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Passini CSM, Cavalcanti MB, Ribas SA, de Carvalho CMP, Bocca C, Lamarca F. Conflict of Interests in the Scientific Production on Vitamin D and COVID-19: A Scoping Review. Front Public Health 2022; 10:821740. [PMID: 35903374 PMCID: PMC9320027 DOI: 10.3389/fpubh.2022.821740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 06/06/2022] [Indexed: 11/25/2022] Open
Abstract
The use of scientific evidence to support the process of formulating and implementing public policies might be biased by studies funded by the pharmaceutical and food industry, which more often than not meet corporate interests. This review aimed to analyze the occurrence of conflict of interest (COI) in academic production regarding vitamin D and COVID-19, considering the facility offered during the pandemic for academic publications of heterogeneous quality. A scoping review of observational studies published in Medline, Lilacs, and Google Scholar databases was carried out. The selected studies were published between December 2019 and August 2021, focused on the relationship between vitamin D and prevention or treatment of COVID-19 in non-institutionalized individuals, with no language restrictions. Twenty-nine studies met eligibility criteria. COI was disclosed in five papers and further identified by review authors in eight other papers, meaning COI was present in thirteen papers (44.8%). Studies were funded by companies in the diagnostics, pharmaceutical and food sectors. Conclusions favorable to vitamin D supplementation were more prevalent in papers where COI was identified (9/13, 69.2%) than among papers where COI was not found (4/16, 25.0%). Omissions of disclosure of COI, funding source, and sponsor functions were observed. The identification of possible corporate political activities in scientific papers about vitamin D published during the COVID-19 pandemic signals a need for greater transparency and guideline development on the prevention of COI in scientific production.
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Affiliation(s)
| | - Maria Birman Cavalcanti
- School of Nutrition, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Simone Augusta Ribas
- Department of Public Health Nutrition, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Graduate Program in Food and Nutrition Security (PPGSAN), Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | | | - Cláudia Bocca
- Department of Public Health Nutrition, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Graduate Program in Food and Nutrition Security (PPGSAN), Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Fernando Lamarca
- Department of Applied Nutrition, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Department of Applied Nutrition, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
- *Correspondence: Fernando Lamarca
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Meloni F, Pandolfi L, Frangipane V, Cova E, Arpicco S, Marengo A, Bocca C, Monti M. Hyaluronic Acid Decorated-Liposome are Good Biocompatible Nano-Carrier for Drug Delivery to Mesenchymal Cells Derived from BAL of Bronchiolitis Obliterans Patients. J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Blasco H, Veyrat-Durebex C, Bocca C, Patin F, Vourc'h P, Kouassi Nzoughet J, Lenaers G, Andres CR, Simard G, Corcia P, Reynier P. Lipidomics Reveals Cerebrospinal-Fluid Signatures of ALS. Sci Rep 2017; 7:17652. [PMID: 29247199 PMCID: PMC5732162 DOI: 10.1038/s41598-017-17389-9] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/22/2017] [Indexed: 12/30/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS), the commonest adult-onset motor neuron disorder, is characterized by a survival span of only 2–5 years after onset. Relevant biomarkers or specific metabolic signatures would provide powerful tools for the management of ALS. The main objective of this study was to investigate the cerebrospinal fluid (CSF) lipidomic signature of ALS patients by mass spectrometry to evaluate the diagnostic and predictive values of the profile. We showed that ALS patients (n = 40) displayed a highly significant specific CSF lipidomic signature compared to controls (n = 45). Phosphatidylcholine PC(36:4), higher in ALS patients (p = 0.0003) was the most discriminant molecule, and ceramides and glucosylceramides were also highly relevant. Analysis of targeted lipids in the brain cortex of ALS model mice confirmed the role of some discriminant lipids such as PC. We also obtained good models for predicting the variation of the ALSFRS-r score from the lipidome baseline, with an accuracy of 71% in an independent set of patients. Significant predictions of clinical evolution were found to be correlated to sphingomyelins and triglycerides with long-chain fatty acids. Our study, which shows extensive lipid remodelling in the CSF of ALS patients, provides a new metabolic signature of the disease and its evolution with good predictive performance.
