57 research outputs found

    The effect of methionine on the uptake, distribution, and binding of the convulsant methionine sulfoximine in the rat

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    The effect of methionine on the uptake, distribution, and binding of the convulsant methionine sulfoximine (MSO) in 7 rat brain regions, the spinal cord, the liver, and the kidney was investigated. The administration of methionine decreased the uptake of MSO in all brain regions. The uptake of MSO by and its distribution in the nervous tissue was uniform and failed to result in any preferential accumulation of the drug. Methionine decreased the amount of MSO bound to cerebral structures and to the spinal cord. MSO bound to the spinal cord was less susceptible to release by Triton X-100 than was brain-bound MSO.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45398/1/11064_2004_Article_BF00965631.pd

    S -Adenosyl- l -homocysteine in brain

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    Administration of methionine sulfoximine (MSO) to rats and mice significantly decreased cerebral levels of S -adenosyl- l -homocysteine (AdoHcy). Concurrent administration of methionine prevented this decrease and, when methionine was given alone, significantly elevated AdoHcy levels resulted in both species. Regionally, AdoHcy levels varied from 20 nmol/g in rat cerebellum and spinal cord to about 60 nmol/g in hypothalamus and midbrain. MSO decreased AdoHcy in all regions tested except striatum, midbrain, and spinal cord. AdoMet/AdoHcy ratios (methylation index) varied from 0.48 in hypothalamus to 2.4 in cerebellum, and MSO administration decreased these ratios in all regions except hypothalamus. AdoHcy hydrolase activity was lowest in hypothalamus, highest in brainstem and, generally, varied inversely with regional AdoHcy levels. MSO decreased AdoHcy hydrolase activity in all regions except hypothalamus and spinal cord. Cycloleucine administration resulted in significantly decreased levels of mouse brain AdoHcy, whereas the administration of dihydroxyphenylalanine (DOPA) failed to affect AdoHcy levels. It is concluded that (a) cerebral AdoHcy levels are more tightly regulated than are those of AdoMet after MSO administration, (b) slight fluctuations of AdoHcy levels may be important in regulating AdoHcy hydrolase activity and hence AdoHcy catabolism in vivo, (c) the AdoMet/AdoHcy ratio reflects the absolute AdoMet concentration rather than the transmethylation flux, (d) the decreased AdoMet levels in midbrain, cortex, and striatum after MSO with no corresponding decrease in AdoHcy suggest an enhanced AdoMet utilization, hence an increased transmethylation in the MSO preconvulsant state.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45411/1/11064_2004_Article_BF00966019.pd

    Effect of methionine sulfoximine on methylation of guanine residues in astroglial transfer ribonucleic acids

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    Culture-grown astrocytes derived from 3-day-old rat brain were incubated in the presence of [ 3 H]guanosine and of the convulsant agent l -methionine- dl -sulfoximine (MSO). The resulting [ 3 H]tRNA was purified from control and MSO-exposed cells at several time points during the incubation and was hydrolyzed to [ 3 H]guanine and four [ 3 H]methyl guanines which were separated by high pressure liquid chromatography. Three of the four [ 3 H]methyl guanines were more highly labeled in the [ 3 H]tRNA of the MSO-exposed cells, relative to that of the control cells throughout the entire incubation period. The findings extend to cultured astrocytes, the stimulatory effect of MSO on the methylation of neural tRNA guanines, previouly observed both in vitro using [ 14 C] S -adenosyl- l -methionine and in vivo using [ methyl 3 -H] l -methionine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45427/1/11064_2004_Article_BF00964832.pd

    Differential Regulation of Cutaneous Oncoprotein HPVE6 by wtp53, Mutant p53R248W and ΔNp63α is HPV Type Dependent

