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Food fortification improves vitamin D intakes but is not yet mandated in many countries. Combining vitamin D with different dietary lipids altered vitamin D absorption in in vitro and postprandial studies. This randomised, placebo-controlled trial examined the effect of the lipid composition of a vitamin D-fortified dairy drink on change in 25-hydroxyvitamin D (25(OH)D) concentrations. Sixty-three healthy adults aged 50+ years were randomised to one of the following for 4 weeks: vitamin D-fortified olive oil dairy drink, vitamin D-fortified coconut oil dairy drink, vitamin D supplement or placebo control dairy drink. All vitamin D groups received 20 µg of vitamin D3 daily. Serum was collected at baseline and post-intervention to measure 25(OH)D concentrations and biomarkers of metabolic health. Repeated-measures general linear model ANCOVA (RM GLM ANCOVA) compared changes over time. There was a significant time × treatment interaction effect on 25(OH)D concentrations for those classified as vitamin D-insufficient (P < 0·001) and -sufficient at baseline (P = 0·004). 25(OH)D concentrations increased significantly for all insufficient participants receiving vitamin D3 in any form. However, for vitamin D-sufficient participants at baseline, 25(OH)D concentrations only increased significantly with the coconut oil dairy drink and supplement. There was no effect of vitamin D on biomarkers of metabolic health. Vitamin D fortification of lipid-containing foods may be used in lieu of supplementation when supplement adherence is low or for individuals with dysphagia. These results are important given the recent recommendation to increase vitamin D intakes to 15-20 µg for older adults in Ireland.
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Deficiencia de Vitamina D , Vitamina D , Persona de Mediana Edad , Humanos , Anciano , Aceite de Coco , Calcifediol , Colecalciferol , Vitaminas , Suplementos Dietéticos , BiomarcadoresRESUMEN
ATF4 is a cellular stress induced bZIP transcription factor that is a hallmark effector of the integrated stress response. The integrated stress response is triggered by phosphorylation of the alpha subunit of the eukaryotic initiation factor 2 complex that can be carried out by the cellular stress responsive kinases; GCN2, PERK, PKR, and HRI. eIF2α phosphorylation downregulates mRNA translation initiation en masse, however ATF4 translation is upregulated. The integrated stress response can output two contradicting outcomes in cells; pro-survival or apoptosis. The mechanism for choice between these outcomes is unknown, however combinations of ATF4 heterodimerisation partners and post-translational modifications have been linked to this regulation. This semi-systematic review article covers ATF4 target genes, heterodimerisation partners and post-translational modifications. Together, this review aims to be a useful resource to elucidate the mechanisms controlling the effects of the integrated stress response. Additional putative roles of the ATF4 protein in cell division and synaptic plasticity are outlined.
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Sleep deficiency is now considered an emerging global epidemic associated with many serious health problems, and a major cause of financial and social burdens. Sleep and mental health are closely connected, further exacerbating the negative impact of sleep deficiency on overall health and well-being. A major drawback of conventional treatments is the wide range of undesirable side-effects typically associated with benzodiazepines and antidepressants, which can be more debilitating than the initial disorder. It is therefore valuable to explore the efficiency of other remedies for complementarity and synergism with existing conventional treatments, leading to possible reduction in undesirable side-effects. This review explores the relevance of microalgae bioactives as a sustainable source of valuable phytochemicals that can contribute positively to mood and sleep disorders. Microalgae species producing these compounds are also catalogued, thus creating a useful reference of the state of the art for further exploration of this proposed approach. While we highlight possibilities awaiting investigation, we also identify the associated issues, including minimum dose for therapeutic effect, bioavailability, possible interactions with conventional treatments and the ability to cross the blood brain barrier. We conclude that physical and biological functionalization of microalgae bioactives can have potential in overcoming some of these challenges.
