Citations

AbstractObjectiveProtein phosphatase 2A (PP2A) is a heterotrimeric holoenzyme composed of a catalytic C subunit, a structural A subunit, and one of several regulatory B subunits that confer substrate specificity. The assembly and activity of PP2A are regulated by reversible methylation of the C subunit. α‐Synuclein, which aggregates in Parkinson disease (PD) and dementia with Lewy bodies (DLB), is phosphorylated at Ser129, and PP2A containing a B55α subunit is a major phospho‐Ser129 phosphatase. The objective of this study was to investigate PP2A in α‐synucleinopathies.MethodsWe compared the state of PP2A methylation, as well as the expression of its methylating enzyme, leucine carboxyl methyltransferase (LCMT‐1), and demethylating enzyme, protein phosphatase methylesterase (PME‐1), in postmortem brains from PD and DLB cases as well as age‐matched Controls. Immunohistochemical studies and quantitative image analysis were employed.ResultsLCMT‐1 was significantly reduced in the substantia nigra (SN) and frontal cortex in both PD and DLB. PME‐1, on the other hand, was elevated in the PD SN. In concert with these changes, the ratio of methylated PP2A to demethylated PP2A was markedly decreased in PD and DLB brains in both SN and frontal cortex. No changes in total PP2A or total B55α subunit were detected.InterpretationThese findings support the hypothesis that PP2A dysregulation in α‐synucleinopathies may contribute to the accumulation of hyperphosphorylated α‐synuclein and to the disease process, raising the possibility that pharmacological means to enhance PP2A phosphatase activity may be a useful disease‐modifying therapeutic approach.

Targeting three defects with one strategy The neurodegenerative diseases amyotrophic lateral sclerosis and frontotemporal dementia are most commonly caused by a mutation in the C9orf72 gene. The mutation is an expanded hexanucleotide repeat in a noncoding region. The expanded repeat produces sense and antisense RNA transcripts, which accumulate in patient cells and appear to sequester RNA-binding proteins. The sense and antisense transcripts are also translated into dipeptide repeat proteins, which are aggregation-prone and accumulate in the brain and spinal cord. Last, loss of function from reduced expression of C9orf72 in neurons and glia could contribute to the disease. Kramer et al. targeted both sense and antisense repeats by blocking a single gene called SPT4 , which mitigated degeneration in human cells by reducing all three types of pathologies. Science , this issue p. 708

SummaryBackgroundRefractory coeliac disease is a severe complication of coeliac disease with heterogeneous outcome.AimTo create a prognostic model to estimate survival of patients with refractory coeliac disease.MethodsWe evaluated predictors of 5‐year mortality using Cox proportional hazards regression on subjects from a multinational registry. Bootstrap resampling was used to internally validate the individual factors and overall model performance. The mean of the estimated regression coefficients from 400 bootstrap models was used to derive a risk score for 5‐year mortality.ResultsThe multinational cohort was composed of 232 patients diagnosed with refractory coeliac disease across seven centres (range of 11–63 cases per centre). The median age was 53 years and 150 (64%) were women. A total of 51 subjects died during a 5‐year follow‐up (cumulative 5‐year all‐cause mortality = 30%). From a multiple variable Cox proportional hazards model, the following variables were significantly associated with 5‐year mortality: age at refractory coeliac disease diagnosis (per 20 year increase, hazard ratio = 2.21; 95% confidence interval, CI: 1.38–3.55), abnormal intraepithelial lymphocytes (hazard ratio = 2.85; 95% CI: 1.22–6.62), and albumin (per 0.5 unit increase, hazard ratio = 0.72; 95% CI: 0.61–0.85). A simple weighted three‐factor risk score was created to estimate 5‐year survival.ConclusionsUsing data from a multinational registry and previously reported risk factors, we create a prognostic model to predict 5‐year mortality among patients with refractory coeliac disease. This new model may help clinicians to guide treatment and follow‐up.

