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1.
Cancers (Basel) ; 15(10)2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37345033

RESUMEN

BACKGROUND: Unprecedented advantages in cancer treatment with immune checkpoint inhibitors (ICIs) remain limited to only a subset of patients. Systemic analyses of the regulatory 3D genome architecture linked to individual epigenetic and immunogenetic controls associated with tumour immune evasion mechanisms and immune checkpoint pathways reveal a highly prevalent molecular profile predictive of response to PD-1/PD-L1 ICIs. A clinical blood test based on a set of eight (8) 3D genomic biomarkers has been developed and validated on the basis of an observational trial to predict response to ICI therapy. METHODS: The predictive eight biomarker set is derived from prospective observational clinical trials, representing 280 treatments with Pembrolizumab, Atezolizumab, Durvalumab, Nivolumab, and Avelumab in a broad range of indications: melanoma, lung, hepatocellular, renal, breast, bladder, colon, head and neck, bone, brain, lymphoma, prostate, vulvar, and cervical cancers. RESULTS: The 3D genomic eight biomarker panel for response to immune checkpoint therapy achieved a high accuracy of 85%, sensitivity of 93%, and specificity of 82%. CONCLUSIONS: This study demonstrates that a 3D genomic approach can be used to develop a predictive clinical assay for response to PD-1/PD-L1 checkpoint inhibition in cancer patients.

2.
Cancers (Basel) ; 15(3)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36765779

RESUMEN

BACKGROUND: Prostate cancer (PCa) has a high lifetime prevalence (one out of six men), but currently there is no widely accepted screening programme. Widely used prostate specific antigen (PSA) test at cut-off of 3.0 ng/mL does not have sufficient accuracy for detection of any prostate cancer, resulting in numerous unnecessary prostate biopsies in men with benign disease and false reassurance in some men with PCa. We have recently identified circulating chromosome conformation signatures (CCSs, Episwitch® PCa test) allowing PCa detection and risk stratification in line with standards of clinical PCa staging. The purpose of this study was to determine whether combining the Episwitch PCa test with the PSA test will increase its diagnostic accuracy. METHODS: n = 109 whole blood samples of men enrolled in the PROSTAGRAM screening pilot study and n = 38 samples of patients with established PCa diagnosis and cancer-negative controls from Imperial College NHS Trust were used. Samples were tested for PSA, and the presence of CCSs in the loci encoding for of DAPK1, HSD3B2, SRD5A3, MMP1, and miRNA98 associated with high-risk PCa identified in our previous work. RESULTS: PSA > 3 ng/mL alone showed a low positive predicted value (PPV) of 0.14 and a high negative predicted value (NPV) of 0.93. EpiSwitch alone showed a PPV of 0.91 and a NPV of 0.32. Combining PSA and Episwitch tests has significantly increased the PPV to 0.81 although reducing the NPV to 0.78. Furthermore, integrating PSA, as a continuous variable (rather than a dichotomised 3 ng/mL cut-off), with EpiSwitch in a new multivariant stratification model, Prostate Screening EpiSwitch (PSE) test, has yielded a remarkable combined PPV of 0.92 and NPV of 0.94 when tested on the independent prospective cohort. CONCLUSIONS: Our results demonstrate that combining the standard PSA readout with circulating chromosome conformations (PSE test) allows for significantly enhanced PSA PPV and overall accuracy for PCa detection. The PSE test is accurate, rapid, minimally invasive, and inexpensive, suggesting significant screening diagnostic potential to minimise unnecessary referrals for expensive and invasive MRI and/or biopsy testing. Further extended prospective blinded validation of the new combined signature in a screening cohort with low cancer prevalence would be the recommended step for PSE adoption in PCa screening.

