Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to find a 3,4-dihydro-2H-naphtho[1,2-b]pyran-5,6-dione more potent than the naturally occurring 2,2-dimethyl derivative [beta-lapachone (10a)], we synthesized a series of analogous compounds with modifications at position 2 of the pyran ring or at positions 8 and 9 of the benzene ring. Of the compounds tested in vitro for inhibition of RNA-dependent DNA polymerase and in mice infected with Rauscher leukemia, all retained good enzyme activity. Inhibition of the reverse transcriptase activity of the 2,2-substituted derivatives 10b-e was as strong as 10a. However, only the 2-methyl-2-phenyl derivative 10e proved to be about as potent as the 2,2-dimethyl reference compound 10a in prolonging the mean survival time of mice with Rauscher leukemia virus induced leukemia.
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PMID:beta-Lapachone: synthesis of derivatives and activities in tumor models. 620 52

To determine which alpha 2-adrenergic receptor subtypes are present in primary afferent and sympathetic postganglionic neurons we have performed in situ hybridization and immunohistochemistry experiments on rat dorsal root and superior cervical ganglia. Reverse transcriptase polymerase chain reaction was used as a preliminary screen for the presence of mRNA encoding alpha 2-adrenergic subtypes in dorsal root and superior cervical ganglia; polymerase chain reaction primers amplified distinct regions of the rat alpha 2A-(RG20), alpha 2B-(RNG) and alpha 2C-(RG10) adrenergic receptor subtypes in mRNA extracted from lumbar dorsal root and superior cervical ganglia. To localize receptors to cell types in the ganglia, in situ hybridization was performed on cryosections of dorsal root and superior cervical ganglia with oligonucleotide probes designed to distinguish between mRNA encoding for alpha 2-adrenergic receptor subtypes. Immunohistochemistry was performed with a polyclonal antibody against the alpha 2A-adrenergic receptor subtype. Our results with reverse transcriptase polymerase chain reaction indicate that all three alpha 2-adrenergic receptor subtypes are expressed in dorsal root and superior cervical ganglia. Data from the in situ hybridization experiments indicated that the mRNA detected with the reverse transcriptase polymerase chain reaction was present in neuronal cell bodies, except for the mRNA encoding the alpha 2A-adrenergic receptor which was not detectable in dorsal root ganglia. The distribution of mRNA encoding alpha 2B- and alpha 2C-adrenergic receptor subtypes among dorsal root ganglion neurons and alpha 2A-, alpha 2B- and alpha 2C-adrenergic receptor subtypes among superior cervical ganglion neurons suggests that multiple adrenergic receptor subtypes are present in a single neuron. Neuronal cell bodies in both the dorsal root and superior cervical ganglion consistently demonstrated alpha 2A-adrenergic receptor-like immunoreactivity. The apparent co-expression of multiple alpha 2-adrenergic receptor subtypes in dorsal root and superior cervical ganglion neurons enables a single transmitter to produce a number of effects in the same neuron; which receptors are functionally active may vary with the presence of nerve injury, inflammation or other physiological and pathophysiological conditions.
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PMID:Alpha 2-adrenergic receptor subtypes in rat dorsal root and superior cervical ganglion neurons. 906 29

Deletions and other genome rearrangements are associated with carcinogenesis and inheritable diseases. The pink-eyed unstable (pun) mutation in the mouse is caused by duplication of a 70-kb internal fragment of the p gene. Spontaneous reversion events in homozygous pun/pun mice occur through deletion of a duplicated sequence. Reversion events in premelanocytes in the mouse embryo detected as black spots on the gray fur of the offspring were inducible by the carcinogen x-rays, ethyl methanesulfonate, methyl methanesulfonate, ethyl nitrosourea, benzo[a]pyrene, trichloroethylene, benzene, and sodium arsenate. The latter three carcinogens are not detectable with several in vitro or in vivo mutagenesis assays. We studied the molecular mechanism of the carcinogen-induced reversion events by cDNA analysis using reverse transcriptase-PCR method and identified the induced reversion events as deletions. DNA deletion assays may be sensitive indicators for carcinogen exposure.
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PMID:Carcinogens induce reversion of the mouse pink-eyed unstable mutation. 911 32

