATING AGENTS L01 ANTINEOPLASTIC AGENTS L01B ANTIMETAB

  12. p300/CBP-mediated p53 acetylation is commonly induced by p53-activating agents and inhibited by MDM2

    OpenAIRE

    2001-01-01

    The tumor suppressor p53 is activated in response to many types of cellular and environmental insults via mechanisms involving post-translational modification. Here we demonstrate that, unlike phosphorylation, p53 invariably undergoes acetylation in cells exposed to a variety of stress-inducing agents including hypoxia, anti-metabolites, nuclear export inhibitor and actinomycin D treatment. In vivo, p53 acetylation is mediated by the p300 and CBP acetyltransferases. Overexpression of either p...

  13. The effect of vitamin E and L-carnitine against methotrexate-induced injury in rat testis

    OpenAIRE

    YÜNCÜ, MEHMET; BÜKÜCÜ, NEZAHAT; BAYAT, NURAY; SENCAR, LEMAN; Tarakçioğlu, Mehmet

    2015-01-01

    Background/aim: Methotrexate (MTX), used commonly as an antimetabolite drug in cancer therapy, leads to acute toxic side effects in tissues or organs containing rapidly dividing cells, such as bone marrow, gastrointestinal mucosa, and seminiferous tubules. In this study, we investigated the protective effects of vitamin E and L-carnitine against MTX-induced injury in rat testis. Materials and methods: Rats were divided into 4 groups, including the control group. The study took 17 days and th...

  14. Drug: D01907 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available s inhibitor purine analogue arabinofuranosyl derivative prodrug, active substance: Fludarabine [DR:D07966] map07041 Antineoplastics...tic category of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics 422 Anti.../USP) USP drug classification [BR:br08302] Antineoplastics Antineoplastics, Other Fludarabine D01907 Fludara...bine phosphate (JAN/USP) Antineoplastics [BR:br08308] Antimetabolites Purine anal

  15. In vitro sensitivity of human ovarian tumours to chemotherapeutic agents.

    OpenAIRE

    1981-01-01

    The in vitro chemosensitivity of primary monolayer cultures of human ovarian tumours to a wide range of chemotherapeutic agents has been determined using 3H-leucine incorporation as an index of cytotoxicity. Of 67 specimens received, 35 have been successfully cultured and tested for chemosensitivity. Drugs tested included alkylating agents, antibiotics, antimitotics, antimetabolites and progestogens. The overall incidence of efficacy of the drugs corresponded with the incidence which might be...

  16. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

    OpenAIRE

    Céspedes, María Virtudes; Guillén, María José; López-Casas, Pedro Pablo; SARNO, Francesca; Gallardo, Alberto; Álamo, Patricia; Cuevas, Carmen; Hidalgo, Manuel; Galmarini, Carlos María; Allavena, Paola; Avilés, Pablo; Mangues, Ramón

    2016-01-01

    ABSTRACT We explored whether the combination of lurbinectedin (PM01183) with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA) mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i) specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii) specific depleti...

  17. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

    OpenAIRE

    María Virtudes Céspedes; María José Guillén; Pedro Pablo López-Casas; Francesca Sarno; Alberto Gallardo; Patricia Álamo; Carmen Cuevas; Manuel Hidalgo; Carlos María Galmarini; Paola Allavena; Pablo Avilés; Ramón Mangues

    2016-01-01

    We explored whether the combination of lurbinectedin (PM01183) with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA) mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i) specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii) specific depletion of tum...

  18. Pemetrexed-Induced Nephrogenic Diabetes Insipidus.

    Science.gov (United States)

    Fung, Enrica; Anand, Shuchi; Bhalla, Vivek

    2016-10-01

    Pemetrexed is an approved antimetabolite agent, now widely used for treating locally advanced or metastatic nonsquamous non-small cell lung cancer. Although no electrolyte abnormalities are described in the prescribing information for this drug, several case reports have noted nephrogenic diabetes insipidus with associated acute kidney injury. We present a case of nephrogenic diabetes insipidus without severely reduced kidney function and propose a mechanism for the isolated finding. Severe hypernatremia can lead to encephalopathy and osmotic demyelination, and our report highlights the importance of careful monitoring of electrolytes and kidney function in patients with lung cancer receiving pemetrexed.

  19. Progression from Sustained BK Viruria to Sustained BK Viremia with Immunosuppression Reduction Is Not Associated with Changes in the Noncoding Control Region of the BK Virus Genome

    Directory of Open Access Journals (Sweden)

    Imran A. Memon

    2012-01-01

    We performed PCR amplification and sequencing of (1 stored urine and (2 plasma samples from the time of peak viremia from 11 patients with sustained viremia who participated in a 200-patient clinical trial. The antimetabolite was withdrawn for BK viremia and reduction of the calcineurin inhibitor for sustained BK viremia. DNA sequencing from the 11 patients with sustained viremia revealed 8 insertions, 16 transversions, 3 deletions, and 17 transitions. None were deemed significant. No patient developed clinically evident BKVAN. Our data support, at a genomic level, the effectiveness of reduction of immunosuppression for prevention of progression from viremia to BKVAN.

  20. S-1 induced secondary acute erythroid leukemia with a chromosome inv(12)(p13;q13)

    Institute of Scientific and Technical Information of China (English)

    Kensuke Matsumoto; Akira Kitanaka; Makiko Uemura; Fusako Waki; Tetsuya Fukumoto; Hiroaki Ohnishi; Yoshitsugu Kubota; Toshihiko Ishida

    2011-01-01

    Adjuvant chemotherapy by S-1 following gastrectomy is considered standard treatment in Japan. Analysis of follow-up data have proved the efficacy of S-1 administration,and that hematological adverse events were relatively rare. PPyrimidine anti-metabolites, including S-1, have shown relatively lower risks for secondary hematological malignancies in comparison to alkylating agents and topoisomerase-Ⅱ inhibitors. We here report a case of therapy-related leukemia after S-1 administration. A patient who had received S-1as the sole adjuvant chemotherapy was diagnosed with acute erythroid leukemia. To the best of our knowledge, our patient represents the first report of S-1 induced acute leukemia.

  1. A Review of the Course and Treatment of Non-Infectious Uveitis during Pregnancy.

    Science.gov (United States)

    Grotting, Lindsay A; Papaliodis, George N

    2017-01-01

    Inflammatory conditions such as autoimmune uveitis often occur in women of childbearing age. During pregnancy, women may experience exacerbations of their disease in the first trimester. In the later stages of pregnancy, however, the uveitis tends to remain less active. The management of uveitis during pregnancy is a challenging task, forcing the physician to re-evaluate the patient's current therapy and offer alternative options that pose the least risk to the patient and fetus. This article will review treatments widely used for uveitis, including corticosteroid therapy, anti-metabolites, calcineurin inhibitors, and biologic therapy. It will evaluate the use of these medications in pregnancy and the postpartum state.

  2. Long term follow-up of remission patients in adult acute leukemia.

    Science.gov (United States)

    Gerecke, D; Kress, M; Hirschmann, W D

    1983-10-03

    31 adults suffering from acute leukemia were followed for a period of more than 5 years after achieving complete remission. Maintenance chemotherapy consisted of antimetabolite treatment (mercaptopurine + methotrexate) as well as COAP reinduction every 3 months. Chemotherapy was stopped if the first complete remission lasted for 3 years ("long term remission"). This was the case in 8 out of 31 remission patients (26%). Analysis of hematological parameters at diagnose for long term remission patients revealed that the initial leukocyte count was of prognostic significance.

  3. Drug: D00341 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available etabolism hsa04115(6241) p53 signaling pathway map07041 Antineoplastics - antimetabolic agents Therapeutic c...ategory of drugs in Japan [BR:br08301] 4 Agents affecting cellular function 42 Antineoplastics 422 Antimetab...:6241] [KO:K10808] Hydroxycarbamide [ATC:L01XX05] D00341 Hydroxycarbamide (JAN/INN); Hydroxyurea (USP) Antineoplastics...ide D00341 Hydroxycarbamide (JAN/INN); Hydroxyurea (USP) USP drug classification [BR:br08302] Antineoplast...ics Antimetabolites Hydroxyurea D00341 Hydroxycarbamide (JAN/INN); Hydroxyurea (USP

  4. Effects of methotrexate on rat P-450 cytochrome mono-oxygenases; Action du methotrexate sur les monooxygenases a cytochromes P-450 chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Guitton, J.; Guilluy, R.; Brazier, J.L. [Faculte de Pharmacie, 69 - Lyon (France); Souillet, G. [Hopital Debrousse, 69 - Lyon (France); Riviere, J.L. [INRA, 69 - Marcy l`Etoile (France); Gerard, F. [Institut Pasteur, 69 - Lyon (France)

    1994-12-31

    Methotrexate, an anti-cancerous agent, acts as an anti-metabolite of the nucleic acids which synthesis is then inhibited. Using aminopyrine breath test after methotrexate processing, the effects of the molecule on activities of the hepatocyte P-450 cytochrome mono-oxygenases, are studied. Breath micro-tests with carbon 13-labelled aminopyrine have been carried out to observe the metabolism evolution. Micro-test results have been compared to microsomal enzymatic activities for various substrates, and also to P-450 cytochrome ratio. Results show that methotrexate induces a reduction in the P-450 cytochrome ratio, and thus reduce the hepatic biotransformation process. 1 fig., 30 refs.

  5. Antineoplastic Drugs : Treatment Principles and Toxicity

    Directory of Open Access Journals (Sweden)

    Bibu John Kariyil

    Full Text Available The therapy of cancer has improved dramatically during the past half century. This improvement can be traced to a number of factors: a better understanding of cancer's cause and natural history, better technologies for early detection and diagnosis, improved control of primary tumors through surgery and radiation therapy and more effective drugs. The evolution of drug therapy for cancer has progressed rapidly from alkylating agents and antimetabolites to natural products, and most recently, molecular targeted drugs such as imatinib and gefitinib. As our understanding of the biology of cancer improves, new targets for therapy are being identified daily. [Vet. World 2011; 4(8.000: 380-382

  6. Biosynthesis of fluorothreonine and fluoroacetic acid by the thienamycin producer, Streptomyces cattleya.

    Science.gov (United States)

    Sanada, M; Miyano, T; Iwadare, S; Williamson, J M; Arison, B H; Smith, J L; Douglas, A W; Liesch, J M; Inamine, E

    1986-02-01

    An antimetabolite, THX, was isolated from fermentation broths of the thienamycin producer, Streptomyces cattleya, when the organism was grown in the presence of a fluorine-containing substrate. THX was subsequently identified as one of the four possible stereoisomers of 4-fluorothreonine. Inorganic fluoride or any one of a number of organofluorine compounds can be used as precursors of 4-fluorothreonine. In addition, 19F NMR has provided evidence that the organism synthesizes fluoroacetate under the same fermentation conditions. The in vitro antibacterial spectrum of 4-fluorothreonine is also presented.

  7. Control of plant defense mechanisms and fire blight pathogenesis through the regulation of 6-thioguanine biosynthesis in Erwinia amylovora.

    Science.gov (United States)

    Coyne, Sébastien; Litomska, Agnieszka; Chizzali, Cornelia; Khalil, Mohammed N A; Richter, Klaus; Beerhues, Ludger; Hertweck, Christian

    2014-02-10

    Fire blight is a devastating disease of Rosaceae plants, such as apple and pear trees. It is characterized by necrosis of plant tissue, caused by the phytopathogenic bacterium Erwinia amylovora. The plant pathogen produces the well-known antimetabolite 6-thioguanine (6TG), which plays a key role in fire blight pathogenesis. Here we report that YcfR, a member of the LTTR family, is a major regulator of 6TG biosynthesis in E. amylovora. Inactivation of the regulator gene (ycfR) led to dramatically decreased 6TG production. Infection assays with apple plants (Malus domestica cultivar Holsteiner Cox) and cell cultures of Sorbus aucuparia (mountain ash, rowan) revealed abortive fire blight pathogenesis and reduced plant response (biphenyl and dibenzofuran phytoalexin production). In the presence of the ΔycfR mutant, apple trees were capable of activating the abscission machinery to remove infected tissue. In addition to unveiling the regulation of 6TG biosynthesis in a major plant pathogen, we demonstrate for the first time that this antimetabolite plays a pivotal role in dysregulating the plant response to infection.

  8. Effects of phytanic acid on the vitamin E status, lipid composition and physical properties of retinal cell membranes: implications for adult Refsum disease.

    Science.gov (United States)

    Young, S P; Johnson, A W; Muller, D P

    2001-12-01

    Adult Refsum disease is an inherited disorder in which phytanic acid accumulates in tissues and serum. Two hypotheses have been proposed to explain the pathogenesis of this condition. The molecular distortion hypothesis suggests that phytanic acid may alter membrane composition and structure, thereby affecting membrane function(s). The anti-metabolite hypothesis suggests that an accumulation of phytanic acid in membranes may interfere with vitamin E function. These two hypotheses were investigated by studying the effects of modulating phytanic acid and alpha-tocopherol concentrations on the fatty acid composition and certain physical parameters of cultured retinal cells. Results showed that (a) the phospholipid fraction of retinal cells readily incorporated phytanic acid, (b) the incorporation of phytanic acid increased membrane fluidity, (c) there was no competition for uptake between phytanic acid and alpha-tocopherol, and (d) the incorporation of phytanic acid did not increase the susceptibility of membranes to lipid peroxidation in vitro. These results obtained with cultured retinal cells suggest that the molecular distortion hypothesis, but not the anti-metabolite hypothesis, could explain the pathogenesis of adult Refsum disease. In vitro tissue culture models can, however, only approximate to the much more complex situation that occurs in vivo.

  9. From molecular insight to therapeutic strategy: The holistic approach for treating triple negative breast cancer.

    Science.gov (United States)

    Bhattacharya, Rittwika; Banerjee, Koyel; Mukherjee, Nupur; Sen, Minakshi; Mukhopadhyay, Ashis

    2017-03-01

    Aim of the present study was to analyze the molecular pathogenesis of TNBC, therapeutic practice, challenges, and future goals in treatment strategies. Based on the alterations of distinct pathways, Lehmann's subgroups of TNBCs were further categorized. Those with defective DNA damage repair and replication pathways, viz. Basal Like 1 & 2 (BL1, BL2) were found susceptible to DNA intercalating drugs while those with upregulated cell signalling & motility (mesenchymal (M), mesemchymal stem like (MSL)), cell survival (BL2, M, MSL), angiogenesis (BL2, MSL), T cell signalling (Immunomodulatory/IM) pathways required targeted therapies. Our Meta-analysis categorized 12 randomized previous trial cases, solely under the following drug regimens: [1] DNA destabilizers, [2] PARP inhibitors, [3] Microtubule stabilizers, [4] Angiogenesis inhibitors, [5] Antimetabolite, [6] T cell targeted therapy; as single or combinational therapy. Best therapeutic efficacies of DNA destabilizers with angiogenesis inhibitors in combination than monotherapy with either (OR: 5.011-7.286; p value<0.001) indicated a significant prevalence of BL1 type TNBCs in populations. Statistical significance with antimetabolites as combination therapy (OR: 2.343; p value: 0.018) and not with microtubule stabilizer (OR: 0.377) were observed. Thus, for best ORR in TNBC, personalized medicine should be the therapeutic choice for the clinicians.

  10. One year follow-up of the cardio-metabolic profile evolution in renal transplant patients treated with alemtuzumab, cyclosporine, and steroids in a reference hospital in Colombia

    Directory of Open Access Journals (Sweden)

    Nieto-Ríos, John Fredy

    2015-10-01

    Full Text Available Introduction: Cardiovascular events occur 50 times more often in kidney transplant patients than in the general population and are the leading cause of death. The aim of the study was to evaluate the behavior of cardio-metabolic profile and determine the incidence of major cardiovascular events in the first year after transplantation. Methods: This prospective study evaluated the behavior of cardio-metabolic profile in adult patients that were transplanted during 2011. Results: The median age was 44.3 ± 12.05 years, 68.7 % were men and 95.5 %, hypertensive. Alemtuzumab-cyclosporine and steroids were used in 89.6 %, delaying the introduction of the antimetabolite. In the first year after transplantation there were three cases of diabetes mellitus, three major cardiovascular events, and 12 cases of acute rejection. Albumin, hemoglobin, weight, body mass index (BMI, calcium and HbA1C increased (p<0.05, whereas paratohormone, phosphorus, creatinine and uric acid decreased (p<0.05. Glomerular filtration rate (GFR was higher in patients without rejection (p=0.001. Conclusion: This immunosuppressive protocol with alemtuzumab, cyclosporine and steroids, and the delayed introduction of the antimetabolite improved bone mineral metabolism, uric acid, albumin and hemoglobin, but there were negative effects on HbA1c, weight and BMI. There was a low incidence of new onset diabetes mellitus and major ardiovascular events.

  11. Overview of immunosuppression in liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Anjana A Pillai; Josh Levitsky

    2009-01-01

    Continued advances in surgical techniques and immunosuppressive therapy have allowed liver transplantation to become an extremely successful treatment option for patients with end-stage liver disease. Beginning with the revolutionary discovery of cyclosporine in the 1970s, immunosuppressive regimens have evolved greatly and current statistics confirm one-year graft survival rates in excess of 80%. Immunosuppressive regimens include calcineurin inhibitors, anti-metabolites, mTOR inhibitors, steroids and antibody-based therapies. These agents target different sites in the T cell activation cascade, usually by inhibiting T cell activation or via T cell depletion. They are used as induction therapy in the immediate periand post-operative period, as long-term maintenance medications to preserve graft function and as salvage therapy for acute rejection in liver transplant recipients. This review will focus on existing immunosuppressive agents for liver transplantation and consider newer medications on the horizon.

  12. Progression from Sustained BK Viruria to Sustained BK Viremia with Immunosuppression Reduction Is Not Associated with Changes in the Noncoding Control Region of the BK Virus Genome

    Science.gov (United States)

    Memon, Imran A.; Parikh, Bijal A.; Gaudreault-Keener, Monique; Skelton, Rebecca; Storch, Gregory A.; Brennan, Daniel C.

    2012-01-01

    Changes in the BK virus archetypal noncoding control region (NCCR) have been associated with BK-virus-associated nephropathy (BKVAN). Whether sustained viremia, a surrogate for BKVAN, is associated with significant changes in the BK-NCCR is unknown. We performed PCR amplification and sequencing of (1) stored urine and (2) plasma samples from the time of peak viremia from 11 patients with sustained viremia who participated in a 200-patient clinical trial. The antimetabolite was withdrawn for BK viremia and reduction of the calcineurin inhibitor for sustained BK viremia. DNA sequencing from the 11 patients with sustained viremia revealed 8 insertions, 16 transversions, 3 deletions, and 17 transitions. None were deemed significant. No patient developed clinically evident BKVAN. Our data support, at a genomic level, the effectiveness of reduction of immunosuppression for prevention of progression from viremia to BKVAN. PMID:22701777

  13. Takotsubo Cardiomyopathy and 5-Fluorouracil: Getting to the Heart of the Matter

    Directory of Open Access Journals (Sweden)

    Stephanie Hui-Su Lim

    2013-01-01

    Full Text Available Takotsubo cardiomyopathy is a rare but increasingly recognized phenomenon, which can occur as a side-effect of chemotherapeutic agents, in particular, the antimetabolite 5-fluorouracil. We describe a case of delayed Takotsubo cardiomyopathy after 3 weeks of adjuvant 5-fluorouracil for resected rectal adenocarcinoma in a 66-year-old female, supported by angiographic, electrocardiographic, and echocardiographic features. As a complication, she developed an apical mural thrombus with subsequent cerebral thromboembolic events and was successfully anticoagulated to make a full recovery. We present a review of the literature on Takotsubo cardiomyopathy secondary to 5-fluorouracil and the rare occurrence of thromboembolic complications. As this is a significant clinical phenomenon which involves a multispeciality approach to management, oncologists and cardiologists need to recognize it as a potential toxicity of a widely administered chemotherapeutic drug.

