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1.
Cell ; 186(9): 1824-1845, 2023 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-37116469

RESUMEN

Cachexia, a systemic wasting condition, is considered a late consequence of diseases, including cancer, organ failure, or infections, and contributes to significant morbidity and mortality. The induction process and mechanistic progression of cachexia are incompletely understood. Refocusing academic efforts away from advanced cachexia to the etiology of cachexia may enable discoveries of new therapeutic approaches. Here, we review drivers, mechanisms, organismal predispositions, evidence for multi-organ interaction, model systems, clinical research, trials, and care provision from early onset to late cachexia. Evidence is emerging that distinct inflammatory, metabolic, and neuro-modulatory drivers can initiate processes that ultimately converge on advanced cachexia.


Asunto(s)
Caquexia , Humanos , Caquexia/tratamiento farmacológico , Caquexia/etiología , Caquexia/metabolismo , Caquexia/patología , Músculo Esquelético/metabolismo , Neoplasias/complicaciones , Neoplasias/metabolismo , Neoplasias/patología , Infecciones/complicaciones , Infecciones/patología , Insuficiencia Multiorgánica/complicaciones , Insuficiencia Multiorgánica/patología
2.
Ann Bot ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38716780

RESUMEN

BACKGROUND AND AIMS: There is ample theoretical and experimental evidence that angiosperms harbouring self-incompatibility (SI) systems are likely to respond to global changes in unique ways relative to taxa with other mating systems. In this paper, we present an updated database on the prevalence of SI systems across angiosperms and examine the relationship between the presence of SI and latitude, biomes, life-history traits and management conditions to evaluate the potential vulnerability of SI taxa to climate change and habitat disturbance. METHODS: We performed literature searches to identify studies that employed controlled crosses, microscopic analyses and/or genetic data to classify taxa as having SI, self-compatibility (SC), partial self-compatibility (PSC) or self-sterility (SS). Where described, the site of the SI reaction and the presence of dimorphic versus monomorphic flowers were also recorded. We then combined this database on the distribution of mating systems with information about the life span, growth habit, management conditions and geographic distribution of taxa. Information about the geographic distribution of taxa was obtained from a manually curated version of the Global Biodiversity Information Facility database, and from vegetation surveys encompassing 9 biomes. We employed multinomial logit regression to assess the relationship between mating system and life-history traits, management condition, latitude and latitude-squared using self-compatible taxa as the baseline. Additionally, we employed LOESS regression to examine the relationship between the probability of SI and latitude. Finally, by summarizing information at the family level, we plotted the distribution of SI systems across angiosperms including information about the presence of SI or dioecy, the inferred reaction site of the SI system when known, as well as the proportion of taxa in a family for which information is available. KEY RESULTS: We obtained information about the SI status of 5686 hermaphroditic taxa, of which 55% exhibited SC, and the remaining 45% harbour SI, self-sterility (SS), or PSC. Highlights of the multinomial logit regression include that taxa with PSC have a greater odds of being short- (OR=1.3) or long- (OR=1.57) lived perennials relative to SC ones, and that SS/SI taxa (pooled) are less likely to be annuals (OR=0.64) and more likely to be long-lived perennials (OR=1.32). SS/SI taxa had a greater odds of being succulent (OR=2.4) or a tree (OR=2.05), and were less likely to be weeds (OR=0.34). Further, we find a quadratic relationship between the probability of being SI with latitude: SI taxa were more common in the tropics, a finding that was further supported by the vegetation surveys which showed fewer species with SS/SI in temperate and northern latitudes compared to mediterranean and tropical biomes. CONCLUSIONS: We conclude that in the short-term habitat fragmentation, pollinator loss and temperature increases may negatively impact plants with SI systems, particularly long-lived perennial and woody species dominant in tropical forests. In the longer term, these and other global changes are likely to select for self-compatible or partially self-compatible taxa which, due to the apparent importance of SI as a driver of plant diversification across the angiosperm tree of life, may globally influence plant species richness.

