Transient loss of Polycomb components induces an epigenetic cancer fate.

Although cancer initiation and progression are generally associated with the accumulation of somatic mutations1,2, substantial epigenomic alterations underlie many aspects of tumorigenesis and cancer susceptibility3-6, suggesting that genetic mechanisms might not be the only drivers of malignant transformation7. However, whether purely non-genetic mechanisms are sufficient to initiate tumorigenesis irrespective of mutations has been unknown. Here, we show that a transient perturbation of transcriptional silencing mediated by Polycomb group proteins is sufficient to induce an irreversible switch to a cancer cell fate in Drosophila. This is linked to the irreversible derepression of genes that can drive tumorigenesis, including members of the JAK-STAT signalling pathway and zfh1, the fly homologue of the ZEB1 oncogene, whose aberrant activation is required for Polycomb perturbation-induced tumorigenesis. These data show that a reversible depletion of Polycomb proteins can induce cancer in the absence of driver mutations, suggesting that tumours can emerge through epigenetic dysregulation leading to inheritance of altered cell fates.

Is it hyperlexia? Toward a deeper understanding of precocious reading skills in two cases of children with Autism Spectrum Disorder.

BACKGROUND: Hyperlexia is defined by a precocious and sponta-neously acquired ability to read at preschool age. Hyperlexia appears to be a wide yet not highly studied phenomenon involving different populations and possibly including children with different neuropsy-chological profiles and outcomes. METHODS: We describe two clinical cases of unrelated children diagnosed with Autism Spectrum Disorder (ASD) who both showed precocious and spontaneous reading ability. We report the neuropsy-chological assessment they underwent. RESULTS: Both children showed above average IQ, reading skills, and text comprehension, whereas one showed below average comprehen-sion only in oral text. We question whether these two phenotypes can be considered forms of hyperlexia, as defined by the most recent and consistent observations, or a subtype of ASD with hyperlexia. CONCLUSION: We conclude that our patients should be considered hyperlexic ASD, with interesting potential implications for progno-sis and rehabilitation.

Widespread activation of developmental gene expression characterized by PRC1-dependent chromatin looping.

Polycomb repressive complexes 1 and 2 have been historically described as transcriptional repressors, but recent reports suggest that PRC1 might also support activation, although the underlying mechanisms remain elusive. Here, we show that stage-specific PRC1 binding at a subset of active promoters and enhancers during Drosophila development coincides with the formation of three-dimensional (3D) loops, an increase in expression during development and repression in PRC1 mutants. Dissection of the dachshund locus indicates that PRC1-anchored loops are versatile architectural platforms that persist when surrounding genes are transcriptionally active and fine-tune their expression. The analysis of RING1B binding profiles and 3D contacts during neural differentiation in mice suggests that this role is conserved in mammals.

Gender differences in clinical presentation and vascular pattern in patients with Takayasu arteritis.

Objective: To compare clinical characteristics and pattern of vascular involvement at disease onset according to gender specificity in patients with Takayasu arteritis (TA).Methods: Data from 117 TA patients (11 male, 106 female), diagnosed according to the American College of Rheumatology criteria, from our centre were retrospectively collected. Differences between men and women regarding demographic features, diagnostic delay, signs and symptoms attributed to TA, and arteries involved at diagnosis were compared. Data were obtained from three published articles describing gender differences in TA. A global analysis of these three cohorts plus ours (a total of 578 patients; 108 men, 470 women) was performed.Results: In our TA cohort, age at disease onset and age at diagnosis were not significantly different between genders. Diagnostic delay was higher in men. Male patients showed higher involvement of iliac arteries (right, p = 0.016; left, p = 0.021); females suffered more frequently from upper limb claudication (p = 0.026). In the overall analysis, men had higher prevalence of arterial hypertension (p = 0.007) and more frequent involvement of abdominal aorta (p = 0.026), renal arteries (right, p < 0.001; left, p < 0.001), and iliac arteries (right, p = 0.009; left, p = 0.002). Women more frequently exhibited upper limb claudication (p = 0.042) and involvement of left subclavian artery (p = 0.005), carotid arteries (right, p < 0.001; left, p < 0.001), and supradiaphragmatic aorta (ascending, p = 0.050; arch, p < 0.001; descending, p = 0.003). Inflammatory markers were more frequently raised in women (p = 0.005).Conclusions: In TA patients, gender has a strong influence on pattern of vascular involvement and consequently on clinical presentation. Specifically, women have a higher involvement of the supradiaphragmatic vessels, whereas in men the abdominal vessels are more frequently affected.