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    UV exposure and p53 mutations are major factors in non-melanoma skin cancer, whereas a role for HPV infections has not been defined. Previous data demonstrated the wtp53-mediated degradation of cutaneous HPV20E6 by caspase-3. ΔNp63α and hot-spot mutant p53R248W conveyed a protective effect on HPV20E6 under these conditions. We demonstrate a differential regulation by wtp53 of the E6 genes of cutaneous types HPV4, HPV5, HPV7, HPV27, HPV38, HPV48, HPV60 and HPV77. Caspase- or proteasome-mediated down-regulation was HPV type dependent. Mutant p53R248W up-regulated expression of all these E6 proteins as did ΔNp63α except for HPV38E6 which was down-regulated by the latter. None of these cellular proteins affected HPV41E6 expression. Ectopic expression of both mutp53R248W and ΔNp63α in the normal NIKS keratinocyte cell line harbouring endogenous p53 and p63however led to a down-regulation of HPV20E6. We demonstrate that HPV20E6 expression in these cells is modulated by additional, yet unidentified, cellular protein(s), which are not necessarily involved in apoptosis or autophagy. We further demonstrate proliferation of HPV20E6-expressing keratinocytes. Levels of proteins involved in cell cycle control, cyclin-D1, cdk6 and p16INK4a, phosphorylated pRB, as well as c-Jun and p-c-Jun, were all increased in these cells. HPV20E6 did not compete for the interaction between p16INK4a with cyclin-D1 or cdk6. Phosphorylation of pRB in the HPV20E6 expressing cells seems to be sufficient to override the cytokenetic block induced by the p16INK4a/pRB pathway. The present study demonstrates the diverse influence of p53 family members on individual cutaneous HPVE6 proteins. HPV20E6 expression also resulted in varying protein levels of factors involved in proliferation and differentiation

    Material deprivation affects the management and clinical outcome of hepatocellular carcinoma in a high-resource environment