3.
Gut ; 71(5): 879-888, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35144974

RESUMEN

OBJECTIVE: We assessed whether famotidine improved inflammation and symptomatic recovery in outpatients with mild to moderate COVID-19. DESIGN: Randomised, double-blind, placebo-controlled, fully remote, phase 2 clinical trial (NCT04724720) enrolling symptomatic unvaccinated adult outpatients with confirmed COVID-19 between January 2021 and April 2021 from two US centres. Patients self-administered 80 mg famotidine (n=28) or placebo (n=27) orally three times a day for 14 consecutive days. Endpoints were time to (primary) or rate of (secondary) symptom resolution, and resolution of inflammation (exploratory). RESULTS: Of 55 patients in the intention-to-treat group (median age 35 years (IQR: 20); 35 women (64%); 18 African American (33%); 14 Hispanic (26%)), 52 (95%) completed the trial, submitting 1358 electronic symptom surveys. Time to symptom resolution was not statistically improved (p=0.4). Rate of symptom resolution was improved for patients taking famotidine (p<0.0001). Estimated 50% reduction of overall baseline symptom scores were achieved at 8.2 days (95% CI: 7 to 9.8 days) for famotidine and 11.4 days (95% CI: 10.3 to 12.6 days) for placebo treated patients. Differences were independent of patient sex, race or ethnicity. Five self-limiting adverse events occurred (famotidine, n=2 (40%); placebo, n=3 (60%)). On day 7, fewer patients on famotidine had detectable interferon alpha plasma levels (p=0.04). Plasma immunoglobulin type G levels to SARS-CoV-2 nucleocapsid core protein were similar between both arms. CONCLUSIONS: Famotidine was safe and well tolerated in outpatients with mild to moderate COVID-19. Famotidine led to earlier resolution of symptoms and inflammation without reducing anti-SARS-CoV-2 immunity. Additional randomised trials are required.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , Famotidina , Adulto , Método Doble Ciego , Famotidina/uso terapéutico , Femenino , Humanos , Inflamación , SARS-CoV-2 , Resultado del Tratamiento
5.
Nat Commun ; 15(1): 4682, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824130

RESUMEN

Interleukin-6 (IL-6) has been long considered a key player in cancer cachexia. It is believed that sustained elevation of IL-6 production during cancer progression causes brain dysfunctions, which ultimately result in cachexia. However, how peripheral IL-6 influences the brain remains poorly understood. Here we show that neurons in the area postrema (AP), a circumventricular structure in the hindbrain, is a critical mediator of IL-6 function in cancer cachexia in male mice. We find that circulating IL-6 can rapidly enter the AP and activate neurons in the AP and its associated network. Peripheral tumor, known to increase circulating IL-6, leads to elevated IL-6 in the AP, and causes potentiated excitatory synaptic transmission onto AP neurons and AP network hyperactivity. Remarkably, neutralization of IL-6 in the brain of tumor-bearing mice with an anti-IL-6 antibody attenuates cachexia and the hyperactivity in the AP network, and markedly prolongs lifespan. Furthermore, suppression of Il6ra, the gene encoding IL-6 receptor, specifically in AP neurons with CRISPR/dCas9 interference achieves similar effects. Silencing Gfral-expressing AP neurons also attenuates cancer cachectic phenotypes and AP network hyperactivity. Our study identifies a central mechanism underlying the function of peripheral IL-6, which may serve as a target for treating cancer cachexia.


Asunto(s)
Caquexia , Interleucina-6 , Neuronas , Receptores de Interleucina-6 , Animales , Caquexia/metabolismo , Caquexia/etiología , Interleucina-6/metabolismo , Masculino , Neuronas/metabolismo , Ratones , Receptores de Interleucina-6/metabolismo , Ratones Endogámicos C57BL , Neoplasias/metabolismo , Neoplasias/complicaciones , Línea Celular Tumoral , Humanos
6.
Front Plant Sci ; 14: 1276727, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38107007