  14. Study of the use possibility of the chemical-biological adduct of the 1,1-bis-[5-bromopyrimidine-2’,4’-diono-1’-il]-2-bromo-2’-chloroethylene and bacterial lectin for the treatment of the Pliss’ lymphosarcoma

    Directory of Open Access Journals (Sweden)

    O. V. Welchinska

    2015-04-01

    Full Text Available Aim. Study of the pyrimidine metabolism antimetabolites that can be preformed compounds in the link of biosynthetic processes and can brake tumour’s growth is a more successful, perspective finding direction of new antitumor medications. New original chemical-biological adduct was studied as potential antitumor agent. Methods and results. It was obtained on the base of 1,1-bis-[5-bromopyrimidine-2’,4’-diono-1’-il]-2-bromo-2’-chloroethylene and antitumour bacterial lectin from Bacillus polymyxa. It was found that new chemical-biological adduct of bis-derivative of pyrimidine and bacterial lectin has little toxic preparation (LD50=635 mg/kg and demonstrates considerable antitumour effect upon to 65.5% on Pliss Limphosarcoma tumour. Conclusion. It confirms that new chemical-biological adduct is perspective for the future investigation as substance with a little toxicity and high antitumour activity on the Pliss Limphosarcoma.

  15. The Pseudomonas aeruginosa toxin L-2-amino-4-methoxy-trans-3-butenoic acid inhibits growth and induces encystment in Acanthamoeba castellanii.

    Science.gov (United States)

    Lee, Xiaoyun; Reimmann, Cornelia; Greub, Gilbert; Sufrin, Janice; Croxatto, Antony

    2012-03-01

    L-2-Amino-4-methoxy-trans-3-butenoic acid (AMB) is a toxic antimetabolite produced by the opportunistic pathogen Pseudomonas aeruginosa. To evaluate its importance as a potential virulence factor, we tested the host response towards AMB using an Acanthamoeba castellanii cell model. We found that AMB (at concentrations ≥ 0.5 mM) caused amoebal encystment in salt buffer, while inhibiting amoebal growth in rich medium in a dose-dependent manner. However, no difference in amoebal plaque formation was observed on bacterial lawns of wild type and AMB-negative P. aeruginosa strains. We thereby conclude that AMB may eventually act as a virulence factor, but only at relatively high concentrations.

  16. Pharmacogenetics of azathioprine in inflammatory bowel disease: a role for glutathione-S-transferase?

    Science.gov (United States)

    Stocco, Gabriele; Pelin, Marco; Franca, Raffaella; De Iudicibus, Sara; Cuzzoni, Eva; Favretto, Diego; Martelossi, Stefano; Ventura, Alessandro; Decorti, Giuliana

    2014-04-01

    Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

  17. Methotrexate Toxicity in Growing Long Bones of Young Rats: A Model for Studying Cancer Chemotherapy-Induced Bone Growth Defects in Children

    Directory of Open Access Journals (Sweden)

    Chiaming Fan

    2011-01-01

    Full Text Available The advancement and intensive use of chemotherapy in treating childhood cancers has led to a growing population of young cancer survivors who face increased bone health risks. However, the underlying mechanisms for chemotherapy-induced skeletal defects remain largely unclear. Methotrexate (MTX, the most commonly used antimetabolite in paediatric cancer treatment, is known to cause bone growth defects in children undergoing chemotherapy. Animal studies not only have confirmed the clinical observations but also have increased our understanding of the mechanisms underlying chemotherapy-induced skeletal damage. These models revealed that high-dose MTX can cause growth plate dysfunction, damage osteoprogenitor cells, suppress bone formation, and increase bone resorption and marrow adipogenesis, resulting in overall bone loss. While recent rat studies have shown that antidote folinic acid can reduce MTX damage in the growth plate and bone, future studies should investigate potential adjuvant treatments to reduce chemotherapy-induced skeletal toxicities.

  18. Systemic Treatments for Noninfectious Vitreous Inflammation

    Directory of Open Access Journals (Sweden)

    Angela Jiang

    2013-01-01

    Full Text Available Vitreous inflammation, or vitritis, may result from many causes, including both infectious and noninfectious, including rheumatologic and autoimmune processes. Vitritis is commonly vision threatening and has serious sequelae. Treatment is frequently challenging, but, today, there are multiple methods of systemic treatment for vitritis. These categories include corticosteroids, antimetabolites, alkylating agents, T-cell inhibitors/calcineurin inhibitors, and biologic agents. These treatment categories were reviewed last year, but, even over the course of just a year, many therapies have made progress, as we have learned more about their indications and efficacy. We discuss here discoveries made over the past year on both existing and new drugs, as well as reviewing mechanisms of action, clinical dosages, specific conditions that are treated, adverse effects, and usual course of treatment for each class of therapy.

  19. Endogenous ethanol--its metabolic, behavioral and biomedical significance.

    Science.gov (United States)

    Ostrovsky YuM

    1986-01-01

    Ethanol is constantly formed endogenously from acetaldehyde, and level of the former can be measured in both human beings and animals. Acetaldehyde can be generated in situ from the metabolism of pyruvate, threonine, deoxyribose-5-phosphate, phosphoethanolamine, alanine and presumably from other substrates. The levels of blood and tissue endogenous ethanol change as a function of various physiologic and experimental conditions such as starvation, aging, stress, cooling, adrenalectomy, etc. and are regulated by many exogenous compounds such as antimetabolites, derivatives of amino acids, lithium salts, disulfiram, cyanamide, etc. Under free choice alcohol selection situations, the levels of endogenous ethanol in rat blood and alcohol preference by the animals are negatively correlated. Similar negative correlations have been found between the levels of blood endogenous ethanol and the frequency of delirium in alcoholic patients undergoing alcohol withdrawal. Endogenous ethanol and acetaldehyde can therefore be regarded as compounds which fulfil substrate, regulatory and modulator functions.

  20. Dermatomyositis and polymyositis in childhood.

    Science.gov (United States)

    Gamstorp, I

    1990-01-01

    Personal experience of 30 years work with 40-50 cases of dermatomyositis and polymyositis in childhood is reviewed, stressing the clinical findings of skin eruptions on the knuckles, elbows and knees (except in the 10 per cent of patients without any skin involvement), weakness of particularly proximal muscles and tightness of tendons. Special diagnostic procedures are reviewed as well as treatment. The basic treatment is corticosteroids, which must be started at a high dose and as soon as possible be given at intervals of 48 hours to diminish the side-effects. In many, though not all, patients the treatment must be continued for years. The parents should always know that extended treatment may be necessary. Physiotherapy should be started cautiously and be slowly increased, close co-operation between the physician and the physiotherapist being necessary. If the patient does not respond to corticosteroids, antimetabolites may be added. Most patients survive with no or only minor sequelae.

  1. Docking Studies in Target Proteins Involved in Antibacterial Action Mechanisms: Extending the Knowledge on Standard Antibiotics to Antimicrobial Mushroom Compounds

    Directory of Open Access Journals (Sweden)

    Maria José Alves

    2014-01-01

    Full Text Available In the present work, the knowledge on target proteins of standard antibiotics was extended to antimicrobial mushroom compounds. Docking studies were performed for 34 compounds in order to evaluate their affinity to bacterial proteins that are known targets for some antibiotics with different mechanism of action: inhibitors of cell wall synthesis, inhibitors of protein synthesis, inhibitors of nucleic acids synthesis and antimetabolites. After validation of the molecular docking approach, virtual screening of all the compounds was performed against penicillin binding protein 1a (PBP1a, alanine racemase (Alr, d-alanyl-d-alanine synthetase (Ddl, isoleucyl-tRNA sinthetase (IARS, DNA gyrase subunit B, topoisomerase IV (TopoIV, dihydropteroate synthetase (DHPS and dihydrofolate reductase (DHFR using AutoDock4. Overall, it seems that for the selected mushroom compounds (namely, enokipodins, ganomycins and austrocortiluteins the main mechanism of the action is the inhibition of cell wall synthesis, being Alr and Ddl probable protein targets.

  2. In vivo response to methotrexate forecasts outcome of acute lymphoblastic leukemia and has a distinct gene expression profile.

    Directory of Open Access Journals (Sweden)

    Michael J Sorich

    2008-04-01

    Patients With Acute Lymphoblastic Leukemia, http://www.ClinicalTrials.gov (NCT00137111; Total XIIIBH, Phase III Randomized Study of Antimetabolite-Based Induction plus High-Dose MTX Consolidation for Newly Diagnosed Pediatric Acute Lymphocytic Leukemia at Intermediate or High Risk of Treatment Failure (NCI-T93-0101D; Total XIIIBL, Phase III Randomized Study of Antimetabolite-Based Induction plus High-Dose MTX Consolidation for Newly Diagnosed Pediatric Acute Lymphocytic Leukemia at Lower Risk of Treatment Failure (NCI-T93-0103D.

  3. Comparative Genomic Analyses of Multiple Pseudomonas Strains Infecting Corylus avellana Trees Reveal the Occurrence of Two Genetic Clusters with Both Common and Distinctive Virulence and Fitness Traits.

    Directory of Open Access Journals (Sweden)

    Simone Marcelletti

    Full Text Available The European hazelnut (Corylus avellana is threatened in Europe by several pseudomonads which cause symptoms ranging from twig dieback to tree death. A comparison of the draft genomes of nine Pseudomonas strains isolated from symptomatic C. avellana trees was performed to identify common and distinctive genomic traits. The thorough assessment of genetic relationships among the strains revealed two clearly distinct clusters: P. avellanae and P. syringae. The latter including the pathovars avellanae, coryli and syringae. Between these two clusters, no recombination event was found. A genomic island of approximately 20 kb, containing the hrp/hrc type III secretion system gene cluster, was found to be present without any genomic difference in all nine pseudomonads. The type III secretion system effector repertoires were remarkably different in the two groups, with P. avellanae showing a higher number of effectors. Homologue genes of the antimetabolite mangotoxin and ice nucleation activity clusters were found solely in all P. syringae pathovar strains, whereas the siderophore yersiniabactin was only present in P. avellanae. All nine strains have genes coding for pectic enzymes and sucrose metabolism. By contrast, they do not have genes coding for indolacetic acid and anti-insect toxin. Collectively, this study reveals that genomically different Pseudomonas can converge on the same host plant by suppressing the host defence mechanisms with the use of different virulence weapons. The integration into their genomes of a horizontally acquired genomic island could play a fundamental role in their evolution, perhaps giving them the ability to exploit new ecological niches.

  4. Koobabul, a promising fodder tree. [Leucaena leucocephala

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, P.C.; Khirwar, S.S.; Kripal, S.

    1983-01-01

    The main uses of koobabul (Leucaena leucocephala.) are listed; they include timber and fuelwood production, improving soil fertility, windbreaks and shade trees, and green manure. Koobabul meal can be used as a green fodder because of its high protein content. However, the results of a feeding trial at the Department of Animal Nutrition, using koobabul hay as sole fodder for sheep, suggest that it should be used with caution. The fodder contains the toxic compound mimosine which acts as an antimetabolite, inhibiting the utilization of tyrosine for formation and growth of normal wool and hair. Main symptoms of toxicity are excessive salivation, weight loss, loss of hair and wool, skin lesions and goitre. The defleecing effect is being tested as a sheep shearing method in Australia. It is suggested that the fodder can be safely given as up to 30% of cattle feed and 5-10% of the feed for non-ruminant species. Methods of reducing the mimosine content of koobabul meal are outlined.

  5. Glaucoma Surgery in Pregnancy: A Case Series and Literature Review

    Science.gov (United States)

    Razeghinejad, Mohammad Reza; Masoumpour, Masoumeh; Eghbal, Mohammad Hossein; Myers, Jonathan S.; Moster, Marlene R.

    2016-01-01

    Glaucoma management in pregnant patients is a real challenge, especially when the glaucoma is not controlled with medications. We report the results of 6 incisional glaucoma surgeries for the management of medically uncontrolled glaucoma patients during pregnancy. This retrospective, case series was conducted on the 6 eyes of 3pregnant patients with uncontrolled glaucoma using maximum tolerable medications. Details of the glaucoma surgical management of these patients as well as their postoperative care and pregnancy and clinical outcomes on longitudinal follow-up are discussed. All 3 patients had juvenile open-angle glaucoma and were on various anti-glaucoma medications, including oral acetazolamide. The first case described underwent trabeculectomy without antimetabolites in both eyes because of uncontrolled intraocular pressure with topical medications. The surgery was done with topical lidocaine jelly and subconjunctival lidocaine during the second and third trimesters. The second patient had an Ahmed valve implantation in both eyes during the second and third trimesters because of uncontrolled IOP with topical medications and no response to selective laser trabeculoplasty. Surgery was done with topical tetracaine and subconjunctival and sub-Tenon’s lidocaine. The third case had a Baerveldt valve implantation under general anesthesia in the second trimester. In selected pregnant glaucoma patients with medically uncontrolled intraocular pressure threatening vision, incisional surgery may lead to good outcomes for the patient with no risk for the fetus. PMID:27582594

  6. Chromosome segregation and organization are targets of 5'-Fluorouracil in eukaryotic cells.

    Science.gov (United States)

    Mojardín, Laura; Botet, Javier; Moreno, Sergio; Salas, Margarita

    2015-01-01

    The antimetabolite 5'-Fluorouracil (5FU) is an analog of uracil commonly employed as a chemotherapeutic agent in the treatment of a range of cancers including colorectal tumors. To assess the cellular effects of 5FU, we performed a genome-wide screening of the haploid deletion library of the eukaryotic model Schizosaccharomyces pombe. Our analysis validated previously characterized drug targets including RNA metabolism, but it also revealed unexpected mechanisms of action associated with chromosome segregation and organization (post-translational histone modification, histone exchange, heterochromatin). Further analysis showed that 5FU affects the heterochromatin structure (decreased levels of histone H3 lysine 9 methylation) and silencing (down-regulation of heterochromatic dg/dh transcripts). To our knowledge, this is the first time that defects in heterochromatin have been correlated with increased cytotoxicity to an anticancer drug. Moreover, the segregation of chromosomes, a process that requires an intact heterochromatin at centromeres, was impaired after drug exposure. These defects could be related to the induction of genes involved in chromatid cohesion and kinetochore assembly. Interestingly, we also observed that thiabendazole, a microtubule-destabilizing agent, synergistically enhanced the cytotoxic effects of 5FU. These findings point to new targets and drug combinations that could potentiate the effectiveness of 5FU-based treatments.

  7. Carcinoma-associated fibroblasts affect sensitivity to oxaliplatin and 5FU in colorectal cancer cells.

    Science.gov (United States)

    Gonçalves-Ribeiro, Samuel; Díaz-Maroto, Natalia Guillen; Berdiel-Acer, Mireia; Soriano, Antonio; Guardiola, Jordi; Martínez-Villacampa, Mercedes; Salazar, Ramon; Capellà, Gabriel; Villanueva, Alberto; Martínez-Balibrea, Eva; Molleví, David G

    2016-09-13

    The importance of tumor microenvironment (TME) as a relevant contributor to cancer progression and its role in the development of de novo resistance to targeted therapies has become increasingly apparent. However, the mechanisms of microenvironment-mediated drug resistance for nonspecific conventional chemotherapeutic agents, such as platinum compounds or antimetabolites, are still unclear.Here we describe a mechanism induced by soluble factors released by carcinoma-associated fibroblasts (CAFs) that induce the translocation of AKT, Survivin and P38 to the nucleus of tumor cells. These changes are guided to ensure DNA repair and the correct entrance and exit from mitosis in the presence of chemotherapy. We used conditioned media (CM) from normal-colonic fibroblasts and paired CAFs to assess dose response curves of oxaliplatin and 5-fluorouracil, separately or combined, compared with standard culture medium. We also evaluated a colony-forming assay and cell death to demonstrate the protective role of CAF-CM. Immunofluorescence confirmed the translocation of AKT, P38 and Survivin to the nucleus induced by CAF-soluble factors. We also have shown that STAT3 or P38 inhibition provides a promising strategy for overcoming microenvironment-mediated resistance. Conversely, pharmacologic AKT inhibition induces an antagonistic effect that relieves a cMET and STAT3-mediated compensatory feedback that might explain the failure of AKT inhibitors in the clinic so far.

  8. Cardiotoxicity of antineoplasic agents: onset, risk factors and clinical manifestation

    Directory of Open Access Journals (Sweden)

    Maria L. Rădulescu

    2011-11-01

    Full Text Available The continuously growing incidence of the neoplasic disease, estimated to be in 2020 themain cause of death in developed countries, has imposed an increasing research to discover newclasses of antineoplasic agents, which alone or in combination with classical chemotherapy agents,may turn cancer into a curable disease for the most of the patients. All these drugs affect the heart inrelation to the presence of risk factors: physiological (age, sex, race, general (malaise, pre-existingchronic diseases, pre-existing cardiovascular affections, previous mediastinal radiation therapy,association with other cardiotoxic substances, as well as in relation to factors related to medication(high daily dose, high cumulative dose, short interval between administrations, bolus injection. Themechanism that produces cardiotoxicity is incompletely elucidated, it appears to be plurifactorial, theproduction of oxygen free radicals being the main cause of morphological alterations. Anthracyclinescardiotoxicity is better known, with its two forms (acute/subacute and late or chronic or even thedelayed cardiotoxicity form in survivors of childhood cancers. There are also presented some cardiacdamage modalities after treatment with alkylating agents, antimetabolites, taxanes, monoclonalantibodies (trastuzumab.

  9. Establishment of a drug sensitivity panel using human lung cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Matsushita A

    1999-04-01

    Full Text Available We established a drug sensitivity panel consisting of 24 human lung cancer cell lines. Using this panel, we evaluated 26 anti-cancer agents: three alkylators, three platinum compounds, four antimetabolites, one topoisomerase I inhibitor, five topoisomerase II inhibitors, seven antimitotic agents and three tyrosine kinase inhibitors. This panel showed the following: a Drug sensitivity patterns reflected their clinically-established patterns of action. For example, doxorubicin and etoposide were shown to be active against small cell lung cancer cell lines and mitomycin-C and 5-fluorouracil were active against non-small cell lung cancer cell lines, in agreement with clinical data. b Correlation analysis of the mean graphs derived from the logarithm of IC50 values of the drugs gave insight into the mechanism of each drug's action. Thus, two drug combinations with reverse or no correlation, such as the combination of cisplatin and vinorelbine, might be good candidates for the ideal two drug combination in the treatment of lung cancer, as is being confirmed in clinical trials. c Using cluster analysis of the cell lines in the panel with their drug sensitivity patterns, we could classify the cell lines into four groups depending on the drug sensitivity similarity. This classification will be useful to elucidate the cellular mechanism of action and drug resistance. Thus, our drug sensitivity panel will be helpful to explore new drugs or to develop a new combination of anti-cancer agents for the treatment of lung cancer.

  10. Multidrug resistance associated proteins in multidrug resistance

    Institute of Scientific and Technical Information of China (English)

    Kamlesh Sodani; Atish Patel; Rishil J. Kathawala; Zhe-Sheng Chen

    2012-01-01

    Multidrug resistance proteins (MRPs) are members of the C family of a group of proteins named ATP-binding cassette (ABC) transporters.These ABC transporters together form the largest branch of proteins within the human body.The MRP family comprises of 13 members,of which MRP1 to MRP9 are the major transporters indicated to cause multidrug resistance in tumor cells by extruding anticancer drugs out of the cell.They are mainly lipophilic anionic transporters and are reported to transport free or conjugates of glutathione (GSH),glucuronate,or sulphate.In addition,MRP1 to MRP3 can transport neutral organic drugs in free form in the presence of free GSH.Collectively,MRPs can transport drugs that differ structurally and mechanistically,including natural anticancer drugs,nucleoside analogs,antimetabolites,and tyrosine kinase inhibitors.Many of these MRPs transport physiologically important anions such as leukotriene C4,bilirubin glucuronide,and cyclic nucleotides.This review focuses mainly on the physiological functions,cellular resistance characteristics,and probable in vivo role of MRP1 to MRP9.

