Citations

SummaryData from the National LymphoCare Study (a prospective, multicentre registry that enrolled follicular lymphoma (FL) patients from 2004 to 2007) were used to determine disease characteristics, treatment patterns, outcomes and prognosis for elderly FL (eFL) patients. Of 2650 FL patients, 209 (8%) were aged >80 years; these eFL patients more commonly had grade 3 disease, less frequently received chemoimmunotherapy and anthracyclines, and had lower response rates when compared to younger patients. With a median follow‐up of 6.9 years, 5‐year overall survival (OS) for eFL patients was 59%; 38% of deaths were lymphoma‐related. No treatment produced superior OS among eFL patients. In multivariate Cox models, anaemia, B‐symptoms and male sex predicted worse OS (P < 0·01); a prognostic index of these factors (0, 1 or ≥2 present) predicted OS [hazard ratio (95% CI): ≥2 vs. 0, 4·72 (2·38–9·33); 1 vs. 0, 2·63 (1·39–4·98)], with a higher concordance index (0·63) versus the Follicular Lymphoma International Prognostic Index (0·55). The index was validated in an independent cohort. In the largest prospective US‐based eFL cohort, no optimal therapy was identified and nearly 40% of deaths were lymphoma‐related, representing baseline outcomes in the modern era.

Background— Genetic studies of cardiomyopathy and heart failure have limited throughput in mammalian models. Adult zebrafish have been recently pursued as a vertebrate model with higher throughput, but genetic conservation must be tested. Methods and Results— We conducted transcriptome analysis of zebrafish heart and searched for fish homologues of 51 known human dilated cardiomyopathy–associated genes. We also identified genes with high cardiac expression and genes with differential expression between embryonic and adult stages. Among tested genes, 30 had a single zebrafish orthologue, 14 had 2 homologues, and 5 had ≥3 homologues. By analyzing the expression data on the basis of cardiac abundance and enrichment hypotheses, we identified a single zebrafish gene for 14 of 19 multiple-homologue genes and 2 zebrafish homologues of high priority for ACTC1 . Of note, our data suggested vmhc and vmhcl as functional zebrafish orthologues for human genes MYH6 and MYH7 , respectively, which are established molecular markers for cardiac remodeling. Conclusions— Most known genes for human dilated cardiomyopathy have a corresponding zebrafish orthologue, which supports the use of zebrafish as a conserved vertebrate model. Definition of the cardiac transcriptome and fetal gene program will facilitate systems biology studies of dilated cardiomyopathy in zebrafish.

ABSTRACTMutations in sarcomere genes have been found in many inheritable human diseases, including hypertrophic cardiomyopathy. Elucidating the molecular mechanisms of sarcomere assembly shall facilitate understanding of the pathogenesis of sarcomere‐based cardiac disease. Recently, biochemical and genomic studies have identified many new genes encoding proteins that localize to the sarcomere. However, their precise functions in sarcomere assembly and sarcomere‐based cardiac disease are unknown. Here, we review zebrafish as an emerging vertebrate model for these studies. We summarize the techniques offered by this animal model to manipulate genes of interest, annotate gene expression, and describe the resulting phenotypes. We survey the sarcomere genes that have been investigated in zebrafish and discuss the potential of applying this in vivo model for larger‐scale genetic studies. Anat Rec, 297:1681–1693, 2014. © 2014 Wiley Periodicals, Inc.

Background. Dilated cardiomyopathy (DCM) is one of the leading causes of heart failure with high morbidity and mortality. Although more than 40 genes have been reported to cause DCM, the role of genetic testing in clinical practice is not well defined. Mutations in the troponin T (TNNT2) gene represent an important subset of known disease-causing mutations associated with DCM. Therefore, the aim of the present study was to determine the genetic variations inTNNT2and the associations of those variations with DCM in Chinese patients.Methods. An approximately 4 kb fragment of theTNNT2gene was isolated from 103 DCM patients and 192 healthy controls and was analyzed by DNA sequence analysis for genetic variations.Results. A total of 6TNNT2mutations were identified in 99 patients, including a G321T missense mutation (Leu84Phe) and 5 novel intronic mutations. Alleles of two novel SNPs (c.192+353C>A, OR=0.095, 95% CI:0.013–0.714,P=0.022; c.192+463G>A, OR=0.090, 95% CI:0.012–0.675,P=0.019) and SNP rs3729843 (OR=1.889, 95% CI:1.252–2.852;P=0.002) were significantly correlated with DCM.Conclusions. These results suggest that the missense mutation (Leu84Phe) and two novel SNPs (c.192+353C>A, c.192+463G>A) inTNNT2gene might be associated with DCM in the Chinese population.