RESUMEN

Introduction: The phenomenal expansion of angiosperms has prompted many investigations into the factors driving their diversification, but there remain significant gaps in our understanding of flowering plant species diversity. Methods: Using the crown age of families from five studies, we used a maximum likelihood approach to classify families as having poor, predicted or high species richness (SR) using strict consensus criteria. Using these categories, we looked for associations between family SR and i) the presence of an inferred familial ancestral polyploidization event, ii) 23 life history and floral traits compiled from previously published datasets and papers, and iii) sexual system (dioecy) or genetically determined self-incompatibility (SI) mating system using an updated version of our own database and iv) geographic distribution using a new database describing the global distribution of plant species/families across realms and biomes and inferred range. Results: We find that more than a third of angiosperm families (65%) had predicted SR, a large proportion (30.2%) were species poor, while few (4.8%) had high SR. Families with poor SR were less likely to have undergone an ancestral polyploidization event, exhibited deficits in diverse traits, and were more likely to have unknown breeding systems and to be found in only one or few biomes and realms, especially the Afrotropics or Australasia. On the other hand, families with high SR were more likely to have animal mediated pollination or dispersal, are enriched for epiphytes and taxa with an annual life history, and were more likely to harbour sporophytic SI systems. Mapping the global distribution of georeferenced taxa by their family DR, we find evidence of regions dominated by taxa from lineages with high vs low SR. Discussion: These results are discussed within the context of the literature describing "depauperons" and the factors contributing to low and high biodiversity in angiosperm clades.

7.
bioRxiv ; 2023 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-36711916

RESUMEN

Interleukin-6 (IL-6) has been long considered a key player in cancer-associated cachexia 1-15 . It is believed that sustained elevation of IL-6 production during cancer progression causes brain dysfunctions, which ultimately result in cachexia 16-20 . However, how peripheral IL-6 influences the brain remains poorly understood. Here we show that neurons in the area postrema (AP), a circumventricular structure in the hindbrain, mediate the function of IL-6 in cancer-associated cachexia in mice. We found that circulating IL-6 can rapidly enter the AP and activate AP neurons. Peripheral tumor, known to increase circulating IL-6 1-5,15,18,21-23 , leads to elevated IL-6 and neuronal hyperactivity in the AP, and causes potentiated excitatory synaptic transmission onto AP neurons. Remarkably, neutralization of IL-6 in the brain of tumor-bearing mice with an IL-6 antibody prevents cachexia, reduces the hyperactivity in an AP network, and markedly prolongs lifespan. Furthermore, suppression of Il6ra , the gene encoding IL-6 receptor, specifically in AP neurons with CRISPR/dCas9 interference achieves similar effects. Silencing of Gfral-expressing AP neurons also ameliorates the cancer-associated cachectic phenotypes and AP network hyperactivity. Our study identifies a central mechanism underlying the function of peripheral IL-6, which may serve as a target for treating cancer-associated cachexia.

8.
bioRxiv ; 2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37292804

RESUMEN

A primary cause of death in cancer patients is cachexia, a wasting syndrome attributed to tumor-induced metabolic dysregulation. Despite the major impact of cachexia on the treatment, quality of life, and survival of cancer patients, relatively little is known about the underlying pathogenic mechanisms. Hyperglycemia detected in glucose tolerance test is one of the earliest metabolic abnormalities observed in cancer patients; however, the pathogenesis by which tumors influence blood sugar levels remains poorly understood. Here, utilizing a Drosophila model, we demonstrate that the tumor secreted interleukin-like cytokine Upd3 induces fat body expression of Pepck1 and Pdk, two key regulatory enzymes of gluconeogenesis, contributing to hyperglycemia. Our data further indicate a conserved regulation of these genes by IL-6/JAK-STAT signaling in mouse models. Importantly, in both fly and mouse cancer cachexia models, elevated gluconeogenesis gene levels are associated with poor prognosis. Altogether, our study uncovers a conserved role of Upd3/IL-6/JAK-STAT signaling in inducing tumor-associated hyperglycemia, which provides insights into the pathogenesis of IL-6 signaling in cancer cachexia.

9.
bioRxiv ; 2023 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-36824830

RESUMEN

The dependency of cancer cells on glucose can be targeted with high-fat low-carbohydrate ketogenic diet (KD). However, hepatic ketogenesis is suppressed in IL-6 producing cancers, which prevents the utilization of this nutrient source as energy for the organism. In two IL-6 associated murine models of cancer cachexia we describe delayed tumor growth but accelerated onset of cancer cachexia and shortened survival when mice are fed KD. Mechanistically, we find this uncoupling is a consequence of the biochemical interaction of two simultaneously occurring NADPH-dependent pathways. Within the tumor, increased production of lipid peroxidation products (LPPs) and, consequently, saturation of the glutathione (GSH) system leads to ferroptotic death of cancer cells. Systemically, redox imbalance and NADPH depletion impairs the biosynthesis of corticosterone, the main regulator of metabolic stress, in the adrenal glands. Administration of dexamethasone, a potent glucocorticoid, improves food intake, normalizes glucose homeostasis and utilization of nutritional substrates, delays onset of cancer cachexia and extends survival of tumor-bearing mice fed KD, while preserving reduced tumor growth. Our study highlights that the outcome of systemic interventions cannot necessarily be extrapolated from the effect on the tumor alone, but that they have to be investigated for anti-cancer and host effects. These findings may be relevant to clinical research efforts that investigate nutritional interventions such as KD in patients with cancer.