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Microalgas , Microalgas/química , SueñoRESUMEN
Vitamin-D deficiency is a global issue and a food fortification strategy may reduce deficiency levels. Mixed micelles (MM) are crucial to vitamin-D absorption in vivo and may enhance vitamin-D food fortification. This study compared the ability of MM based delivery systems to oil-in-water emulsions to improve vitamin-D bioaccessibility in vitro. Vitamin-D loaded emulsions were formed with olive or coconut oil alone or with added l-α-phosphatidylcholine, as well as two MM based systems. Particle size throughout digestion, fatty acid release, and vitamin-D bioaccessibility were measured. After digestion, particles in the MM size range (â¼6-10 nm) were observed for emulsions but not for MM based systems. The bioaccessibility of vitamin-D in olive and coconut emulsions was 75% and 78%, respectively, and â¼ 90% with added l-α-phosphatidylcholine. Bioaccessibility for the MM alone was 93% and 90% when mixed with a protein/lactose base. Overall, MM show good potential as a delivery system for vitamin-D in vitro.
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Micelas , Vitamina D , Disponibilidad Biológica , Digestión , Emulsiones , Lecitinas , Tamaño de la Partícula , VitaminasRESUMEN
The transcription factor BACH1 is a potential therapeutic target for a variety of chronic conditions linked to oxidative stress and inflammation, as well as cancer metastasis. However, only a few BACH1 degraders/inhibitors have been described. BACH1 is a transcriptional repressor of heme oxygenase 1 (HMOX1), which is positively regulated by transcription factor NRF2 and is highly inducible by derivatives of the synthetic oleanane triterpenoid 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO). Most of the therapeutic activities of these compounds are due to their anti-inflammatory and antioxidant properties, which are widely attributed to their ability to activate NRF2. However, with such a broad range of action, these compounds have other molecular targets that have not been fully identified and could also be of importance for their therapeutic profile. Herein we identified BACH1 as a target of two CDDO-derivatives (CDDO-Me and CDDO-TFEA), but not of CDDO. While both CDDO and CDDO-derivatives activate NRF2 similarly, only CDDO-Me and CDDO-TFEA inhibit BACH1, which explains the much higher potency of these CDDO-derivatives as HMOX1 inducers compared with unmodified CDDO. Notably, we demonstrate that CDDO-Me and CDDO-TFEA inhibit BACH1 via a novel mechanism that reduces BACH1 nuclear levels while accumulating its cytoplasmic form. In an in vitro model, both CDDO-derivatives impaired lung cancer cell invasion in a BACH1-dependent and NRF2-independent manner, while CDDO was inactive. Altogether, our study identifies CDDO-Me and CDDO-TFEA as dual KEAP1/BACH1 inhibitors, providing a rationale for further therapeutic uses of these drugs.
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Ácido Oleanólico , Triterpenos , Proteína 1 Asociada A ECH Tipo Kelch , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/farmacología , Estrés Oxidativo , Triterpenos/farmacologíaRESUMEN
In-vitro evidence suggests that the lipid component of foods alters vitamin D absorption. This single-blinded, cross-over postprandial study examined the effect of changing the lipid component of a 20 µg vitamin D3 fortified dairy drink on postprandial 25(OH)D concentrations. Participants consumed one dairy drink per visit: a non-lipid, a pre-formed oleic acid micelle, an olive oil and a fish oil dairy drink. There was a significant time*drink*baseline status effect on 25(OH)D concentrations (p = 0.039). There were no time*drink, time or drink effects on 25(OH)D in vitamin D sufficient participants (>50nmol/L). However, there was an effect of time on changes in 25(OH)D concentrations after the olive oil dairy drink (p = 0.034) in vitamin D insufficient participants (<50nmol/L). There were no effects after the other diary drinks. Olive oil may improve vitamin D absorption from fortified foods. Further research is needed to examine the practical implications of changing the lipid component of fortified foods.
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Colecalciferol , Deficiencia de Vitamina D , Calcifediol , Alimentos Fortificados , Humanos , Aceite de Oliva , Vitamina D/análogos & derivados , VitaminasRESUMEN
Deficiency of vitamin-D is prevalent globally and can lead to negative health consequences. The fat-soluble nature of vitamin-D, coupled with its sensitivity to heat, light and oxygen limits its incorporation into foods. Mixed micelles (MM) have potential to enhance bioavailability of vitamin-D. This study explores the stability of MM to food processing regimes and their ability to protect vitamin-D. Subjecting MM to a range of shearing speeds (8,000-20,500 rpm) and to high pressure processing (600 MPa, 120sec) resulted in no change in MM size (4.1-4.5 nm). MM improved the retention of vitamin-D following exposure to UV-C light, near UV/visible light, and heat treatment. MM suspensions protected vitamin-D over a four week storage period at refrigeration or freezer conditions. Overall MM show potential to protect vitamin-D from degradation encountered in food processing and storage and may be beneficial as a mechanism to fortify foods with vitamin-D.
