RESUMO
The rapid dynamics of COVID-19 calls for quick and effective tracking of virus transmission chains and early detection of outbreaks, especially in the "phase 2" of the pandemic, when lockdown and other restriction measures are progressively withdrawn, in order to avoid or minimize contagion resurgence. For this purpose, contact-tracing apps are being proposed for large scale adoption by many countries. A centralized approach, where data sensed by the app are all sent to a nation-wide server, raises concerns about citizens' privacy and needlessly strong digital surveillance, thus alerting us to the need to minimize personal data collection and avoiding location tracking. We advocate the conceptual advantage of a decentralized approach, where both contact and location data are collected exclusively in individual citizens' "personal data stores", to be shared separately and selectively (e.g., with a backend system, but possibly also with other citizens), voluntarily, only when the citizen has tested positive for COVID-19, and with a privacy preserving level of granularity. This approach better protects the personal sphere of citizens and affords multiple benefits: it allows for detailed information gathering for infected people in a privacy-preserving fashion; and, in turn this enables both contact tracing, and, the early detection of outbreak hotspots on more finely-granulated geographic scale. The decentralized approach is also scalable to large populations, in that only the data of positive patients need be handled at a central level. Our recommendation is two-fold. First to extend existing decentralized architectures with a light touch, in order to manage the collection of location data locally on the device, and allow the user to share spatio-temporal aggregates-if and when they want and for specific aims-with health authorities, for instance. Second, we favour a longer-term pursuit of realizing a Personal Data Store vision, giving users the opportunity to contribute to collective good in the measure they want, enhancing self-awareness, and cultivating collective efforts for rebuilding society.
RESUMO
Epidemiological investigation and animal studies have shown that dietary n-3 PUFA prevent the development and progression of certain types of cancer. However, conflicting results have been reported by the few studies that focused on the effect of dietary n-3 PUFA on the development of metastases. In the present study, we investigated the metastatic dissemination of murine T lymphoma lines with different metastatic potential transplanted into mice fed a fish oil diet, compared with mice fed a maize oil diet. Transplantation of highly metastatic S11 cells into animals fed a fish oil diet induced a large lymphomatoid infiltration in the spleen, associated with an eight-fold increase in spleen weight, compared with normal animals on the same diet. In contrast, only a limited increase in spleen weight was found in animals transplanted with S11 cells while fed a maize oil diet. No significant increase in spleen weight was found in animals transplanted with low-metastatic 164T2 cells regardless of whether they were fed a fish oil or a maize oil diet. At the end of experiment, an overt cachexia was shown by animals fed a fish oil diet transplanted with S11 cells, but not by those transplanted with 164T2 cells. The particularly high pro-metastatic effect of dietary n-3 PUFA on S11 cells rules out the generalisation that dietary n-3 PUFA inhibit tumour growth and progression.
Assuntos
Ácidos Graxos Ômega-3/toxicidade , Óleos de Peixe/toxicidade , Linfoma de Células T/patologia , Animais , Caquexia/etiologia , Feminino , Linfoma de Células T/complicações , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica , Transplante de Neoplasias , Óleos de Plantas/toxicidade , Baço/patologia , Células Tumorais Cultivadas , Aumento de Peso/efeitos dos fármacosRESUMO
Both epidemiological and experimental studies indicate that dietary n-3 PUFA inhibit carcinogenesis and tumour growth. Metastatic diffusion has also been found to be affected in animals fed diets containing purified n-3 PUFA or fish oil. In the present study, we investigated whether the metastatic diffusion of a highly metastatic variant (F10-SR cells) isolated from the B16 melanoma F10 line was affected by feeding host animals a diet containing 5 % fish oil. In these animals, compared with those fed a diet containing 5 % maize oil, there was a reduced number of metastatic pulmonary colonies. The immunohistochemical analysis of appropriate markers revealed that the antimetastatic effect of dietary n-3 PUFA was not related to a reduction of proliferation, but rather to an enhanced apoptotic activity. The reduction of von Willebrand factor immunoreactivity found in pulmonary colonies of F10-SR cells grown in fish oil-fed animals indicates that a decrease of angiogenesis contributes to the antimetastatic effect of dietary n-3 PUFA. This conclusion stands in spite of the higher expression of vascular endothelial growth factor observed in pulmonary colonies grown in fish oil-fed animals.