3.
J Travel Med ; 30(1)2023 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-36222148

RESUMEN

OBJECTIVES: Neurocysticercosis (NCC) is a parasitic disease caused by the larval stage of the tapeworm Taenia solium. NCC mainly occurs in Africa, Latin America and South-East Asia and can cause a variety of clinical signs/symptoms. Although it is a rare disease in Europe, it should nonetheless be considered as a differential diagnosis. The aim of this study was to describe clinical characteristics and management of patients with NCC diagnosed and treated in Europe. METHODS: We conducted a systematic search of published and unpublished data on patients diagnosed with NCC in Europe (2000-2019) and extracted demographic, clinical and radiological information on each case, if available. RESULTS: Out of 293 identified NCC cases, 59% of patients presented initially with epileptic seizures (21% focal onset); 52% presented with headache and 54% had other neurological signs/symptoms. The majority of patients had a travel or migration history (76%), mostly from/to Latin America (38%), Africa (32%) or Asia (30%). Treatment varied largely depending on cyst location and number. The outcome was favorable in 90% of the cases. CONCLUSIONS: Management of NCC in Europe varied considerably but often had a good outcome. Travel and migration to and from areas endemic for T. solium will likely result in continued low prevalence of NCC in Europe. Therefore, training and guidance of clinicians is recommended for optimal patient management.


Asunto(s)
Neurocisticercosis , Taenia solium , Animales , Humanos , Neurocisticercosis/diagnóstico , Neurocisticercosis/tratamiento farmacológico , Neurocisticercosis/epidemiología , Estudios Retrospectivos , Europa (Continente) , Prevalencia
4.
Biomedicines ; 10(10)2022 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-36289648

RESUMEN

The definitive diagnosis and early treatment of many immune-mediated inflammatory diseases (IMIDs) is hindered by variable and overlapping clinical manifestations. Psoriatic arthritis (PsA), which develops in ~30% of people with psoriasis, is a key example. This mixed-pattern IMID is apparent in entheseal and synovial musculoskeletal structures, but a definitive diagnosis often can only be made by clinical experts or when an extensive progressive disease state is apparent. As with other IMIDs, the detection of multimodal molecular biomarkers offers some hope for the early diagnosis of PsA and the initiation of effective management and treatment strategies. However, specific biomarkers are not yet available for PsA. The assessment of new markers by genomic and epigenomic profiling, or the analysis of blood and synovial fluid/tissue samples using proteomics, metabolomics and lipidomics, provides hope that complex molecular biomarker profiles could be developed to diagnose PsA. Importantly, the integration of these markers with high-throughput histology, imaging and standardized clinical assessment data provides an important opportunity to develop molecular profiles that could improve the diagnosis of PsA, predict its occurrence in cohorts of individuals with psoriasis, differentiate PsA from other IMIDs, and improve therapeutic responses. In this review, we consider the technologies that are currently deployed in the EU IMI2 project HIPPOCRATES to define biomarker profiles specific for PsA and discuss the advantages of combining multi-omics data to improve the outcome of PsA patients.

5.
Front Oncol ; 12: 990842, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36059613

RESUMEN

Background: Three-dimensional chromosome loop conformations are powerful regulators of gene expression. These chromosome conformations can be detected both in tumour and in circulating cells and have significant disease biomarker potential. We have recently detected specific chromosome conformations in circulating cells of patients with prostate cancer (PCa) which were similar to ones found in their primary tumours, however, the possibility of horizontal transfer of chromosome conformations was not studied previously. Methods: Human monocytes (U937) were co-cultured in Boyden chambers through 0.4 uM membrane with or without PC-3 human PCa cells or their conditioned media and a custom DNA microarray for 900,000 chromosomal loops covering all coding loci and non-coding RNA genes was performed on each part of the co-culture system. Results: We have detected 684 PC-3 cell-specific chromosome conformations across the whole genome that were absent in naïve monocytes but appeared in monocytes co-cultured with PC-3 cells or with PC-3-conditioned media. Comparing PC3-specific conformations to the ones we have previously detected in systemic circulation of high-risk PCa patients revealed 9 positive loops present in both settings. Conclusions: Our results demonstrate for the first time a proof of concept for horizontal transfer of chromosome conformations without direct cell-cell contact. This carries high clinical relevance as we have previously observed chromatin conformations in circulating cells of patients with melanoma and PCa similar to ones in their primary tumours. These changes can be used as highly specific biomarkers for diagnosis and prognosis. Further studies are required to elucidate the specific mechanism of chromosome conformations transfer and its clinical significance in particular diseases.