  11. The cell's nucleolus: an emerging target for chemotherapeutic intervention.

    Science.gov (United States)

    Pickard, Amanda J; Bierbach, Ulrich

    2013-09-01

    The transient nucleolus plays a central role in the up-regulated synthesis of ribosomal RNA (rRNA) to sustain ribosome biogenesis, a hallmark of aberrant cell growth. This function, in conjunction with its unique pathohistological features in malignant cells and its ability to mediate apoptosis, renders this sub-nuclear structure a potential target for chemotherapeutic agents. In this Minireview, structurally and functionally diverse small molecules are discussed that have been reported to either interact with the nucleolus directly or perturb its function indirectly by acting on its dynamic components. These molecules include all major classes of nucleic-acid-targeted agents, antimetabolites, kinase inhibitors, anti-inflammatory drugs, natural product antibiotics, oligopeptides, as well as nanoparticles. Together, these molecules are invaluable probes of structure and function of the nucleolus. They also provide a unique opportunity to develop novel strategies for more selective and therefore better-tolerated chemotherapeutic intervention. In this regard, inhibition of RNA polymerase-I-mediated rRNA synthesis appears to be a promising mechanism for killing cancer cells. The recent development of molecules targeted at G-quadruplex-forming rRNA gene sequences, which are currently undergoing clinical trials, seems to attest to the success of this approach.

  12. Mechanisms of Anticancer Drugs Resistance: An Overview

    Directory of Open Access Journals (Sweden)

    M. R. Chorawala

    2012-01-01

    Full Text Available The management of cancer involves surgery, radiotherapy and chemotherapy. Development of chemoresistance is a persistent problem during the chemotherapy treatment. Cytotoxic drugs that selectively, but not exclusively, target actively proliferating cells include such diverse groups as DNA-alkylating agents, anti-metabolites, intercalating agents and mitotic inhibitors. Resistance constitutes a lack of response to drug-induced tumour growth inhibition; it may be inherent in a subpopulation of heterogeneous cancer cells or be acquired as a cellular response to drug exposure. Principle mechanisms may include altered membrane transport involving the p-glycoprotein product of the multidrug resistance (MDR gene as well as other associated proteins, altered target enzyme, decreased drug activation, increased drug degradation due to altered expression of drug metabolising enzymes, drug inactivation due to conjugation with increased glutathione, subcellular redistribution, drug interaction, enhanced DNA repair and failure to apoptosis as a result of mutated cell cycle proteins such as p53. Attempts to overcome resistance involves the use of combination drug therapy using different classes of drugs with minimally overlapping toxicities to allow maximal dosages, necessary for bone marrow recovery. Adjuvant therapy with p-glycoprotein inhibitors and in specific instances, the use of growth factor and protein kinase C inhibitors are newer experimental approaches that may also prove effective in delaying onset of resistance. Gene knockout using antisense molecules may be effective way of blocking drug resistance.

  13. Radioiodination and biological evaluation of Cladribine as potential agent for tumor imaging and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bayoumi, Noha Anwer; Amin, Abeer M.; El-Kolaly, Mohamed T. [Egyptian Atomic Energy Authority, Cairo (Egypt). Hot Lab Center; Ismail, Nasser S.M.; Abouzid, Khaled A.M. [Ain-Shams Univ., Cairo (Egypt). Pharmaceutical Chemistry Dept.

    2015-07-01

    Cladribine, a purine analogue antimetabolite, was radioiodinated with {sup 125}I via direct electrophilic substitution reaction. The maximum radiochemical yield (92.5 ± 0.8%) was obtained when the reaction was done at ambient temperature for 30 min using 100 μg of Cladribine and 10 μg N-chlorosuccinamide (NCS) in 150 μL of 0.2 M phosphate buffer, pH 7. In vitro stability studies of HPLC purified {sup 125}I-Cladribine sample dissolved in 0.5 ml of 0.2 M phosphate buffer pH 7 at ambient temperature showed that {sup 125}I-Cladribine is stable up to 12 h post labeling. Biodistribution results revealed excretion of {sup 125}I-Cladribine mainly by kidneys. The uptake of {sup 125}I-Cladribine in the induced Ehrlich Ascites Carcinoma was 2.8 ± 0.4%ID/g at 1 h post injection with maximum tumor/muscle ratio of 5.5. The good uptake of {sup 125}I-Cladribine confirms the molecular docking studies results which indicate that iodinated Cladribine binds with polymerase enzyme with a good-CDOCKER energy. As a result, radioiodinated Cladribine may be used as a valuable agent for tumor diagnosis and therapy.

  14. The biochemical basis for l-canavanine tolerance by the tobacco budworm Heliothis virescens (Noctuidae)

    Science.gov (United States)

    Melangeli, Coromoto; Rosenthal, Gerald A.; Dalman, Douglas L.

    1997-01-01

    The tobacco budworm, Heliothis virescens (Noctuidae), a destructive insect pest, is remarkably resistant to l-canavanine, l-2-amino-4-(guanidinooxy)butyric acid, an arginine antimetabolite that is a potent insecticide for nonadapted species. H. virescens employs a constitutive enzyme of the larval gut, known trivially as canavanine hydrolase (CH), to catalyze an irreversible hydrolysis of l-canavanine to l-homoserine and hydroxyguanidine. As such, it represents a new type of hydrolase, one acting on oxygen–nitrogen bonds (EC 3.13.1.1). This enzyme has been isolated from the excised gut of H. virescens and purified to homogeneity; it exhibits an apparent Km value for l-canavanine of 1.1 mM and a turnover number of 21.1 μmol·min−1·μmol−1. This enzyme has a mass of 285 kDa and is composed of two subunits with a mass of 50 kDa or 47.5 kDa. CH has a high degree of specificity for l-canavanine as it cannot function effectively with either l-2-amino-5-(guanidinooxy)pentanoate or l-2-amino-3-(guanidinooxy)propionate, the higher or lower homolog of l-canavanine, respectively. l-Canavanine derivatives such as methyl-l-canavanine, or l-canaline and O-ureido-l-homoserine, are not metabolized significantly by CH. PMID:9122181

  15. Hepatocyte SLAMF3 reduced specifically the multidrugs resistance protein MRP-1 and increases HCC cells sensitization to anti-cancer drugs.

    Science.gov (United States)

    Fouquet, Grégory; Debuysscher, Véronique; Ouled-Haddou, Hakim; Eugenio, Mélanie Simoes; Demey, Baptiste; Singh, Amrathlal Rabbind; Ossart, Christèle; Al Bagami, Mohammed; Regimbeau, Jean-Marc; Nguyen-Khac, Eric; Naassila, Mickael; Marcq, Ingrid; Bouhlal, Hicham

    2016-05-31

    Multidrug resistance MDR proteins (MRPs) are members of the C family of a group of proteins named ATP binding cassette (ABC) transporters. MRPs can transport drugs including anticancer drugs, nucleoside analogs, antimetabolites and tyrosine kinase inhibitors. Drugs used in HCC therapy, such as tyrosine kinase inhibitor sorafenib, are substrates of uptake and/or efflux transporters. Variable expression of MRPs at the plasma membrane of tumor cells may contribute to drug resistance and subsequent clinical response. Recently, we reported that the hepatocyte SLAMF3 expression (Signaling Lymphocytic Activation Molecule Family member 3) was reduced in tumor cells from hepatocellular carcinoma (HCC) compared to its high expression in adjacent tissues. In the present study, we make a strong correlation between induced SLAMF3 overexpression and the specific loss of MRP-1 expression and its functionalities as a drugs resistance transporter. No changes were observed on expression of ABCG2 and MDR. More importantly, we highlight a strong inverse correlation between MRP-1 and SLAMF3 expression in patients with HCC. We propose that the SLAMF3 overexpression in cancerous cells could represent a potential therapeutic strategy to improve the drugs sensibility of resistant cells and thus control the therapeutic failure in HCC patients.

  16. Treatment of acute promyelocytic leukemia during pregnancy.

    Science.gov (United States)

    Yang, Daisy; Hladnik, Lindsay

    2009-06-01

    Management of the pregnant patient with acute promyelocytic leukemia (APL) is a challenge. Immediate treatment of APL is critical, as it is an oncologic emergency, with a high risk of morbidity and mortality associated with disseminated intravascular coagulation. However, administration of chemotherapy and differentiating agents in pregnancy is controversial because of potential teratogenic effects. In addition, complications associated with APL, including retinoic acid syndrome, add to the complexity of management. To better understand how to manage this complex patient care situation, we searched the PubMed database (January 1972-May 2008) for English-language articles about maternal and fetal outcomes resulting from APL treatment during pregnancy. A total of 42 cases from 35 articles were identified: 12 first-trimester, 21 second-trimester, and 9 third-trimester cases. The most commonly administered agents were all-trans-retinoic acid (ATRA), anthracyclines, and antimetabolites. Complete remission was reported in 35 (83%) of 42 patients. Administration of ATRA or chemotherapy in the first trimester was associated with an increased risk of fetal malformations and spontaneous abortion, whereas administration in the second and third trimesters was associated with relatively favorable fetal outcomes. The overall treatment of the pregnant patient with APL should include a discussion about pregnancy termination, especially if APL is diagnosed in the first trimester. If the pregnancy is to continue, then the appropriate chemotherapy regimen needs to be determined. Frequent fetal monitoring, along with aggressive management of potential APL-related complications, is necessary to allow for optimal maternal and fetal outcomes.

  17. Management of glaucoma in pregnancy: risks or choices, a dilemma?

    Science.gov (United States)

    Sethi, Harinder Singh; Naik, Mayuresh; Gupta, Vishnu Swarup

    2016-01-01

    The treatment of glaucoma in and around pregnancy offers the unique challenge of balancing the risk of vision loss to the mother as against the potential harm to the fetus or newborn. Most anti-glaucoma drugs (i.e. beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors topical and systemic, cholinergics, anticholinesterases, and apraclonidine) are considered category C agents and ophthalmologists are usually limited to treating patients with the category B drugs of brimonidine and dipivefrin. Brimonidine is generally the preferred first-line drug in the first, second and early third trimester. Late in the third trimester, brimonidine should be discontinued because it can induce central nervous system depression in newborns wherein topical carbonic anhydrase inhibitors may be the optimal choice. Glaucoma surgery can be performed with caution in second and third trimester if the patients have a strong indication for the procedure. However, anesthetics, sedative agents, and antimetabolites still have potential risk for the fetus. Argon laser trabeculoplasty (ALT) or selective laser trabeculoplasty (SLT) is an alternative treatment that can be performed in all trimesters. Carbonic anhydrase inhibitors and β-blockers are certified by the American Academy of Pediatrics for use during nursing. However, low doses of these medications should be considered when used in the breast feeding period. Optimum treatment for glaucoma in pregnancy must not be withheld so as to prevent any further deterioration in progressive vision loss and quality of life.

  18. Usp9x- and Noxa-mediated Mcl-1 downregulation contributes to pemetrexed-induced apoptosis in human non-small-cell lung cancer cells.

    Science.gov (United States)

    Yan, J; Zhong, N; Liu, G; Chen, K; Liu, X; Su, L; Singhal, S

    2014-07-03

    Pemetrexed, a folate antimetabolite, combined with cisplatin is used as a first-line therapy for malignant pleural mesothelioma (MPM) and locally advanced or metastatic non-small-cell lung cancer (NSCLC). Pemetrexed arrests cell cycle by inhibiting three enzymes in purine and pyrimidine synthesis that are necessary for DNA synthesis. Pemetrexed also promotes apoptosis in target cells, but little is known about its mechanism in cancer cells. We have previously shown that pemetrexed can result in endoplasmic reticulum (ER) stress, and it can lead to downstream apoptosis. In this study, we further elucidate this mechanism. Our data show that pemetrexed increases Noxa expression through activating transcription factor 4 (ATF4) and activating transcription factor 3 (ATF3) upregulation. Furthermore, pemetrexed induces apoptosis by activating the Noxa-Usp9x-Mcl-1 pathway. Inhibition of Noxa by small interfering RNA (siRNA) promotes Usp9x (ubiquitin-specific peptidase 9, X-linked) expression. Moreover, downregulation of the deubiquitinase Usp9x by pemetrexed results in downstream reduction of myeloid cell leukemia 1 (Mcl-1) expression. Mechanistically, Noxa upregulation likely reduces the availability of Usp9x to Mcl-1, thereby promoting its ubiquitination and degradation, leading to the apoptosis of neoplastic cells. Thus, our findings demonstrate that Noxa-Usp9x-Mcl-1 axis may contribute to pemetrexed-induced apoptosis in human lung cancer cells.

  19. Vitamin D in combination cancer treatment

    Science.gov (United States)

    Ma, Yingyu; Trump, Donald L.; Johnson, Candace S.

    2010-01-01

    As a steroid hormone that regulates mineral homeostasis and bone metabolism, 1α, 25-dihydroxycholecalciferol (calcitriol) also has broad spectrum anti-tumor activities as supported by numerous epidemiological and experimental studies. Calcitriol potentiates the anti-tumor activities of multiple chemotherapeutics agents including DNA-damaging agents cisplatin, carboplatin and doxorubicin; antimetabolites 5-fluorouracil, cytarabine, hydroxyurea, cytarabine and gemcitabine; and microtubule-disturbing agents paclitaxel and docetaxel. Calcitriol elicits anti-tumor effects mainly through the induction of cancer cell apoptosis, cell cycle arrest, differentiation, angiogenesis and the inhibition of cell invasiveness by a number of mechanisms. Calcitriol enhances the cytotoxic effects of gamma irradiation and certain antioxidants and naturally derived compounds. Inhibition of calcitriol metabolism by 24-hydroxylase promotes growth inhibition effect of calcitriol. Calcitriol has been used in a number of clinical trials and it is important to note that sufficient dose and exposure to calcitriol is critical to achieve anti-tumor effect. Several trials have demonstrated that safe and feasible to administer high doses of calcitriol through intermittent regimen. Further well designed clinical trials should be conducted to better understand the role of calcitriol in cancer therapy. PMID:20842231

  20. No evidence of occult hepatitis C virus (HCV) infection in serum of HCV antibody-positive HCV RNA-negative kidney-transplant patients.

    Science.gov (United States)

    Nicot, Florence; Kamar, Nassim; Mariamé, Bernard; Rostaing, Lionel; Pasquier, Christophe; Izopet, Jacques

    2010-06-01

    Persistence of hepatitis C virus (HCV) in patients who cleared HCV is still debated. Occult HCV infection is described as the presence of detectable HCV RNA in liver or peripheral blood mononuclear cells (PBMCs) of patients with undetectable plasma HCV-RNA by conventional PCR assays. We have assessed the persistence of HCV in 26 kidney-transplant patients, followed up for 10.5 years (range 2-16), after HCV elimination while on hemodialysis. If HCV really did persist, arising out of the loss of immune control caused by institution of the regimen of immunosuppressive drugs after kidney transplantation, HCV reactivation would have taken place. Their immunosuppression relied on calcineurin inhibitors (100%), and/or steroids (62%), and/or antimetabolites (94%). An induction therapy, given to 22 patients, relied on rabbit antithymocyte globulin (59%) or anti-IL2-receptor blockers (32%). All patients had undetectable HCV RNA as ascertained by several conventional tests. At the last follow-up, no residual HCV RNA was detected in the five liver biopsies, the 26 plasma, and in the 37 nonstimulated and 24 stimulated PBMCs tested with an ultrasensitive RT-PCR assay (detection limit, 2 IU/ml). No biochemical or virologic relapse was seen during follow-up. The absence of HCV relapse in formerly HCV-infected immunocompromised patients suggests the complete eradication of HCV after its elimination while on dialysis.

  1. Novel agents in the management of lung cancer.

    LENUS (Irish Health Repository)

    Kennedy, B

    2012-01-31

    Lung cancer is the leading cause of cancer death worldwide. Survival remains poor as approximately 80% of cases present with advanced stage disease. However, new treatments are emerging which offer hope to patients with advanced disease. Insights into cell biology have identified numerous intracellular and extracellular peptides that are pivotal in cancer cell signalling. Disrupting the function of these peptides inhibits intracellular signal transduction and diminishes uncontrolled proliferation, resistance to apoptosis and tumour angiogenesis. The most widely studied signalling pathway is the Epidermal Growth Factor (EGF) pathway. EGF signalling can be disrupted at numerous points. Blockade of the cell surface receptor is achieved by the monoclonal antibody cetuximab; intracellular tyrosine kinase activity is inhibited by erlotinib. Vascular Endothelial Growth Factor (VEGF) regulates another pathway important for tumour growth. Inhibition of VEGF impairs angiogenesis and disrupts metastatic spread. Bevacizumab is a monoclonal antibody that binds to VEGF and blocks interaction with its cell surface receptor. Clinical trials have demonstrated that disruption of these signalling pathways can improve survival in advanced lung cancer. New compounds including folate antimetabolites such as pemetrexed, proteasome inhibitors such as bortezomib, modified glutathione analogues such as TLK286, and other agents such as epothilones and other small molecules are currently being evaluated in patients with lung cancer. As more and more signalling peptides are targeted for manipulation, it is hoped that a new era is dawning in the treatment of advanced stage lung cancer. This review will focus on emerging new therapies in the management of lung cancer.

  2. Vitamin D in combination cancer treatment

    Directory of Open Access Journals (Sweden)

    Yingyu Ma, Donald L. Trump, Candace S. Johnson

    2010-01-01

    Full Text Available As a steroid hormone that regulates mineral homeostasis and bone metabolism, 1α, 25-dihydroxycholecalciferol (calcitriol also has broad spectrum anti-tumor activities as supported by numerous epidemiological and experimental studies. Calcitriol potentiates the anti-tumor activities of multiple chemotherapeutics agents including DNA-damaging agents cisplatin, carboplatin and doxorubicin; antimetabolites 5-fluorouracil, cytarabine, hydroxyurea, cytarabine and gemcitabine; and microtubule-disturbing agents paclitaxel and docetaxel. Calcitriol elicits anti-tumor effects mainly through the induction of cancer cell apoptosis, cell cycle arrest, differentiation, angiogenesis and the inhibition of cell invasiveness by a number of mechanisms. Calcitriol enhances the cytotoxic effects of gamma irradiation and certain antioxidants and naturally derived compounds. Inhibition of calcitriol metabolism by 24-hydroxylase promotes growth inhibition effect of calcitriol. Calcitriol has been used in a number of clinical trials and it is important to note that sufficient dose and exposure to calcitriol is critical to achieve anti-tumor effect. Several trials have demonstrated that safe and feasible to administer high doses of calcitriol through intermittent regimen. Further well designed clinical trials should be conducted to better understand the role of calcitriol in cancer therapy.

  3. Gemcitabine-loaded liposomes: rationale, potentialities and future perspectives

    Directory of Open Access Journals (Sweden)

    Federico C

    2012-11-01

    Full Text Available Cinzia Federico, Valeria M Morittu, Domenico Britti, Elena Trapasso, Donato CoscoDepartment of Health Sciences, Building of BioSciences, University “Magna Græcia” of Catanzaro, Campus Universitario “S Venuta”, Germaneto, ItalyAbstract: This review describes the strategies used in recent years to improve the biopharmaceutical properties of gemcitabine, a nucleoside analog deoxycytidine antimetabolite characterized by activity against many kinds of tumors, by means of liposomal devices. The main limitation of using this active compound is the rapid inactivation of deoxycytidine deaminase following administration in vivo. Consequently, different strategies based on its encapsulation/complexation in innovative vesicular colloidal carriers have been investigated, with interesting results in terms of increased pharmacological activity, plasma half-life, and tumor localization, in addition to decreased side effects. This review focuses on the specific approaches used, based on the encapsulation of gemcitabine in liposomes, with particular attention to the results obtained during the last 5 years. These approaches represent a valid starting point in the attempt to obtain a novel, commercializable drug formulation as already achieved for liposomal doxorubicin (Doxil®, Caelyx®.Keywords: gemcitabine, liposomes, multidrug, poly(ethylene glycol, tumors

  4. Alanylclavam Biosynthetic Genes Are Clustered Together with One Group of Clavulanic Acid Biosynthetic Genes in Streptomyces clavuligerus▿ §

    Science.gov (United States)

    Zelyas, Nathan J.; Cai, Hui; Kwong, Thomas; Jensen, Susan E.

