Diffuse midline glioma invasion and metastasis rely on cell-autonomous signaling.

BACKGROUND: Diffuse midline gliomas (DMG) are pediatric tumors with negligible 2-year survival after diagnosis characterized by their ability to infiltrate the central nervous system. In the hope of controlling the local growth and slowing the disease, all patients receive radiotherapy. However, distant progression occurs frequently in DMG patients. Current clues as to what causes tumor infiltration circle mainly around the tumor microenvironment, but there are currently no known determinants to predict the degree of invasiveness. METHODS: In this study, we use patient-derived glioma stem cells (GSCs) to create patient-specific 3D avatars to model interindividual invasion and elucidate the cellular supporting mechanisms. RESULTS: We show that GSC models in 3D mirror the invasive behavior of the parental tumors, thus proving the ability of DMG to infiltrate as an autonomous characteristic of tumor cells. Furthermore, we distinguished 2 modes of migration, mesenchymal and ameboid-like, and associated the ameboid-like modality with GSCs derived from the most invasive tumors. Using transcriptomics of both organoids and primary tumors, we further characterized the invasive ameboid-like tumors as oligodendrocyte progenitor-like, with highly contractile cytoskeleton and reduced adhesion ability driven by crucial over-expression of bone morphogenetic pathway 7 (BMP7). Finally, we deciphered MEK, ERK, and Rho/ROCK kinases activated downstream of the BMP7 stimulation as actionable targets controlling tumor cell motility. CONCLUSIONS: Our findings identify 2 new therapeutic avenues. First, patient-derived GSCs represent a predictive tool for patient stratification in order to adapt irradiation strategies. Second, autocrine and short-range BMP7-related signaling becomes a druggable target to prevent DMG spread and metastasis.

Residual inflammation in psoriatic arthritis patients in stable minimal disease activity.

Background: In psoriatic arthritis (PsA), low disease activity as defined by the Minimal Disease Activity (MDA) index is considered a good treatment target. However, as MDA is based only on clinical findings, it might not capture pauci-symptomatic inflammation. Sensitive imaging such as ultrasound (US) might disclose residual inflammatory signs in PsA patients in MDA. Methods: In this cross-sectional multicentre study, adult PsA patients on biologic treatment in MDA for at least 6 months were consecutively enrolled for a thorough clinical and US examination. Data collection included demographics, personal history, main patient's reported outcomes, clinical and US findings of joints, tendon sheaths, tendons, bursae, and entheses involvement. All centers performed the US investigation in B-mode and Power Doppler (PD)-mode using a similar US machine equipped with a 18-6 and 13-5 MHz multifrequency linear probe. Statistical analysis included comparisons between groups and correlation tests. Results: The 72 PsA patients enrolled in the study had a median duration of MDA of 12 (6-65) months. Overall, US examination revealed a low number of acute lesions. However, 54% of patients had at least one PD signal in the examined tissues. A joint or enthesis positive PD signal was found in about 19 and 24% of patients, respectively. Synovial hypertrophy, at least one acute entheseal lesions, and bursitis were the most common changes, detected in 41.7, 41.7 and 26% of patients, respectively. Conclusions: PsA patients in a stable state of MDA may still have residual inflammation in peripheral articular structures detectable by US examination.

Pediatric brain tumors as a developmental disease.

PURPOSE OF REVIEW: Brain tumors are the most frequent solid cancer in the pediatric population. Owing to the rarity of environmental clues about their origin, it is tempting to consider these neoplasms as developmental processes gone awry. Our review will explore the heuristic power of this hypothesis and the influence of these findings on the clinical management. RECENT FINDING: A more accurate description of cancer predisposition syndrome has shown their frequent association with developmental abnormalities. Several genes involved in pediatric brain tumor oncogenesis are involved in developmental processes. Modeling of several pediatric brain tumor in cerebral organoids, mimicking embryonal stage of brain development, indicates that early events during brain development create the conditions necessary for their oncogenesis. SUMMARY: The onset of multiple brain tumor types early in life suggests a functional relationship between brain development and oncogenesis. A growing body of evidence seems to support the hypothesis that some of the main developmental steps in the brain can be highjacked by the tumors during their initiation. Collaborations between neuroscientists and oncologists should provide room for improvement in the knowledge for these neoplasms.

Modeling the Interaction between the Microenvironment and Tumor Cells in Brain Tumors.