10.
Cell Metab ; 35(7): 1147-1162.e7, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37311455

RESUMEN

Glucose dependency of cancer cells can be targeted with a high-fat, low-carbohydrate ketogenic diet (KD). However, in IL-6-producing cancers, suppression of the hepatic ketogenic potential hinders the utilization of KD as energy for the organism. In IL-6-associated murine models of cancer cachexia, we describe delayed tumor growth but accelerated cachexia onset and shortened survival in mice fed KD. Mechanistically, this uncoupling is a consequence of the biochemical interaction of two NADPH-dependent pathways. Within the tumor, increased lipid peroxidation and, consequently, saturation of the glutathione (GSH) system lead to the ferroptotic death of cancer cells. Systemically, redox imbalance and NADPH depletion impair corticosterone biosynthesis. Administration of dexamethasone, a potent glucocorticoid, increases food intake, normalizes glucose levels and utilization of nutritional substrates, delays cachexia onset, and extends the survival of tumor-bearing mice fed KD while preserving reduced tumor growth. Our study emphasizes the need to investigate the effects of systemic interventions on both the tumor and the host to accurately assess therapeutic potential. These findings may be relevant to clinical research efforts that investigate nutritional interventions such as KD in patients with cancer.


Asunto(s)
Dieta Cetogénica , Ferroptosis , Neoplasias , Ratones , Animales , Caquexia , Corticosterona , Interleucina-6 , NADP , Cuerpos Cetónicos , Glucosa , Neoplasias/complicaciones
11.
Cell Genom ; 3(8): 100347, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37601967

RESUMEN

Cystatin C (CyC), a secreted cysteine protease inhibitor, has unclear biological functions. Many patients exhibit elevated plasma CyC levels, particularly during glucocorticoid (GC) treatment. This study links GCs with CyC's systemic regulation by utilizing genome-wide association and structural equation modeling to determine CyC production genetics in the UK Biobank. Both CyC production and a polygenic score (PGS) capturing predisposition to CyC production were associated with increased all-cause and cancer-specific mortality. We found that the GC receptor directly targets CyC, leading to GC-responsive CyC secretion in macrophages and cancer cells. CyC-knockout tumors displayed significantly reduced growth and diminished recruitment of TREM2+ macrophages, which have been connected to cancer immunotherapy failure. Furthermore, the CyC-production PGS predicted checkpoint immunotherapy failure in 685 patients with metastatic cancer from combined clinical trial cohorts. In conclusion, CyC may act as a GC effector pathway via TREM2+ macrophage recruitment and may be a potential target for combination cancer immunotherapy.

12.
Ann Bot ; 110(3): 535-53, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22684683

RESUMEN

BACKGROUND AND SCOPE: New data are presented on the distribution and frequency of self-sterility (SS) - predominantly pre-zygotic self-incompatibility (SI) systems - in flowering plants and the hypothesis is tested that families with self-sterile taxa have higher net diversification rates (DRs) than those with exclusively self-compatible taxa using both absolute and relative rate tests. KEY RESULTS: Three major forms of SI systems (where pollen is rejected at the stigmatic, stylar or ovarian interface) are found to occur in the oldest families of flowering plants, with times of divergence >100 million years before the present (mybp), while post-fertilization SS and heterostyly appear in families with crown ages of 81 and 87 mybp, respectively. It is also founnd that many (22) angiosperm families exhibit >1 SI phenotype and that the distribution of different types of SS does not show strong phylogenetic clustering, collectively suggesting that SS and SI systems have evolved repeatedly de novo in angiosperm history. Families bearing self-sterile taxa have higher absolute DRs using all available calibrations of the angiosperm tree, and this affect is caused mostly by the high DR of families with homomorphic SI systems (in particular stigmatic SI) or those in which multiple SS/SI phenotypes have been observed (polymorphic). Lastly, using sister comparisons, it is further demonstrated that in 29 of 38 sister pairs (including 95 families), the self-sterile sister group had higher species richness and DR than its self-compatible sister based on either the total number of taxa in the clade with SS or only the estimated fraction to harbour SS based on literature surveys. CONCLUSIONS: Collectively, these analyses point to the importance of SS, particularly pre-zygotic SI in the evolution of flowering plants.