6.
Oncoimmunology ; 11(1): 2104070, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35936985

RESUMEN

Bone disease represents a major cause of morbidity and mortality in Multiple Myeloma (MM); primarily driven by osteoclasts whose differentiation is dependent on expression of RANKL by MM cells. Notably, costimulation by ITAM containing receptors (i.e., FcγR) can also play a crucial role in osteoclast differentiation. Modeling the pathology of the bone marrow microenvironment with an ex vivo culture system of primary human multiple myeloma cells, we herein demonstrate that FcγR-mediated signaling, via staphylococcal protein A (SpA) IgG immune-complexes, can act as a critical negative regulator of MM-driven osteoclast differentiation. Interrogation of the mode-of-action revealed that FcγR-mediated signaling causes epigenetic modulation of chromosomal 3D architecture at the RANK promoter; with altered spatial orientation of a proximal super enhancer. Combined this leads to substantial down-regulation of RANK at a transcript, protein, and functional level. These observations shed light on a novel mechanism regulating RANK expression and provide a rationale for targeting FcγR-signaling for the amelioration of osteolytic bone pathology in disease.


Asunto(s)
Mieloma Múltiple , Osteogénesis , Diferenciación Celular/genética , Humanos , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Osteoclastos/metabolismo , Osteogénesis/genética , Receptores de IgG/genética , Receptores de IgG/metabolismo , Microambiente Tumoral
7.
Ann Clin Microbiol Antimicrob ; 20(1): 85, 2021 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-34969393

RESUMEN

BACKGROUND: There is growing evidence that antibody responses play a role in the resolution of SARS-CoV-2 infection. Patients with primary or secondary antibody deficiency are at increased risk of persistent infection. This challenging clinical scenario is associated with adverse patient outcome and potentially creates an ecological niche for the evolution of novel SARS-CoV-2 variants with immune evasion capacity. Case reports and/or series have implied a therapeutic role for convalescent plasma (CP) to secure virological clearance, although concerns have been raised about the effectiveness of CP and its potential to drive viral evolution, and it has largely been withdrawn from clinical use in the UK. CASE PRESENTATION: We report two cases in which persistent SARS-CoV-2 infection was cleared following administration of the monoclonal antibody combination casirivimab and imdevimab (REGN-COV2, Ronapreve). A 55-year-old male with follicular lymphoma, treated with B cell depleting therapy, developed SARS-CoV-2 infection in September 2020 which then persisted for over 200 days. He was hospitalised on four occasions with COVID-19 and suffered debilitating fatigue and malaise throughout. There was no clinical response to antiviral therapy with remdesivir or CP, and SARS-CoV-2 was consistently detected in nasopharyngeal swabs. Intrahost evolution of several spike variants of uncertain significance was identified by viral sequence analysis. Delivery of REGN-COV2, in combination with remdesivir, was associated with clinical improvement and viral clearance within 6 days, which was sustained for over 150 days despite immunotherapy for relapsed follicular lymphoma. The second case, a 68-year-old female with chronic lymphocytic leukaemia on ibrutinib, also developed persistent SARS-CoV-2 infection. Despite a lack of response to remdesivir, infection promptly cleared following REGN-COV2 in combination with remdesivir, accompanied by resolution of inflammation and full clinical recovery that has been maintained for over 290 days. CONCLUSIONS: These cases highlight the potential benefit of REGN-COV2 as therapy for persistent SARS-CoV-2 infection in antibody deficient individuals, including after failure of CP treatment. Formal clinical studies are warranted to assess the effectiveness of REGN-COV2 in antibody-deficient patients, especially in light of the emergence of variants of concern, such as Omicron, that appear to evade REGN-COV2 neutralisation.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Infección Persistente/virología , Anciano , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes , COVID-19/terapia , Combinación de Medicamentos , Femenino , Humanos , Inmunización Pasiva , Linfoma Folicular , Masculino , Persona de Mediana Edad , Infección Persistente/tratamiento farmacológico , SARS-CoV-2 , Resultado del Tratamiento , Sueroterapia para COVID-19
8.
J Transl Med ; 19(1): 46, 2021 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-33509203