Chromosome aberrations in peripheral blood lymphocytes have been used for many years to monitor human populations exposed to potential carcinogens. Recent reports have confirmed the validity of this approach by demonstrating that elevated levels of chromosome aberrations in lymphocytes are associated with subsequent increased cancer risk, especially for increased mortality from hematological malignancies including acute myeloid leukemia (AML). We postulated that this approach could be improved in two ways: (a) by detecting oncogenic disease-specific aberrations; and (b) by using chromosome painting so that many more metaphases could be analyzed. Numerical and structural aberrations in chromosomes 8 and 21 are commonly observed in AML. In the present study, we painted chromosomes 8 and 21 in lymphocyte metaphases from 43 healthy workers exposed to benzene, an established cause of AML, and from 44 matched controls. To examine dose-response relationships the workers were divided into two groups at the median exposure level, a lower-exposed group (< or = 31 ppm; n = 21), and a higher-exposed group (> 31 ppm; n = 22). Benzene exposure was associated with significant increases in hyperdiploidy of chromosomes 8 (1.2, 1.5, and 2.4 per 100 metaphases; P < 0.0001) and 21 (0.9, 1.1, and 1.9 per 100 metaphases; P < 0.0001). Translocations between chromosomes 8 and 21 were increased up to 15-fold in highly exposed workers (0.01, 0.04, and 0.16 per 100 metaphases; P < 0.0001). In one highly exposed individual, these translocations were reciprocal and were detectable by reverse transcriptase-PCR. These data indicate a potential role for t(8;21) in benzene-induced leukemogenesis and are consistent with the hypothesis that detection of specific chromosome aberrations may be a powerful approach to identify populations at increased risk of leukemia.
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PMID:Increased translocations and aneusomy in chromosomes 8 and 21 among workers exposed to benzene. 960 63

In the presence of sodium hydride, reaction of aryl-disulphides with ethyl esters of indole-2-carboxylic acids furnished ethyl 3-arylthioindole-2-carboxylates, which were cyclized intramolecularly to afford 5H-indolo[3,2-b][1,5]benzothiazepin-6(7H)-ones or hydrolysed in alkaline medium to give 3-arylthioindole-2-carboxylic acids. These acids, also obtained by the action of aryldisulphides on indole-2-carboxylic acids, afforded tetracyclic 5H-indolo [3,2-b][1,5]benzothiazepin-6(7H)-ones upon treatment with EDCI-DMAP. Transformation of cyclic sulphides into the required sulphones was achieved by treatment with hydrogen peroxide or with m-chloroperbenzoic acid. The title derivatives are conformationally constrained analogues of the potent human immunodeficiency virus type 1 (HIV-1) reverse transcriptase inhibitor 3-benzene-sulphonyl-5-chloroindole-2-carboxamide (L-737, 126). Although the indolobenzothiazepine derivatives, as well as the indolyl aryl sulphones used for their synthesis, were endowed with anti-HIV-1 activities in the submicromolar and micromolar range, none of them proved more potent than L-737,126.
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PMID:Synthesis and biological evaluation of 5H-indolo [3,2-b][1,5]benzothiazepine derivatives, designed as conformationally constrained analogues of the human immunodeficiency virus type 1 reverse transcriptase inhibitor L-737,126. 987 85

Using a known human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitor (NNRTI), 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TBZ NSC 625487) as the lead structure for drug design, a series of novel 1H,3H-thiazolo[3,4-a]benzimidazole derivatives substituted on the benzene-fused ring was prepared. Their in vitro anti-HIV-1 activity, as well as their inhibitory effects on the viral reverse transcriptase, were evaluated. The structure-activity relationships for these compounds are described and the results suggest that the apolar binding pocket of RT, into which the NNRTIs must fit, can accommodate only groups with a limited size and shape.
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PMID:Synthesis and biological activity of novel 1H,3H-thiazolo[3,4-a]benzimidazoles: non-nucleoside human immunodeficiency virus type 1 reverse transcriptase inhibitors. 1048 Jul 39