Asunto(s)
Flores/fisiología , Magnoliopsida/genética , Infertilidad Vegetal/genética , Polen/fisiología , Autofecundación/genética , Evolución Biológica , Variación Genética , Fenotipo , Filogenia
13.
Cancer Cell ; 40(7): 703-705, 2022 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-35750051

RESUMEN

In this issue of Cancer Cell, Kurz et al. demonstrate in an orthotopic pancreatic cancer model that low-intensity exercise improves tumor control and response to immunotherapy in an IL-15-dependent manner. Combination therapy, IL-15 super-agonist, anti-PD-1 antibody and chemotherapy, strongly reduces tumor growth. Therefore, the study opens rich translational avenues.


Asunto(s)
Interleucina-15 , Neoplasias Pancreáticas , Línea Celular Tumoral , Terapia Combinada , Humanos , Inmunoterapia , Interleucina-15/uso terapéutico , Neoplasias Pancreáticas/tratamiento farmacológico , Microambiente Tumoral
14.
Plants (Basel) ; 11(22)2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36432829

RESUMEN

During domestication, the selection of cultivated plants often reduces microbiota diversity compared with their wild ancestors. Microbiota in compartments such as the phyllosphere or rhizosphere can promote fruit tree health, growth, and development. Cordia dodecandra is a deciduous tree used by Maya people for its fruit and wood, growing, to date, in remnant forest fragments and homegardens (traditional agroforestry systems) in Yucatán. In this work, we evaluated the microbiota's alpha and beta diversity per compartment (phyllosphere and rhizosphere) and per population (forest and homegarden) in the Northeast and Southwest Yucatán regions. Eight composite DNA samples (per compartment/population/region combination) were amplified for 16S-RNA (bacteria) and ITS1-2 (fungi) and sequenced by Illumina MiSeq. Bioinformatic analyses were performed with QIIME and phyloseq. For bacteria and fungi, from 107,947 and 128,786 assembled sequences, 618 and 1092 operating taxonomic units (OTUs) were assigned, respectively. The alpha diversity of bacteria and fungi was highly variable among samples and was similar among compartments and populations. A significant species turnover among populations and regions was observed in the rhizosphere. The core microbiota from the phyllosphere was similar among populations and regions. Forests and homegarden populations are reservoirs of the C. dodecandra phyllosphere core microbiome and significant rhizosphere biodiversity.

15.
Cancers (Basel) ; 14(4)2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-35205709

RESUMEN

An elevated neutrophil-lymphocyte ratio negatively predicts the outcome of patients with cancer and is associated with cachexia, the terminal wasting syndrome. Here, using murine model systems of colorectal and pancreatic cancer we show that neutrophilia in the circulation and multiple organs, accompanied by extramedullary hematopoiesis, is an early event during cancer progression. Transcriptomic and metabolic assessment reveals that neutrophils in tumor-bearing animals utilize aerobic glycolysis, similar to cancer cells. Although pharmacological inhibition of aerobic glycolysis slows down tumor growth in C26 tumor-bearing mice, it precipitates cachexia, thereby shortening the overall survival. This negative effect may be explained by our observation that acute depletion of neutrophils in pre-cachectic mice impairs systemic glucose homeostasis secondary to altered hepatic lipid processing. Thus, changes in neutrophil number, distribution, and metabolism play an adaptive role in host metabolic homeostasis during cancer progression. Our findings provide insight into early events during cancer progression to cachexia, with implications for therapy.