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    none94Aim: This study investigated how material deprivation in Italy influences the stage of hepatocellular carcinoma (HCC) at diagnosis and the chance of cure. Methods: 4114 patients from the Italian Liver Cancer database consecutively diagnosed with HCC between January 2008 and December 2018 were analysed about severe material deprivation (SMD) rate tertiles of the region of birth and region of managing hospitals, according to the European Statistics on Income and Living Conditions. The main outcomes were HCC diagnosis modalities (during or outside surveillance), treatment adoption and overall survival. Results: In more deprived regions, HCC was more frequently diagnosed during surveillance, while the incidental diagnosis was prevalent in the least deprived. Tumour characteristics did not differ among regions. The proportion of patients undergoing potentially curative treatments progressively decreased as the SMD worsened. Consequently, overall survival was better in less deprived regions. Patients who moved from most deprived to less deprived regions increased their probability of receiving potentially curative treatments by 1.11 times (95% CI 1.03 to 1.19), decreasing their mortality likelihood (hazard ratio 0.78 95% CI 0.67 to 0.90). Conclusions: Socioeconomic status measured through SMD does not seem to influence HCC features at diagnosis but brings a negative effect on the chance of receiving potentially curative treatments. Patient mobility from the most deprived to the less deprived regions increased the access to curative therapies, with the ultimate result of improving survival.openCucchetti A.; Gramenzi A.; Johnson P.; Giannini E.G.; Tovoli F.; Rapaccini G.L.; Marra F.; Cabibbo G.; Caturelli E.; Gasbarrini A.; Svegliati-Baroni G.; Sacco R.; Zoli M.; Morisco F.; Di Marco M.; Mega A.; Foschi F.G.; Biasini E.; Masotto A.; Nardone G.; Raimondo G.; Azzaroli F.; Vidili G.; Brunetto M.R.; Farinati F.; Trevisani F.; Avanzato F.; Biselli M.; Caraceni P.; Garuti F.; Neri A.; Santi V.; Pellizzaro F.; Imondi A.; Sartori A.; Penzo B.; Sanmarco A.; Granito A.; Muratori L.; Piscaglia F.; Sansone V.; Forgione A.; Dajti E.; Marasco G.; Ravaioli F.; Cappelli A.; Golfieri R.; Mosconi C.; Renzulli M.; Cela E.M.; Facciorusso A.; Cacciato V.; Casagrande E.; Moscatelli A.; Pellegatta G.; de Matthaeis N.; Allegrini G.; Lauria V.; Ghittoni G.; Pelecca G.; Chegai F.; Coratella F.; Ortenzi M.; Missale G.; Olivani A.; Inno A.; Marchetti F.; Busacca A.; Camma C.; Di Martino V.; Maria Rizzo G.E.; Franze M.S.; Saitta C.; Sauchella A.; Berardinelli D.; Bevilacqua V.; Borghi A.; Gardini A.C.; Conti F.; Dall'Aglio A.C.; Ercolani G.; Adotti V.; Arena U.; Di Bonaventura C.; Campani C.; Dragoni G.; Gitto S.; Laffi G.; Coccoli P.; Malerba A.; Guarino M.; Capasso M.; Oliveri F.; Romagnoli V.Cucchetti, A.; Gramenzi, A.; Johnson, P.; Giannini, E. G.; Tovoli, F.; Rapaccini, G. L.; Marra, F.; Cabibbo, G.; Caturelli, E.; Gasbarrini, A.; Svegliati-Baroni, G.; Sacco, R.; Zoli, M.; Morisco, F.; Di Marco, M.; Mega, A.; Foschi, F. G.; Biasini, E.; Masotto, A.; Nardone, G.; Raimondo, G.; Azzaroli, F.; Vidili, G.; Brunetto, M. R.; Farinati, F.; Trevisani, F.; Avanzato, F.; Biselli, M.; Caraceni, P.; Garuti, F.; Neri, A.; Santi, V.; Pellizzaro, F.; Imondi, A.; Sartori, A.; Penzo, B.; Sanmarco, A.; Granito, A.; Muratori, L.; Piscaglia, F.; Sansone, V.; Forgione, A.; Dajti, E.; Marasco, G.; Ravaioli, F.; Cappelli, A.; Golfieri, R.; Mosconi, C.; Renzulli, M.; Cela, E. M.; Facciorusso, A.; Cacciato, V.; Casagrande, E.; Moscatelli, A.; Pellegatta, G.; de Matthaeis, N.; Allegrini, G.; Lauria, V.; Ghittoni, G.; Pelecca, G.; Chegai, F.; Coratella, F.; Ortenzi, M.; Missale, G.; Olivani, A.; Inno, A.; Marchetti, F.; Busacca, A.; Camma, C.; Di Martino, V.; Maria Rizzo, G. E.; Franze, M. S.; Saitta, C.; Sauchella, A.; Berardinelli, D.; Bevilacqua, V.; Borghi, A.; Gardini, A. C.; Conti, F.; Dall'Aglio, A. C.; Ercolani, G.; Adotti, V.; Arena, U.; Di Bonaventura, C.; Campani, C.; Dragoni, G.; Gitto, S.; Laffi, G.; Coccoli, P.; Malerba, A.; Guarino, M.; Capasso, M.; Oliveri, F.; Romagnoli, V

    Landscape of alcohol-related hepatocellular carcinoma in the last 15 years highlights the need to expand surveillance programs