    2008-01-01

    Streptomyces clavuligerus produces at least five different clavam metabolites, including clavulanic acid and the methionine antimetabolite, alanylclavam. In vitro transposon mutagenesis was used to analyze a 13-kb region upstream of the known paralogue gene cluster. The paralogue cluster includes one group of clavulanic acid biosynthetic genes in S. clavuligerus. Twelve open reading frames (ORFs) were found in this area, and mutants were generated in each using either in vitro transposon or PCR-targeted mutagenesis. Mutants with defects in any of the genes orfA, orfB, orfC, or orfD were unable to produce alanylclavam but could produce all of the other clavams, including clavulanic acid. orfA encodes a predicted hydroxymethyltransferase, orfB encodes a YjgF/YER057c/UK114-family regulatory protein, orfC encodes an aminotransferase, and orfD encodes a dehydratase. All of these types of proteins are normally involved in amino acid metabolism. Mutants in orfC or orfD also accumulated a novel clavam metabolite instead of alanylclavam, and a complemented orfC mutant was able to produce trace amounts of alanylclavam while still producing the novel clavam. Mass spectrometric analyses, together with consideration of the enzymes involved in its production, led to tentative identification of the novel clavam as 8-OH-alanylclavam, an intermediate in the proposed alanylclavam biosynthetic pathway. PMID:18931110

  5. The mbo operon is specific and essential for biosynthesis of mangotoxin in Pseudomonas syringae.

    Science.gov (United States)

    Carrión, Víctor J; Arrebola, Eva; Cazorla, Francisco M; Murillo, Jesús; de Vicente, Antonio

    2012-01-01

    Mangotoxin is an antimetabolite toxin produced by certain Pseudomonas syringae pv. syringae strains. This toxin is an oligopeptide that inhibits ornithine N-acetyl transferase, a key enzyme in the biosynthesis of ornithine and arginine. Previous studies have reported the involvement of the putative nonribosomal peptide synthetase MgoA in virulence and mangotoxin production. In this study, we analyse a new chromosomal region of P. syringae pv. syringae UMAF0158, which contains six coding sequences arranged as an operon (mbo operon). The mbo operon was detected in only mangotoxin-producing strains, and it was shown to be essential for the biosynthesis of this toxin. Mutants in each of the six ORFs of the mbo operon were partially or completely impaired in the production of the toxin. In addition, Pseudomonas spp. mangotoxin non-producer strains transformed with the mbo operon gained the ability to produce mangotoxin, indicating that this operon contains all the genetic information necessary for mangotoxin biosynthesis. The generation of a single transcript for the mbo operon was confirmed and supported by the allocation of a unique promoter and Rho-independent terminator. The phylogenetic analysis of the P. syringae strains harbouring the mbo operon revealed that these strains clustered together.

  6. A review and update on orphan drugs for the treatment of noninfectious uveitis

    Science.gov (United States)

    You, Caiyun; Sahawneh, Haitham F; Ma, Lina; Kubaisi, Buraa; Schmidt, Alexander; Foster, C Stephen

    2017-01-01

    Introduction Uveitis, a leading cause of preventable blindness around the world, is a critically underserved disease in regard to the medications approved for use. Multiple immunomodulatory therapy (IMT) drugs are appropriate for uveitis therapy but are still off-label. These IMT agents, including antimetabolites, calcineurin inhibitors, alkylating agents, and biologic agents, have been designated as “orphan drugs” and are widely used for systemic autoimmune diseases or organ transplantation. Area covered The purpose of this paper is to comprehensively review and summarize the approved orphan drugs and biologics that are being used to treat systemic diseases and to discuss drugs that have not yet received approval as an “orphan drug for treating uveitis” by the US Food and Drug Administration (FDA). Our perspective IMT, as a steroid-sparing agent for uveitis patients, has shown promising clinical results. Refractory and recurrent uveitis requires combination IMT agents. IMT is continued for a period of 2 years while the patient is in remission before considering tapering medication. Our current goals include developing further assessments regarding the efficacy, optimal dose, and safety in efforts to achieve FDA approval for “on-label” use of current IMT agents and biologics more quickly and to facilitate insurance coverage and expand access to the products for this orphan disease. PMID:28203051

  7. Promising biological therapies for ulcerative colitis: A review of the literature

    Institute of Scientific and Technical Information of China (English)

    Hirotada; Akiho; Azusa; Yokoyama; Shuichi; Abe; Yuichi; Nakazono; Masatoshi; Murakami; Yoshihiro; Otsuka; Kyoko; Fukawa; Mitsuru; Esaki; Yusuke; Niina; Haruei; Ogino

    2015-01-01

    Ulcerative colitis(UC) is a chronic lifelong condition characterized by alternating flare-ups and remission. There is no single known unifying cause, and the pathogenesis is multifactorial, with genetics, environmental factors, microbiota, and the immune system all playing roles. Current treatment modalities for UC include 5-aminosalicylates, corticosteroids, immunosuppressants(including purine antimetabolites, cyclosporine, and tacrolimus), and surgery. Therapeutic goals for UC are evolving. Medical treatment aims to induce remission and prevent relapse of disease activity. Infliximab, an anti-tumor necrosis factor(TNF)-α monoclonal antibody, is the first biological agent for the treatment of UC. Over the last decade, infliximab and adalimumab(anti-TNF-α agents) have been used for moderate to severe UC, and have been shown to be effective in inducing and maintaining remission. Recent studies have indicated that golimumab(another anti-TNF-α agent), tofacitinib(a Janus kinase inhibitor), and vedolizumab and etrolizumab(integrin antagonists), achieved good clinical remission and response rates in UC. Recently, golimumab and vedolizumab have been approved for UC by the United States Food and Drug Administration. Vedolizumab may be used as a first-line alternative to anti-TNF-α therapy in patients with an inadequate response to corticosteroids and/or immunosuppressants. Here, we provide updated information on various biological agents in the treatment of UC.

  8. Elevated Levels of DNA Strand Breaks Induced by a Base Analog in the Human Cell Line with the P32T ITPA Variant

    Directory of Open Access Journals (Sweden)

    Irina S.-R. Waisertreiger

    2010-01-01

    Full Text Available Base analogs are powerful antimetabolites and dangerous mutagens generated endogenously by oxidative stress, inflammation, and aberrant nucleotide biosynthesis. Human inosine triphosphate pyrophosphatase (ITPA hydrolyzes triphosphates of noncanonical purine bases (i.e., ITP, dITP, XTP, dXTP, or their mimic: 6-hydroxyaminopurine (HAP deoxynucleoside triphosphate and thus regulates nucleotide pools and protects cells from DNA damage. We demonstrate that the model purine base analog HAP induces DNA breaks in human cells and leads to elevation of levels of ITPA. A human polymorphic allele of the ITPA, 94C->A encodes for the enzyme with a P32T amino-acid change and leads to accumulation of nonhydrolyzed ITP. The polymorphism has been associated with adverse reaction to purine base-analog drugs. The level of both spontaneous and HAP-induced DNA breaks is elevated in the cell line with the ITPA P32T variant. The results suggested that human ITPA plays a pivotal role in the protection of DNA from noncanonical purine base analogs.

  9. Are we giving azathioprine too late? The case for early immunomodulation in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    María Josefina Etchevers; Montserrat Aceituno; Miquel Sans

    2008-01-01

    Inflammatory bowel disease (IBD) includes two entities, Crohn's disease and ulcerative colitis. Both are chronic conditions with frequent complications and surgical procedures and a great impact on patient's quality of life. The thiopurine antimetabolites azathioprine and 6-mercaptopurine are widely used in IBD patients. Current indications include maintenance therapy, steroid-dependant disease, fistula closure, prevention of infliximab immunogenicity and prevention of Crohn's disease recurrence. Surprisingly, the wide use of immunosuppressants in the last decades has not decreased the need of surgery, probably because these treatments are introduced at too late stages in disease course. An earlier use of immunossupressants is now advocated by some authors. The rational includes: (1) failure to modify IBD natural history of present therapeutic approach, (2) demonstration that azathioprine can induce mucosal healing, a relevant prognostic factor for Crohn's disease and ulcerative colitis, and (3) demonstration that early immunossupression has a very positive impact on pediatric, recently diagnosed Crohn's disease patients. We are now awaiting the results of new studies, to clarify the contribution of azathioprine, as compared to infliximab (SONIC Study), and to demonstrate the usefulness of azathioprine in recently diagnosed adult Crohn's disease patients (AZTEC study).

  10. In Silico Screening, Synthesis and In Vitro Evaluation of Some Quinazolinone and Pyridine Derivatives as Dihydrofolate Reductase Inhibitors for Anticancer Activity

    Directory of Open Access Journals (Sweden)

    A. G. Nerkar

    2009-01-01

    Full Text Available Dihydrofolate reductase (DHFR is the important target for anticancer drugs belonging to the class of antimetabolites as the enzyme plays important role in the de novo purine synthesis. We here report the in silico screening to obtain best fit molecules as DHFR inhibitors, synthesis of some ʻbest fitʼ quinazolinone from 2-phenyl-3-(substituted-benzilidine-amino quinazolinones (Quinazolinone Shiff's bases QSB1-5 and pyridine-4-carbohydrazide Shiff's bases (ISB1-5 derivatives and their in vitro anticancer assay. Synthesis of the molecules was performed using microwave assisted synthesis. The structures of these molecules were elucidated by IR and 1H-NMR. These compounds were then subjected for in vitro anticancer evaluation against five human cancer cell-lines for anticancer cyto-toxicity assay. Methotrexate (MTX was used as standard for this evaluation to give a comparable inhibition of the cell proliferation by DHFR inhibition. Placlitaxel, adriamycin and 5-fluoro-uracil were also used as standard to give a comparable activity of these compounds with other mechanism of anticancer activity. ISB3 (4-(N, N-dimethyl-amino-phenyl Schiff''s base derivative of pyridine carbohydrazide showed equipotent activity with the standards used in in vitro anticancer assay as per the NCI (National Cancer Institute guidelines.

  11. Controlled release of 6-aminonicotinamide from aligned, electrospun fibers alters astrocyte metabolism and dorsal root ganglia neurite outgrowth

    Science.gov (United States)

    Schaub, Nicholas J.; Gilbert, Ryan J.

    2011-08-01

    Following central nervous system (CNS) injury, activated astrocytes form a glial scar that inhibits the migration of axons ultimately leading to regeneration failure. Biomaterials developed for CNS repair can provide local delivery of therapeutics and/or guidance mechanisms to encourage cell migration into damaged regions of the brain or spinal cord. Electrospun fibers are a promising type of biomaterial for CNS injury since these fibers can direct cellular and axonal migration while slowly delivering therapy to the injury site. In this study, it was hypothesized that inclusion of an anti-metabolite, 6-aminonicotinamide (6AN), within poly-l-lactic acid electrospun fibers could attenuate astrocyte metabolic activity while still directing axonal outgrowth. Electrospinning parameters were varied to produce highly aligned electrospun fibers that contained 10% or 20% (w/w) 6AN. 6AN release from the fiber substrates occurred continuously over 2 weeks. Astrocytes placed onto drug-releasing fibers were less active than those cultured on scaffolds without 6AN. Dorsal root ganglia placed onto control and drug-releasing scaffolds were able to direct neurites along the aligned fibers. However, neurite outgrowth was stunted by fibers that contained 20% 6AN. These results show that 6AN release from aligned, electrospun fibers can decrease astrocyte activity while still directing axonal outgrowth.

  12. Acute methotrexate ingestions in adults: A review on ever-rising consumption of methotrexate since 1980s

    Directory of Open Access Journals (Sweden)

    Ranjita Santra(Dhali

    2015-01-01

    Full Text Available To review the possible association between methotrexate (MTX intake and increased toxicity. A MEDLINE literature search MEDLINE (1980-August 2014 was performed using the search terms MTX, antifolate, MTX toxicity, glucarpidase, and leucovorin. Additional references were identified from a review of literature citations. All English-language observational studies and case reports were considered. Methotrexate (meth" oh trex′ ate is an antifolate and antimetabolite that is used extensively in the therapy of leukemia, lymphoma, and several solid organ tumors. It also has potent activity against psoriasis and has immunomodulatory activity against inflammatory bowel disease and the inflammatory arthritidies. It exhibits a wide range of toxic effects profile. Leucovorin is indicated to diminish the toxicity and counteract the effect of inadvertently administered overdosages of MTX. In post marketing experience, overdose with MTX has generally occurred with oral and intrathecal administration, although intravenous and intramuscular overdose have also been reported. Supporting care strategies, extracorporeal measures, and glucarpidase are some of the means to overcome MTX overdosage. At present, pharmacogenomics tends to contribute toward the emergence of adverse effects following the widespread use of MTX for various indications.

  13. Rapid identification of antifungal compounds against Exserohilum rostratum using high throughput drug repurposing screens.

    Directory of Open Access Journals (Sweden)

    Wei Sun

    Full Text Available A recent large outbreak of fungal infections by Exserohilum rostratum from contaminated compounding solutions has highlighted the need to rapidly screen available pharmaceuticals that could be useful in therapy. The present study utilized two newly-developed high throughput assays to screen approved drugs and pharmaceutically active compounds for identification of potential antifungal agents. Several known drugs were found that have potent effects against E. rostratum including the triazole antifungal posaconazole. Posaconazole is likely to be effective against infections involving septic joints and may provide an alternative for refractory central nervous system infections. The anti-E. rostratum activities of several other drugs including bithionol (an anti-parasitic drug, tacrolimus (an immunosuppressive agent and floxuridine (an antimetabolite were also identified from the drug repurposing screens. In addition, activities of other potential antifungal agents against E. rostratum were excluded, which may avoid unnecessary therapeutic trials and reveals the limited therapeutic alternatives for this outbreak. In summary, this study has demonstrated that drug repurposing screens can be quickly conducted within a useful time-frame. This would allow clinical implementation of identified alternative therapeutics and should be considered as part of the initial public health response to new outbreaks or rapidly-emerging microbial pathogens.

  14. [Acute toxicity by methotrexate used for abortion purpose. Case report].

    Science.gov (United States)

    Estrada-Altamirano, Ariel; Chacón-Solís, Rogerio Armando; Hernández-Pacheco, José Antonio; Belmont-Gómez, Aurora; Valenzuela-Jirón, Arlen; Carvajal-Valencia, Javier Andrés; Maya-Quiñones, José Luis

    2011-01-01

    We report the case of a 16 years old female patient, with a pregnancy history of 11.4 weeks by ultrasound and intrauterine fetal death. In a private clinic were prescribed methotrexate 500 mg intramuscular single dose, and vaginal misoprostol. She had a clinical feature of five days of evolution characterized by fever of 39 degrees C, nausea, general attack and vomiting. The initial diagnosis was severe sepsis secondary to septic abortion, oral candidiasis and acute poisoning by methotrexate. After that, she was referred to the Instituto Nacional de Perinatologia, where stayed with fever for four days, and was managed with hydration, antibiotics, folinic acid and alkalizing. Her recovery was gradual. She was discharged after 12 days with significant clinical improvement. The literature review describes that the use of methotrexate for abortion purpose with therapeutic-dose presents a similar adverse effects to those found in our patient, however there are no case reports that describe the use of this drug in macrodosis for the same purpose, and their cytotoxic effects. We present this case because the patient used a macrodosis of this antimetabolite and due to the premature and empirical management with folinic acid, joined with alkalinization of urine, is the ideal treatment and as it is illustrated in our case.

  15. Antifungal susceptibility profiles of 1698 yeast reference strains revealing potential emerging human pathogens.

    Directory of Open Access Journals (Sweden)

    Marie Desnos-Ollivier

    Full Text Available New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes. Interestingly, geometric mean minimum inhibitory concentrations (MICs of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001. Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically "resistant" to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens.

  16. Beyond the guidelines in the treatment of peripheral T-cell lymphoma: new drug development.

    Science.gov (United States)

    Chen, Andy I; Advani, Ranjana H

    2008-04-01

    Peripheral T-cell lymphomas (PTCLs) are a rare and diverse group of neoplasms with a poor prognosis. Management of these disorders has been largely extrapolated from the treatment of aggressive B-cell lymphomas; however, therapeutic responses to this approach are neither adequate nor durable for most patients with PTCL. Given the rarity of PTCL, much of the literature consists of studies with small sample size and anecdotal case reports. Therefore, no consensus exists on the best therapeutic strategy for either newly diagnosed or relapsed/refractory PTCL. This article reviews promising novel approaches in the treatment of PTCL and its subtypes. Investigation into the pathogenesis of PTCL has also identified new targets for treatment. These emerging therapies include new uses of existing agents and the development of novel agents specifically targeted against T-cell lymphoma. Results using antimetabolites, immunotherapies, and histone deacetylase inhibitors have been particularly encouraging. These novel therapies are being tested as single agents and in combination with conventional lymphoma regimens in the frontline and salvage settings. Because of the rarity and heterogeneity of PTCL, national and international cooperation is needed to conduct the clinical studies required for the development of more effective treatment paradigms. These efforts are ongoing and will hopefully guide new strategies to improve the historically poor outcome of PTCL.

  17. The efficiency of granulocyte colony-stimulating factor in hemorrhagic mucositis and febrile neutropenia resulted from methotrexate toxicity.

    Science.gov (United States)

    Ozkol, Hatice Uce; Toptas, Tayfur; Calka, Omer; Akdeniz, Necmettin

    2015-01-01

    Methotrexate (MTX) remains one of the most frequently used anti-metabolite agents in dermatology. MTX is an analog of folate that competitively and irreversibly inhibits dihydrofolate reductase. Oral mucositis is a common side effect of chemotherapy drugs and is characterized by erythema, pain, poor oral intake, pseudomembranous destruction, open ulceration and hemorrhage of the oral mucosa. In this paper, we report a 32-year-old female with a case of mucositis due to MTX intoxication that resulted from an overdose for rheumatoid arthritis. The patient had abdominal pain, vomiting, and nausea. During follow-up, the patient's white blood cell count was found to be 0.9 × 10(9)/L (4-10 × 10(9)/L). The patient developed fever exceeding 40 °C. The patient was consulted to the hematology service. They suggested using granulocyte colony-stimulating factor for febrile neutropenia. On the fifth day of treatment, the white blood cell count reached 5.3 × 10(9)/L and the patient's fever and mucositis started to resolve. Here, we presented a case of hemorrhagic mucositis and febrile neutropenia resulted from high-dose MTX that responded very well to granulocyte colony-stimulating factor treatment and we reviewed the literature.

  18. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models.

    Science.gov (United States)

    Céspedes, María Virtudes; Guillén, María José; López-Casas, Pedro Pablo; Sarno, Francesca; Gallardo, Alberto; Álamo, Patricia; Cuevas, Carmen; Hidalgo, Manuel; Galmarini, Carlos María; Allavena, Paola; Avilés, Pablo; Mangues, Ramón

    2016-12-01

    We explored whether the combination of lurbinectedin (PM01183) with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA) mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i) specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii) specific depletion of tumor-associated macrophages (TAMs). We evaluated the in vivo antitumor activity of lurbinectedin and gemcitabine as single agents and in combination in SW-1990 and MIA PaCa-2 cell-line xenografts and in patient-derived PDA models (AVATAR). Lurbinectedin-gemcitabine combination induced a synergistic effect on both MIA PaCa-2 [combination index (CI)=0.66] and SW-1990 (CI=0.80) tumor xenografts. It also induced complete tumor remissions in four out of six patient-derived PDA xenografts. This synergism was associated with enhanced DNA damage (anti-γ-H2AX), cell cycle blockage, caspase-3 activation and apoptosis. In addition to the enhanced DNA damage, which is a consequence of the interaction of the two drugs with the DNA, lurbinectedin induced TAM depletion leading to cytidine deaminase (CDA) downregulation in PDA tumors. This effect could, in turn, induce an increase of gemcitabine-mediated DNA damage that was especially relevant in high-density TAM tumors. These results show that lurbinectedin can be used to develop 'molecularly targeted' combination strategies.

  19. Genome-wide association study of chemotherapeutic agent-induced severe neutropenia/leucopenia for patients in Biobank Japan.