16.
Ann Bot ; 103(7): 1077-89, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19218580

RESUMEN

BACKGROUND AND AIMS: Selection may favour a partial or complete loss of self-incompatibility (SI) if it increases the reproductive output of individuals in the presence of low mate availability. The reproductive output of individuals varying in their strength of SI may also be affected by population density via its affect on the spatial structuring and number of S-alleles in populations. Modifiers increasing levels of self-compatibility can be selected when self-compatible individuals receive reproductive compensation by, for example, increasing seed set and/or when they become associated with high fitness genotypes. METHODS: The effect of variation in the strength of SI and scrub density (low versus high) on seed set, seed germination and inbreeding depression in seed germination (delta(germ)) was investigated in the partially self-incompatible species Flourensia cernua by analysing data from self-, cross- and open-pollinated florets. KEY RESULTS: Examination of 100 plants in both high and low scrub densities revealed that 51% of plants were strongly self-incompatible and 49 % varied from being self-incompatible to self-compatible. Seed set after hand cross-pollination was higher than after open-pollination for self-incompatible, partially self-incompatible and self-compatible plants but was uniformly low for strongly self-incompatible plants. Strongly self-incompatible and self-incompatible plants exhibited lower seed set, seed germination and multiplicative female fitness (floral display x seed set x seed germination) in open-pollinated florets compared with partially self-incompatible and self-compatible plants. Scrub density also had an effect on seed set and inbreeding depression: in low-density scrubs seed set was higher after open-pollination and delta(germ) was lower. CONCLUSIONS: These data suggest that (a) plants suffered outcross pollen limitation, (b) female fitness in partially self-incompatible and self-compatible plants is enhanced by increased mate-compatibility and (c) plants in low-density scrubs received higher quality pollen via open-pollination than plants in high-density scrubs.


Asunto(s)
Asteraceae/fisiología , Polinización/fisiología , Semillas/fisiología , Asteraceae/crecimiento & desarrollo , Germinación/fisiología , Semillas/crecimiento & desarrollo
17.
Semin Oncol ; 45(3): 170-175, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-30262396

RESUMEN

Despite their abilities to elicit immune responses, both syngeneic tumors and the half-mismatched placenta grow in the host, unlike a tissue allograft that is aggressively rejected. This is because of local and systemic factors that contribute to the immunologic privilege of tumors and the placenta. Checkpoint blockade immunotherapies subvert this privilege, with spectacularly beneficial outcomes in subsets of patients with certain types of cancer. A challenge for the community of scientists and clinicians is to replicate these successes in pregnant patients with cancer, without harm to the placenta. Here we compare and contrast the immunology of cancers and the placenta, and suggest that immunotherapy for pregnant patients with cancer may be a reasonable option, but that this should be explored systematically.


Asunto(s)
Privilegio Inmunológico/inmunología , Inmunoterapia/métodos , Neoplasias/terapia , Placenta/inmunología , Complicaciones Neoplásicas del Embarazo/terapia , Femenino , Antígenos HLA/inmunología , Humanos , Neoplasias/inmunología , Neoplasias/metabolismo , Placenta/metabolismo , Embarazo , Complicaciones Neoplásicas del Embarazo/inmunología , Complicaciones Neoplásicas del Embarazo/metabolismo , Linfocitos T/inmunología
18.
DNA Repair (Amst) ; 5(5): 556-65, 2006 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-16513431

RESUMEN

The Fanconi anemia (FA) protein FANCE is an essential component of the nuclear FA core complex, which is required for monoubiquitination of the downstream target FANCD2, an important step in the FA pathway of DNA cross-link repair. FANCE is predominantly localized in the nucleus and acts as a molecular bridge between the FA core complex and FANCD2, through direct binding of both FANCC and FANCD2. At present, it is poorly understood how the nuclear accumulation of FANCE is regulated and therefore we investigated the nuclear localization of this FA protein. We found that FANCE has a strong tendency to localize in the nucleus, since the addition of a nuclear export signal does not interfere with the nuclear localization of FANCE. We also demonstrate that the nuclear accumulation of FANCE does not rely solely on its nuclear localization signal motifs, but also on FANCC. The other FA proteins are not involved in the nuclear accumulation of FANCE, indicating a tight relationship between FANCC and FANCE, as suggested from their direct interaction. Finally, we show that the region of FANCE interacting with FANCC appears to be different from the region involved in binding FANCD2. This strengthens the idea that FANCE recruits FANCD2 to the core complex, without interfering with the binding of FANCC.