BACKGROUNDThe authors examined the “real‐world” effectiveness of rituximab (R) maintenance therapy (R‐maintenance) compared with observation after R‐based induction therapy in patients with previously untreated follicular lymphoma (FL) in the United States.METHODSThe National LymphoCare Study is a prospective, multicenter, observational study that enrolled > 2700 untreated patients with FL diagnosed from 2004 to 2007 at 265 sites in the United States. Among these, patients who achieved at least stable disease after R‐based induction therapy were eligible for the current analysis. Patients who initiated R‐maintenance within 215 days of completing induction therapy were categorized as the R‐maintenance group, and those who did not initiate therapy during this period were categorized as the observation group. The objective of the current study was to determine the effect of R‐maintenance on progression‐free survival (PFS), time to next treatment (TTNT), and overall survival (OS).RESULTSA total of 1439 patients completed R‐based induction therapy, 1186 of whom met all inclusion criteria (541 patients received R‐maintenance and 645 patients were observed). Characteristics that were found to be predictive of receiving R‐maintenance were histology grade (1/2), Ann Arbor stage of disease (III/IV), geographic region (region other than the West), and practice setting (community practice). With a median follow‐up of 5.7 years, R‐maintenance was associated with superior PFS (hazards ratio [HR], 0.68; 95% confidence interval [95% CI], 0.56‐0.84 [P = .0003]) and TTNT (HR, 0.66; 95% CI, 0.52‐0.84 [P = .0007]). No significant difference in OS was observed (HR, 0.81; 95% CI, 0.58‐1.14 [P = .23]).CONCLUSIONSR‐maintenance in patients with FL and at least stable disease after R‐based induction therapy provided significantly longer PFS and TTNT in comparison with observation, but no significant difference in OS was observed with 5‐years of follow‐up. This comparative effectiveness study aligns with the results of randomized trials suggesting that similar outcomes occur with R‐maintenance in FL with the treatment variations observed in clinical practice. Cancer 2014;120:1830–1837. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Contraction regulates heart development via a complex mechanotransduction process controlled by various mechanical forces. Here, we exploit zebrafish embryos as an in vivo animal model to discern the contribution from different mechanical forces and identify the underlying mechanotransductive signaling pathways of cardiogenesis. We treated 2 days postfertilization zebrafish embryos with Blebbistatin, a myosin II inhibitor, to stop cardiac contraction, which induces a response termed cessation of contraction-induced cardiomyocyte (CM) enlargement (CCE). Accompanying the CCE, lateral fusion of myofibrils was attenuated within CMs. The CCE can be blunted by loss of blood in tail-docked zebrafish but not in cloche mutant fish, suggesting that transmural pressure rather than shear stress is accountable for the chamber enlargement. By screening a panel of small molecule inhibitors, our data suggested essential functions of phosphoinositide 3-kinase signaling and protein synthesis in CCE, which are independent of the sarcomere integrity. In summary, we defined a unique CCE response in genetically tractable zebrafish embryos. A panel of assays was established to verify the contribution from extrinsic forces and interrogate underlying signaling pathways.

Recent advances in the burgeoning field of genome engineering are accelerating the realization of personalized therapeutics for cardiovascular disease. In the postgenomic era, sequence-specific gene-editing tools enable the functional analysis of genetic alterations implicated in disease. In partnership with high-throughput model systems, efficient gene manipulation provides an increasingly powerful toolkit to study phenotypes associated with patient-specific genetic defects. Herein, this review emphasizes the latest developments in genome engineering and how applications within the field are transforming our understanding of personalized medicine with an emphasis on cardiovascular diseases.