    Science.gov (United States)

    Low, Siew-Kee; Chung, Suyoun; Takahashi, Atsushi; Zembutsu, Hitoshi; Mushiroda, Taisei; Kubo, Michiaki; Nakamura, Yusuke

    2013-08-01

    Chemotherapeutic agents are notoriously known to have a narrow therapeutic range that often results in life-threatening toxicity. Hence, it is clinically important to identify the patients who are at high risk for severe toxicity to certain chemotherapy through a pharmacogenomics approach. In this study, we carried out multiple genome-wide association studies (GWAS) of 13 122 cancer patients who received different chemotherapy regimens, including cyclophosphamide- and platinum-based (cisplatin and carboplatin), anthracycline-based (doxorubicin and epirubicin), and antimetabolite-based (5-fluorouracil and gemcitabine) treatment, antimicrotubule agents (paclitaxel and docetaxel), and topoisomerase inhibitors (camptothecin and etoposide), as well as combination therapy with paclitaxel and carboplatin, to identify genetic variants that are associated with the risk of severe neutropenia/leucopenia in the Japanese population. In addition, we used a weighted genetic risk scoring system to evaluate the cumulative effects of the suggestive genetic variants identified from GWAS in order to predict the risk levels of individuals who carry multiple risk alleles. Although we failed to identify genetic variants that surpassed the genome-wide significance level (P < 5.0 × 10(-8) ) through GWAS, probably due to insufficient statistical power and complex clinical features, we were able to shortlist some of the suggestive associated loci. The current study is at the relatively preliminary stage, but does highlight the complexity and problematic issues associated with retrospective pharmacogenomics studies. However, we hope that verification of these genetic variants through local and international collaborations could improve the clinical outcome for cancer patients.

  20. Three biotechnical processes using Ashbya gossypii, Candida famata, or Bacillus subtilis compete with chemical riboflavin production.

    Science.gov (United States)

    Stahmann, K P; Revuelta, J L; Seulberger, H

    2000-05-01

    Chemical riboflavin production, successfully used for decades, is in the course of being replaced by microbial processes. These promise to save half the costs, reduce waste and energy requirements, and use renewable resources like sugar or plant oil. Three microorganisms are currently in use for industrial riboflavin production. The hemiascomycetes Ashbya gossypii, a filamentous fungus, and Candida famata, a yeast, are naturally occurring overproducers of this vitamin. To obtain riboflavin production with the gram-positive bacterium Bacillus subtilis requires at least the deregulation of purine synthesis and a mutation in a flavokinase/FAD-synthetase. It is common to all three organisms that riboflavin production is recognizable by the yellow color of the colonies. This is an important tool for the screening of improved mutants. Antimetabolites like itaconate, which inhibits the isocitrate lyase in A. gossypii, tubercidin, which inhibits purine biosynthesis in C. famata, or roseoflavin, a structural analog of riboflavin used for B. subtilis, have been applied successfully for mutant selections. The production of riboflavin by the two fungi seems to be limited by precursor supply, as was concluded from feeding and gene-overexpression experiments. Although flux studies in B. subtilis revealed an increase both in maintenance metabolism and in the oxidative part of the pentose phosphate pathway, the major limitation there seems to be the riboflavin pathway. Multiple copies of the rib genes and promoter replacements are necessary to achieve competitive productivity.

  1. Treatment of non-small cell lung cancer: new cytostatic agents.

    Science.gov (United States)

    Sorensen, J B

    1993-12-01

    The literature on new cytostatic drugs in the treatment of non-small cell lung cancer and on new methods for administration of established drugs has been reviewed back to 1985. Two well-known cytostatic drugs, ifosfamide and etoposide, have been evaluated in trials using oral administration instead of the usual intravenous route, and a total of 26 new investigative drugs has also been evaluated. Oral administration of etoposide is associated with an accumulated response rate of 17% in four studies using a dose of 50 mg/m2 daily for 2-3 weeks, followed by 1 week's rest. Oral administration of ifosfamide yields an accumulated response rate of 18% when the dose intensity is 7 g or more during a 4-week period. Among the new drugs tested, the most promising seem to be campthothecin-11, gemcitabine, vinorelbine, taxol, fotemustine, and zeniplatin which have all shown response rates above 20% among previously untreated patients. Also, the antimetabolites 10-EDAM and trimetrexate and the platinum analogues carboplatin and (glycolate-0,0) diammine-platinum(II) are of interest, with cumulative response rates above 15% in previously untreated patients.

  2. Jane Cooke Wright (1919-2013): Pioneering oncologist, woman and humanitarian.

    Science.gov (United States)

    Crosby, Harriet L

    2016-02-01

    Jane Wright was a fundamental researcher in cancer chemotherapy in the 1950s-1980s and was one of the first scientists to test anti-cancer drugs on humans rather than solely on mice, discovering the use of the popular antimetabolite drug methotrexate on solid tumours. From her research she was able to conclude which specific anti-cancer agents would have the greatest lethal effect on a patient's certain cancer type and she invented a method of delivering chemotherapy agents directly to an internal cancer site. During a time when the Civil Rights in the United States of America were undergoing a transformation to reduce the discrimination and segregation imposed on African Americans and the civil rights activist Martin Luther King Jr made a speech to call for an end to racism in 1963, Jane Wright became the first African American to hold such a high position at a nationally recognised institution and the first woman to be elected President of the New York Cancer Society. US President Lyndon B Johnson appointed Jane to the President's Commission of Heart Disease, Cancer and Stroke (serving 1964-1965) and the National Cancer Advisory Board (serving 1966-1970). Jane retired in 1987 by which time she had published more than 75 scientific papers, led delegations of oncologists in China, the former Soviet Union, Africa and Europe and held key positions in various international and national organisations. Jane Wright passed away on 19 February 2013 aged 93 but her legacy lives on in the name of an award from the American Association of Cancer Research.

  3. A review and update on orphan drugs for the treatment of noninfectious uveitis

    Directory of Open Access Journals (Sweden)

    You C

    2017-01-01

    Full Text Available Caiyun You,1–3 Haitham F Sahawneh,1,2 Lina Ma,1,2 Buraa Kubaisi,1,2 Alexander Schmidt,1,2 C Stephen Foster1,2,4 1Massachusetts Eye Research and Surgery Institution (MERSI, Waltham, 2Ocular Immunology and Uveitis Foundation, Weston, MA, USA; 3Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China; 4Harvard Medical School, Boston, MA, USA Introduction: Uveitis, a leading cause of preventable blindness around the world, is a critically underserved disease in regard to the medications approved for use. Multiple immunomodulatory therapy (IMT drugs are appropriate for uveitis therapy but are still off-label. These IMT agents, including antimetabolites, calcineurin inhibitors, alkylating agents, and biologic agents, have been designated as “orphan drugs” and are widely used for systemic autoimmune diseases or organ transplantation.Area covered: The purpose of this paper is to comprehensively review and summarize the approved orphan drugs and biologics that are being used to treat systemic diseases and to discuss drugs that have not yet received approval as an “orphan drug for treating uveitis” by the US Food and Drug Administration (FDA.Our perspective: IMT, as a steroid-sparing agent for uveitis patients, has shown promising clinical results. Refractory and recurrent uveitis requires combination IMT agents. IMT is continued for a period of 2 years while the patient is in remission before considering tapering medication. Our current goals include developing further assessments regarding the efficacy, optimal dose, and safety in efforts to achieve FDA approval for “on-label” use of current IMT agents and biologics more quickly and to facilitate insurance coverage and expand access to the products for this orphan disease. Keywords: immunomodulatory, orphan drug, steroid sparing, uveitis

  4. Research Progress on 5-FU Derivatives%5-氟尿嘧啶及其衍生物的研究进展

    Institute of Scientific and Technical Information of China (English)

    袁吉; 倪孟祥

    2012-01-01

    5-FU is an antimetabolite, which possesses activity against a wide range of solid tumors. The main mechanism of 5-FU is interfering with DNA synthesis and mRNA translation. However,because of the nonspecific cytotoxicity of 5-FU,the patients display several side effects. Numerous modifications of the 5-FU structure have been performed in order to overcome these disadvantages. In this paper,the mechanism and pharmacokinetics of 5-FU are briefly introduced, then several 5-FU derivatives including oral 5-FU prodrugs are presented ,finally the new innovative methods of increasing bioavailability of 5-FU and derivatives are described. All these will provide the theoretical basis for rational administration.%尿嘧啶的氟化类似物5-FU是一种抗代谢物,它对很多实体肿瘤有较好活性.5-FU抗肿瘤活性是通过干扰DNA合成和mRNA翻译来实现的.然而,由于5-FU具有非特异性细胞毒性,故采用5-FU治疗的患者表现出多种副作用.为了改善这些缺点,研究者们对5-FU的结构展开了大量的修饰工作.文章综述了5-FU的作用机理以及药代动力学情况,介绍了5-FU的几种新型修饰衍生物.最后,对提高5-FU衍生物生物利用度的研究进展进行了综述,为5-FU衍生药物的合理使用提供了理论依据.

  5. Drugs in development for prophylaxis of rejection in kidney-transplant recipients

    Directory of Open Access Journals (Sweden)

    Sanders ML

    2015-08-01

    Full Text Available Marion Lee Sanders,1 Anthony James Langone2 1Department of Medicine, Division of Nephrology and Hypertension, University of Iowa, Iowa City, IA, 2Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA Abstract: Transplantation is the preferred treatment option for individuals with end-stage renal disease. Individuals who undergo transplantation must chronically be maintained on an immunosuppression regimen for rejection prophylaxis to help ensure graft survival. Current rejection prophylaxis consists of using a combination of calcineurin inhibitors, mTOR inhibitors, antimetabolite agents, and/or corticosteroids. These agents have collectively improved the short-term outcomes of renal transplantation, but improvements in late/chronic graft loss and recipient survival have lagged significantly behind challenging the field of transplantation to develop novel prophylactic agents. There have been several clinical trials conducted within the last 5 years in an attempt to bring such novel agents to the commercial market. These trials have resulted in the US Food and Drug Administration (FDA approval of extended-release tacrolimus, as well as belatacept, which has the potential to replace calcineurin inhibitors for rejection prophylaxis. Other trials have focused on the development of novel calcineurin inhibitors (voclosporin, costimulation blockade (ASKP1240 and alefacept, kinase inhibitors (tofacitinib and sotrastaurin, and inhibitors of leukocyte migration (efalizumab. While these later agents have not been FDA-approved for use in transplantation, they remain noteworthy, as these agents explore pathways not previously targeted for allograft-rejection prophylaxis. The purpose of this review was to consolidate available clinical trial data with regard to the recent developments in rejection prophylaxis in kidney transplantation. Keywords: rejection, prophylaxis, immunosuppression

  6. UCLA Translational Biomarker Development Program (UTBD)

    Energy Technology Data Exchange (ETDEWEB)

    Czernin, Johannes [Univ. of California, Los Angeles, CA (United States)

    2014-09-01

    The proposed UTBD program integrates the sciences of diagnostic nuclear medicine and (radio)chemistry with tumor biology and drug development. UTBD aims to translate new PET biomarkers for personalized medicine and to provide examples for the use of PET to determine pharmacokinetic (PK) and pharmacodynamic (PD) drug properties. The program builds on an existing partnership between the Ahmanson Translational Imaging Division (ATID) and the Crump Institute of Molecular Imaging (CIMI), the UCLA Department of Chemistry and the Division of Surgical Oncology. ATID provides the nuclear medicine training program, clinical and preclinical PET/CT scanners, biochemistry and biology labs for probe and drug development, radiochemistry labs, and two cyclotrons. CIMI provides DOE and NIH-funded training programs for radio-synthesis (START) and molecular imaging (SOMI). Other participating entities at UCLA are the Department of Chemistry and Biochemistry and the Division of Surgical Oncology. The first UTBD project focuses on deoxycytidine kinase, a rate-limiting enzyme in nucleotide metabolism, which is expressed in many cancers. Deoxycytidine kinase (dCK) positive tumors can be targeted uniquely by two distinct therapies: 1) nucleoside analog prodrugs such as gemcitabine (GEM) are activated by dCK to cytotoxic antimetabolites; 2) recently developed small molecule dCK inhibitors kill tumor cells by starving them of nucleotides required for DNA replication and repair. Since dCK-specific PET probes are now available, PET imaging of tumor dCK activity could improve the use of two different classes of drugs in a wide variety of cancers.

  7. Effects of 5-FU.

    Science.gov (United States)

    Wigmore, Peter M; Mustafa, Sarah; El-Beltagy, Maha; Lyons, Laura; Umka, Jariya; Bennett, Geoff

    2010-01-01

    5-fluorouracil (5-FU) is a chemotherapeutical agent used to treat cancers including breast and colorectal. Working as an antimetabolite to prevent cell proliferation, it primarily inhibits the enzyme thymidylate synthase blocking the thymidine formation required for DNA synthesis. Although having a relatively short half-life (fog" These accounts have come primarily from patients undergoing treatment for breast cancer who report symptoms including confusion and memory impairment, which can last for months to years. Psychometric studies of patients have suffered from confounding variables, which has led to the use of rodent models to assess the cognitive effects of this drug. Researchers have used behavioral and physiological tests including the Morris water maze, novel object location/recognition tests, shock motivated T-maze, sensory gating and conditioning, to investigate the effect of this drug on cognition. The variety of cognitive tests and the difference in dosing and administration of 5-FU has led to varied results, possibly due to the different brain regions associated with each test and the subtlety of the drug's effect, but overall these studies indicates that 5-FU has a negative effect on memory, executive function and sensory gating. 5-FU has also been demonstrated to have biochemical and structural changes on specific regions of the brain. Evidence shows it can induce apoptosis and depress cell proliferation in the neurogenic regions of the adult brain including the sub granular zone (SGZ) within the hippocampus and in oligodendrocyte precursor populations within white matter tracts. Furthermore, investigations indicate levels ofdoublecortin, a marker for newly formed neurons and brain derived neurotrophic factor, a cell survival modulator, are also reduced by 5-FU in the SGZ. Thus, 5-FU appears to have a lasting negative impact on cognition and to affect cellular and biochemical markers in various brain regions. Further work is needed to understand the

  8. Degradation of 5-FU by means of advanced (photo)oxidation processes: UV/H2O2, UV/Fe2+/H2O2 and UV/TiO2--Comparison of transformation products, ready biodegradability and toxicity.

    Science.gov (United States)

    Lutterbeck, Carlos Alexandre; Wilde, Marcelo Luís; Baginska, Ewelina; Leder, Christoph; Machado, Ênio Leandro; Kümmerer, Klaus

    2015-09-15

    The present study investigates the degradation of the antimetabolite 5-fluorouracil (5-FU) by three different advanced photo oxidation processes: UV/H2O2, UV/Fe(2+)/H2O2 and UV/TiO2. Prescreening experiments varying the H2O2 and TiO2 concentrations were performed in order to set the best catalyst concentrations in the UV/H2O2 and UV/TiO2 experiments, whereas the UV/Fe(2+)/H2O2 process was optimized varying the pH, Fe(2+) and H2O2 concentrations by means of the Box-Behnken design (BBD). 5-FU was quickly removed in all the irradiation experiments. The UV/Fe(2+)/H2O2 and UV/TiO2 processes achieved the highest degree of mineralization, whereas the lowest one resulted from the UV/H2O2 treatment. Six transformation products were formed during the advanced (photo)oxidation processes and identified using low and high resolution mass spectrometry. Most of them were formed and further eliminated during the reactions. The parent compound of 5-FU was not biodegraded, whereas the photolytic mixture formed in the UV/H2O2 treatment after 256 min showed a noticeable improvement of the biodegradability in the closed bottle test (CBT) and was nontoxic towards Vibrio fischeri. In silico predictions showed positive alerts for mutagenic and genotoxic effects of 5-FU. In contrast, several of the transformation products (TPs) generated along the processes did not provide indications for mutagenic or genotoxic activity. One exception was TP with m/z 146 with positive alerts in several models of bacterial mutagenicity which could demand further experimental testing. Results demonstrate that advanced treatment can eliminate parent compounds and its toxicity. However, transformation products formed can still be toxic. Therefore toxicity screening after advanced treatment is recommendable.

  9. Combination of metformin with chemotherapeutic drugs via different molecular mechanisms.

    Science.gov (United States)

    Peng, Mei; Darko, Kwame Oteng; Tao, Ting; Huang, Yanjun; Su, Qiongli; He, Caimei; Yin, Tao; Liu, Zhaoqian; Yang, Xiaoping

    2017-03-01

    Metformin, a widely prescribed drug for treating type II diabetes, is one of the most extensively recognized metabolic modulators which has shown an important anti-cancer property. However, fairly amount of clinical trials on its single administration have not demonstrated a convincing efficiency yet. Thus, recent studies tend to combine metformin with clinical commonly used chemotherapeutic drugs to decrease their toxicity and attenuate their tumor resistance. These strategies have displayed promising clinical benefits. Interestingly, metformin experiences a diversity of molecular mechanisms when it combines different chemotherapeutic drugs. For example, AMPK/mTOR signaling pathway activation plays a major role when it combines with hormone modulating drugs. In contrast, suppression of HIF-1, p-gp and MRP1 protein expression is its main mechanism when metformin combines with anti-metabolites. Furthermore, when combining of metformin with antibiotics, inhibition of oxidative stress and inflammatory signaling pathway becomes a novel pharmaceutical mechanism for its cardio-protective effect. Induction of apoptotic mitochondria and nucleus could be the major player for the synergistic effect of its combination with cisplatin. In contrast, down-regulation of lipoprotein or cholesterol synthesis might be the undefined molecular base when metformin combines with taxane. Thus, deep exploration of molecular mechanisms of metformin with these different drugs is critical to understand its synergistic effect and help for personalized administration. In this mini-review, detailed molecular mechanisms of these combinations are discussed and summarized. This work will promote better understanding of molecular mechanisms of metformin and provide precise targets to identify specific patient groups to achieve satisfactory treatment efficacy.

  10. Metformin and cancer: Between the bioenergetic disturbances and the antifolate activity.

    Science.gov (United States)

    Jara, J A; López-Muñoz, R

    2015-11-01

    For decades, metformin has been the first-line drug for the treatment of type II diabetes mellitus, and it thus is the most widely prescribed antihyperglycemic drug. Retrospective studies associate the use of metformin with a reduction in cancer incidence and cancer-related death. However, despite extensive research about the molecular effects of metformin in cancer cells, its mode of action remains controversial. In this review, we summarize the current molecular evidence in an effort to elucidate metformin's mode of action against cancer cells. Some authors describe that metformin acts directly on mitochondria, inhibiting complex I and restricting the cell's ability to cope with energetic stress. Furthermore, as the drug interrupts the tricarboxylic acid cycle, metformin-induced alteration of mitochondrial function leads to a compensatory increase in lactate and glycolytic ATP. It has also been reported that cell cycle arrest, autophagy, apoptosis and cell death induction is mediated by the activation of AMPK and Redd1 proteins, thus inhibiting the mTOR pathway. Additionally, unbiased metabolomics studies have provided strong evidence to support that metformin alters the methionine and folate cycles, with a concomitant decrease in nucleotide synthesis. Indeed, purines such as thymidine or hypoxanthine restore the proliferation of tumor cells treated with metformin in vitro. Consequently, some authors prefer to refer to metformin as an "antimetabolite drug" rather than a "mitochondrial toxin". Finally, we also review the current controversy concerning the relationship between the experimental conditions of in vitro-reported effects and the plasma concentrations achieved by chronic treatment with metformin.

  11. A new paradigm for pattern recognition of drugs.

    Science.gov (United States)

    Potemkin, Vladimir A; Grishina, Maria A

    2008-01-01

    A new paradigm is suggested for pattern recognition of drugs. The approach is based on the combined application of the 4D/3D quantitative structure-activity relationship (QSAR) algorithms BiS and ConGO. The first algorithm, BiS/MC (multiconformational), is used for the search for the conformers interacting with a receptor. The second algorithm, ConGO, has been suggested for the detailed study of the selected conformers' electron density and for the search for the electron structure fragments that determine the pharmacophore and antipharmacophore parts of the compounds. In this work we suggest using a new AlteQ method for the evaluation of the molecular electron density. AlteQ describes the experimental electron density (determined by low-temperature highly accurate X-ray analysis) much better than a number of quantum approaches. Herein this is shown using a comparison of the computed electron density with the results of highly accurate X-ray analysis. In the present study the desirability function is used for the first time for the analysis of the effects of the electron structure in the process of pattern recognition of active and inactive compounds. The suggested method for pattern recognition has been used for the investigation of various sets of compounds such as DNA-antimetabolites, fXa inhibitors, 5-HT(1A), and alpha(1)-AR receptors inhibitors. The pharmacophore and antipharmacophore fragments have been found in the electron structures of the compounds. It has been shown that the pattern recognition cross-validation quality for the datasets is unity.