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Colecalciferol/química , Industria de Procesamiento de Alimentos/métodos , Micelas , Colecalciferol/análisis , Almacenamiento de Alimentos , Rayos UltravioletaRESUMEN
Basal cell carcinoma (BCC) is associated with aberrant Hedgehog (HH) signalling through mutational inactivation of PTCH1; however, there is conflicting data regarding MEK/ERK signalling in BCC and the signalling pathway interactions in these carcinomas. To address this, expression of active phospho (p) MEK and ERK was examined in a panel of 15 non-aggressive and 14 aggressive BCCs. Although not uniformly expressed, both phospho-proteins were detected in the nuclei and/or cytoplasm of normal and tumour-associated epidermal cells however, whereas phospho-MEK (pMEK) was present in all non-aggressive BCCs (14/14), phospho-ERK (pERK) was rarely expressed (2/14). In contrast pERK expression was more prevalent in aggressive tumours (11/14). Interestingly, pMEK was only localized to the tumour mass whereas pERK was expressed in tumours and stroma of aggressive BCCs. Similarly, pERK (but not pMEK) was absent in mouse BCC-like tumours derived from X-ray irradiated Ptch1+/- mice with stromal pERK observed in myofibroblasts of the aggressive variant as well as in the tumour mass. RNA sequencing analysis of tumour epithelium and stroma of aggressive and non-aggressive BCC revealed the upregulation of epidermal growth factor receptor- and ERK-related pathways. Angiogenesis and immune response pathways were also upregulated in the stroma compared with the tumour. PTCH1 suppressed NEB1 immortalized keratinocytes (shPTCH1) display upregulated pERK that can be independent of MEK expression. Furthermore, epidermal growth factor pathway inhibitors affect the HH pathway by suppressing GLI1. These studies reveal differential expression of pERK between human BCC subtypes that maybe active by a pathway independent of MEK.
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Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/patología , Carcinoma Basocelular/patología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación Neoplásica de la Expresión Génica , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Receptor Patched-1/fisiología , Animales , Apoptosis , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma Basocelular/genética , Carcinoma Basocelular/metabolismo , Proliferación Celular , Quinasas MAP Reguladas por Señal Extracelular/genética , Femenino , Humanos , Ratones , Ratones Noqueados , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Fosforilación , Pronóstico , RNA-Seq , Células del Estroma , Tasa de Supervivencia , Células Tumorales CultivadasRESUMEN
Casein, ß-lactoglobulin and α-lactalbumin are major milk protein allergens. In the present study, the structural modifications and antigenic response of these bovine milk allergens as induced by non-thermal treatment by atmospheric cold plasma were investigated. Spark discharge (SD) and glow discharge (GD), as previously characterized cold plasma systems, were used for protein treatments. Casein, ß-lactoglobulin and α-lactalbumin were analyzed before and after plasma treatment using SDS-PAGE, FTIR, UPLC-MS/MS and ELISA. SDS-PAGE results revealed a reduction in the casein and α-lactalbumin intensity bands after SD or GD treatments; however, the ß-lactoglobulin intensity band remained unchanged. FTIR studies revealed alterations in protein secondary structure induced by plasma, particularly contents of ß-sheet and ß-turn. The UPLC-MS/MS results showed that the amino acid compositions decreased after plasma treatments. ELISA of casein and α-lactalbumin showed a decrease in antigenicity post plasma treatment, whereas ELISA of ß-lactoglobulin showed an increase in antigenicity. The study indicates that atmospheric cold plasma can be tailored to mitigate the risk of bovine milk allergens in the dairy processing and ingredients sectors.