Nutrient availability and nutrient use efficiency in plants growing in the transition zone between land and water.

The transition zone between terrestrial and freshwater habitats is highly dynamic, with large variability in environmental characteristics. Here, we investigate how these characteristics influence the nutritional status and performance of plant life forms inhabiting this zone. Specifically, we hypothesised that: (i) tissue nutrient content differs among submerged, amphibious and terrestrial species, with higher content in submerged species; and (ii) PNUE gradually increases from submerged over amphibious to terrestrial species, reflecting differences in the availability of N and P relative to inorganic C across the land-water ecotone. We found that tissue nutrient content was generally higher in submerged species and C:N and C:P ratios indicated that content was limiting for growth for ca. 20% of plant individuals, particularly those belonging to amphibious and terrestrial species groups. As predicted, the PNUE increased from submerged over amphibious to terrestrial species. We suggest that this pattern reflects that amphibious and terrestrial species allocate proportionally more nutrients into processes of importance for photosynthesis at saturating CO2 availability, i.e. enzymes involved in substrate regeneration, compared to submerged species that are acclimated to lower availability of CO2 in the aquatic environment. Our results indicate that enhanced nutrient loading may affect relative abundance of the three species groups in the land-water ecotone of stream ecosystems. Thus, species of amphibious and terrestrial species groups are likely to benefit more from enhanced nutrient availability in terms of faster growth compared to aquatic species, and that this can be detrimental to aquatic species growing in the land-water ecotone, e.g. Ranunculus and Callitriche.

Efficacy and safety of biological agents in adult-onset Still's disease.

OBJECTIVES: To describe the efficacy and safety of different biological agents in a large cohort of 20 patients with adult-onset Still's disease (AOSD). METHOD: We retrospectively evaluated 20 patients with severe or refractory AOSD treated with at least one biological agent (anakinra, etanercept, tocilizumab, and adalimumab), followed up for at least 12 months at our Institution. We collected and analysed data on the disease course, treatment outcome, and adverse effects, and compared our data with other published series. RESULTS: The median duration of follow-up was 5 years. In 12 patients a single biological drug induced a clinical response. In eight patients the biological agent that was first administered proved ineffective, and a switch to a different biologic was necessary. In three patients a third biologic was necessary to achieve disease control. The biologics eventually determined a clinical response in all patients. Patients with systemic disease showed better responses than patients with chronic articular disease (p < 0.05). Biological agents allowed either the withdrawal or the tapering of corticosteroid therapy (p < 0.0001) and of disease-modifying anti-rheumatic agents (DMARDs; p < 0.05). Three patients experienced herpes zoster reactivation. CONCLUSIONS: This is the longest follow-up of a cohort of AOSD patients treated with biological agents. Our data show that biologics are safe and generally effective in the long-term management of AOSD, particularly in cases with systemic disease, and suggest that a clinical response can be obtained in almost all AOSD patients, although a switch to drugs with a different mechanism of action may be necessary.

Developmental determinants in non-communicable chronic diseases and ageing.

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Chromatin folding: from linear chromosomes to the 4D nucleus.