Pyrrolobenzoxazepinone (PBO) derivatives represent a new class of human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase (RT) inhibitors (NNRTs) whose prototype is (+/-)-6-ethyl-6-phenylpyrrolo[2,1-d][1,5]benzoxazepin-7(6H)- one (6). Docking studies based on the three-dimensional structure of RT prompted the synthesis and biological evaluation of novel derivatives and analogues of 6 featuring a meta-substituted phenyl or a 2-thienyl ring at C-6 and a pyridine system in place of the fused-benzene ring to yield pyrrolopyridooxazepinones (PPOs). Compared with the lead 6 and nevirapine, several of the synthesized compounds (PBOs 13a-d and PPOs 13i-k) displayed higher inhibitory activity against wild-type RT and clinically relevant mutant RTs containing the single amino acid substitutions L100I, K103N, V106A, Y181I, and Y188L. The most potent inhibitors were further evaluated for in vitro antiviral activity on lymphocytes and monocyte-macrophages, for cytotoxicity on a panel of cell lines, and for potential synergistic antiviral activity with AZT. Pharmacokinetic studies performed on 13b, 13c, and 13i showed that these compounds achieve high concentrations in the brain. The results of the biological and pharmacokinetic experiments suggest a potential clinical utility of analogues such as 13b-d, 13i, and 13j, in combination with nucleoside RT inhibitors, against strains of HIV-1 bearing those mutations that confer resistance to known NNRTI.
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PMID:Pyrrolobenzoxazepinone derivatives as non-nucleoside HIV-1 RT inhibitors: further structure-activity relationship studies and identification of more potent broad-spectrum HIV-1 RT inhibitors with antiviral activity. 1054 90

A novel family of non-nucleoside reverse transcriptase inhibitors (NNRTIs) active at submicromolar concentrations was discovered. The new derivatives are 1-[2-(diarylmethoxy)ethyl]imidazoles bearing substituents both at benzene and imidazole rings. The most potent derivatives were those having nitro and methyl groups as substituents in the imidazole ring. Among 10 test derivatives compound 6d was found to be as potent as nevirapine and was selected as a lead for further studies.
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PMID:1-[2-(Diphenylmethoxy)ethyl]-2-methyl-5-nitroimidazole: a potent lead for the design of novel NNRTIs. 1069 47

A human cervical explant culture was utilized for the preclinical assessment of anti-human immunodeficiency virus type 1 (HIV-1) activity and tissue toxicity of formulated, candidate topical microbicides. Products tested included cellulose acetate 1,2-benzene dicarboxylate (CAP), a carrageenan-based product (PC-515), a naphthalene sulfonate polymer (PRO 2000), a lysine dendrimer (SPL7013), a nonnucleoside reverse transcriptase inhibitor (UC781), and an antimicrobial peptide (D2A21), along with their placebos. Cervical explants were cultured overnight with HIV-1 with or without product, washed, and monitored for signs of HIV-1 infection. HIV-1 infection was determined by p24gag levels in the basolateral medium and by immunohistochemical analysis of the explant. Product toxicity was measured by the MTT [1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan] assay and histology. CAP, PRO 2000, SPL7013, and UC781 consistently prevented HIV-1 infection in all explants tested. PC-515 and D2A21 prevented HIV-1 infection in 50% or fewer of the explants tested. Placebos did not prevent infection in any of the explants tested. With the exception of PRO 2000 (4%), the MTT assay and histological analysis of the other products and placebos showed minimal toxicity to the epithelium and submucosa. Collectively, these data suggest that this culture system can be used for evaluating the safety and efficacy of topical microbicides designed for vaginal use.
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PMID:Preclinical testing of candidate topical microbicides for anti-human immunodeficiency virus type 1 activity and tissue toxicity in a human cervical explant culture. 1735 37

The improvement of the transfection efficiency of the non-viral-based gene delivery systems is a key issue for the application in gene therapy. We have previously described an archaeal histone-like protein-based (HPhA) gene delivery system and showed that HPhA formed stable non-covalent complexes with nucleic acids and improved their delivery by using beta-galactosidase as a reporter gene. In this study, the wild-type p53 gene was transfected into the cancer cells using the HPhA as a vector, and the expression level and the activity of p53 gene were evaluated both in vitro and in vivo. Gene expression was determined by real-time reverse transcriptase-PCR and western blotting analysis. The cellular growth inhibition and apoptosis of HPhA-mediated p53 transfection were assessed by XTT (sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene sulfonic acid hydrate) assay and annexin V-FITC (fluorescein isothiocyanate) staining, respectively. Further more, transfection of HPhA/p53 into CNE (nasopharyngeal carcinoma cell line)-xenografted nude mice was performed and tumor growth was measured. The present study demonstrates that HPhA enhances the efficiency of p53 gene transfer and antitumor activity compared with the widely used Lipofectamine. These results demonstrate that HPhA enhances the in vitro and in vivo efficiency of p53 gene transfer and suggest that it may be served as a promising tool for gene delivery and gene therapy.
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PMID:An archaeal histone-like protein mediates efficient p53 gene transfer and facilitates its anti-cancer effect in vitro and in vivo. 1785 24


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