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Atmósfera/química , Caseínas/química , Caseínas/inmunología , Leche/química , Gases em Plasma/química , Proteína de Suero de Leche/química , Proteína de Suero de Leche/inmunología , Alérgenos/química , Alérgenos/inmunología , Animales , Bovinos , Leche/inmunologíaRESUMEN
Dynamic modifications of chromatin allow rapid access of the gene regulatory machinery to condensed genomic regions facilitating subsequent gene expression. Inflammatory cytokine stimulation of cells can cause rapid gene expression changes through direct signalling pathway-mediated transcription factor activation and regulatory element binding. Here we used the Assay for Transposase Accessible Chromatin with high-throughput sequencing (ATAC-seq) to assess regions of the genome that are differentially accessible following treatment of cells with interleukin-1 (IL-1). We identified 126,483 open chromatin regions, with 241 regions significantly differentially accessible following stimulation, with 64 and 177 more or less accessible, respectively. These differentially accessible regions predominantly correspond to regions of the genome marked as enhancers. Motif searching identified an overrepresentation of a number of transcription factors, most notably RelA, in the regions becoming more accessible, with analysis of ChIP-seq data confirmed RelA binding to these regions. A significant correlation in differential chromatin accessibility and gene expression was also observed. Functionality in regulating gene expression was confirmed using CRISPR/Cas9 genome-editing to delete regions that became more accessible following stimulation in the genes MMP13, IKBKE and C1QTNF1. These same regions were also accessible for activation using a dCas9-transcriptional activator and showed enhancer activity in a cellular model. Together, these data describe and functionally validate a number of dynamically accessible chromatin regions involved in inflammatory signalling.
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Ensamble y Desensamble de Cromatina/efectos de los fármacos , Interleucina-1/farmacología , Línea Celular Tumoral , Secuenciación de Inmunoprecipitación de Cromatina , Elementos de Facilitación Genéticos , Células HEK293 , Humanos , Quinasa I-kappa B/genética , Quinasa I-kappa B/metabolismo , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Unión Proteica , Proteínas/genética , Factor de Transcripción ReIA/metabolismoRESUMEN
Vitamin D (VD) is a fat-soluble vitamin with high deficiency levels evident globally. Bioaccessibility of VD is influenced by formation of mixed micelles (MM) during digestion. This study assessed the impact of fatty acid (FA) type, phospholipid concentration on MM formation and stability of MM to salts. MM formation occurred at NaCl and KCl concentrations ranging from 20 to 100 mM, when octanoic acid (C8) or stearic acid (C18) were used. MM hydrodynamic size increased with increasing l-α-phosphatidylcholine concentration (1.5-7.5 mM) for both C8 and C18, above which concentration MM did not form. FA chain length impacted MM with hydrodynamic size increasing from 3.8 nm for decanoic acid (C10) to 4.4 nm for C18. VD3 incorporation in MM was not influenced by the FA used (C10 or C18). Understanding stability and formation of MM and VD3 loading is an essential first step towards manipulating food structures for improving delivery of VD.
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Colecalciferol/química , Colecalciferol/farmacocinética , Portadores de Fármacos/química , Ácidos Grasos/química , Micelas , Fosfatidilcolinas/química , Cloruro de Sodio/química , Disponibilidad Biológica , DigestiónRESUMEN
The aim of this study was to investigate the adequacy of the reporting of cochlear implant device failures. Data from a parallel study involving over 6300 children [1] was used to calculate the instantaneous failure rate for explantations. We found that this is comparable to what manufacturers term 'Cumulative Failure Percentage' (CFP). This finding raises concerns about the information provided by manufacturers on the reliability of their implants.
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The aim of this study was to determine the magnitude of the risks associated with cochlear implantation. Results from a pool of thirty clinical studies involving cochlear implantation in over 6300 children were obtained from an internet search. The relevant data were transformed to a common time base (patient time) to allow an evaluation of events following implantation. The main outcome measure was cumulative survival probability for all-cause revision surgery. Over 10 years this was estimated to be 0.71. Thus, at 10 years post-implantation close to 30% of children with unilateral implants will have undergone revision surgery. This figure is considerably greater than that commonly reported for overall revision rates and illustrates the importance of interpreting results with respect to the relevant time frame. When non and low-use is incorporated into the analysis the above figure rises to about 37% of children affected. The findings raise concerns about the information provided to both individuals and regulatory bodies regarding the risks associated with cochlear implantation. The consequences for bilateral implantation are apparent. Our recommendations are i) a full disclosure to parents and children of the true magnitude of the risks and ii) for a body with significant expertise in reliability and systems engineering, and no conflicts of interest, to play a major role in the regulatory management of this service.