RESUMEN

BACKGROUND: Current diagnostic blood tests for prostate cancer (PCa) are unreliable for the early stage disease, resulting in numerous unnecessary prostate biopsies in men with benign disease and false reassurance of negative biopsies in men with PCa. Predicting the risk of PCa is pivotal for making an informed decision on treatment options as the 5-year survival rate in the low-risk group is more than 95% and most men would benefit from surveillance rather than active treatment. Three-dimensional genome architecture and chromosome structures undergo early changes during tumourigenesis both in tumour and in circulating cells and can serve as a disease biomarker. METHODS: In this prospective study we screened whole blood of newly diagnosed, treatment naïve PCa patients (n = 140) and cancer-free controls (n = 96) for the presence of 14,241 chromosomal loops in the loci of 425 genes. RESULTS: We have detected specific chromosome conformation changes in the loci of ETS1, MAP3K14, SLC22A3 and CASP2 genes in peripheral blood from PCa patients yielding PCa detection with 80% sensitivity and 80% specificity. Further analysis between PCa risk groups yielded prognostic validation sets consisting of HSD3B2, VEGFC, APAF1, BMP6, ERG, MSR1, MUC1, ACAT1 and DAPK1 genes that achieved 80% sensitivity and 93% specificity stratifying high-risk category 3 vs low risk category 1 and 84% sensitivity and 89% specificity stratifying high risk category 3 vs intermediate risk category 2 disease. CONCLUSIONS: Our results demonstrate specific chromosome conformations in the blood of PCa patients that allow PCa diagnosis and risk stratification with high sensitivity and specificity.


Asunto(s)
Cromatina , Neoplasias de la Próstata , Humanos , Masculino , Pronóstico , Estudios Prospectivos , Antígeno Prostático Específico , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/genética
10.
Surgery ; 165(1): 44-49, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30377001

RESUMEN

BACKGROUND: Fine needle aspiration has been the traditional method for diagnosing thyroid cancer. Epigenetic chromatin conformation changes offer an alternative method of diagnosing cancer. The purpose of this study is to evaluate an EpiSwitch assay of epigenetic markers that can be used to diagnose thyroid cancer in blood samples. METHODS: From 2014 to 2016, adult patients with thyroid nodules having thyroidectomy were recruited and grouped based on benign, malignant, and atypia of undetermined significance or follicular lesions of undetermined significance fine needle aspiration cytology. Blood samples were collected before surgery. Final pathologic diagnosis was made from the thyroid specimens. Patients' blood samples were analyzed using the EpiSwitch assay, (Oxford Biodynamics, Oxford, UK), and the results were compared with surgical pathology to determine assay performance. RESULTS: In total, 58 patients were recruited: 20 benign, 20 malignant, and 18 atypia or follicular lesions of undetermined significance. An analysis of the malignant and benign fine needle aspiration groups found 6 epigenetic markers for thyroid. A total of 28 (48%) patients had thyroid cancer. The assay was able to correctly identify 25 of the 28 malignant nodules, showing sensitivity of 89.3% and specificity of 66.7%. The positive predictive value for the assay was 71.4%, whereas the negative predictive value was 87.0%. CONCLUSION: An epigenetic assay of peripheral blood shows high sensitivity in detecting thyroid cancer and provides an additional method for its diagnosis.


Asunto(s)
Biomarcadores de Tumor/genética , Cromatina/genética , Aberraciones Cromosómicas , Epigénesis Genética , Neoplasias de la Tiroides/diagnóstico , Adulto , Biomarcadores de Tumor/sangre , Biopsia con Aguja Fina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conformación de Ácido Nucleico , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Glándula Tiroides , Neoplasias de la Tiroides/sangre , Nódulo Tiroideo/genética , Nódulo Tiroideo/patología , Nódulo Tiroideo/cirugía , Tiroidectomía
11.
Trans R Soc Trop Med Hyg ; 112(7): 326-334, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29982795

RESUMEN

Background: Neurocysticercosis is the commonest infectious cause of epilepsy in endemic countries, and accounts for a greater number of cases worldwide than any other single pathology. Infection is associated with long-term exposure in low-income countries, although acquisition after travel has been recognized. The standard of care in the UK is inpatient treatment with anti-helminthic drugs and steroids. Methods: The authors reviewed all cases of neurocysticercosis managed at the Hospital for Tropical Diseases in London, England, between 2001 and 2015. Active disease was defined as evidence of either viable cysts or involuting cysts with associated parenchymal inflammation. Results: Of 26 active cases, 65.4% were migrants from nine different countries; 34.6% were UK-born travellers who had visited 19 countries across South and Central America, sub-Saharan Africa, South and South-east Asia; India was the commonest country of exposure in both groups. Only 73.1% presented with seizures; two diagnoses were made through brain imaging of patients with peripheral cysticerci; 53.8% had a single cyst. Migrants were more likely to be seropositive than travellers (p=0.033). Only two patients had seizures during admission, one of whom had multiple seizures prior to diagnosis. Conclusions: Neurocysticercosis presents in a non-endemic setting in both migrants and travellers. Travellers are less likely to be sero-positive. Not all cases of neurocysticercosis present with seizures. Outpatient management could be considered for selected patients.