The organization of chromatin within the nucleus influences gene expression during cell differentiation and development. Recent work took advantage of the genome-wide localization of molecular marks on chromosomes to analyze their linear distributions at different length scales. Moreover, chromosome conformation capture techniques detect spatial proximity inside the cell nucleus and allow us to characterize local and long-range chromatin loops as well as interchromosomal contacts. These techniques have improved our understanding of chromatin composition in eukaryotic chromosomes, but the principles governing nuclear organization are still little understood. On the one hand, proteins might localize in stable nuclear structures, such as transcription factories, on which chromatin would have to be targeted to be processed. On the other hand, proteins binding to chromatin might induce the formation of specialized nuclear compartments de novo. Current work is aimed at distinguishing between these possibilities and at elaborating predictive models of chromatin folding.

Evidence of an increased nitric oxide production in primary biliary cirrhosis.

OBJECTIVE: Although possible implications of nitric oxide in the pathophysiology of liver cirrhosis have been extensively studied, until now few articles have addressed the assessment of nitric oxide production in primary biliary cirrhosis. This study was directed to evaluate circulating nitrosyl-hemoglobin levels as well as neutrophil elastase and soluble adhesion molecule concentrations in this condition, by assuming these parameters as possible markers of either inflammatory response or neutrophil activation. METHODS: Laboratory investigations were performed in 30 patients with primary biliary cirrhosis, in 13 patients with postviral and/or alcoholic cirrhosis, and in a group of eight subjects with chronic hepatitis. RESULTS: Although no difference was detected with respect to chronic hepatitis subjects, higher levels of nitrosyl-hemoglobin adducts were found in primary biliary cirrhosis patients than in postviral or alcoholic cirrhotics and in normal subjects (3.55+/-1.75 arbitrary units vs 1.95+/-0.57 and 0.84+/-0.34, p = 0.0004 and p < 0.0001, respectively). Similarly, more elevated concentrations of neutrophil elastase (213.7+/-192.0 microg/L vs 51.1+/-34.3 and 38.0+/-11.5, p < 0.0001 and p < 0.0001, respectively) as well as of soluble forms of intercellular adhesion molecule 1 and endothelial-leukocyte adhesion molecule 1 were shown in primary biliary cirrhosis patients than in subjects with cirrhosis of other etiologies and in controls. CONCLUSIONS: Highly enhanced nitric oxide production in primary biliary cirrhosis could be related to the development of strong inflammation and at least partially to neutrophil activation, thus suggesting a putative role of these cellular mediators in the development of liver damage owing to their ability to synthesize and release a wide variety of important factors, including elastase and nitric oxide.

Body composition, sex steroids, IGF-1, and bone mineral status in aging men.

BACKGROUND: Bone loss in elderly men is associated with changes in body composition and reduced secretion of endogenous anabolizing hormones. The independent influences of body composition and endocrine factors on male bone metabolism, however, are unclear. METHODS: Bone mass density (BMD) (bone mass content [BMC, g]/projected bone area [BA, cm2]) at different skeletal sites, skeletal muscle, and body fat mass were measured by dual-energy X-ray absorptiometry in 129 men aged 20 to 95 years. Free testosterone, 17-beta-estradiol, dehydroepiandrosterone-sulfate, and insulin-like growth factor 1 (IGF-1) serum concentrations were measured. Because BMD may fail to control for differences in skeletal size, the associations of bone mass with body composition and hormones were studied by comparing BMD regression models incorporating age and knee height only with BMC regression models also incorporating BA. RESULTS: Skeletal muscle had close associations (p at least < .01) with BMD and BMC at almost all skeletal sites, but the strength of these associations was generally reduced in BMC with respect to BMD models. Weak associations (p < .05) were found in both models for fatness with femoral bone and for 17-beta-estradiol with total body and femoral bone. The association of 17-beta-estradiol with spinal bone was significant (p < .05) in the BMD but not in the BMC model. No association of BMC or BMD with androgens and IGF-1 reached significancy. CONCLUSIONS: Skeletal muscle may be more important than fatness and anabolizing hormones in preserving bone mass in elderly men. In contrast to traditional belief, estrogens may be more important than androgens and IGF-1 in male bone metabolism.