Despite considerable recent advances in understanding and treating many other cancers, malignant brain tumors remain associated with low survival or severe long-term sequelae. Limited progress, including development of immunotherapies, relates in part to difficulties in accurately reproducing brain microenvironment with current preclinical models. The cellular interactions among resident microglia, recruited tumor-associated macrophages, stromal cells, glial cells, neurons, and cancer cells and how they affect tumor growth or behavior are emerging, yet many questions remain. The role of the blood-brain barrier, extracellular matrix components, and heterogeneity among tumor types and within different regions of a single tumor further complicate the matter. Here, we focus on brain microenvironment features impacted by tumor biology. We also discuss limits of current preclinical models and how complementary models, such as humanized animals and organoids, will allow deeper mechanistic insights on cancer biology, allowing for more efficient testing of therapeutic strategies, including immunotherapy, for brain cancers.

Loss of Apc Rapidly Impairs DNA Methylation Programs and Cell Fate Decisions in Lgr5+ Intestinal Stem Cells.

Colorectal cancer initiation and progression result from the accumulation of genetic and epigenetic alterations. Although aberrant gene expression and DNA methylation profiles are considered hallmarks of colorectal cancer development, the precise timing at which these are produced during tumor establishment remains elusive. Here we investigated the early transcriptional and epigenetic changes induced by adenomatous polyposis coli (Apc) inactivation in intestinal crypts. Hyperactivation of the Wnt pathway via Apc inactivation in crypt base columnar intestinal stem cells (ISC) led to their rapid accumulation driven by an impaired molecular commitment to differentiation, which was associated with discrete alterations in DNA methylation. Importantly, inhibiting the enzymes responsible for de novo DNA methylation restored the responsiveness of Apc-deficient intestinal organoids to stimuli regulating the proliferation-to-differentiation transition in ISC. This work reveals that early DNA methylation changes play critical roles in the establishment of the impaired fate decision program consecutive to Apc loss of function. SIGNIFICANCE: This study demonstrates the functional impact of changes in DNA methylation to determine the colorectal cancer cell phenotype following loss of Apc function.

The Epigenetic Progenitor Origin of Cancer Reassessed: DNA Methylation Brings Balance to the Stem Force.

Cancer initiation and progression toward malignant stages occur as the results of accumulating genetic alterations and epigenetic dysregulation. During the last decade, the development of next generation sequencing (NGS) technologies and the increasing pan-genomic knowledge have revolutionized how we consider the evolving epigenetic landscapes during homeostasis and tumor progression. DNA methylation represents the best studied mark and is considered as a common mechanism of epigenetic regulation in normal homeostasis and cancer. A remarkable amount of work has recently started clarifying the central role played by DNA methylation dynamics on the maintenance of cell identity and on cell fate decisions during the different steps of normal development and tumor evolution. Importantly, a growing number of studies show that DNA methylation is key in the maintenance of adult stemness and in orchestrating commitment in multiple ways. Perturbations of the normal DNA methylation patterns impair the homeostatic balance and can lead to tumor initiation. Therefore, DNA methylation represents an interesting therapeutic target to recover homeostasis in tumor stem cells.

Cyclopenta[d]isoxazoline ß-Turn Mimics: Synthetic Approach, Turn Driving Force, Scope, and Limitations.

Model ß-turn inducers were prepared from constrained oxazanorbornene aminols. Taking advantage of the starting materials geometry, new diastereoisomeric compounds were synthesized, introducing different amino acidic residues. The products were spectroscopically characterized (VT and NMR titration). Temperature coefficients in dimethyl sulfoxide denote the existence of an intramolecular hydrogen bond. Chiroptical properties disclosed a ß-turn arrangement of the synthesized compounds. The fused isoxazoline ring constraints the cyclopentane moiety, stabilizing a boatlike conformation that ensures the turn efficiency but limiting the accessibility to hindered amino acids.

Diagnosis and treatment of rheumatoid arthritis in the Emilia Romagna region: a prospective population-based study.