  12. Supplementation with fish oil and genistein, individually or in combination, protects bone against the adverse effects of methotrexate chemotherapy in rats.

    Directory of Open Access Journals (Sweden)

    Rethi Raghu Nadhanan

    Full Text Available Cancer chemotherapy has been shown to induce long-term skeletal side effects such as osteoporosis and fractures; however, there are no preventative treatments. This study investigated the damaging effects of anti-metabolite methotrexate (MTX subcutaneous injections (0.75 mg/kg BW for five days and the potential protective benefits of daily oral gavage of fish oil at 0.5 mL/100 g BW (containing 375 mg of n-3 PUFA/100 g BW, genistein (2 mg/100 g BW, or their combination in young adult rats. MTX treatment alone significantly reduced primary spongiosa height and secondary spongiosa trabecular bone volume. Bone marrow stromal cells from the treated rats showed a significant reduction in osteogenic differentiation but an increase in adipogenesis ex vivo. Consistently, stromal cells had significantly higher mRNA levels of adipogenesis-related proliferator activator activated receptor-γ (PPAR-γ and fatty acid binding protein (FABP4. MTX significantly increased the numbers of bone-resorbing osteoclasts and marrow osteoclast precursor cell pool while significantly enhancing the mRNA expression of receptor activator for nuclear factor kappa B ligand (RANKL, the RANKL/osteoprotegerin (OPG ratio, interleukin-6 (IL-6, and tumor necrosis factor-α (TNF-α in the bone. Supplementary treatment with fish oil and/or genistein significantly preserved trabecular bone volume and osteogenesis but suppressed MTX-induced adipogenesis and increases in osteoclast numbers and pro-osteoclastogenic cytokine expression. Thus, Fish oil and/or genistein supplementation during MTX treatment enabled not only preservation of osteogenic differentiation, osteoblast number and bone volume, but also prevention of MTX treatment-induced increases in bone marrow adiposity, osteoclastogenic cytokine expression and osteoclast formation, and thus bone loss.

  13. Medication treatment of pediatric noninfectious uveitis%儿童非感染性葡萄膜炎的药物治疗

    Institute of Scientific and Technical Information of China (English)

    王敏; 张美芬

    2015-01-01

    儿童葡萄膜炎占所有葡萄膜炎的5%~10%,多数起病隐匿、病程迁延,常合并多种眼部并发症.儿童葡萄膜炎多为非感染性,其中绝大多数为特发性,最常见的全身病因为幼年特发性关节炎.儿童葡萄膜炎治疗棘手,常用药物为糖皮质激素、抗代谢药、T细胞抑制剂.近年来生物制剂的使用为儿童非感染性葡萄膜炎的治疗提供了新方法.玻璃体腔植入糖皮质激素缓释装置可长时间控制眼内炎症,但在儿童中使用的安全性及有效性仍待进一步研究.%Pediatric uveitis is accounting for 5%~ 10% of all the uveitis.Most individuals have an insidious onset and persistent duration,ocular complications are common.Most pediatric uveitis are noninfectious and idiopathic,the most common etiologic diagnosis is juvenile idiopathic arthritis.Treatment of pediatric uveitis is tough,the mainstays of therapy include corticosteroids,antimetabolites,and T-cell inhibitors.In the last decade,biologic agents provide us new methods for treating pediatric uveitis.Intravitreal corticosteroid delivery devices have enhanced our ability to provide longer-lasting local disease control,but there are very limited data showing the efficacy and safety in children.

  14. Characterisation of the mgo operon in Pseudomonas syringae pv. syringae UMAF0158 that is required for mangotoxin production

    Directory of Open Access Journals (Sweden)

    Arrebola Eva

    2012-01-01

    Full Text Available Abstract Background Mangotoxin is an antimetabolite toxin that is produced by strains of Pseudomonas syringae pv. syringae; mangotoxin-producing strains are primarily isolated from mango tissues with symptoms of bacterial apical necrosis. The toxin is an oligopeptide that inhibits ornithine N-acetyl transferase (OAT, a key enzyme in the biosynthetic pathway of the essential amino acids ornithine and arginine. The involvement of a putative nonribosomal peptide synthetase gene (mgoA in mangotoxin production and virulence has been reported. Results In the present study, we performed a RT-PCR analysis, insertional inactivation mutagenesis, a promoter expression analysis and terminator localisation to study the gene cluster containing the mgoA gene. Additionally, we evaluated the importance of mgoC, mgoA and mgoD in mangotoxin production. A sequence analysis revealed an operon-like organisation. A promoter sequence was located upstream of the mgoB gene and was found to drive lacZ transcription. Two terminators were located downstream of the mgoD gene. RT-PCR experiments indicated that the four genes (mgoBCAD constitute a transcriptional unit. This operon is similar in genetic organisation to those in the three other P. syringae pathovars for which complete genomes are available (P. syringae pv. syringae B728a, P. syringae pv. tomato DC3000 and P. syringae pv. phaseolicola 1448A. Interestingly, none of these three reference strains is capable of producing mangotoxin. Additionally, extract complementation resulted in a recovery of mangotoxin production when the defective mutant was complemented with wild-type extracts. Conclusions The results of this study confirm that mgoB, mgoC, mgoA and mgoD function as a transcriptional unit and operon. While this operon is composed of four genes, only the last three are directly involved in mangotoxin production.

  15. Cytochrome P450 1B1 gene polymorphisms as predictors of anticancer drug activity: studies with in vitro models.

    Science.gov (United States)

    Laroche-Clary, Audrey; Le Morvan, Valérie; Yamori, Takao; Robert, Jacques

    2010-12-01

    Cytochrome P450 1B1 (CYP1B1) is found in tumor tissue and is suspected to play a role in oncogenesis and drug resistance. CYP1B1 gene polymorphisms have been associated with the risk of developing lung and other cancers. They may be associated with tumor response to anticancer drugs. We have determined 4 frequent nonsynonymous gene polymorphisms of CYP1B1 in the human tumor cell lines panels of the National Cancer Institute (NCI) and the Japanese Foundation for Cancer Research (JFCR): rs10012 (R48G), rs1056827 (A119S), rs1056836 (L432V), and rs1800440 (N453S). Numerous anticancer drugs have been tested against these panels that offer the opportunity to detect associations between gene polymorphisms and drug sensitivity. CYP1B1 single nucleotide polymorphisms were in marked linkage disequilibrium. The L432V allelic variants were significantly associated with reduced sensitivity to DNA-interacting anticancer agents, alkylators, camptothecins, topoisomerase II inhibitors, and some antimetabolites. For instance, in the NCI panel, cell lines homozygous for the V432 allele were globally 2-fold resistant to alkylating agents (P = 5 × 10(-10)) and 4.5-fold to camptothecins (P = 6.6 × 10(-9)) than cell lines homozygous for the L432 allele. Similar features were exhibited by the JFCR panel. Cell lines homozygous for the V432 allele were globally less sensitive to DNA-interfering drugs than cell lines having at least 1 common allele. There was no significant association between mRNA expression of CYP1B1 and CYP1B1 genotype, and no significant association between CYP1B1 mRNA expression and drug cytotoxicity. These observations open the way to clinical studies exploring the role of CYP1B1 gene polymorphisms for predicting tumor sensitivity to chemotherapy.

  16. Advanced glaucoma: Management pearls

    Directory of Open Access Journals (Sweden)

    Girum W Gessesse

    2013-01-01

    Full Text Available A significant proportion of glaucoma patients present late, particularly in the developing world, and unfortunately, in an advanced stage of the disease. They are at imminent danger of losing remaining vision, and may also be afflicted with various socioeconomic and health challenges. The encounter with such a patient is typically characterized by anxiety/fear and sometimes hopelessness from the patient′s perspective. The physician may also feel that they are in a difficult position managing the patient′s disease. When dealing with such cases, we suggest a holistic, individualized approach taking into account the ′biopsychosociospiritual′ (BPSS profile of each patient. The BPSS model takes into account relevant ocular as well as systemic biology (factors such as the mechanism of glaucoma, level of intraocular pressure [IOP], rate of progression, life expectancy, general health, psychological considerations (e.g., fear, depression, socio-economic factors and spiritual/cultural values and beliefs before being able to decide with the patient and their care partner(s what treatment goals should be and how they can best be approached. Treatment for advanced glaucoma can be highly effective, and patients and their care partners should be informed that aggressive IOP lowering to the low teens or even single digits offers the best chance of protecting remaining vision. This can be achieved safely and effectively in most cases with trabeculectomy (including an antimetabolite, and in some cases with medical and/or laser therapy. Vision rehabilitation and psychosocial support should also be considered in order to optimize remaining vision, replace fear with hope as appropriate, and thus improve the overall quality of life.

  17. Repurposing the anticancer drug mitomycin C for the treatment of persistent Acinetobacter baumannii infections.

    Science.gov (United States)

    Cruz-Muñiz, Martha Yumiko; López-Jacome, Luis Esau; Hernández-Durán, Melissa; Franco-Cendejas, Rafael; Licona-Limón, Paula; Ramos-Balderas, Jose Luis; Martinéz-Vázquez, Mariano; Belmont-Díaz, Javier A; Wood, Thomas K; García-Contreras, Rodolfo

    2017-01-01

    Acinetobacter baumannii is an emergent opportunistic bacterial pathogen responsible for recalcitrant infections owing to its high intrinsic tolerance to most antibiotics; therefore, suitable strategies to treat these infections are needed. One plausible approach is the repurposing of drugs that are already in use. Among them, anticancer drugs may be especially useful due their cytotoxic activities and ample similarities between bacterial infections and growing tumours. In this work, the effectiveness of four anticancer drugs on the growth of A. baumannii ATTC BAA-747 was evaluated, including the antimetabolite 5-fluorouracil and three DNA crosslinkers, namely cisplatin, mitomycin C (MMC) and merphalan. MMC was the most effective drug, having a minimum inhibitory concentration for 50% of growth in Luria-Bertani medium at ca. 7 µg/mL and completely inhibiting growth at 25 µg/mL. Hence, MMC was tested against a panel of 21 clinical isolates, including 18 multidrug-resistant (MDR) isolates, 3 of which were sensitive only to colistin. The minimum inhibitory concentrations and minimum bactericidal concentrations of MMC in all tested strains were found to be similar to those of A. baumannii ATCC BAA-747, and MMC also effectively killed stationary-phase, persister and biofilm cells. Moreover, MMC was able to increase survival of the insect larvae Galleria mellonella against an otherwise lethal A. baumannii infection from 0% to ≥53% for the antibiotic-sensitive A. baumannii ATCC BAA-747 strain and the MDR strains A560 and A578. Therefore, MMC is highly effective at killing the emergent opportunistic pathogen A. baumannii.

  18. Acute onset lactobacillus endophthalmitis after trabeculectomy: a case report

    Directory of Open Access Journals (Sweden)

    Droutsas Konstantinos

    2010-06-01

    Full Text Available Abstract Introduction We report a case of early lactobacillus endophthalmitis which occurred ten days after trabeculectomy. Case presentation A 76-year-old Caucasian diabetic woman underwent uncomplicated trabeculectomy with a collagen implant as an adjunct, in her left phakic eye, for the treatment of uncontrolled open-angle glaucoma. Ten days post-operatively, our patient complained of left phakic eye discharge pain and visual acuity decreased to "light-perception". The anterior chamber had 3+ cells and flare, and there was also 2 mm layered hypopyon. Vitreous involvement was present obscuring visualization of the fundus. On the same day our patient underwent vitrectomy surgery and intra-vitreal and systemic antibiotics were administered. Vitreous cultures grew Lactobacillus brevis. Our patient responded well to treatment and 30 days after vitrectomy visual acuity improved to 1/10. Six months later our patient underwent cataract surgery. Eight months after initial surgery visual acuity was 2/10 and intra-ocular pressure was 14 mmHg without any anti-glaucoma medication. Conclusions This is the first report of acute lactobacillus endophthalmitis in the phakic eye of a diabetic patient after trabeculectomy. Glaucoma surgeons should be aware of the potential for acute post-operative endophthalmitis due to rare microorganisms, such as lactobacillus, in glaucoma filtration surgery, especially in diabetic patients. The literature shows an increased risk of endophthalmitis when anti-metabolites are used in conjunction with trabeculectomy. Perhaps, any type of wound healing modulation, such as collagen or mitomycin-C may increase this risk. However, it is unclear at this time and more studies need to be done. In this single case, vitrectomy combined with intra-vitreal and systemic antibiotics were efficient in limiting the devastating sequels of this complication.

  19. Progress in prevention and treatment of traumatic proliferative vitreoretinopathy%外伤性增生性玻璃体视网膜病变防治的研究进展

    Institute of Scientific and Technical Information of China (English)

    张琼; 陈松

    2015-01-01

    Traumatic proliferative vitreoretinopathy (PVR) is the main reason for the failure of retinal detachment surgery,which is very difficult to be cure.Internal hmiting membrane peeling,retinal release incision,vitreous cavity filling using perfluorocarbon liquid or using combined weight and light silicone oil are the new surgery treatment direction of PVR.Medications,such as antimetabolites,corticosteroids,drugs inhibiting cellulose,as well as the new therapy,such as gene therapy,immunosuppressants,phosphorylated glycoprotein etc.And the sustained-release fine particles therapy can reduce the morbidity and the severity of the PVR.%外伤性增生性玻璃体视网膜病变(proliferative vitreoretinopathy,PVR)是视网膜脱离手术失败的主要原因,治疗棘手.玻璃体视网膜手术中内界膜的剥除、松解性视网膜切开术、玻璃体腔填充使用的全氟化碳液体、联合重轻型硅油填充等成为外伤性PVR手术治疗的新方向;药物治疗包括抗代谢药物、糖皮质激素、抑制纤维素生成药物等.新的药物治疗进展有基因治疗、免疫抑制剂、磷酸化糖蛋白等.可通过缓释微粒治疗等新疗法降低PVR发病率和严重程度.

  20. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

    Science.gov (United States)

    Céspedes, María Virtudes; Guillén, María José; López-Casas, Pedro Pablo; Sarno, Francesca; Gallardo, Alberto; Álamo, Patricia; Cuevas, Carmen; Hidalgo, Manuel; Galmarini, Carlos María; Allavena, Paola; Avilés, Pablo; Mangues, Ramón

    2016-01-01

    ABSTRACT We explored whether the combination of lurbinectedin (PM01183) with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA) mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i) specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii) specific depletion of tumor-associated macrophages (TAMs). We evaluated the in vivo antitumor activity of lurbinectedin and gemcitabine as single agents and in combination in SW-1990 and MIA PaCa-2 cell-line xenografts and in patient-derived PDA models (AVATAR). Lurbinectedin-gemcitabine combination induced a synergistic effect on both MIA PaCa-2 [combination index (CI)=0.66] and SW-1990 (CI=0.80) tumor xenografts. It also induced complete tumor remissions in four out of six patient-derived PDA xenografts. This synergism was associated with enhanced DNA damage (anti-γ-H2AX), cell cycle blockage, caspase-3 activation and apoptosis. In addition to the enhanced DNA damage, which is a consequence of the interaction of the two drugs with the DNA, lurbinectedin induced TAM depletion leading to cytidine deaminase (CDA) downregulation in PDA tumors. This effect could, in turn, induce an increase of gemcitabine-mediated DNA damage that was especially relevant in high-density TAM tumors. These results show that lurbinectedin can be used to develop ‘molecularly targeted’ combination strategies. PMID:27780828

  1. Current trends in the management of ocular symptoms in Adamantiades-Behçet’s disease

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    Fouad R Zakka

    2009-10-01

    Full Text Available Fouad R Zakka,1 Peter Y Chang,1 Gian P Giuliari,1 C Stephen Foster1,21Massachusetts Eye Research and Surgery institution (MERSI, Cambridge, Massachusetts, USA; 2Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USAAbstract: Adamantiades-Behçet’s disease (ABD is a multisystemic vasculitic disease. It is most prevalent in the Eastern Mediterranean countries and the Eastern region of Asia. Its effect on the eye can range from mild to debilitating, resulting in total blindness. A necrotizing and obliterative vasculitis affects both arteries and veins of organs. Recurrent attacks of uveitis, oral aphthous ulcers, skin lesions, and genital ulcers are common. Topical and systemic corticosteroids have been the mainstay in the treatment of ocular inflammation for many years; however, due to the several known side effects of corticosteroids and thanks to scientific advances, more novel approaches to ABD treatment have been emerging. Antimetabolites such as methotrexate and azathioprine have been utilized with the latter showing positive results. Chlorambucil has been utilized effectively for ocular manifestations of ABD. Interferon alpha has shown encouraging results in the management of refractory ocular inflammation associated with ABD, either alone or in combination with other immunosuppressive agents. Surgical interventions to deal with complications from ABD can be safely done if adequate control of inflammation is achieved peri-operatively. Early detection and aggressive treatment, when needed, have proven to be essential in the management of this relentlessly explosive disease.Keywords: Adamantiades-Behçet’s disease, Behçet’s disease, ocular inflammation, uveitis, immunomodulatory therapy, immunosuppressive therapy

  2. 激光泪道成形术联合抗代谢药物治疗复发性泪道阻塞疗效分析%Clinical observation of lacrimal laser angioplasty combined with anti-metabolism drug treatment for recurrent lacrimal duct obstruction

    Institute of Scientific and Technical Information of China (English)

    李强; 曹东; 杨兴旺; 李博; 高雪辉

    2010-01-01

    目的 观察分析激光泪道成形术联合抗代谢药物治疗复发性泪道阻塞的疗效.方法 对101 例激光泪道成形术后复发病例实施激光泪道成形术联合抗代谢药物治疗.结果 术后随访观察3月,治愈85只眼,占84.2%;好转11只眼,占10.9%,总有效率95%.失败5只眼,占4.9%.结论 激光泪道成形术联合抗代谢药物治疗复发性泪道阻塞效果肯定,并发症少,值得推广.%Objective To observe and analyze the results of lacrimal laser angioplasty combined with antimetabolites in the treatment of recurrgnt lacrimal duct obstruction.Methods One hundred and one recurrent lacrimal laser angioplasty cases were implemented lacrimal laser angioplasty combined with anti-metabolism drug treatment.Results Postoperative follow-up time were three months,of which 85 cured,accounted for 84.2%;11 improvement;accounted for 10.9%,the total effective rate was 95%:5 failed,accounted for 4.9%.Conclusions Lacrimal laser angioplasty combined with anti-metabolism drug treatment is effective for treatment of recurrent lacrimal duct obstruction and has few complications,it is worth promoting.

  3. Second-Line Immunosuppressive Treatment of Childhood Nephrotic Syndrome: A Single-Center Experience

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    J. Kim

    2014-01-01

    Full Text Available Objective: Most cases of idiopathic nephrotic syndrome in childhood are responsive to corticosteroids. However, there is a small group of children that demonstrate steroid resistance (steroid-resistant nephrotic syndrome; SRNS, steroid dependence, or that frequently relapse (frequent-relapse steroid-sensitive nephrotic syndrome; FR-SSNS which are more clinically difficult to treat. Therefore, second-line immunosuppressants, such as alkylating agents, calcineurin inhibitors, antimetabolites and, more recently, rituximab, have been used with varying success. The objective was to evaluate the response rates of various second-line therapies in the treatment of childhood nephrotic syndrome. Study Design: A retrospective chart review of pediatric subjects with idiopathic nephrotic syndrome was conducted at a single tertiary care center (2007-2012. Drug responses were classified as complete response, partial response, and no response. Results: Of the 188 charts reviewed, 121 children were classified as SSNS and 67 children as SRNS; 58% were classified as FR-SSNS. Sixty-five subjects were diagnosed with focal segmental glomerulosclerosis via biopsy. Follow-up ranged from 6 months to 21 years. The combined rate of complete and partial response for mycophenolate mofetil (MMF was 65% (33/51 in SSNS and 67% (6/9 in SRNS. For tacrolimus, the response rate was 96% (22/23 for SSNS and 77% (17/22 for SRNS. Eighty-three percent (5/6 of SSNS subjects treated with rituximab went into complete remission; 60% relapsed after B-cell repletion. Eight refractory subjects were treated with combined MMF/tacrolimus/corticosteroid therapy with a 75% response rate. Conclusion: Our experience demonstrates that older medications can be replaced with newer ones such as MMF, tacrolimus, and rituximab with good outcomes and better side effect profiles. The treatment of refractory cases with combination therapy is promising.