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Affiliation(s)
- H Blasco
- Université François-Rabelais, Inserm, U930, Tours, France. .,Laboratoire de Biochimie, CHRU de Tours, France. .,Institut MITOVASC, UMR CNRS6015-INSERM1083, Université d'Angers, Angers, France.
| | - C Veyrat-Durebex
- Institut MITOVASC, UMR CNRS6015-INSERM1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, France
| | - C Bocca
- Institut MITOVASC, UMR CNRS6015-INSERM1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, France
| | - F Patin
- Université François-Rabelais, Inserm, U930, Tours, France.,Laboratoire de Biochimie, CHRU de Tours, France
| | - P Vourc'h
- Université François-Rabelais, Inserm, U930, Tours, France.,Laboratoire de Biochimie, CHRU de Tours, France
| | | | - G Lenaers
- Département de Biochimie et Génétique, CHU d'Angers, France
| | - C R Andres
- Université François-Rabelais, Inserm, U930, Tours, France.,Laboratoire de Biochimie, CHRU de Tours, France
| | - G Simard
- Institut MITOVASC, UMR CNRS6015-INSERM1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, France
| | - P Corcia
- Université François-Rabelais, Inserm, U930, Tours, France.,Centre de Ressources et de Compétences SLA, Service de Neurologie, CHRU Bretonneau, Tours, France.,Fédération des CRCSLA Tours et Limoges, LITORALS, Limoges, France
| | - P Reynier
- Institut MITOVASC, UMR CNRS6015-INSERM1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, France
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Bruno C, Patin F, Bocca C, Nadal-Desbarats L, Bonnier F, Reynier P, Emond P, Vourc'h P, Joseph-Delafont K, Corcia P, Andres CR, Blasco H. The combination of four analytical methods to explore skeletal muscle metabolomics: Better coverage of metabolic pathways or a marketing argument? J Pharm Biomed Anal 2017; 148:273-279. [PMID: 29059617 DOI: 10.1016/j.jpba.2017.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Metabolomics is an emerging science based on diverse high throughput methods that are rapidly evolving to improve metabolic coverage of biological fluids and tissues. Technical progress has led researchers to combine several analytical methods without reporting the impact on metabolic coverage of such a strategy. The objective of our study was to develop and validate several analytical techniques (mass spectrometry coupled to gas or liquid chromatography and nuclear magnetic resonance) for the metabolomic analysis of small muscle samples and evaluate the impact of combining methods for more exhaustive metabolite covering. DESIGN AND METHODS We evaluated the muscle metabolome from the same pool of mouse muscle samples after 2 metabolite extraction protocols. Four analytical methods were used: targeted flow injection analysis coupled with mass spectrometry (FIA-MS/MS), gas chromatography coupled with mass spectrometry (GC-MS), liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS), and nuclear magnetic resonance (NMR) analysis. We evaluated the global variability of each compound i.e., analytical (from quality controls) and extraction variability (from muscle extracts). We determined the best extraction method and we reported the common and distinct metabolites identified based on the number and identity of the compounds detected with low analytical variability (variation coefficient<30%) for each method. Finally, we assessed the coverage of muscle metabolic pathways obtained. RESULTS Methanol/chloroform/water and water/methanol were the best extraction solvent for muscle metabolome analysis by NMR and MS, respectively. We identified 38 metabolites by nuclear magnetic resonance, 37 by FIA-MS/MS, 18 by GC-MS, and 80 by LC-HRMS. The combination led us to identify a total of 132 metabolites with low variability partitioned into 58 metabolic pathways, such as amino acid, nitrogen, purine, and pyrimidine metabolism, and the citric acid cycle. This combination also showed that the contribution of GC-MS was low when used in combination with other mass spectrometry methods and nuclear magnetic resonance to explore muscle samples. CONCLUSION This study reports the validation of several analytical methods, based on nuclear magnetic resonance and several mass spectrometry methods, to explore the muscle metabolome from a small amount of tissue, comparable to that obtained during a clinical trial. The combination of several techniques may be relevant for the exploration of muscle metabolism, with acceptable analytical variability and overlap between methods However, the difficult and time-consuming data pre-processing, processing, and statistical analysis steps do not justify systematically combining analytical methods.
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Affiliation(s)
- C Bruno
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; UMR INSERM U930, Université François Rabelais de Tours, France
| | - F Patin
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; UMR INSERM U930, Université François Rabelais de Tours, France
| | - C Bocca
- Institut MITOVASC, CNRS 6015, INSERM U1083, Université d'Angers, Angers, France
| | | | - F Bonnier
- Université François-Rabelais de Tours, Faculté de Pharmacie, EA 6295 Nanomédicaments et Nanosondes, Tours, France
| | - P Reynier
- Institut MITOVASC, CNRS 6015, INSERM U1083, Université d'Angers, Angers, France
| | - P Emond
- UMR INSERM U930, Université François Rabelais de Tours, France
| | - P Vourc'h
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; UMR INSERM U930, Université François Rabelais de Tours, France
| | - K Joseph-Delafont
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France
| | - P Corcia
- UMR INSERM U930, Université François Rabelais de Tours, France; Centre de Ressources et de Compétences SLA, CHU Tours, France; Fédération des Centres de Ressources et de Compétences de Tours et Limoges, Litorals, France
| | - C R Andres
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; UMR INSERM U930, Université François Rabelais de Tours, France
| | - H Blasco
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; UMR INSERM U930, Université François Rabelais de Tours, France.