OBJECTIVES: To perform a population-based study in rheumatoid arthritis (RA) patients, in order to evaluate the efficacy and safety of pharmacologic treatments. METHODS: 1087 patients with RA were enrolled; inclusion criteria were: newly diagnosed RA, already diagnosed RA with high disease activity (HDA) (DAS28≥4.2) starting biologic DMARDs (bDMARDs), already diagnosed RA with HDA continuing with conventional DMARDs (cDMARDs). The following data were collected: demographics, clinical and laboratory features, imaging and prescribed drugs. All parameters except immunology and imaging (performed yearly) were repeated at each follow-up evaluations (after 3, 6 and 12 months, and thereafter every 12 months). In order to evaluate clinical response, the EULAR response criteria were used as the gold standard. RESULTS: 414 (38.1%) newly diagnosed patients with RA, 477 (43.9%) RA patients who started bDMARDs and 196 (18.0%) RA patients who continued with cDMARDs were enrolled from April 2012 to March 2015 at 12 Rheumatology Centres in the Emilia Romagna Region. Statistical analyses showed a relative risk ratio (RRR) for moderate response of 1.65 in RA patients who started bDMARDs (p=0.16) and 2.49 for newly diagnosed RA (p=0.01). Sex, age and Health Assessment Questionnaire were not statistically significant. A RRR of 2.00 has been confirmed for RA patients who started bDMARDs (p<0.0005) for a good response as well as 2.20 for newly diagnosed RA (p<0.0005). An increase in adverse events among bDMARDs was found, but when looking at infections or neoplasia, no differences were highlighted between RA which started bDMARDs and RA who continued with cDMARDs. CONCLUSIONS: Our results are in line with already published papers from British and Swedish Registries: a greater likelihood to have a good response is demonstrated for not longstanding RA starting cDMARDs or RA with HDA when a bDMARD is started. Also a good safety profile is demonstrated.

Intestinal epithelial tuft cells initiate type 2 mucosal immunity to helminth parasites.

Helminth parasitic infections are a major global health and social burden. The host defence against helminths such as Nippostrongylus brasiliensis is orchestrated by type 2 cell-mediated immunity. Induction of type 2 cytokines, including interleukins (IL) IL-4 and IL-13, induce goblet cell hyperplasia with mucus production, ultimately resulting in worm expulsion. However, the mechanisms underlying the initiation of type 2 responses remain incompletely understood. Here we show that tuft cells, a rare epithelial cell type in the steady-state intestinal epithelium, are responsible for initiating type 2 responses to parasites by a cytokine-mediated cellular relay. Tuft cells have a Th2-related gene expression signature and we demonstrate that they undergo a rapid and extensive IL-4Rα-dependent amplification following infection with helminth parasites, owing to direct differentiation of epithelial crypt progenitor cells. We find that the Pou2f3 gene is essential for tuft cell specification. Pou2f3(-/-) mice lack intestinal tuft cells and have defective mucosal type 2 responses to helminth infection; goblet cell hyperplasia is abrogated and worm expulsion is compromised. Notably, IL-4Rα signalling is sufficient to induce expansion of the tuft cell lineage, and ectopic stimulation of this signalling cascade obviates the need for tuft cells in the epithelial cell remodelling of the intestine. Moreover, tuft cells secrete IL-25, thereby regulating type 2 immune responses. Our data reveal a novel function of intestinal epithelial tuft cells and demonstrate a cellular relay required for initiating mucosal type 2 immunity to helminth infection.

Cyclin D3 critically regulates the balance between self-renewal and differentiation in skeletal muscle stem cells.

Satellite cells are mitotically quiescent myogenic stem cells resident beneath the basal lamina surrounding adult muscle myofibers. In response to injury, multiple extrinsic signals drive the entry of satellite cells into the cell cycle and then to proliferation, differentiation, and self-renewal of their downstream progeny. Because satellite cells must endure for a lifetime, their cell cycle activity must be carefully controlled to coordinate proliferative expansion and self-renewal with the onset of the differentiation program. In this study, we find that cyclin D3, a member of the family of mitogen-activated D-type cyclins, is critically required for proper developmental progression of myogenic progenitors. Using a cyclin D3-knockout mouse we determined that cyclin D3 deficiency leads to reduced myofiber size and impaired establishment of the satellite cell population within the adult muscle. Cyclin D3-null myogenic progenitors, studied ex vivo on isolated myofibers and in vitro, displayed impaired cell cycle progression, increased differentiation potential, and reduced self-renewal capability. Similarly, silencing of cyclin D3 in C2 myoblasts caused anticipated exit from the cell cycle and precocious onset of terminal differentiation. After induced muscle damage, cyclin D3-null myogenic progenitors exhibited proliferation deficits, a precocious ability to form newly generated myofibers and a reduced capability to repopulate the satellite cell niche at later stages of the regeneration process. These results indicate that cyclin D3 plays a cell-autonomous and nonredundant function in regulating the dynamic balance between proliferation, differentiation, and self-renewal that normally establishes an appropriate pool size of adult satellite cells.

Epidemiology of systemic sclerosis in a district of northern Italy.