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    Background & Aims: Alcohol abuse and metabolic disorders are leading causes of hepatocellular carcinoma (HCC) worldwide. Alcohol-related aetiology is associated with a worse prognosis compared with viral agents, because of the lower percentage of patients diagnosed with HCC under routine surveillance and a higher burden of comorbidity in alcohol abusers. This study aimed to describe the evolving clinical scenario of alcohol-related HCC over 15 years (2006–2020) in Italy. Methods: Data from the Italian Liver Cancer (ITA.LI.CA) registry were used: 1,391 patients were allocated to three groups based on the year of HCC diagnosis (2006–2010; 2011–2015; 2016–2020). Patient characteristics, HCC treatment, and overall survival were compared among groups. Survival predictors were also investigated. Results: Approximately 80% of alcohol-related HCCs were classified as cases of metabolic dysfunction-associated fatty liver disease. Throughout the quinquennia, <50% of HCCs were detected by surveillance programmes. The tumour burden at diagnosis was slightly reduced but not enough to change the distribution of the ITA.LI.CA cancer stages. Intra-arterial and targeted systemic therapies increased across quinquennia. A modest improvement in survival was observed in the last quinquennia, particularly after 12 months of patient observation. Cancer stage, HCC treatment, and presence of oesophageal varices were independent predictors of survival. Conclusions: In the past 15 years, modest improvements have been obtained in outcomes of alcohol-related HCC, attributed mainly to underuse of surveillance programmes and the consequent low amenability to curative treatments. Metabolic dysfunction-associated fatty liver disease is a widespread condition in alcohol abusers, but its presence did not show a pivotal prognostic role once HCC had developed. Instead, the presence of oesophageal varices, an independent poor prognosticator, should be considered in patient management and refining of prognostic systems. Impact and Implications: Alcohol abuse is a leading and growing cause of hepatocellular carcinoma (HCC) worldwide and is associated with a worse prognosis compared with other aetiologies. We assessed the evolutionary landscape of alcohol-related HCC over 15 years in Italy. A high cumulative prevalence (78%) of metabolic dysfunction-associated fatty liver disease, with signs of metabolic dysfunction, was observed in HCC patients with unhealthy excessive alcohol consumption. The alcohol + metabolic dysfunction-associated fatty liver disease condition tended to progressively increase over time. A modest improvement in survival occurred over the study period, likely because of the persistent underuse of surveillance programmes and, consequently, the lack of improvement in the cancer stage at diagnosis and the patients’ eligibility for curative treatments. Alongside the known prognostic factors for HCC (cancer stage and treatment), the presence of oesophageal varices was an independent predictor of poor survival, suggesting that this clinical feature should be carefully considered in patient management and should be included in prognostic systems/scores for HCC to improve their performance

    E6-mediated activation of JNK drives EGFR signalling to promote proliferation and viral oncoprotein expression in cervical cancer

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    Human papillomaviruses (HPV) are a major cause of malignancy worldwide, contributing to ~5% of all human cancers including almost all cases of cervical cancer and a growing number of ano-genital and oral cancers. HPV-induced malignancy is primarily driven by the viral oncogenes, E6 and E7, which manipulate host cellular pathways to increase cell proliferation and enhance cell survival, ultimately predisposing infected cells to malignant transformation. Consequently, a more detailed understanding of viral-host interactions in HPV-associated disease offers the potential to identify novel therapeutic targets. Here, we identify that the c-Jun N-terminal kinase (JNK) signalling pathway is activated in cervical disease and in cervical cancer. The HPV E6 oncogene induces JNK1/2 phosphorylation in a manner that requires the E6 PDZ binding motif. We show that blockade of JNK1/2 signalling using small molecule inhibitors, or knockdown of the canonical JNK substrate c-Jun, reduces cell proliferation and induces apoptosis in cervical cancer cells. We further demonstrate that this phenotype is at least partially driven by JNK-dependent activation of EGFR signalling via increased expression of EGFR and the EGFR ligands EGF and HB-EGF. JNK/c-Jun signalling promoted the invasive potential of cervical cancer cells and was required for the expression of the epithelial to mesenchymal transition (EMT)-associated transcription factor Slug and the mesenchymal marker Vimentin. Furthermore, JNK/c-Jun signalling is required for the constitutive expression of HPV E6 and E7, which are essential for cervical cancer cell growth and survival. Together, these data demonstrate a positive feedback loop between the EGFR signalling pathway and HPV E6/E7 expression, identifying a regulatory mechanism in which HPV drives EGFR signalling to promote proliferation, survival and EMT. Thus, our study has identified a novel therapeutic target that may be beneficial for the treatment of cervical cancer

    Telomeres and telomerase in head and neck squamous cell carcinoma: from pathogenesis to clinical implications

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