Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A number of studies have indicated that an endogenous brain protein, PrP, is associated with transmissible agents causing spongiform encephalopathies such as scrapie, kuru, and Creutzfeldt-Jakob disease. It has been proposed that PrP derived from scrapie brain is the scrapie agent itself. To test directly whether the PrP mRNA in scrapie brain tissue can encode the scrapie agent, we expressed PrP cDNA cloned from scrapie-infected mouse brain in vitro. The expressed PrP did not transmit scrapie to susceptible mice. Thus either PrP is not the scrapie agent, or the expressed PrP requires additional modification to be infectious. The normal function of PrP is unknown, however, comparison of the amino acid sequences of PrP from mouse, hamster, and human revealed that many structural features of potential functional significance have been conserved during evolution. To learn about normal PrP and whether it is altered by scrapie infection in vitro, we have performed studies of PrP biosynthesis in normal and scrapie-infected mouse neuroblastoma tissue culture cells. The major PrP species were glycoproteins anchored at the cell surface by covalent linkage to phosphatidylinositol. No scrapie-associated modifications of PrP biosynthesis were observed, and, none of the metabolically labeled PrP observed in either scrapie-infected normal cells was resistant to proteinase K.
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PMID:Comparative sequence analysis, in vitro expression and biosynthesis of mouse PrP. 257 73

The mouse neuroblastoma cell line N2a was persistently infected with the Chandler strain of the mouse scrapie agent. Although the infection did not spread to infect > 1% of the cells, clones were established that had from 50 to 100% infected cells. These clones expressed the abnormal protease-resistant form of prion protein (PrP), which is believed to mediate brain degeneration in animals with scrapie and bovine spongiform encephalopathy and in humans with kuru, Creutzfeldt-Jakob disease, and Gerstmann-Straussler-Scheinker syndrome. With this in vitro system, Congo red and several sulfated polysaccharides, including heparin and pentosan polysulfate, were found to inhibit accumulation of protease-resistant PrP. These results and additional data confirming PrP binding to heparin suggested a possible role for sulfated glycosaminoglycans in the generation of protease-resistant PrP during scrapie infection. Accumulation of protease-resistant PrP was also blocked in vitro by expression of foreign PrP molecules, indicating that PrP from different species might compete for common substrates in this process. These results using scrapie-infected cell lines provide new opportunities for development of drugs capable of blocking the brain degeneration caused by scrapie and other transmissible spongiform encephalopathies.
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PMID:Prion protein and the scrapie agent: in vitro studies in infected neuroblastoma cells. 781 55

Prion diseases are a group of fatal neurodegenerative disorders that include Creutzfeldt-Jakob disease (CJD) and kuru in humans, BSE in cattle, and scrapie in sheep. Such illnesses are caused by the conversion and accumulation of a misfolded pathogenic isoform (termed PrPSc) of a normally benign, host cellular protein, denoted PrPC. We employed high-throughput screening (HTS) ELISAs to evaluate compounds for their ability to reduce the level of PrPSc in Rocky Mountain Laboratory (RML) prion-infected mouse neuroblastoma cells (ScN2a-cl3). Arylpiperazines were among the active compounds identified but the initial hits suffered from low potency and poor drug-likeness. The best of those hits, such as 1, 7, 13, and 19, displayed moderate antiprion activity with EC50 values in the micromolar range. Key analogs were designed and synthesized based on the SAR, with analogs 41, 44, 46, and 47 found to have sub-micromolar potency. Analogs 41 and 44 were able to penetrate the blood-brain barrier (BBB) and achieved excellent drug concentrations in the brains of mice after oral dosing. These compounds represent good starting points for further lead optimization in our pursuit of potential drug candidates for the treatment of prion diseases.
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PMID:Discovery and Preliminary SAR of Arylpiperazines as Novel, Brainpenetrant Antiprion Compounds. 2384 18