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The objective of this study was to investigate the effects of nasal valve area, valve stiffness, and turbinate region cross-sectional area on airflow rate, nasal resistance, flow limitation, and inspiratory "hysteresis" by the use of a mathematical model of nasal airflow. The model of O'Neill and Tolley (Clin Otolaryngol Allied Sci 13: 273-277, 1988) describing the effects of valve area and stiffness on the nasal pressure-flow relationship was improved by the incorporation of additional terms involving 1) airflow through the turbinate region, 2) the dependence of the flow coefficients for the valve and turbinate region on the Reynolds number, and 3) effects of unsteady flow. The model was found to provide a good fit for normal values for nasal resistance and for pressure-flow curves reported in the literature for both congested and decongested states. Also, by showing the relative contribution of the nasal valve and turbinate region to nasal resistance, the model sheds light in explaining the generally poor correlation between nasal resistance measurements and the results from acoustic rhinometry. Furthermore, by proposing different flow conditions for the acceleration and deceleration phases of inspiration, the model produces an inspiratory loop (commonly referred to as hysteresis) consistent with those reported in the literature. With simulation of nasal flaring, the magnitude of the loop, the nasal resistance, and flow limitation all show change similar to that observed in the experimental results.NEW & NOTEWORTHY The present model provides considerable insight into some difficult conundrums in both clinical and technical aspects of nasal airflow. Also, the description of nasal airflow mechanics based on the Hagen-Poiseuille equation and Reynolds laminar-turbulent transition in long straight tubes, which has figured prominently in medical textbooks and journal articles for many years, is shown to be seriously in error at a fundamental level.
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Inhalación , Modelos Biológicos , Cornetes Nasales/fisiología , HumanosRESUMEN
Small-molecule inhibitors of the Hedgehog (HH) pathway receptor Smoothened (SMO) have been effective in treating some patients with basal cell carcinoma (BCC), where the HH pathway is often activated, but many patients respond poorly. In this study, we report the results of investigations on PTCH1 signaling in the HH pathway that suggest why most patients with BCC respond poorly to SMO inhibitors. In immortalized human keratinocytes, PTCH1 silencing led to the generation of a compact, holoclone-like morphology with increased expression of SMO and the downstream HH pathway transcription factor GLI1. Notably, although siRNA silencing of SMO in PTCH1-silenced cells was sufficient to suppress GLI1 activity, this effect was not phenocopied by pharmacologic inhibition of SMO, suggesting the presence of a second undefined pathway through which SMO can induce GLI1. Consistent with this possibility, we observed increased nuclear localization of SMO in PTCH1-silenced cells as mediated by a putative SMO nuclear/nucleolar localization signal [N(o)LS]. Mutational inactivation of the N(o)LS ablated this increase and suppressed GLI1 induction. Immunohistologic analysis of human and mouse BCC confirmed evidence of nuclear SMO, although the pattern was heterogeneous between tumors. In PTCH1-silenced cells, >80% of the genes found to be differentially expressed were unaffected by SMO inhibitors, including the putative BCC driver gene CXCL11. Our results demonstrate how PTCH1 loss results in aberrant regulation of SMO-independent mechanisms important for BCC biology and highlights a novel nuclear mechanism of SMO-GLI1 signaling that is unresponsive to SMO inhibitors.Significance: This study describes novel noncanonical Hedgehog signaling, where SMO enters the nucleus to activate GLI1, a mode that is unaffected by SMO inhibitors, thus prompting re-evaluation of current BCC treatment as well as new potential therapies targeting nuclear SMO. Cancer Res; 78(10); 2577-88. ©2018 AACR.