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Abstract
Este trabalho se baseia em revisão da literatura internacional sobre abordagens conceituais relacionadas às políticas de alimentação e nutrição e de segurança alimentar e nutricional, como food policy; nutrition policy e food regimes. Propõe-se a reconhecer as relações entre os conceitos, os arranjos institucionais do Estado e a ação política em cada abordagem no contexto internacional. Adotou-se a perspectiva de que uma proposta conceitual não nasce do ponto de vista apenas do conhecimento, mas da ação política dos atores envolvidos, sendo reinventada e ressignificada em cada contexto histórico e geopolítico. Assim, carrega consigo uma intenção política, sendo resultante de projetos permanentemente em disputa, orientando e se modificando em função do que é considerado o objeto de cada política, as tentativas de resposta frente aos problemas e os arranjos institucionais necessários. Destaca-se a visão de que a construção do conhecimento transborda a contribuição acadêmica, envolvendo diferentes atores e grupos de interesse e, ao mesmo tempo, sinaliza a produção de conhecimento como militância política. Aponta, ainda, uma reflexão sobre o processo histórico de construção das abordagens conceituais e as respectivas inflexões no modo de se conceber uma política. Desta forma, os modos de explicar os fenômenos relacionados à alimentação e nutrição ou à segurança alimentar e nutricional se modificaram ao longo do tempo e revelam arranjos institucionais distintos, mais ou menos intersetoriais, ancorados em visões distintas de como tratar o problema em questão.
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Magalhães R, Coelho AV, Nogueira MF, Bocca C. Intersetorialidade, convergência e sustentabilidade: desafios do programa Bolsa Família em Manguinhos, RJ. Ciênc saúde coletiva 2011; 16:4442-53. [DOI: 10.1590/s1413-81232011001200017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Accepted: 05/10/2010] [Indexed: 11/22/2022] Open
Abstract
Alguns estudos têm revelado o impacto de programas de transferência condicionada de renda na melhoria das condições de vida e no acesso a serviços básicos de saúde e educação em diferentes países. No entanto, persistem lacunas no que se refere à avaliação dos benefícios de tais intervenções entre os grupos que apresentam maiores dificuldades em acessar serviços públicos ou dos avanços na qualidade do ensino e desempenho escolar. Além disso, existem poucas evidências sobre a adequação das ações aos respectivos contextos de implementação, níveis de adesão e cooperação, local e estratégias adotadas para a integração com as demais políticas de proteção social. O artigo discute os resultados da pesquisa avaliativa sobre a implementação do programa de transferência condicionada de renda Bolsa Família em Manguinhos (RJ) realizada entre os anos de 2007 e 2008. Foram realizadas entrevistas com gestores das secretarias municipais de assistência social, saúde e educação e agentes implementadores locais. Em Manguinhos, a sustentabilidade das ações voltadas à redução da pobreza e promoção da saúde envolve o fortalecimento de canais de interlocução entre níveis de governo, gestores públicos e associações civis, reconhecimento da complexidade das demandas sociais locais e pactuação de uma agenda intersetorial.
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Magalhães R, Bodstein R, Coelho AV, Nogueira MF, Bocca C. The Bolsa Família (family grant) program in Manguinhos: challenges and lessons learned in a case study: implementation process: development of strategies and evidence. Glob Health Promot 2011; 18:13-5. [PMID: 21721293 DOI: 10.1177/1757975910393164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article discusses the results of an evaluation research on the implementation of the Bolsa Família, a conditional cash program targeted at poor families in Manguinhos, Brazil. The program pursues two main objectives: reducing current poverty and promoting human capital through the increased utilization of educational and health services. Connecting different agencies and stakeholders and building capacity for collaboration are two strategies associated with program effectiveness. Implementation evaluation showed that in Manguinhos, there were large gaps concerning the action's adequacy in relation to the specific implementation context, intersectoral collaboration and shared knowledge. Evidence from this research was used to spearhead concrete changes in policy at the local level.
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Affiliation(s)
- Rosana Magalhães
- Escola Nacional de Saúde Pública – Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.