Assuntos
Apoptose/efeitos dos fármacos , Gorduras Insaturadas na Dieta/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Neoplasias Pulmonares/prevenção & controle , Melanoma Experimental/secundário , Neovascularização Patológica/prevenção & controle , Animais , Feminino , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neovascularização Patológica/patologiaRESUMO
The aim of this study was to investigate whether tumor cells as well as tumor-associated macrophages (TAMs) contribute to the generation of protease activities essential to tumor cell invasiveness, such as matrix metalloproteinase 2 and 9 (MMP-2 and MMP-9), and the urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR). We found that the enhanced invasiveness through Matrigel-coated filters of B16 murine melanoma cells stimulated with IFNgamma was associated with an higher expression of uPAR and MMP-9 in these cells. Moreover, treatment with anti-MMP-9 or anti-uPAR monoclonal antibodies abrogated the increase of invasiveness in IFNgamma-stimulated melanoma cells, suggesting a cooperation of uPA system and MMP-9 in cytokine-stimulated invasiveness. Invasiveness through Matrigel was also enhanced in B16 melanoma cells exposed to a medium conditioned by TAMs, represented in our experimental model by thioglycollate-elicited macrophages co-cultivated with melanoma cells. Macrophages isolated from these co-cultures were found to express higher levels of uPAR and MMP-9 compared to macrophage cultures alone, and the pro-invasive activity of the co-culture-conditioned medium was abrogated by anti-MMP-9 monoclonal antibodies, but not anti-uPAR monoclonal antibodies. Furthermore, the enhanced uPAR and MMP-9 expression in macrophages co-cultivated with tumor cells seems a rather specific phenomenon, generated through a cell-to-cell contact mechanism. On the whole, our data point to a cooperation between tumor cells and macrophages elicited by tumor cells themselves in generating key enzymes essential in the promotion of tumor invasiveness, such as uPAR and MMP-9.
Assuntos
Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Melanoma Experimental/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Anticorpos Monoclonais , Western Blotting , Movimento Celular , Técnicas de Cocultura , Colágeno , Meios de Cultivo Condicionados , Combinação de Medicamentos , Fibroblastos/citologia , Fibroblastos/metabolismo , Interferon gama/farmacologia , Laminina , Macrófagos/patologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/imunologia , Inibidores de Metaloproteinases de Matriz , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Invasividade Neoplásica , Proteoglicanas , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/metabolismoRESUMO
In previous studies, we found that IFNgamma and TNFalpha generated by activated macrophages stimulate the metastatic potential in F10-M3 cells, a clone isolated from B16-F10 murine melanoma line. In this phenomenon, TNFalpha promoted the expression of a metastatic phenotype in tumor cells previously primed with IFNgamma. Here, we demonstrate that IFNalpha or IFNbeta may replace IFNgamma in priming tumor cells. We also noticed that an enhancement of the expression of p55TNFalpha receptor was associated with the preconditioning of tumor cells with IFNgamma and IFNbeta. By the use of an appropriate inhibitor, we observed that JAK1 signal transduction pathway was involved in the expression of a metastatic phenotype and of p55TNFalpha receptor shown in IFNgamma- and IFNbeta-primed melanoma cells stimulated with TNFalpha. Furthermore, the activity of the protein kinase C (PKC) was required for IFNgamma-primed melanoma cells to express a metastatic phenotype after stimulation with TNFalpha. In conclusion, our study shows that a metastatic phenotype was expressed in B16 murine melanoma cells stimulated with TNFalpha regardless of whether the cells were primed with IFNgamma IFNalpha or IFNbeta. The molecular events leading to the expression of a metastatic phenotype in F10-M3 melanoma cells are represented by: (a) an enhanced expression of p55TNFalpha receptor in IFNs-primed tumor cells dependent on JAK1 signal transduction pathway; and (b) an intact PKC activity during TNFalpha stimulation.