AimsBiphenotypic sinonasal sarcoma (SNS) is a locally aggressive tumour that occurs in the sinonasal region. PAX3–MAML3 has recently been identified as a recurrent fusion gene event in this entity; however, a subset of tumours harbour alternative PAX3 rearrangement without the involvement of MAML3. In this study we sought to characterize the molecular profile of a large series of cases, with a special emphasis on tumours with alternative fusions.Methods and resultsForty‐four examples of SNS were screened by fluorescence in‐situ hybridization and reverse transcription polymerase chain reaction to better characterize its molecular profile and identify potential novel fusion genes. Twenty‐four were positive for PAX3–MAML3 (55%), 15 showed rearrangements of PAX3 without MAML3 involvement (34%), one showed rearrangement of MAML3 without PAX3 involvement, and four were negative for the involvement of either gene (9%). Among 15 cases with PAX3 involvement only, three were found to harbour PAX3–FOXO1. Two of these cases arose in the nasal cavities of female patients (aged 31 and 47 years), and one showed bilateral involvement of the nasal cavities of a 35‐year‐old male. A fourth case involved the skull base of a 47‐year‐old male, and was positive for PAX3–NCOA1. Patients with fusion‐negative tumours were slightly older.ConclusionMore than half of the SNSs in this series were positive for PAX3–MAML3. However, a subset of tumours may harbour alternative PAX3 fusion genes or show no involvement of PAX3. Except for a possible weak association between age and molecular profile, the overall morphological and immunophenotypic features of all cases seem to be similar. Because of the rarity of these tumours, the impact of the molecular profile on the clinical course of these tumours remains to be determined.

Prior studies in with irritable bowel syndrome with diarrhea (IBS-D) patients showed immune activation, secretion, and barrier dysfunction in jejunal or colorectal mucosa. We measured mRNA expression by RT-PCR of 91 genes reflecting tight junction proteins, chemokines, innate immunity, ion channels, transmitters, housekeeping genes, and controls for DNA contamination and PCR efficiency in small intestinal mucosa from 15 IBS-D and 7 controls (biopsies negative for celiac disease). Fold change was calculated using 2(−ΔΔCT) formula. Nominal P values ( P < 0.05) were interpreted with false detection rate (FDR) correction ( q value). Cluster analysis with Lens for Enrichment and Network Studies (LENS) explored connectivity of mechanisms. Upregulated genes (uncorrected P < 0.05) were related to ion transport (INADL, MAGI1, and SONS1), barrier (TJP1, 2, and 3 and CLDN) or immune functions (TLR3, IL15, and MAPKAPK5), or histamine metabolism (HNMT); downregulated genes were related to immune function (IL-1β, TGF-β1, and CCL20) or antigen detection (TLR1 and 8). The following genes were significantly upregulated ( q < 0.05) in IBS-D: INADL, MAGI1, PPP2R5C, MAPKAPK5, TLR3, and IL-15. Among the 14 nominally upregulated genes, there was clustering of barrier and PDZ domains (TJP1, TJP2, TJP3, CLDN4, INADL, and MAGI1) and clustering of downregulated genes (CCL20, TLR1, IL1B, and TLR8). Protein expression of PPP2R5C in nuclear lysates was greater in patients with IBS-D and controls. There was increase in INADL protein (median 9.4 ng/ml) in patients with IBS-D relative to controls (median 5.8 ng/ml, P > 0.05). In conclusion, altered transcriptome (and to lesser extent protein) expression of ion transport, barrier, immune, and mast cell mechanisms in small bowel may reflect different alterations in function and deserves further study in IBS-D.