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Carcinoma Basocelular/patología , Receptor Patched-1/metabolismo , Neoplasias Cutáneas/patología , Receptor Smoothened/metabolismo , Proteína con Dedos de Zinc GLI1/metabolismo , Línea Celular Tumoral , Quimiocina CXCL11/genética , Humanos , Queratinocitos/patología , Receptor Patched-1/genética , Interferencia de ARN , ARN Interferente Pequeño/genética , Receptor Smoothened/antagonistas & inhibidores , Receptor Smoothened/genéticaRESUMEN
This study investigated the kinetics of immobilisation and release of riboflavin, amino acids and peptides from whey microbeads. Blank whey microbeads were placed in solutions of the compounds. As the volume of microbeads added to the solution was increased, the uptake of the compounds increased, to a maximum of 95% for the pentapeptide and 56%, 57% and 45% for the dipeptide, riboflavin and tryptophan respectively, however, the rate of uptake remained constant. The rate of uptake increased with increasing molecule hydrophobicity. The opposite was observed in the release studies, the more hydrophobic compounds had lower release rate constants (kr). When whey microbeads are used as sorbents, they show excellent potential to immobilise small hydrophobic molecules and minimise subsequent diffusion, even in high moisture environments.
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Proteínas de la Leche/química , Péptidos/química , Riboflavina/química , Triptófano/química , Concentración de Iones de Hidrógeno , Cinética , Proteína de Suero de LecheRESUMEN
Whey microbeads manufactured using a cold-set gelation process, have been used to encapsulate bioactives. In this study whey microbeads were used to encapsulate riboflavin using 2 methods. Riboflavin was added to the microbead forming solution however diffusional losses of riboflavin occurred during the subsequent bead preparation. To overcome riboflavin loss, a second approach to 'load' whey microbeads by soaking in riboflavin was assessed. Significantly (p⩽0.05) higher concentrations of riboflavin were obtained in 'loaded' microbeads (361 mg/L) compared to riboflavin added to the microbead forming solution (48 mg/L). Riboflavin uptake by the microbeads was shown to be via a partition process. As partitioning is often driven by hydrophobic interactions the uptake of amino acids and peptides of varying hydrophobicities by the microbeads was examined. The % encapsulation increased with increasing molecule hydrophobicity with a maximum of 89% encapsulation. Whey microbeads are well suited to act as sorbents for encapsulation.
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Péptidos/administración & dosificación , Riboflavina/administración & dosificación , Aminoácidos/química , Animales , Cloruro de Calcio/farmacología , Interacciones Hidrofóbicas e Hidrofílicas , Microesferas , Proteínas de la Leche/química , Péptidos/química , Riboflavina/químicaRESUMEN
Aberrant Hedgehog (Hh) signalling has been reported in a number of malignancies, particularly basal cell carcinoma (BCC) of the skin. Clinical trials of Hh inhibitors are underway in many cancers, and these have produced significant clinical benefit in BCC patients, although regrowth of new, or clinically aggressive, variants, as well as development of secondary malignancies, has been reported. αvß6 integrin is expressed in many cancers, where it has been shown to correlate with an aggressive tumour phenotype and poor prognosis. We have previously reported αvß6 up-regulation in aggressive, morphoeic BCC variants, where it modulates the stromal response and induces invasion. To examine a possible link between Hh and αvß6 function, we generated BCC models, overexpressing Gli1 in immortalized keratinocytes (NTert1, HaCaT). Unexpectedly, we found that suppressing Gli1 significantly increased αvß6 expression. This promoted tumour cell motility and also stromal myofibroblast differentiation through integrin-dependent TGF-ß1 activation. Gli1 inhibited αvß6 expression by suppressing TGF-ß1-induced Smad2/3 activation, blocking a positive feedback loop maintaining high αvß6 levels. A similar mechanism was observed in AsPC1 pancreatic cancer cells expressing endogenous Gli1, suggesting a common mechanism across tumour types. In vitro findings were supported using human clinical samples, where we showed an inverse correlation between αvß6 and Gli1 expression in different BCC subtypes and pancreatic cancers. In summary, we show that expression of Gli1 and αvß6 inversely correlates in tumours in vivo, and Hh targeting up-regulates TGF-ß1/Smad2/3-dependent αvß6 expression, promoting pro-tumourigenic cell functions in vitro. These results have potential clinical significance, given the reported recurrence of BCC variants and secondary malignancies in patients treated by Hh targeting.