SummaryPatients with myelofibrosis (MF) have significant debilitating symptoms, physical disabilities, and poor health‐related quality of life (HRQoL). Here, we report post‐hoc analyses of the impact of ruxolitinib, a potent and selective JAK1 and JAK2 inhibitor, on disease‐related symptoms and HRQoL in MF patients from the large phase 3 COMFORT‐II study (N = 219). During the follow‐up period of 48 weeks, HRQoL and MF‐associated symptoms improved from baseline for ruxolitinib‐treated patients but remained the same or worsened for best available therapy (BAT)‐treated patients. Based on the European Organization for Research and Treatment of Cancer QoL Questionnaire core 30 items (EORTC QLQ‐C30), treatment‐induced differences in physical and role functioning, fatigue, and appetite loss significantly favoured ruxolitinib versus BAT from week 8 (P < 0·05) up to week 48 (P < 0·05). Ruxolitinib resulted in significantly higher response rates in global health status/QoL and Functional Assessment of Cancer Therapy‐Lymphoma (FACT‐Lym) summary scores versus BAT at most time points (P < 0·05). Significant improvements in the Lymphoma subscale (including symptoms of pain, fever, itching, fatigue, weight loss, loss of appetite, and other patient concerns), FACT‐General, FACT‐Lym trial outcome index, and FACT‐Lym total were also observed with ruxolitinib versus BAT starting at week 8 and continuing thereafter. Overall, these data demonstrated that ruxolitinib improved HRQoL in MF patients and further support the use of ruxolitinib for the treatment of symptomatic MF.

Rationale: Mutagenesis screening is a powerful genetic tool for probing biological mechanisms underlying vertebrate development and human diseases. However, the increased colony management efforts in vertebrates impose a significant challenge for identifying genes affecting a particular organ, such as the heart, especially those exhibiting adult phenotypes on depletion. Objective: We aim to develop a facile approach that streamlines colony management efforts via enriching cardiac mutants, which enables us to screen for adult phenotypes. Methods and Results: The transparency of the zebrafish embryos enabled us to score 67 stable transgenic lines generated from an insertional mutagenesis screen using a transposon-based protein trapping vector. Fifteen lines with cardiac monomeric red fluorescent protein reporter expression were identified. We defined the molecular nature for 10 lines and bred them to homozygosity, which led to the identification of 1 embryonic lethal, 1 larval lethal, and 1 adult recessive mutant exhibiting cardiac hypertrophy at 1 year of age. Further characterization of these mutants uncovered an essential function of methionine adenosyltransferase II, α a (mat2aa) in cardiogenesis, an essential function of mitochondrial ribosomal protein S18B (mrps18b) in cardiac mitochondrial homeostasis, as well as a function of DnaJ (Hsp40) homolog, subfamily B, member 6b (dnajb6b) in adult cardiac hypertrophy. Conclusions: We demonstrate that transposon-based gene trapping is an efficient approach for identifying both embryonic and adult recessive mutants with cardiac expression. The generation of a zebrafish insertional cardiac mutant collection shall facilitate the annotation of a vertebrate cardiac genome, as well as enable heart-based adult screens.

α ‐Actinin2 (Actn2) is a predominant protein in the sarcomere Z disc whose mutation can lead to cardiomyopathy. However, the function of Actn2 in Z‐disc assembly and cardiomyopathy in vertebrates remains elusive. We leveraged genetic tools in zebrafish embryos to elucidate the function of Actn2. We identified a single Actn2 homologue expressed in the zebrafish heart and conducted loss‐of‐function studies by antisense morpholino technology. Although zebrafish Actn2 assembles early into the Z disc, depletion of actn2 did not affect the early steps of sarcomere assembly. Instead, Actn2 is required for Z bodies to register laterally, forming well‐aligned Z discs. Presumably as a consequence to this structural defect in the sarcomere, the depletion of Actn2 resulted in reduced cardiac function, primarily characterized as a reduced end‐diastolic diameter. The depletion of actn2 also significantly reduced the ventricle chamber size, due to both reduced cardiomyocyte (CM) size and CM number. Interestingly, reduced CM size can be rescued by the cessation of heart contractions. The genetic studies of zebrafish uncovered a function for actn2 in lateral registration of Z body. In actn2 morphant fish, the Z ‐disc defect sequentially affects cardiac function, which leads to morphological changes in the ventricle through a mechanical force‐dependent mechanism.—Yang, J., Xu, X. α ‐Actinin2 is required for the lateral alignment of Z discs and ventricular chamber enlargement during zebrafish cardiogenesis. FASEB J. 26, 4230–4242 (2012). www.fasebj.org