Asunto(s)
Proteína del Grupo de Complementación C de la Anemia de Fanconi/metabolismo , Proteína del Grupo de Complementación E de la Anemia de Fanconi/metabolismo , Transporte Activo de Núcleo Celular , Secuencia de Aminoácidos , Sitios de Unión , Línea Celular , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Proteína del Grupo de Complementación C de la Anemia de Fanconi/química , Proteína del Grupo de Complementación C de la Anemia de Fanconi/genética , Proteína del Grupo de Complementación E de la Anemia de Fanconi/química , Proteína del Grupo de Complementación E de la Anemia de Fanconi/genética , Células HeLa , Humanos , Mutagénesis Sitio-Dirigida , Señales de Exportación Nuclear/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfección , Técnicas del Sistema de Dos Híbridos
19.
Clin Lung Cancer ; 6(4): 250-4, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15694018

RESUMEN

Fanconi's anemia (FA) is a genetically heterogeneous disease characterized by cancer susceptibility and hypersensitivity to cross-linking agents such as cisplatin. Recently, inactivation of the FA pathway has been proposed to contribute to genomic instability and an increased sensitivity to cisplatin-based therapy in a subset of ovarian tumors. Platinum-based chemotherapy constitutes standard systemic therapy for advanced non-small-cell lung cancer (NSCLC), but resistance to platinum chemotherapy is common. In this study, we evaluated the status of the FA pathway in tumor samples derived from patients with NSCLC in relation to their response to platinum-based chemotherapy. For this purpose, we assessed the expression of FANCD2 protein (a marker for FA pathway functioning) by immunohistochemistry in tumor specimens from 47 patients treated with platinum-based chemotherapy. FANCD2 expression could be detected in 32% of the cases (15 of 47). Expression of FANCD2 was not correlated with any patient or tumor characteristics, and FANCD2 expression was not a predictor of response to chemotherapy or patient survival. In conclusion, the activation status of the FA pathway had no value in predicting sensitivity to platinum-based chemotherapy in patients with advanced NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Proteínas Nucleares/metabolismo , Adulto , Anciano , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/patología , Cisplatino/uso terapéutico , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad
20.
Cancer Gene Ther ; 11(8): 539-46, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15192709

RESUMEN

Fanconi anemia (FA) is a rare genetic disorder characterized by bone-marrow failure and cellular hypersensitivity to crosslinking agents, including cisplatin. Here, we studied the use of the FA pathway as a possible target for cancer gene therapy with the aim to sensitize tumor cells for cisplatin by interfering with the FA pathway. As proof-of-principle, FA and non-FA lymphoblast-derived tumors were grown subcutaneously in scid mice and treated with two different concentrations of cisplatin. As predicted, the antitumor response was considerably improved in FA tumors. An adenoviral vector encoding a dominant-negative form of FANCA, FANCA600DN, was generated that interfered with endogenous FANCA-FANCG interaction resulting in the disruption of the FA pathway as illustrated by disturbed FANCD2 monoubiquitination. A panel of cell lines, including non-small-cell lung cancer cells, could be sensitized approximately two- to three-fold for cisplatin after Ad.CMV.FANCA600DN infection that may increase upon enhanced infection efficiency. In conclusion, targeting the FA pathway may provide a novel strategy for the sensitization of solid tumors for cisplatin and, in addition, provides a tool for examining the role of the FA pathway in determining chemoresistance in different tumor types.


Asunto(s)
Adenoviridae/genética , Antineoplásicos/uso terapéutico , Cisplatino/uso terapéutico , Proteínas de Unión al ADN/genética , Terapia Genética/métodos , Neoplasias/terapia , Animales , Extractos Celulares/inmunología , Línea Celular Tumoral , Proteínas de Unión al ADN/análisis , Proteínas de Unión al ADN/metabolismo , Resistencia a Antineoplásicos/genética , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Proteína del Grupo de Complementación A de la Anemia de Fanconi , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi , Proteína del Grupo de Complementación G de la Anemia de Fanconi , Expresión Génica , Vectores Genéticos/genética , Humanos , Inmunoprecipitación , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Proteínas Nucleares/análisis , Proteínas Nucleares/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
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