Blood micronutrient and thyroid hormone concentrations in the oldest-old.

Several micronutrients are involved in thyroid hormone metabolism, but it is unclear whether their marginal deficits may contribute to the alterations in thyroid function observed in extreme aging. The relationships among blood concentrations of thyroid hormones and selenium, zinc, retinol, and alpha-tocopherol were studied in 44 healthy Northern Italian oldest-old subjects (age range, 90-107 yr), selected by the criteria of the SENIEUR protocol. Control groups included 44 healthy adult (age range, 20-65 yr) and 44 SENIEUR elderly (age range, 65-89 yr) subjects. Oldest-old subjects had higher TSH (P < 0.01) and lower free T3 (FT3)/freeT4 (FT4) ratio, zinc, and selenium serum values (P < 0.001) than adult and elderly control subjects. No significant difference was found for plasma retinol and a-tocopherol values. The associations between micronutrients and thyroid hormones were evaluated by multivariate analysis. In oldest-old subjects, plasma retinol was negatively associated with FT4 (P = 0.019) and TSH serum levels (P = 0.040), whereas serum zinc was positively associated with serum FT3 (P = 0.010) and FT3/FT4 ratio (P = 0.011). In younger subjects, no significant association was found among thyroid variables and micronutrients. In conclusion, blood levels of specific micronutrients are associated with serum iodothyronine levels in extreme aging.

Elevated plasma homocysteine levels in centenarians are not associated with cognitive impairment.

BACKGROUND: Previous reports have shown elevated plasma total homocysteine (tHcy) levels in elderly person with impaired cognition. OBJECTIVE: To study the association between cognitive status and plasma tHcy levels in centenarians. DESIGN: Cross-sectional survey. SETTING: Centenarians living in two northern Italian provinces. PARTICIPANTS: Thirteen cognitively normal centenarians, ten cognitively impaired not-demented centenarians, and 34 demented centenarians with a clinical diagnosis of Alzheimer's disease (AD). MEASUREMENTS: Blood levels of homocysteine's biological determinants vitamin B12, folate, and vitamin B6. RESULTS: Elevated plasma tHcy levels (>17 micromol/l) were common in the general population (77% of normal centenarians, 100% of cognitively impaired not-demented centenarians, 82% of AD centenarians). Demented centenarians had the lowest folate serum levels. Low or borderline vitamin B12 serum levels (<221 pmol/l) and low vitamin B6 plasma levels (<11.7 nmol/l) were found in 33 and 66% of all centenarians independently of cognitive status. Among demented centenarians only plasma tHcy correlated inversely with both serum vitamin B12 and folate. No significant difference was found for plasma tHcy levels among the three diagnostic groups, even after adjusting for B vitamin levels. CONCLUSIONS: Hyperhomocysteinemia is very common among centenarians, probably due to vitamin deficiencies, but does not seem to be associated with cognitive impairment.

Epigenetic inheritance of active chromatin after removal of the main transactivator.

The Drosophila Polycomb and trithorax group proteins act through chromosomal elements such as Fab-7 to maintain repressed or active gene expression, respectively. A Fab-7 element is switched from a silenced to a mitotically heritable active state by an embryonic pulse of transcription. Here, histone H4 hyperacetylation was found to be associated with Fab-7 after activation, suggesting that H4 hyperacetylation may be a heritable epigenetic tag of the activated element. Activated Fab-7 enables transcription of a gene even after withdrawal of the primary transcription factor. This feature may allow epigenetic maintenance of active states of developmental genes after decay of their early embryonic regulators.

Prevalence and severity of dementia among northern Italian centenarians.

Using diagnostic criteria from the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, dementia was clinically diagnosed in 57 (62%) of 92 centenarians living in two northern Italian provinces. The condition was severely disabling in approximately 70% of the demented patients. Although clinically diagnosed AD accounted for 79% of dementia cases, almost one third of patients with AD had risk factors for vascular dementia, suggesting that the aging brain may be susceptible to multiple additive factors that impair cognition.