OBJECTIVES: To estimate, using both the American College of Rheumatology-ACR 1980 classification criteria and revised LeRoy and Medsger 2001 criteria, the incidence and prevalence of systemic sclerosis (SSc) in an area in north-eastern Italy with a referral base population of about 346,000 inhabitants. METHODS: Retrospective examination of all patients 16 years and older of native Italian origin and resident in the Ferrara district who had either been admitted to hospital or referred to our outpatient clinic with a diagnosis of SSc between 1st January 1999 and 31st December 2007. SSc subjects were identified both by a search of hospital discharge code 710.1, as per the international classification of disease-9 codes, and using a computerised search for this pathology code in the national health care system. The subjects referred to our outpatient clinic were identified from a dedicated data base. Incidence and prevalence rates were calculated as the number of cases per 100,000 inhabitants (population data based on the October 2001 national census). The medical records of each potential case were accurately examined and reviewed by the same physician who determined whether those patients identified as having a diagnosis of SSc did indeed meet the ACR 1980 classification criteria for SSc and/or the LeRoy and Medsger 2001 criteria. RESULTS: After reviewing all cases, of the 118 patients meeting the LeRoy-Medsger 2001 criteria, only 88 patients had a definitive diagnosis of SSc according to the ACR 1980 criteria. Considering the ACR criteria, the prevalence rate was 25.4 cases per 100,000 (95% CI: 22.2-28.6), and the annual incidence rate over the study period was 3.2 per 100,000 (95% CI: 2.0-4.4). Considering the LeRoy and Medsger criteria epidemiological data were respectively 34.1 cases per 100,000 (95% CI: 30.4-37.8) and 4.3 cases per 100,000 (95% CI: 3.0-5.6). According to the LeRoy and Medsger criteria, the SSc subsets were broken down as follows: 20 limited-SSc (19.2%), 76 limited cutaneous-SSc (62.1%), 22 diffuse cutaneous-SSc (18.7%). The female/male ratio was 9.7:1. CONCLUSIONS: Incidence and prevalence of SSc observed in an area in north-eastern Italy were found to be higher than reported in the various geographical area (UK, US, Australia, etc.) but similar to another Italian study adopting, as here, the LeRoy-Medsger criteria. The different diagnostic criteria adopted may explain some of the differences found in comparison to the studies based only on the ACR criteria, however, regional discrepancies in disease occurrence cannot easily be dismissed only on the basis of methodological approaches to case definition or ascertainment; genetic, ethnic and environmental factors should also be considered. Currently the main challenge remains to determine the scientific basis for the observed differences, distinguishing between changes deriving from geographic/ethnic features and from the analytic methods.

Wegener's granulomatosis and giant cell tumor of tendon sheaths: casual or causal combination? First case report.

Giant cell tumor of tendon sheath (GCTTS) and Wegener's granulomatosis (WG) are rare conditions both characterized by polyclonal cellular proliferation and multinucleated giant cells formation. Here, we report the case of a 27-year-old Caucasian woman affected by WG who experienced the metachrone appearance of two different GCTTSs at the right hand within a time of 3 years. To our knowledge, the combination of GCTT with WG is exceptional and this could probably be the first case reported. The subsequent appearance of two rare diseases both characterized by giant cell formation apparently points to similarities in their pathogenesis. However, at present no pathogenic relationship between GCTTS and WG is demonstrable and their simultaneous occurrence has to be considered coincidental. Actually, an emerging opinion is to consider GCTTS as a mixed lesion in which both tumoral and non-tumoral inflammatory cells play a central pathogenic action. On this view, the proposed case could support the evidence about the crucial role of a chronic inflammatory injury in enhancing GCTTS appearance.

Elderly-onset gout: a review.

Elderly-onset gout (EOG), defined as a disease with onset at age 65 years or over, shows relevant epidemiological, clinical and therapeutic differences from the typical middle-age form. The main differences are the more frequent subacute/chronic polyarticular onset with hand involvement, the unusual localization of tophi on ostheoarthritis (OA) nodes, the increased female/male ratio and the frequent association with drugs that decrease renal urate excretion (diuretics and low-dose aspirin) and/or with primitive renal impairment. EOG has recently been confirmed as the most common inflammatory arthropathy in older people, with important demographic implications and substantial impact on daily clinical practice. Despite the high prevalence, gout, in the elderly, often remains misdiagnosed or diagnosed late in its clinical course. Even when correctly recognized, its treatment is often difficult or unsatisfactory.