Assuntos
Interferon-alfa/farmacologia , Interferon beta/farmacologia , Janus Quinases/fisiologia , Melanoma Experimental/secundário , Fator de Necrose Tumoral alfa/farmacologia , Animais , Linhagem Celular Tumoral , Neoplasias Pulmonares/secundário , Melanoma Experimental/metabolismo , Camundongos , Transdução de SinaisRESUMO
Previous studies conducted in our laboratory showed that the reproduction of spontaneous and experimental metastases was reduced in host animals deprived of essential fatty acids (EFA). In the present study, we have explored the possibility whether apoptosis, proliferation, and angiogenesis might be involved in the antimetastatic effect of EFA deficiency. To this aim, in pulmonary colonies developed from B16-F10 cells in EFA-deficient animals or in animals fed a 5% corn oil diet, we performed an immunohistochemical analysis of bcl-2/bax proteins, PCNA, and VEGF and von Willebrand Factor (vWF), typical markers of apoptosis, proliferation, and angiogenesis, respectively. Apoptosis was also evaluated by detecting DNA fragments in metastatic cells. We found that the reduction of pulmonary colonies grown in EFA-deficient animals was associated with a high expression of apoptotic activity as revealed by the presence of apoptotic nuclei and a high immunoreactivity for bax. Cell proliferation seemed not to be influenced by EFA deficiency in view of the observation that PCNA was highly expressed in pulmonary colonies of control as well as EFA-deficient animals. Pulmonary colonies developed in EFA- deficient animals showed a lower expression of VEGF and a decreased microvessel density, indicating that a reduced angiogenesis contributes to the antimetastatic effects of EFA deficiency. Our analysis of the results invokes the possibility that a relationship between angiogenesis and apoptosis may account for the diminution of the development of experimental metastases in the lungs of EFA-deficient animals.
Assuntos
Apoptose , Ácidos Graxos Essenciais/metabolismo , Neoplasias Pulmonares/secundário , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Neovascularização Patológica , Animais , Proliferação de Células , Ácidos Graxos Essenciais/deficiência , Feminino , Camundongos , Células Tumorais CultivadasRESUMO
In this study, we investigated whether PAF synthesized by F10-M3 cells (a clone of B16-F10 melanoma line) mediates the increased capacity of these cells to penetrate into Matrigel upon stimulation with IFN gamma. The determination of PAF synthesized by IFN gamma-stimulated tumor cells revealed that 70% of newly synthesized PAF was released into growth media, while the remaining 30% was associated with the cell bodies. An experimental protocol based on the use of WEB 2086, a PAF receptorial antagonist, was designed to explore which of the two fractions of PAF synthesized by IFN gamma-stimulated F10-M3 cells (released into the growth medium or associated with the cell bodies) is essential to their capacity to migrate through Matrigel. We found that the PAF secreted into growth medium is the fraction responsible for the enhanced invasiveness of melanoma cells stimulated with IFN gamma. We also investigated whether motility of melanoma cells is stimulated by IFN gamma, and, if so, whether PAF is involved in this effect. We found that WEB 2086 prevented the remodeling of stress fibers, examined as an index of cell motility, that we observed in F10-M3 cells stimulated with IFN gamma. Furthermore, the observation that PAF receptor is expressed in IFN gamma-stimulated melanoma cells suggests that the invasive phenotype (e.g. migration through a reconstituted basement membrane and motility) promoted by PAF is based on an autocrine mechanism. On the whole, these results might indicate that PAF contributes to the expression of properties typical of an invasive phenotype in tumor cells stimulated with cytokines.
Assuntos
Movimento Celular/efeitos dos fármacos , Interferon gama/farmacologia , Melanoma/patologia , Invasividade Neoplásica/patologia , Fator de Ativação de Plaquetas/farmacologia , Animais , Azepinas , Colágeno/química , Meios de Cultivo Condicionados , Combinação de Medicamentos , Laminina/química , Camundongos , Fenótipo , Inibidores da Agregação Plaquetária/farmacologia , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Proteoglicanas/química , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Fibras de Estresse/efeitos dos fármacos , Fibras de Estresse/patologia , Fatores de Tempo , Triazóis , Células Tumorais CultivadasRESUMO
In the present study we investigated whether synthesis of nitric oxide (NO) by macrophages is affected by contact with tumor cells. Although it is well known that NO generated by macrophages influences different activities related to tumor progression, there is limited information on the modulatory role of tumor cells on NO release by macrophages. The experimental protocol used in our study consisted in the determination of NO secreted by macrophages, either resident or inflammatory, co-cultivated with tumor cells (B16 melanoma and L929 fibrosarcoma cells) at different cell densities and macrophage:tumor cell ratios. This experimental in vitro protocol simulates the different interactions between macrophages and tumor cells that occur during the development of a tumor mass. We found that the co-cultivation with tumor cells induced an increased secretion of NO in macrophages provided that they express an inflammatory phenotype, and they were challenged with LPS or IFNgamma/LPS. Two more variables were found to be critical in the increase of NO generation in inflammatory macrophages cultivated with tumor cells: a high cell density and a prevalence of tumor cells over macrophages. The enhancement of NO secreted in inflammatory macrophages stimulated by tumor cells was not observed in normal murine fibroblasts co-cultivated with tumor cells.