Abstract Introduction. For patients with non-small cell lung cancer (NSCLC) to benefit from ALK inhibitors, sensitive and specific detection of ALK genomic rearrangements is needed. ALK break-apart fluorescence in situ hybridization (FISH) is the U.S. Food and Drug Administration approved and standard-of-care diagnostic assay, but identification of ALK rearrangements by other methods reported in NSCLC cases that tested negative for ALK rearrangements by FISH suggests a significant false-negative rate. We report here a large series of NSCLC cases assayed by hybrid-capture-based comprehensive genomic profiling (CGP) in the course of clinical care. Materials and Methods. Hybrid-capture-based CGP using next-generation sequencing was performed in the course of clinical care of 1,070 patients with advanced lung cancer. Each tumor sample was evaluated for all classes of genomic alterations, including base-pair substitutions, insertions/deletions, copy number alterations and rearrangements, as well as fusions/rearrangements. Results. A total of 47 patients (4.4%) were found to harbor ALK rearrangements, of whom 41 had an EML4-ALK fusion, and 6 had other fusion partners, including 3 previously unreported rearrangement events: EIF2AK-ALK, PPM1B-ALK, and PRKAR1A-ALK. Of 41 patients harboring ALK rearrangements, 31 had prior FISH testing results available. Of these, 20 were ALK FISH positive, and 11 (35%) were ALK FISH negative. Of the latter 11 patients, 9 received crizotinib based on the CGP results, and 7 achieved a response with median duration of 17 months. Conclusion. Comprehensive genomic profiling detected canonical ALK rearrangements and ALK rearrangements with noncanonical fusion partners in a subset of patients with NSCLC with previously negative ALK FISH results. In this series, such patients had durable responses to ALK inhibitors, comparable to historical response rates for ALK FISH-positive cases.

Nodular fasciitis (NF) is a clonal self‐limited neoplastic proliferation characterized by rearrangements of the USP6 locus in most examples. To our knowledge well‐documented malignant behavior has never been previously observed in NF. In this report we present an unusual case of NF with classical histologic features that showed a protracted clinical course characterized by multiple recurrences and eventual metastatic behavior over a period of 10 years. Molecular analyses revealed the presence and amplification of the novel PPPR6‐USP6 gene fusion, which resulted in USP6 mRNA transcriptional upregulation. These findings further support the oncogenic role of the USP6 protease in mesenchymal neoplasia and expand the biologic potential of NF. © 2016 Wiley Periodicals, Inc.

Purpose To develop a system prognostic of outcome in those undergoing allogeneic hematopoietic cell transplantation (allo HCT) for myelodysplastic syndrome (MDS). Patients and Methods We examined 2,133 patients with MDS undergoing HLA-matched (n = 1,728) or -mismatched (n = 405) allo HCT from 2000 to 2012. We used a Cox multivariable model to identify factors prognostic of mortality in a training subset (n = 1,151) of the HLA-matched cohort. A weighted score using these factors was assigned to the remaining patients undergoing HLA-matched allo HCT (validation cohort; n = 577) as well as to patients undergoing HLA-mismatched allo HCT. Results Blood blasts greater than 3% (hazard ratio [HR], 1.41; 95% CI, 1.08 to 1.85), platelets 50 × 109/L or less at transplantation (HR, 1.37; 95% CI, 1.18 to 1.61), Karnofsky performance status less than 90% (HR, 1.25; 95% CI, 1.06 to 1.28), comprehensive cytogenetic risk score of poor or very poor (HR, 1.43; 95% CI, 1.14 to 1.80), and age 30 to 49 years (HR, 1.60; 95% CI, 1.09 to 2.35) were associated with increased hazard of death and assigned 1 point in the scoring system. Monosomal karyotype (HR, 2.01; 95% CI, 1.65 to 2.45) and age 50 years or older (HR, 1.93; 95% CI, 1.36 to 2.83) were assigned 2 points. The 3-year overall survival after transplantation in patients with low (0 to 1 points), intermediate (2 to 3), high (4 to 5) and very high (≥ 6) scores was 71% (95% CI, 58% to 85%), 49% (95% CI, 42% to 56%), 41% (95% CI, 31% to 51%), and 25% (95% CI, 4% to 46%), respectively (P < .001). Increasing score was predictive of increased relapse (P < .001) and treatment-related mortality (P < .001) in the HLA-matched set and relapse (P < .001) in the HLA-mismatched cohort. Conclusion The proposed system is prognostic of outcome in patients undergoing HLA-matched and -mismatched allo HCT for MDS.