Asunto(s)
Hospitales , Neurocisticercosis/epidemiología , Taenia , Migrantes , Viaje , Medicina Tropical , Adulto , Animales , Encéfalo/patología , Quistes/etiología , Epilepsia/etiología , Femenino , Hospitales/estadística & datos numéricos , Humanos , Inflamación/etiología , Londres/epidemiología , Masculino , Neurocisticercosis/complicaciones , Neurocisticercosis/patología , Convulsiones/etiología , Adulto Joven
12.
Sci Rep ; 7(1): 2186, 2017 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-28526829

RESUMEN

Stretched histone regions, such as super-enhancers and broad H3K4me3 domains, are associated with maintenance of cell identity and cancer. We connected super-enhancers and broad H3K4me3 domains in the K562 chronic myelogenous leukemia cell line as well as the MCF-7 breast cancer cell line with chromatin interactions. Super-enhancers and broad H3K4me3 domains showed higher association with chromatin interactions than their typical counterparts. Interestingly, we identified a subset of super-enhancers that overlap with broad H3K4me3 domains and show high association with cancer-associated genes including tumor suppressor genes. Besides cell lines, we could observe chromatin interactions by a Chromosome Conformation Capture (3C)-based method, in primary human samples. Several chromatin interactions involving super-enhancers and broad H3K4me3 domains are constitutive and can be found in both cancer and normal samples. Taken together, these results reveal a new layer of complexity in gene regulation by super-enhancers and broad H3K4me3 domains.


Asunto(s)
Cromatina/genética , Cromatina/metabolismo , Elementos de Facilitación Genéticos , Regulación de la Expresión Génica , Histonas/metabolismo , Complejos Multiproteicos/metabolismo , Dominios y Motivos de Interacción de Proteínas , Histonas/química , Humanos , Complejos Multiproteicos/química
13.
Melanoma Res ; 25(5): 406-11, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26225582

RESUMEN

Prognosis is markedly improved when melanoma is diagnosed early. Improved methods are needed for earlier detection and screening. We hypothesized that epigenetic analysis of blood samples could discriminate patients with melanoma from patients with other cutaneous lesions and from healthy volunteers. After institutional review board approval and consent, whole blood was obtained from 59 patients with melanoma, 20 patients with other skin cancers, 20 patients with benign skin conditions, and 20 healthy volunteers. Fifteen conformation biomarkers from five gene loci were analyzed on chromatin with the EpiSwitch technology using a modified chromatin conformation capture assay. Differentiation between patients with melanoma and those with nonmelanoma skin cancers was correct 85% of the time, resulting in a sensitivity of 88% and a specificity of 82%. Differentiation of patients with melanoma from healthy controls was correct 80% of the time, resulting in a sensitivity of 85% and a specificity of 75%. The noninvasive test was more accurate in early-stage melanoma (1/10 and 1/16 stage I and stage II patients were misclassified, respectively) and became less accurate with more advanced disease (3/14 and 4/19 stage III and IV patients were misclassified, respectively). We report the results of a noninvasive test using chromosomal aberrations and epigenetic changes identified in peripheral blood that, in this pilot study, distinguished patients with early-stage melanoma from other cohorts.