  4. Optimal dose of gemcitabine for the treatment of biliary tract or pancreatic cancer in patients with liver dysfunction.

    Science.gov (United States)

    Shibata, Takashi; Ebata, Tomoki; Fujita, Ken-ichi; Shimokata, Tomoya; Maeda, Osamu; Mitsuma, Ayako; Sasaki, Yasutsuna; Nagino, Masato; Ando, Yuichi

    2016-02-01

    A clear consensus does not exist about whether the initial dose of gemcitabine, an essential anticancer antimetabolite, should be reduced in patients with liver dysfunction. Adult patients with biliary tract or pancreatic cancer were divided into three groups according to whether they had mild, moderate, or severe liver dysfunction, evaluated on the basis of serum bilirubin and liver transaminase levels at baseline. As anticancer treatment, gemcitabine at a dose of 800 or 1000 mg/m(2) was given as an i.v. infusion once weekly for 3 weeks of a 4-week cycle. The patients were prospectively evaluated for adverse events during the first cycle, and the pharmacokinetics of gemcitabine and its inactive metabolite, difluorodeoxyuridine, were studied to determine the optimal initial dose of gemcitabine as monotherapy according to the severity of liver dysfunction. A total of 15 patients were studied. Liver dysfunction was mild in one patient, moderate in six, and severe in eight. All 15 patients had been undergoing biliary drainage for obstructive jaundice when they received gemcitabine. Grade 3 cholangitis developed in one patient with moderate liver dysfunction who received gemcitabine at the dose level of 1000 mg/m(2). No other patients had severe treatment-related adverse events resulting in the omission or discontinuation of gemcitabine treatment. The plasma concentrations of gemcitabine and difluorodeoxyuridine were similar among the groups. An initial dose reduction of gemcitabine as monotherapy for the treatment of biliary tract or pancreatic cancers is not necessary for patients with hyperbilirubinemia, provided that obstructive jaundice is well managed. (Clinical trial registration no. UMIN000005363.)

  5. Cytotoxicity of new duplex drugs linking 3'-C-ethynylcytidine and 5-fluor-2'-deoxyuridine against human melanoma cells.

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    Schott, Sarah; Niessner, Heike; Sinnberg, Tobias; Venturelli, Sascha; Berger, Alexander; Ikenberg, Kristian; Villanueva, Jessie; Meier, Friedegund; Garbe, Claus; Busch, Christian

    2012-11-01

    Melanoma is an increasingly common and potentially fatal malignancy of the skin and some mucous membranes. As no cure exists for metastatic disease, there is an urgent need for novel drugs. 2'-Deoxy-5-fluorouridylyl-(3'-5')-3'-C-ethynylcytidine [5-FdU(3'-5')ECyd] and 3'-C-ethynylcytidinylyl-(5' → 1-O)-2-O-octadecyl-sn-glycerylyl-(3-O → 5')-2'-deoxy-5-fluorouridine [ECyd-lipid-5-FdU] represent cytostatic active duplex drugs, which can be metabolized into various active antimetabolites. We evaluated the cytotoxicity of these heterodinucleoside phosphate analogs, their corresponding monomers ECyd and 5-FdU and combinations thereof on six metastatic melanoma cell lines and six ex vivo patient-derived melanoma cells in comparison to current standard cytostatic agents and the BRAF V600E inhibitor Vemurafenib. In vitro (real-time)-proliferation assays demonstrated that 5-FdU(3'-5')ECyd and ECyd-lipid-5-FdU had a high cytotoxic efficacy causing 75% melanoma cell death at concentrations in the nanomolar and micromolar range. Cytotoxicity was conducted by induction of DNA cleavage indicating apoptotic cells. Chicken embryotoxicity demonstrated that the duplex drugs were less toxic than 5-FdU at 0.01 μM. In vivo the duplex drug 5-FdU(3'-5')ECyd was efficacious in the murine LOX IMVI melanoma xenograph model on administration of 11.2 mg/kg/injection every fourth day. Both duplex drugs are promising novel cytostatic agents for the treatment of malignant melanoma meriting clinical evaluation.

  6. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

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    María Virtudes Céspedes

    2016-12-01

    Full Text Available We explored whether the combination of lurbinectedin (PM01183 with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii specific depletion of tumor-associated macrophages (TAMs. We evaluated the in vivo antitumor activity of lurbinectedin and gemcitabine as single agents and in combination in SW-1990 and MIA PaCa-2 cell-line xenografts and in patient-derived PDA models (AVATAR. Lurbinectedin-gemcitabine combination induced a synergistic effect on both MIA PaCa-2 [combination index (CI=0.66] and SW-1990 (CI=0.80 tumor xenografts. It also induced complete tumor remissions in four out of six patient-derived PDA xenografts. This synergism was associated with enhanced DNA damage (anti-γ-H2AX, cell cycle blockage, caspase-3 activation and apoptosis. In addition to the enhanced DNA damage, which is a consequence of the interaction of the two drugs with the DNA, lurbinectedin induced TAM depletion leading to cytidine deaminase (CDA downregulation in PDA tumors. This effect could, in turn, induce an increase of gemcitabine-mediated DNA damage that was especially relevant in high-density TAM tumors. These results show that lurbinectedin can be used to develop ‘molecularly targeted’ combination strategies.

  7. Differences in treatment of anti-NMDA receptor encephalitis: results of a worldwide survey.

    Science.gov (United States)

    Bartolini, Luca; Muscal, Eyal

    2017-02-02

    The objective of the study was to identify differences in treatment strategies for anti-NMDA receptor encephalitis based on specialty of treating physicians, geographic location, and years in practice. We conducted an anonymous worldwide electronic survey through the Practice Current section of Neurology(®) Clinical Practice to appraise differences in decisions about first- and second-line treatment and timing for initiation of second-line treatment for anti-NMDA receptor encephalitis. 399 participants answered all questions of the survey and were included in the analysis. 261 (65%) were adult neurologists, 86 (22%) were neurologists treating children, and 52 (13%) were pediatric rheumatologists. 179 (45%) responders practiced in the US. The majority agreed on the use of steroids and/or IVIg for first-line therapy and rituximab alone as second line. Differences in initial treatment regimen based on specialty included increased use of plasma exchange by adult neurologists (27%) and rituximab by pediatric rheumatologists (29%) (χ (2)(4) = 27.43, p < 0.001). Trainees opted for plasma exchange (35%) and junior faculty picked rituximab (15%) more as part of first line (χ (2)(4) = 13.37, p = 0.010). There was greater usage of anti-metabolites for second-line therapy outside of the US (15%) (χ (2)(4) = 11.67, p = 0.020). US physicians also utilized second-line treatment earlier than their mostly European counterparts (14 vs. 23% used later than 2 weeks; χ (2)(1) = 4.96, p = 0.026). Although treatment patterns were similar, differences observed across specialties and geographic locations may guide the development of consensus-driven guidelines by multi-disciplinary task forces. These guidelines may promote treatment trials of immunomodulators in autoimmune encephalitides.

  8. A kinome screen identifies checkpoint kinase 1 (CHK1 as a sensitizer for RRM1-dependent gemcitabine efficacy.

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    Jun Zhou

    Full Text Available Gemcitabine is among the most efficacious and widely used antimetabolite agents. Its molecular targets are ribonucleotide reductase M1 (RRM1 and elongating DNA. Acquired and de novo resistance as a result of RRM1 overexpression are major obstacles to therapeutic efficacy. We deployed a synthetic lethality screen to investigate if knockdown of 87 selected protein kinases by siRNA could overcome RRM1-dependent gemcitabine resistance in high and low RRM1-expressing model systems. The models included genetically RRM1-modified lung and breast cancer cell lines, cell lines with gemcitabine-induced RRM1 overexpression, and a series of naturally gemcitabine-resistant cell lines. Lead molecular targets were validated by determination of differential gemcitabine activity using cell lines with and without target knock down, and by assessing synergistic activity between gemcitabine and an inhibitor of the lead target. CHK1 was identified has the kinase with the most significant and robust interaction, and it was validated using AZD7762, a small-molecule ATP-competitive inhibitor of CHK1 activation. Synergism between CHK1 inhibition and RRM1-dependent gemcitabine efficacy was observed in cells with high RRM1 levels, while antagonism was observed in cells with low RRM1 levels. In addition, four cell lines with natural gemcitabine resistance demonstrated improved gemcitabine efficacy after CHK1 inhibition. In tumor specimens from 187 patients with non-small-cell lung cancer, total CHK1 and RRM1 in situ protein levels were significantly (p = 0.003 and inversely correlated. We conclude that inhibition of CHK1 may have its greatest clinical utility in malignancies where gemcitabine resistance is a result of elevated RRM1 levels. We also conclude that CHK1 inhibition in tumors with low RRM1 levels may be detrimental to gemcitabine efficacy.

  9. Dynamic metabolic labeling of DNA in vivo with arabinosyl nucleosides.

    Science.gov (United States)

    Neef, Anne B; Luedtke, Nathan W

    2011-12-20

    Commonly used metabolic labels for DNA, including 5-ethynyl-2'-deoxyuridine (EdU) and BrdU, are toxic antimetabolites that cause DNA instability, necrosis, and cell-cycle arrest. In addition to perturbing biological function, these properties can prevent metabolic labeling studies where subsequent tissue survival is needed. To bypass the metabolic pathways responsible for toxicity, while maintaining the ability to be metabolically incorporated into DNA, we synthesized and evaluated a small family of arabinofuranosyl-ethynyluracil derivatives. Among these, (2'S)-2'-deoxy-2'-fluoro-5-ethynyluridine (F-ara-EdU) exhibited selective DNA labeling, yet had a minimal impact on genome function in diverse tissue types. Metabolic incorporation of F-ara-EdU into DNA was readily detectable using copper(I)-catalyzed azide-alkyne "click" reactions with fluorescent azides. F-ara-EdU is less toxic than both BrdU and EdU, and it can be detected with greater sensitivity in experiments where long-term cell survival and/or deep-tissue imaging are desired. In contrast to previously reported 2'-arabino modified nucleosides and EdU, F-ara-EdU causes little or no cellular arrest or DNA synthesis inhibition. F-ara-EdU is therefore ideally suited for pulse-chase experiments aimed at "birth dating" DNA in vivo. As a demonstration, Zebrafish embryos were microinjected with F-ara-EdU at the one-cell stage and chased by BrdU at 10 h after fertilization. Following 3 d of development, complex patterns of quiescent/senescent cells containing only F-ara-EdU were observed in larvae along the dorsal side of the notochord and epithelia. Arabinosyl nucleoside derivatives therefore provide unique and effective means to introduce bioorthogonal functional groups into DNA for diverse applications in basic research, biotechnology, and drug discovery.

  10. 青光眼术后滤过泡感染及滤过泡相关性眼内炎的临床观察%Clinical observation of filtering bleb infections and filtration bleb-related endophthalmitis after glaucoma surgery

    Institute of Scientific and Technical Information of China (English)

    张蕾; 陶静; 吴雅颖

    2012-01-01

    目的 探讨青光眼术后滤过泡感染及滤过泡眼内炎的危险因素以及临床表现和预后转归.方法 查阅近5年医院行青光眼滤过手术的病历,依据术中是否放置丝裂霉素C(MMC)分为两组,讨论MMC的放置增加滤过泡感染的可能性;并总结医院近5年滤过泡感染及相关性眼内炎的病历,将其分为单纯感染组和眼内炎组,探讨其临床表现、病原学、治疗及临床预后.结果 手术中巩膜下放置抗代谢药物,术后发生滤过泡相关感染的患者为1.36%,而手术中未使用抗代谢药物组为0.44%,两组比较差异有统计学意义(P<0.05),单纯滤过泡感染组治疗前后眼内压分别为(16.25±3.30)、(14.88±3.42) mm Hg,眼内炎组治疗前后眼内压分别为(18.36±14.12)、(15.00±3.12)mm Hg,两组比较差异无统计学意义;在病原学检查方面眼内炎组革兰阴性菌和革兰阳性菌感染的例数分别为8例和7例,而单纯滤过泡感染组则为7例和3例,两组比较差异无统计学意义.结论 术中单次应用抗代谢类药物可以有效提高滤过泡的功能化率,但其与滤过泡相关性感染密切相关,术中慎用.%OBJECTIVE To discuss the risk factors for filtering bleb infections and filtration bleb-related endophthalmitis after glaucoma surgery and the clinical manifestation as well as the prognosis outcomes. METHODS The medical cases with filtering bleb infections who underwent glaucoma surgery in recent 5 years were retrospectively investigated, those participants were divided into two groups according to the intraoperative placing MMC, the possibility of placing MMC in increasing the risk of filtering bleb infections was discussed. The filtering bleb infection cases were divided into the simple infection group and the endophthalmitis group, the clinical manifestations, etiology, treatment, and the clinical prognosis were discussed. RESULTS The incidence of postoperative bleb infections in the non-antimetabolites

  11. The use of amniotic membrane in trabeculectomy for the treatment of primary open-angle glaucoma: a prospective study

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    Stavrakas P

    2012-02-01

    Full Text Available Panagiotis Stavrakas1, Gerasimos Georgopoulos1, Maria Milia1, Dimitris Papaconstantinou1, Maria Bafa2, Efthymios Stavrakas2, Mihalis Moschos11Department of Ophthalmology, University of Athens Medical School, General Hospital of Athens (Geniko Kratiko Hospital, Athens, Greece; 2Department of Ophthalmology, Thriassio General Hospital, Athens, GreeceBackground: To investigate the effectiveness of amniotic membrane transplantation (AMT on improving the outcomes of trabeculectomy in primary open-angle glaucoma (POAG.Methods: Fifty-nine eyes affected by primary open-angle glaucoma were enrolled in this prospective randomized study. Thirty-two eyes underwent amnion-shielded trabeculectomy (study group and 27 eyes underwent trabeculectomy without any antimetabolites (control group. Success was defined as intraocular pressure (IOP <21 mmHg without any medications at 24 months follow-up. The two groups were compared in terms of IOP, bleb morphology, bleb survival and risk of failure, glaucoma medications, and complications.Results: There was no statistically significant difference in terms of postoperative IOP between the two groups and at 24 months median IOP was 15.5 mmHg for the AMT group and 16 mmHg for the control group. IOP postoperative reduction was 8 mmHg for the AMT group versus 6 mmHg for the non AMT group (P = 0.276. Two patients from the study group developed IOP >21 mmHg in contrast to seven patients from the classic trabeculectomy group. The study group had 61.0% less risk of developing IOP >21 mmHg (P = 0.203. No major complications in the AMT group were observed. AMT blebs were diffuse with mild vascularization.Conclusion: In patients with POAG, AMT showed favorable effects on bleb survival, however data failed to provide firm evidence that AMT could be used as a routine procedure in trabeculectomy.Keywords: amniotic membrane, trabeculectomy, primary open-angle glaucoma, glaucoma filtering blebIn memory of Professor Mihalis Moschos. "We

  12. Removal of the anti-cancer drug methotrexate from water by advanced oxidation processes: Aerobic biodegradation and toxicity studies after treatment.

    Science.gov (United States)

    Lutterbeck, Carlos Alexandre; Baginska, Ewelina; Machado, Ênio Leandro; Kümmerer, Klaus

    2015-12-01

    Anti-cancer drugs are discussed as high risk substances in regard to human health and considered as problematic for the environment. They are of potential environmental relevance due to their poor biodegradability and toxicological properties. Methotrexate (MTX) is an antimetabolite that was introduced in the pharmaceutical market in the 40's and still today is one of the most consumed cytotoxic compounds around the world. In the present study MTX was only partially biodegraded in the closed bottle test (CBT). Therefore, it was submitted to three different advanced oxidation processes (AOPs): UV/H2O2, UV/Fe(2+)/H2O2 and UV/TiO2. The irradiation was carried out with a Hg medium-pressure lamp during 256min whereas the analytical monitoring was done through LC-UV-MS/MS and DOC analysis. MTX was easily removed in all the irradiation experiments, while the highest mineralization values and rates were achieved by the UV/Fe(2+)/H2O2 treatment. The lowest resulted from the UV/H2O2 reactions. The UV/H2O2 treatment resulted in little biodegradable transformation products (TPs). However, the same treatment resulted in a reduction of the toxicity of MTX by forming less toxic TPs. Analysis by LC-UV-MS/MS revealed the existence of nine TPs formed during the photo-catalytic treatments. The pH of the solutions decreased from 6.4 (t 0min) to 5.15 in the UV/H2O2 and from 6.4 (t 0min) to 5.9 in the UV/TiO2 at the end of the experiments. The initial pH of the UV/Fe(2+)/H2O2 experiments was adjusted to 5 and after the addition of H2O2 the pH decreased to around 3 and remained in this range until the end of the treatments.

  13. Degradation of 5-FU by means of advanced (photo)oxidation processes: UV/H{sub 2}O{sub 2}, UV/Fe{sup 2+}/H{sub 2}O{sub 2} and UV/TiO{sub 2} — Comparison of transformation products, ready biodegradability and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbeck, Carlos Alexandre, E-mail: lutterbeck@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University of Lüneburg, Scharnhorststraße 1/C13, DE-21335 Lüneburg (Germany); Graduate Program in Environmental Technology, Universidade de Santa Cruz do Sul — UNISC, Av. Independência, 2293, CEP 96815-900 Santa Cruz do Sul, Rio Grande do Sul (Brazil); Wilde, Marcelo Luís, E-mail: wilde@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University of Lüneburg, Scharnhorststraße 1/C13, DE-21335 Lüneburg (Germany); Baginska, Ewelina, E-mail: ewelina.baginska@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University of Lüneburg, Scharnhorststraße 1/C13, DE-21335 Lüneburg (Germany); Leder, Christoph, E-mail: cleder@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University of Lüneburg, Scharnhorststraße 1/C13, DE-21335 Lüneburg (Germany); Machado, Ênio Leandro, E-mail: enio@unisc.br [Graduate Program in Environmental Technology, Universidade de Santa Cruz do Sul — UNISC, Av. Independência, 2293, CEP 96815-900 Santa Cruz do Sul, Rio Grande do Sul (Brazil); and others

    2015-09-15

    The present study investigates the degradation of the antimetabolite 5-fluorouracil (5-FU) by three different advanced photo oxidation processes: UV/H{sub 2}O{sub 2}, UV/Fe{sup 2+}/H{sub 2}O{sub 2} and UV/TiO{sub 2}. Prescreening experiments varying the H{sub 2}O{sub 2} and TiO{sub 2} concentrations were performed in order to set the best catalyst concentrations in the UV/H{sub 2}O{sub 2} and UV/TiO{sub 2} experiments, whereas the UV/Fe{sup 2+}/H{sub 2}O{sub 2} process was optimized varying the pH, Fe{sup 2+} and H{sub 2}O{sub 2} concentrations by means of the Box–Behnken design (BBD). 5-FU was quickly removed in all the irradiation experiments. The UV/Fe{sup 2+}/H{sub 2}O{sub 2} and UV/TiO{sub 2} processes achieved the highest degree of mineralization, whereas the lowest one resulted from the UV/H{sub 2}O{sub 2} treatment. Six transformation products were formed during the advanced (photo)oxidation processes and identified using low and high resolution mass spectrometry. Most of them were formed and further eliminated during the reactions. The parent compound of 5-FU was not biodegraded, whereas the photolytic mixture formed in the UV/H{sub 2}O{sub 2} treatment after 256 min showed a noticeable improvement of the biodegradability in the closed bottle test (CBT) and was nontoxic towards Vibrio fischeri. In silico predictions showed positive alerts for mutagenic and genotoxic effects of 5-FU. In contrast, several of the transformation products (TPs) generated along the processes did not provide indications for mutagenic or genotoxic activity. One exception was TP with m/z 146 with positive alerts in several models of bacterial mutagenicity which could demand further experimental testing. Results demonstrate that advanced treatment can eliminate parent compounds and its toxicity. However, transformation products formed can still be toxic. Therefore toxicity screening after advanced treatment is recommendable. - Highlights: • Full primary elimination of 5-FU was