Assuntos
Comunicação Celular , Fibrossarcoma/patologia , Melanoma/patologia , Óxido Nítrico/metabolismo , Neoplasias Cutâneas/patologia , Animais , Técnicas de Cultura de Células , Progressão da Doença , Inflamação , Macrófagos/fisiologia , Camundongos , Fenótipo , Células Tumorais CultivadasRESUMO
Although there is a great deal of interest in the role played by tumor-associated macrophages in tumor progression, the knowledge of the biological mediators involved in the interplay between macrophages and tumor cells is still limited. In the present study, we investigated whether the lipoxygenase pathway in resident murine peritoneal macrophages is affected by contact with tumor cells of a different origin, e.g. murine B16 melanoma and L929 fibrosarcoma cells, and human Hs294T melanoma and HT1080 fibrosarcoma cells. Our experiments have been carried out by using macrophages co-cultivated with tumor cells at different ratios, in order to simulate the relative proportions between macrophages and tumor cells during the in vivo development of a tumor. Reverse phase HPLC analyses of the lipoxygenase products of resident peritoneal macrophages revealed a rather complex profile characterized by a high level of 12(S)-hydroxyeicosatetraenoic acid and 15(S)-hydroxyeicosatetraenoic acid followed by leukotriene B(4), 5(S)-hydroxyeicosatetraenoic acid, and lipoxins. Macrophages co-cultivated with tumor cells, both murine and human, showed a marked reduction of lipoxygenase products, mainly in the co-cultures where tumor cells prevailed over macrophages. The characteristic profile of macrophage lipoxygenase products was re-established after removal of tumor cells from the co-cultures. The inhibitory effect on lipoxygenase pathways exerted by tumor cells, was not seen when macrophages were co-cultivated with normal primary murine and human fibroblasts.
Assuntos
Comunicação Celular , Lipoxigenase/fisiologia , Macrófagos/enzimologia , Neoplasias/patologia , Animais , Cromatografia Líquida de Alta Pressão , Técnicas de Cocultura , Humanos , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
In the present study, we found that murine peritoneal macrophages elicited by BCG or Listeria monocytogenes release into the media an activity capable of stimulating the lung colonization as well as the expression of MHC class I antigens in B16 melanoma cells. A similar activity has previously been found in media conditioned by Corynebacterium parvum-elicited macrophages. Analysis by gel filtration chromatography of media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages revealed that the material responsible for the pro-clonogenic activity concentrated in chromatographic fractions corresponding to molecular weights (25 to 52 kDa) which are characteristic of certain cytokines. Thus, we challenged the various macrophage-conditioned media with polyclonal antibodies against IFNgamma and TNFalpha, and found that the macrophage pro-clonogenic activity was completely abolished in the presence of anti-IFNgamma antibodies, but only partially inhibited by anti-TNFalpha antibodies. This finding suggests a cooperative participation of the two cytokines to the pro-clonogenic activity of the media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages.
Assuntos
Interferon gama/metabolismo , Macrófagos/metabolismo , Peritônio/citologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Células Cultivadas , Cromatografia em Gel , Feminino , Humanos , Listeria monocytogenes/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Neoplasias Pulmonares/microbiologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Transplante de Neoplasias , Propionibacterium acnes/metabolismo , Fatores de Tempo , Células Tumorais CultivadasRESUMO
Interest in the possible involvement of the platelet-activating factor (PAF) in tumor growth and invasiveness has been stimulated by the recognition that PAF influences various biological responses relevant to metastatic diffusion, such as angiogenesis, adhesiveness to endothelia and cellular motility. In the present study, we investigated the extent to which PAF is synthesized by a series of human and murine transformed cell lines of a different histotype. Synthesis of PAF was studied by combining the 14C-acetate incorporation into PAF with the quantitative analysis of PAF performed by a procedure based on gas chromatography-mass spectrometry with a negative ion chemical ionization. In the presence of the Ca2+ ionophore A23187, cultures of human melanoma (Hs294T), fibrosarcoma (HT1080) and colon carcinoma (LS180) cell lines synthesized conspicuous amounts of PAF, comparable to those produced by resident peritoneal macrophages. Substantial quantities of PAF were also synthesized by the murine melanoma (F10-M3 cells). PAF synthesis was rather limited in RSV-transformed Balb/c3T3 (B77-3T3) cells and in one of their high metastatic variants (B77-AA6 cells), although it was more abundant in the latter. We also investigated whether certain cytokines, such as TNFalpha and IFNgamma might induce PAF synthesis in our systems of cell lines which we found to express mRNAs encoding receptors for these cytokines. We observed that PAF synthesis was enhanced in human melanoma and colon carcinoma cell lines and in the murine B77-AA6 cells to levels comparable to those obtained with the Ca2+ ionophore. Synthesis of PAF was not inducible by TNFalpha in murine F10-M3 melanoma cells. IFNgamma also stimulated PAF synthesis in human and murine melanoma lines, and in human LS180 colon carcinoma line, but not in the B77-AA6 cells. PAF synthesis was also inducible by exogenous PAF in the human and murine melanoma lines, and in the human LS180 colon carcinoma line, all of which expressed cell surface PAF receptors. PAF synthesis was not inducible by exogenous PAF in the B77-AA6 cells, which do not express PAF receptors.