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Bocca C, Bozzo F, Cannito S, Colombatto S, Miglietta A. CLA reduces breast cancer cell growth and invasion through ERalpha and PI3K/Akt pathways. Chem Biol Interact 2010; 183:187-93. [PMID: 19800873 DOI: 10.1016/j.cbi.2009.09.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 09/21/2009] [Accepted: 09/25/2009] [Indexed: 12/24/2022]
Abstract
We previously reported that conjugated linoleic acid (CLA), a naturally occurring fatty acid, inhibits the growth of ERalpha(+) MCF-7 and ERalpha(-) MDA-MB-231 human breast cancer cells by negative modulation of the ERK/MAPK pathway and apoptosis induction. Here we show that in these cell lines CLA also down-regulates the PI3K/Akt cascade. In MCF-7 cells CLA also triggers ERalpha/PP2A complex formation reducing the phosphorylation state and transcriptional activity of Eralpha whereas in MDA-MB-231 cells CLA does not induce PP2A activation. Moreover, CLA induces the expression of proteins involved in cell adhesion and inhibits cell migration and MMP-2 activity. These findings suggest that CLA may induce the down-regulation of ERalpha signalling and the reduction of cell invasion through the modulation of balancing between phosphatases and kinases.
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Affiliation(s)
- C Bocca
- Department of Experimental Medicine and Oncology, University of Torino, C.so Raffaello 30, 10125 Torino, Italy.
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Marino G, Motta E, Mosso L, Bocca C, Ravarino N, Torchio B. Primary signet ring cell adenocarcinoma of the bladder. MINERVA UROL NEFROL 2005; 57:125-7. [PMID: 15951737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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Abstract
Geiparvarin, a natural compound isolated from the leaves of Geijera parviflora, inhibits the growth of various tumor cell lines with a mode of action which may be attributed to its anti-microtubular activity. Our previous findings indicated that geiparvarin is able to inhibit the in vitro polymerization of tubulin and to derange the microtubular network in fibroblasts more effectively in the presence of paclitaxel. To further explore its biological activity here we have studied the effects exerted on the other components of the cytoskeleton by geiparvarin and two derivatives obtained by conjugating the 3(2H)-furanone ring of geiparvarin with diethylstilbestrol (DES). Firstly, observations by electron microscopy confirmed anti-microtubular properties, a near-total absence of microtubules is detected when tubulin is incubated with drugs in the presence of paclitaxel, whereas microtubule formation is not inhibited by drugs when assembly is induced by guanosine 5'-triphosphate (GTP). Immunofluorescence assays demonstrated that geiparvarin and DES act in a vinblastine-like fashion, causing a marked depletion of intermediate filaments while the network of microfilaments is not affected. Both the conjugates alter the 'stress fibers' organization of actin and disrupt the vimentin pattern; generally they derange cytoskeleton more markedly than the parent compounds. The cell growth inhibiting effects of geiparvarin and derivatives are dose-dependent; they vary according to the cell line used, when compounds were administered either alone or simultaneously with paclitaxel. Unlike other anti-microtubule agents, they do not exhibit cell-cycle compartment specificity and do not influence thymidine uptake in the cell.
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Affiliation(s)
- C Bocca
- Department of Experimental Medicine and Oncology, University of Torino, Corso Raffaello 30, 10125, Torino, Italy.
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Miglietta A, Bocca C, Gabriel L, Rampa A, Bisi A, Valenti P. Antimicrotubular and cytotoxic activity of geiparvarin analogues, alone and in combination with paclitaxel. Cell Biochem Funct 2001; 19:181-9. [PMID: 11494307 DOI: 10.1002/cbf.919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Geiparvarin is an antiproliferative compound isolated from the leaves of Geijera parviflora, and may represent a new drug which targets tubulin. To better explore the potential use of this agent, we investigated the antimicrotubular and cytotoxic effects of new synthetic aromatic derivatives of geiparvarin. These drugs inhibited polymerization of microtubular protein, particularly when the assembly was induced by paclitaxel. The microtubular network organization of fibroblasts was altered more effectively by some drugs. Normal microtubule architecture completely disappeared when the cells were treated simultaneously with drugs and paclitaxel: microtubules depolymerized or were reorganized into bundles, in a similar but more disarrayed fashion than that observed after treatment with paclitaxel alone. Cytotoxicity studies showed a dose-dependent effect, whereas combined administration of drugs and paclitaxel increased cytotoxicity, more effectively in paclitaxel versus derivatives administration alone.