  14. What is the impact of immunosuppressive treatment on the post-transplant renal osteopathy?

    Science.gov (United States)

    Blaslov, Kristina; Katalinic, Lea; Kes, Petar; Spasovski, Goce; Smalcelj, Ruzica; Basic-Jukic, Nikolina

    2014-05-01

    Although glucocorticoid therapy is considered to be the main pathogenic factor, a consistent body of evidence suggests that other immunosuppressants might also play an important role in the development of the post-transplant renal osteopathy (PRO) through their pleiotropic pharmacological effects. Glucocorticoids seem to induce osteoclasts' activity suppressing the osteoblasts while data regarding other immunosuppressive drugs are still controversial. Mycophenolate mofetil and azathioprine appear to be neutral regarding the bone metabolism. However, the study analyzing any independent effect of antimetabolites on bone turnover has not been conducted yet. Calcineurin inhibitors (CNIs) induce trabecular bone loss in rodent, with contradictory results in renal transplant recipients. Suppression of vitamin D receptor is probably the underlying mechanism of renal calcium wasting in renal transplant recipients receiving CNI. In spite of an increased 1,25(OH)2 vitamin D level, the kidney is not able to reserve calcium, suggesting a role of vitamin D resistance that may be related to bone loss. More efforts should be invested to determine the role of CNI in PRO. In particular, data regarding the role of mammalian target of rapamycin inhibitors (mTORi), such as sirolimus and everolimus, in the PRO development are still controversial. Rapamycin markedly decreases bone longitudinal growth as well as callus formation in experimental models, but also lowers the rate of bone resorption markers and glomerular filtration in clinical studies. Everolimus potently inhibits primary mouse and human osteoclast activity as well as the osteoclast differentiation. It also prevents the ovariectomy-induced loss of cancellous bone by 60 %, an effect predominantly associated with a decreased osteoclast-mediated bone resorption, resulting in a partial preservation of the cancellous bone. At present, there is no clinical study analyzing the effect of everolimus on bone turnover in renal

  15. Causes of uveitis in children without juvenile idiopathic arthritis

    Directory of Open Access Journals (Sweden)

    Engelhard SB

    2015-06-01

    Full Text Available Stephanie B Engelhard, Asima Bajwa, Ashvini K ReddyDepartment of Ophthalmology, University of Virginia, Charlottesville, VA, USABackground: The purpose of this study was to report the demographics, disease characteristics, treatments, and visual outcomes of pediatric uveitis patients without juvenile idiopathic arthritis managed in a tertiary medical center.Methods: A retrospective, observational study was performed in pediatric uveitis patients without juvenile idiopathic arthritis and aged 0–18 years, who were seen at the University of Virginia from 1984 to 2014.Results: Thirty-nine pediatric uveitis patients (57 eyes were identified. The patient population was 51.28% female, 51.28% Caucasian, and 33.33% African American. The mean age at diagnosis was 11.9 years. The mean duration of follow-up was 3.11 years. The mean number of visits to the clinic was 10.41. Of 57 eyes, 31 (54.39% had anterior uveitis, 12 (21.05% had intermediate uveitis, nine (15.79% had posterior uveitis, and five (8.77% had panuveitis. The leading diagnoses were traumatic uveitis (25.64%, undifferentiated anterior uveitis (17.95%, undifferentiated intermediate uveitis (15.38%, HLA-B27-associated anterior uveitis (7.69%, and herpetic anterior uveitis (7.69%. Systemic associations included sarcoidosis, ulcerative colitis, and psoriatic arthritis (n=3. The most common treatment modalities included local steroids (66.67%, systemic steroids (23.08%, and antimetabolites (20.51%. Ocular hypertension was found in five (12.82% patients. Ocular surgery was performed in six (15.38% patients. Mean best-corrected visual acuity (BCVA at baseline across all anatomical locations was 0.458 logMAR, and was 0.411 logMAR at final follow-up. Mean BCVA improved during follow-up in all but the anterior uveitis group. The mean baseline intraocular pressure was 14.27 mmHg, and was 14.22 mmHg at final follow-up.Conclusion: Uveitis in childhood is a vision-threatening group of inflammatory

  16. Surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients

    Directory of Open Access Journals (Sweden)

    Salim S

    2012-06-01

    postoperative complications, and overall reduced inflammation. Keywords: glaucoma, trabeculectomy, Ex-PRESS glaucoma filtration device, antimetabolites, African American, White

  17. The bioenergetic signature of isogenic colon cancer cells predicts the cell death response to treatment with 3-bromopyruvate, iodoacetate or 5-fluorouracil

    Directory of Open Access Journals (Sweden)

    Cuezva José M

    2011-02-01

    Full Text Available Abstract Background Metabolic reprogramming resulting in enhanced glycolysis is a phenotypic trait of cancer cells, which is imposed by the tumor microenvironment and is linked to the down-regulation of the catalytic subunit of the mitochondrial H+-ATPase (β-F1-ATPase. The bioenergetic signature is a protein ratio (β-F1-ATPase/GAPDH, which provides an estimate of glucose metabolism in tumors and serves as a prognostic indicator for cancer patients. Targeting energetic metabolism could be a viable alternative to conventional anticancer chemotherapies. Herein, we document that the bioenergetic signature of isogenic colon cancer cells provides a gauge to predict the cell-death response to the metabolic inhibitors, 3-bromopyruvate (3BrP and iodoacetate (IA, and the anti-metabolite, 5-fluorouracil (5-FU. Methods The bioenergetic signature of the cells was determined by western blotting. Aerobic glycolysis was determined from lactate production rates. The cell death was analyzed by fluorescence microscopy and flow cytometry. Cellular ATP concentrations were determined using bioluminiscence. Pearson's correlation coefficient was applied to assess the relationship between the bioenergetic signature and the cell death response. In vivo tumor regression activities of the compounds were assessed using a xenograft mouse model injected with the highly glycolytic HCT116 colocarcinoma cells. Results We demonstrate that the bioenergetic signature of isogenic HCT116 cancer cells inversely correlates with the potential to execute necrosis in response to 3BrP or IA treatment. Conversely, the bioenergetic signature directly correlates with the potential to execute apoptosis in response to 5-FU treatment in the same cells. However, despite the large differences observed in the in vitro cell-death responses associated with 3BrP, IA and 5-FU, the in vivo tumor regression activities of these agents were comparable. Conclusions Overall, we suggest that the

  18. Early changes in [{sup 18}F]FLT uptake after chemotherapy: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Dittmann, Helmut; Dohmen, Bernhard Matthias; Bartusek, Gabi; Pritzkow, Maren; Bares, Roland [Department of Nuclear Medicine, Eberhard-Karls-University, Roentgenweg 13, 72076 Tuebingen (Germany); Kehlbach, Rainer [Department of Diagnostic Radiology, Eberhard-Karls-University, Tuebingen (Germany); Sarbia, Mario [Institute of Pathology, Heinrich-Heine-University, Duesseldorf (Germany)

    2002-11-01

    This study evaluated the use of 3'-deoxy-3'-[{sup 18}F]fluorothymidine ([{sup 18}F]FLT) for monitoring of the early effects of anticancer chemotherapy on tumour cell proliferation. Cells derived from human oesophageal squamous cell carcinoma (OSC-1) were grown for 2 days and incubated with cisplatin (CDDP), 5-fluorouracil (5-FU), methotrexate (MTX) or gemcitabine (GEM) for 4 h. Cultures were incubated with drug doses (CDDP: 0.67, 6.7, 67 {mu}M; 5-FU 15.4, 154, 1,540 {mu}M; MTX: 4.4, 44, 440 {mu}M; GEM: 0.0067, 0.067, 0.67 {mu}M) corresponding to approximately 10%-95% proliferation inhibition (MTX: 10%-75%). Treatment was stopped and cells were allowed to recover for 4, 24 or 72 h. [{sup 18}F]FLT was added for 10-180 min. Control cultures were incubated with [{sup 18}F]fluorodeoxyglucose (FDG). Cell counts, viability, clonogenic activity and cell cycle distribution estimated by flow cytometry were used to evaluate the cytotoxic effects of chemotherapy. Strikingly, FLT uptake per 10{sup 5} viable cells was increased seven- to tenfold 24 h after treatment with 5-FU or MTX irrespective of dose. Thus, total FLT uptake per tissue culture exceeded that of controls despite a considerable decrease in overall cell counts due to cytostasis up to 72 h after treatment. 5-FU-treated cells showed accumulation in early S phase (overall S phase: 88% vs 42%). GEM treatment resulted in a more moderate increase in total FLT accumulation, to a maximum of fivefold at the dose close to the IC{sub 50}. In contrast, FLT accumulation was significantly reduced at cytostatic concentrations of CDDP and was still decreasing in a dose-related manner at 72 h despite considerable S phase arrest. With 5-FU or CDDP, the uptake of FDG did not differ significantly from control values 24 h after treatment. These findings demonstrate that tumour cell uptake of FLT - in contrast to that of FDG - reveals specific changes depending on the cytostatic drug used for treatment. The antimetabolites 5

  19. Efficacy, safety, and lack of interactions with the use of raltegravir in HIV-infected patients undergoing antineoplastic chemotherapy

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    Sara Bañón

    2014-11-01

    Full Text Available Introduction: Concomitant use of combination antiretroviral regimen (cART and cancer chemotherapy is difficult due to complex interactions and increased toxicity. Raltegravir could be an adequate option through its favourable drug-drug interaction profile. Methods: Prospective longitudinal study of HIV patients with cancer, AIDS related or not, undergoing chemotherapy. Patients without resistance or previous failure were switched or initiated raltegravir plus two nucleoside analogues. Plasma trough levels of raltegravir were measured. Results: Overall, 28 patients receiving a raltegravir-based regimen (4 naive with tenofovir-emtricitabine (18 cases or abacavir-lamivudine (10 cases were included. Mean age was 46.2 years (IQR, 39–52.7, and 79% were male. Median time of HIV was 201.7 months, CD4+ nadir was 268 cells/mm3, and 75% had previous AIDS. At the diagnosis of neoplasia, 17 were on protease inhibitors and 4 with efavirenz. Ten patients had a non-HIV-related cancer (three breast, two pancreatic, one Ewing sarcoma, one myeloblastic leukemia, one melanoma, one parotid adenocarcinoma, one lung, and 18 had an HIV-related cancer (nine non-Hodgkin lymphoma, seven Hodgkin disease, two anal. Overall, 43% of patients received more than one line of chemotherapy, including antimetabolites in 12 patients (5-FU, capecitabine, methotrexate, gemcitabine, alkylating agents in 12 cases (ciclophosphamide, iphosphamide, vinca alkaloids in 20 patients (vincristine, vinblastine, vindesine, antitumor antibiotics in 16 cases (adriamycin, cisplatin o carboplatin in six and monoclonal antibodies in six patients (rituximab, trastuzumab, cetuximab. Six patients modified the doses of antineoplastic agents due to toxicity (four neutropenia, not related to raltegravir. During a median follow up of 12.7 patients-year in concomitant therapy, there was only 1 case of virological failure and no patient discontinued raltegravir. Plasma concentrations of raltegravir in eight

  20. The balance of estrogen metabolites in breast cancer and the ways of its correction

    Directory of Open Access Journals (Sweden)

    L. A. Ashrafyan

    2015-01-01

    of metabolic disturbances with antimetabolites is one of the important, pathogenetically sound areas in the prevention of BC. 

  1. Non-coding MicroRNAs hsa-let-7g and hsa-miR-181b are Associated with Chemoresponse to S-1 in Colon Cancer.

    Science.gov (United States)

    Nakajima, Go; Hayashi, Kazuhiko; Xi, Yaguang; Kudo, Kenji; Uchida, Kazumi; Takasaki, Ken; Yamamoto, Masakazu; Ju, Jingfang

    2006-10-01

    BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs (~22 nucleotides) that regulate gene expression at a post-transcriptional level via imperfect base pairing to the 3'-UTR of their target mRNAs. Previous studies from our group identified a number of deregulated miRNAs due to the loss of p53 tumor suppressor in colon cancer cell lines. To further investigate the in vivo biological significance of these miRNAs, the expressions of hsa-let-7g, hsa-miR-143, hsa-miR-145, hsa-miR-181b and hsa-miR-200c were investigated using formalin-fixed paraffin-embedded (FFPE) colon cancer specimens to evaluate the potential relationship with chemosensitivity and tumorigenesis. PATIENTS AND METHODS: Forty-six patients with recurrent or residual colon cancer lesions were treated with the 5-fluorouracil-based antimetabolite S-1. This includes twenty-one pairs of tumor and normal samples. Total RNAs were isolated and the expression level of each particular miRNA was quantified using real time qRT-PCR analysis. RESULTS: The expression levels of hsa-let-7g, hsa-miR-181b and hsa-miR-200c were over-expressed in tumor tissues compared to normal tissues. The expression levels of hsa-let-7g (p=0.03; Mann-Whitney test) and hsa-miR-181b (p=0.02; Mann-Whitney test) were strongly associated with clinical response to S-1. Although hsa-let-7g and hsa-miR-181b are strongly associated with patient's response to S-1 treatment, they are not significant prognostic factors for predicting survival. CONCLUSION: hsa-let-7g, hsa-miR-181b and hsa-miR-200c may be associated with tumorigenesis in colon cancer. In addition, hsa-let-7g and hsa-miR-181b may be potential indicators for chemoresponse to S-1 based chemotherapy.

  2. Flavor vs Energy Sensing in Brain Reward Circuits

    Directory of Open Access Journals (Sweden)

    Ivan E De Araujo

    2014-07-01

    intake produces significantly greater levels of dopamine efflux compared to artificial sweetener intake in dorsal striatum, whereas disrupting glucose oxidation suppresses dorsal striatum dopamine efflux; conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent glucoprivation [1]. This is consistent with data using physiological preparations demonstrating that intravenous administration of the glucose anti-metabolite 2-deoxy-D-glucose robustly suppresses dopamine efflux in dorsal striatum, an effect annulled by subsequent infusions of glucose via the same route [2]. Of note is the fact that the same study demonstrates that glucose utilization rates control both nutrient choice in tasteless mutant mice. Overall, these results point to the notion that glucose oxidation controls intake levels of sweet tastants by regulating the midbrain dopaminergic nigro-striatal pathway, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake [1]. It is equally striking, on the other hand, that the other major midbrain dopaminergic system, the mesolimbic pathway, is considerably less selective in their responses to sweeteners: sweetness and energy appear to independently stimulate dopamine release into the nucleus accumbens of ventral striatum, in the absence of any apparent additive effects; in fact, while artificial sweeteners cause dopamine to be released in ventral striatum of wild-type mice, sugar (bot not sweeteners induces similar effluxes in ventral striatum of tasteless mutant mice [3]. Such nigro-striatal selectivity to energy-containing sweeteners may have a deeper behavioral meaning: dopamine release into dorsal striatum is not only critical for motivation to eat [4], but also for the formation of compulsive behavioral habits (whereas the nucleus accumbens seem to play a

  3. Trifluoperazine decreases scar thickness in a rabbit model of hypertrophic scar ear%三氟拉嗪干预兔耳增生性瘢痕模型:降低瘢痕厚度的作用

    Institute of Scientific and Technical Information of China (English)

    关键; 王冶

    2014-01-01

    BACKGROUND:Conventional treatments for hypertrophic scars include excision, steroid hormones, anti-metabolite drugs, immunosuppressive agents and radiation therapy. Easy to relapse or serious reaction limits their clinical use. In recent years, application of calcium channel blockers in treatment of hypertrophic scars has made more good progresses, but little adverse reactions are obtained. OBJECTIVE:To explore the effects of calcium channel blocker trifluoperazine on hypertrophic scar of rabbit ears. METHODS:A total of 24 rabbits were enrol ed in this study. After 1 week of accommodation, models of rabbit ear scar were established in accordance with the method of Morris and Li et al. Rabbit models were randomly assigned to three group (n=8). At 30 days after model induction, when scar formed, trifluoperazine and triamcinolone acetonide groups received trifluoperazine and triamcinolone acetonide injection. Blank control group was left intact. Changes in hyperplastic scar, hypertrophic index, levels of matrix metal oproteinase-2, tissue inhibitor of metal oproteinase-2, transforming growth factorβ1,α-smooth muscle actin and proliferating cellnuclear antigen were compared and observed in each group. RESULTS AND CONCLUSION:At 10 and 20 days after treatment, in the three groups, skin bulge was visible in rabbit ears and no rabbit hair grew. Rabbit ears had obvious softening in the trifluoperazine group compared with the triamcinolone acetonide group, showing dark red. In the blank control group, rabbit ear scar was evident and showed red color. At 20 days after treatment, scar thickness and scar index were lower in the trifluoperazine and triamcinolone acetonide groups than in the blank control group. Matrix metal oproteinase 2 expression was significantly higher, but tissue inhibitor of metal oproteinase-2 and transforming growth factorβ1 levels were lower in the trifluoperazine and triamcinolone acetonide groups than in the blank control group. Results indicated

  4. Polymorphism in the Methylenetetrahydrofolate Reductase and Thymidylate Synthase Gene Predicts for Response to Fluorouracil-based Chemotherapy in Advanced Gastric Cancer Patients%亚甲基四氢叶酸还原酶和胸苷酸合成酶基因多态预测氟尿嘧啶为基础化疗方案治疗晚期胃癌疗效关系的研究

    Institute of Scientific and Technical Information of China (English)

    陆建伟; 高长明; 吴建中; 曹海霞; Kazuo Tajima; 陈环球; 陈嘉; 冯继峰

    2009-01-01

    目的 观察亚甲基四氢叶酸还原酶(MTHFR)(C677T、A1298C)和胸苷酸合成酶(TS 3'-UTR)多态与5-Fu为基础化疗方案及晚期胃癌敏感性的关系.方法 选取173例晚期胃癌患者,所有病例均接受5-Fu为基础化疗方案(FOLFOX,FP和DCF方案)化疗.在化疗前获取外周血白细胞DNA.采用PCR-RELP检测基因型.在2个基因中共检测了9种遗传多态.173例中检测了MTHFR(C677T、A1298C)和TS(3'-TUR)多态.结果 所有患者化疗总有效率为35.8%.DCF方案的有效率显著高于FP和FOLFOX方案(55.8%vs 27.1%,31.1%;P=0.006).MTHFR C677T T/T基因型患者的有效率显著高于C/C和C/T基因型(73.3%VS 28.O%;P=0.000).在MTHFR A1298C中,A/A基因型患者的有效率显著高于C/C和A/C基因型(41.8%vs 21.6%,P=0.011).在TS 3'-UTR中,-6/-6 bp和-6/+6bp基因型患者的有效率显著高于+6/+6 bp基因型(40.3%vs 17.6%,P=0.014).FOLFOX和FP方案中,MTHFR C677T T/T基因型患者的有效率均显著高于C/C和C/T基因型(P=0.008;P=0.000),但在DCF方案中没有发现差异.在MTHFR C/T和C/C基因型中,DCF方案的有效率显著高于FP和FOLFOX方案(P=0.000).MTHFR C677T T/T基因型患者的Ⅲ~Ⅳ度呕吐(66.7%)和口腔炎(30.0%)发生率显著高于C/C和C/T基因型(41.3%,9.8%;P=0.011,0.003).MTHFR A1298C A/A基因型患者的Ⅲ~Ⅳ度口腔炎(17.2%)和腹泻(13.9%)发生率同样显著高于A/C和C/C基因(3.9%,2.0%:P=0.025,0.026).TS 3'-UTR的不同多态之间没有发现毒性差异.结论 检测外周血白细胞DNA中的MTHFR和TS基因多态能预测以5-Fu为基础化疗方案治疗晚期胃癌的有效性和化疗相关的毒性反应.%Background & Aims Fluorouracil (5-FU) is widely used in the treatment of gastric cancer. Meth-ylenetetrahydrofolate reductase (MTHFR) and thymidylate synthetase (TS) are important targets of many anti-metabolites, including 5-FU. The aim of the present study is to investigate the relationship between polymor-phism in the MTHFR (C677T, A1298C) and TS (3'-UTR