Assuntos
Fator de Ativação de Plaquetas/biossíntese , Receptores Acoplados a Proteínas G , Células 3T3 , Ácido Acético/metabolismo , Animais , Linhagem Celular Transformada , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Interferon gama/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Fator de Ativação de Plaquetas/farmacologia , Glicoproteínas da Membrana de Plaquetas/análise , RNA Mensageiro/análise , Receptores de Superfície Celular/análise , Receptores de Interferon/análise , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia , Receptor de Interferon gamaRESUMO
Schöpf-Schulz-Passarge syndrome is a rare ectodermal dysplasia, characterized chiefly by multiple eyelid apocrine hidrocystomas, palmo-plantar keratoderma, hypodontia, hypotrichosis and nail dystrophy. The clinical spectrum and the most likely inheritance pattern(s) have not yet been completely defined. We report here on two, unrelated patients presenting with additional, previously unreported features, including hypoplastic nipples and optic atrophy. Both individuals were born to consanguineous parents, and one also has affected siblings. A literature review identified 23 additional cases. Multiple eyelid apocrine hidrocystomas, described in all of the cases, are the hallmark of this condition, although they usually appear in adulthood. The concomitant presence of eccrine syringofibroadenoma in most patients and of other adnexal skin tumours in 44% of affected subjects indicates that Schöpf-Schulz-Passarge is a genodermatosis with skin appendage neoplasms. However, the risk of skin and visceral malignancies is not increased. Pedigree study demonstrates that 9 of the 13 published familial cases may be explained by an autosomal recessive mutation, while the remaining pedigrees show apparent vertical transmission compatible with genetic heterogeneity. The benign disease course and advanced age at diagnosis could also suggest locus homogeneity for a recessive mutation with instances of pseudodominant inheritance.
Assuntos
Displasia Ectodérmica/genética , Idoso , Anodontia/genética , Consanguinidade , Neoplasias Palpebrais/genética , Feminino , Hidrocistoma/genética , Humanos , Hipotricose/genética , Ceratodermia Palmar e Plantar/genética , Masculino , Unhas Malformadas/genética , Mamilos/anormalidades , Atrofia Óptica/genética , Fenótipo , Neoplasias das Glândulas Sudoríparas/genética , SíndromeRESUMO
Platelet Activating Factor (PAF), an inflammatory bioactive lipid, has been shown to be involved in the regulation of the activity of matrix metalloproteinases (MMPs). In view of the role played by MMPs in tumor cell invasiveness, we investigated whether PAF influences MMP activity in a system of neuroblastoma clones, the AA5 and AE12 cells, isolated from the human LaN1 neuroblastoma cell line. These clones were characterized by an inverse relationship between invasiveness and differentiative capacity and by the expression of specific cell surface PAF receptors. We found that the levels of mRNAs specific for MMP-2 and for MT1-MMP, the MMP-2 activator, were reduced in both clones treated with 300 nM PAF. These changes are consistent with the reduced secretion and activation of MMP-2 found in the neuroblastoma clones exposed to PAF. These effects were accompanied by an inhibition of invasiveness through Matrigel and by a promotion of differentiation, as revealed by an increased percentage of cells with neurites. The finding that both neuroblastoma clones exposed to the metalloproteinase inhibitors, BB3103 and 1,10-phenanthroline, increased their differentiative capacity and reduced their invasiveness through Matrigel, represents a further indication that PAF modulates differentiation and invasiveness by affecting the activity of MMPs.