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Affiliation(s)
- A Miglietta
- Department of Experimental Medicine and Oncology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
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Miglietta A, Cavalli R, Bocca C, Gabriel L, Gasco MR. Cellular uptake and cytotoxicity of solid lipid nanospheres (SLN) incorporating doxorubicin or paclitaxel. Int J Pharm 2000; 210:61-7. [PMID: 11163988 DOI: 10.1016/s0378-5173(00)00562-7] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Solid Lipid Nanospheres (SLN) are colloidal therapeutic systems proposed for several administration routes and obtained by dispersing warm microemulsions in cold water. SLN as carriers of doxorubicin and paclitaxel have been previously studied. In this study, the cellular uptake of SLN and the cytotoxicity of doxorubicin and paclitaxel incorporated into SLN were investigated on two cell-lines, human promyelocytic leukemia (HL60) and human breast carcinoma (MCF-7). Cellular uptake of SLN was determined by incorporating 6-coumarin as fluorescent marker. The cellular uptake of fluorescent SLN was clearly evidenced by fluorescence microscopy. The cytotoxicity of doxorubicin incorporated in SLN was higher compared to the conventional doxorubicin solution, even at the lower concentrations. Paclitaxel in SLN was about 100-fold more effective than free paclitaxel on MCF-7 cells, while on HL60 cells a lower sensitivity was achieved with paclitaxel in SLN. Unloaded SLN had no cytotoxic effect on HL60 and MCF-7 cells.
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Affiliation(s)
- A Miglietta
- Dipartimento di Medicina ed Oncologia Sperimentale, Università degli Studi di Torino, Italy
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Miglietta A, Bocca C, Rampa A, Bisi A, Gabriel L. Geiparvarin and derivatives in combination with taxol: effect on microtubular organization in 3T3 fibroblasts. Anticancer Drug Des 1997; 12:607-20. [PMID: 9448701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Geiparvarin, a natural product that exhibits antiproliferative activity, inhibits the growth of various tumour cell lines with a mechanism of action so far unknown. Our preliminary findings showed that geiparvarin and some derivatives obtained from its conjugation with diethylstilboestrol and meso-hexestrol significantly inhibit taxol-induced in vitro polymerization of both tubulin and microtubular protein. In this study we investigated the effect of geiparvarin and of the oestrogen-combined derivatives on the cellular microtubular network of fibroblasts. Geiparvarin altered the microtubular organization of fibroblasts and strengthened the derangement of the microtubular pattern in cells exposed simultaneously to taxol. However, the microtubular network remained quite well organized in fibroblasts exposed to geiparvarin and preincubated with taxol, which in this case prevented the deranging effect of the former. The antimicrotubular activity of the oestrogen-combined derivatives was more similar to that of geiparvarin than to that of the oestrogens, and often this activity was stronger than that of each reference drug alone; the cytotoxic activity examined in the same experimental conditions generally confirmed the microscopic analysis.
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Affiliation(s)
- A Miglietta
- Department of Experimental Medicine and Oncology, University of Torino, Italy
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Miglietta A, Bocca C, Gadoni E, Gabriel L, Rampa A, Bisi A, Valenti P, Da Re P. Interaction of geiparvarin and related compounds with purified microtubular protein. Anticancer Drug Des 1996; 11:35-48. [PMID: 8639247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Geiparvarin is an antiproliferative compound whose mechanism of action has not yet been identified. We have investigated the biochemical action on purified microtubular protein, as well as on tubulin, of geiparvarin and of some derivatives resulting from its conjugation with two synthetic oestrogens, diethylstilboestrol and meso-hexoestrol, in comparison with the antimicrotubular action of the reference oestrogens. Geiparvarin and derivatives did not inhibit colchicine binding to tubulin nor did they significantly influence GTP-induced polymerization. On the contrary, they effectively counteracted the stimulating effect of taxol on microtubule formation, both in the presence and in the absence of microtubule-associated proteins. A competitive inhibition mechanism at the taxol binding site of tubulin may thus be proposed to explain the antimicrotubular action of geiparvarin.
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Affiliation(s)
- A Miglietta
- Department of Experimental Medicine and Oncology, University of Torino, Italy
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Abstract
A structure-activity relationship has been established between calvatic acid and some related synthetic compounds, and their ability to inhibit GTP-induced microtubular protein polymerization in vitro. These compounds were effective in a dose- and a time-dependent manner. The most active drug was the p-chloro substituted compound, which showed its inhibitory activity without any preincubation period, which the others needed. Since if cysteine was present, polymerization was no longer affected, an involvement of titratable -SH groups of tubulin could be suggested. In contrast, taxol-induced polymerization was only slightly inhibited by these compounds, and colchicine-binding activity was not generally impaired.
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Affiliation(s)
- E Gadoni
- Department of Experimental Medicine and Oncology, Section of General Pathology, University of Turin, Corso Raffaello 30, 10125 Torino, Italy
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