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Antígenos de Neoplasias/metabolismo , Carcinoma Basocelular/metabolismo , Transformación Celular Neoplásica/metabolismo , Proteínas Hedgehog/metabolismo , Integrinas/metabolismo , Neoplasias Pancreáticas/metabolismo , Transducción de Señal , Neoplasias Cutáneas/metabolismo , Factores de Transcripción/metabolismo , Antígenos de Neoplasias/genética , Carcinoma Basocelular/genética , Carcinoma Basocelular/patología , Línea Celular , Movimiento Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Técnicas de Cocultivo , Regulación hacia Abajo , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Integrinas/genética , Queratinocitos/metabolismo , Queratinocitos/patología , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Interferencia de ARN , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Factores de Transcripción/genética , Transfección , Factor de Crecimiento Transformador beta1/metabolismo , Proteína con Dedos de Zinc GLI1RESUMEN
The GLI (GLI1/GLI2) transcription factors have been implicated in the development and progression of prostate cancer although our understanding of how they actually contribute to the biology of these common tumours is limited. We observed that GLI reporter activity was higher in normal (PNT-2) and tumourigenic (DU145 and PC-3) androgen-independent cells compared to androgen-dependent LNCaP prostate cancer cells and, accordingly, GLI mRNA levels were also elevated. Ectopic expression of GLI1 or the constitutively active ΔNGLI2 mutant induced a distinct cobblestone-like morphology in LNCaP cells that, regarding the former, correlated with increased GLI2 as well as expression of the basal/stem-like markers CD44, ß1-integrin, ΔNp63 and BMI1, and decreased expression of the luminal marker AR (androgen receptor). LNCaP-GLI1 cells were viable in the presence of the AR inhibitor bicalutamide and gene expression profiling revealed that the transcriptome of LNCaP-GLI1 cells was significantly closer to DU145 and PC-3 cells than to control LNCaP-pBP (empty vector) cells, as well as identifying LCN2/NGAL as a highly induced transcript which is associated with hormone independence in breast and prostate cancer. Functionally, LNCaP-GLI1 cells displayed greater clonal growth and were more invasive than control cells but they did not form colonies in soft agar or prostaspheres in suspension suggesting that they do not possess inherent stem cell properties. Moreover, targeted suppression of GLI1 or GLI2 with siRNA did not reverse the transformed phenotype of LNCaP-GLI1 cells nor did double GLI1/GLI2 knockdowns activate AR expression in DU145 or PC-3 cells. As such, early targeting of the GLI oncoproteins may hinder progression to a hormone independent state but a more detailed understanding of the mechanisms that maintain this phenotype is required to determine if their inhibition will enhance the efficacy of anti-hormonal therapy through the induction of a luminal phenotype and increased dependency upon AR function.
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Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Receptores Androgénicos/genética , Factores de Transcripción/genética , Andrógenos/metabolismo , Western Blotting , Adhesión Celular , Línea Celular , Línea Celular Tumoral , Proliferación Celular , Forma de la Célula , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Interferencia de ARN , Receptores Androgénicos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/metabolismo , Proteína con Dedos de Zinc GLI1RESUMEN
Although deregulated Hedgehog signalling and elevated Gli transcription factor expression are known to promote the development of basal cell carcinoma (BCC), little is known about molecular mechanisms driving the development of specific growth pattern subtypes. Using gene array analysis, we have previously observed that over-expression of GLI1 in human keratinocytes promotes increased expression of the neuronal differentiation markers ARC and ULK1. We asked whether neuronal differentiation is a characteristic of BCC and whether there is any correlation with BCC subtype. Using RT-PCR and immunohistochemistry, we confirmed that the neuronal markers ARC, beta-tubulin III, GAP-43 and Neurofilament are expressed in human BCC but not in normal epidermis. Moreover, we found that expression of these neuronal differentiation markers showed strong correlation to BCC subtype, with more aggressive infiltrative and morphoeic BCC showing low levels or lack of expression compared to nodular, superficial and micronodular subtypes. Primary human keratinocytes retrovirally expressing GLI1(-) and GLI2(-) showed elevated levels of beta-tubulin III and ARC but not Neurofilament or GAP-43, suggesting that beta-tubulin III and Arc may be early targets of aberrant Gli expression in BCC, whereas expression of Neurofilament and GAP-43 are either later, downstream targets or under control of alternative pathways. We propose that neuronal differentiation is a feature of BCC and that expression of these markers is in part due to aberrant Hedgehog signalling. Moreover, we suggest that correlation between loss of expression of neuronal markers in infiltrative and morphoeic BCC subtypes reflects dedifferentiation of more aggressive BCC subtypes.