Asunto(s)
Células Sanguíneas/metabolismo , Aberraciones Cromosómicas , Epigénesis Genética , Melanoma/genética , Neoplasias Cutáneas/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Células Sanguíneas/patología , Carcinoma Basocelular/sangre , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/genética , Carcinoma Basocelular/patología , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Melanoma/sangre , Melanoma/diagnóstico , Melanoma/patología , Persona de Mediana Edad , Proyectos Piloto , Pronóstico , Sensibilidad y Especificidad , Neoplasias Cutáneas/sangre , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/patología
14.
Trop Med Int Health ; 20(9): 1171-1179, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25940786

RESUMEN

OBJECTIVE: To assess the contribution of neurocysticercosis (NCC) to the burden of epilepsy in a rural Tanzanian population. METHODS: We identified adult people with epilepsy (PWE) in a door-to-door study in an established demographic surveillance site. PWE and community controls were tested for antibodies to Taenia solium, the causative agent of NCC, and all PWE were offered a computed tomography (CT) head scan. Data on household occupancy and sanitation, pig-keeping and pork consumption were collected from PWE and controls and associations with epilepsy were assessed using chi-square or Fisher's exact tests. RESULTS: Six of 218 PWE had antibodies to T. solium (2.8%; 95% CI 0.6-4.9), compared to none of 174 controls (Fisher's exact test, P = 0.04). Lesions compatible with NCC were seen in eight of 200 CT scans (4.0%; 95% CI 1.3-6.7). A total of 176 PWE had both investigations of whom two had positive serology along with NCC-compatible lesions on CT (1.1%; 95% 0.3-4.0). No associations between epilepsy and any risk factors for NCC were identified. CONCLUSIONS: Neurocysticercosis is present in this population but at a lower prevalence than elsewhere in Tanzania and sub-Saharan Africa. Insights from low-prevalence areas may inform public health interventions designed to reduce the burden of preventable epilepsy.

15.
PLoS One ; 8(5): e63991, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23734180

RESUMEN

Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs' behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means.


Asunto(s)
Migración Animal/fisiología , Braquiuros/fisiología , Mariscos , Telecomunicaciones/instrumentación , Animales , Femenino , Geografía , Océanos y Mares , Dinámica Poblacional , Reproducibilidad de los Resultados , Reproducción/fisiología , Estaciones del Año , Temperatura , Factores de Tiempo , Reino Unido
16.
BMC Genomics ; 12: 476, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-21961992

RESUMEN

BACKGROUND: The transcription factor MYC is a critical regulator of diverse cellular processes, including both replication and apoptosis. Differences in MYC-regulated gene expression responsible for such opposing outcomes in vivo remain obscure. To address this we have examined time-dependent changes in global gene expression in two transgenic mouse models in which MYC activation, in either skin suprabasal keratinocytes or pancreatic islet ß-cells, promotes tissue expansion or involution, respectively. RESULTS: Consistent with observed phenotypes, expression of cell cycle genes is increased in both models (albeit enriched in ß-cells), as are those involved in cell growth and metabolism, while expression of genes involved in cell differentiation is down-regulated. However, in ß-cells, which unlike suprabasal keratinocytes undergo prominent apoptosis from 24 hours, there is up-regulation of genes associated with DNA-damage response and intrinsic apoptotic pathways, including Atr, Arf, Bax and Cycs. In striking contrast, this is not the case for suprabasal keratinocytes, where pro-apoptotic genes such as Noxa are down-regulated and key anti-apoptotic pathways (such as Igf1-Akt) and those promoting angiogenesis are up-regulated. Moreover, dramatic up-regulation of steroid hormone-regulated Kallikrein serine protease family members in suprabasal keratinocytes alone could further enhance local Igf1 actions, such as through proteolysis of Igf1 binding proteins. CONCLUSIONS: Activation of MYC causes cell growth, loss of differentiation and cell cycle entry in both ß-cells and suprabasal keratinocytes in vivo. Apoptosis, which is confined to ß-cells, may involve a combination of a DNA-damage response and downstream activation of pro-apoptotic signalling pathways, including Cdc2a and p19(Arf)/p53, and downstream targets. Conversely, avoidance of apoptosis in suprabasal keratinocytes may result primarily from the activation of key anti-apoptotic signalling pathways, particularly Igf1-Akt, and induction of an angiogenic response, though intrinsic resistance to induction of p19(Arf) by MYC in suprabasal keratinocytes may contribute.


Asunto(s)
Regulación de la Expresión Génica , Proteínas Proto-Oncogénicas c-myc/metabolismo , Animales , Apoptosis/genética , Adhesión Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular/genética , Supervivencia Celular/genética , Daño del ADN/genética , Islotes Pancreáticos/citología , Islotes Pancreáticos/metabolismo , Queratinocitos/citología , Queratinocitos/metabolismo , Ratones , Ratones Transgénicos , Activación Transcripcional
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