TALEN-mediated apc mutation in Xenopus tropicalis phenocopies familial adenomatous polyposis

Truncating mutations in the tumor suppressor gene adenomatous polyposis coli (APC) are the initiating step in the vast majority of sporadic colorectal cancers, and they underlie familial adenomatous polyposis (FAP) syndromes. Modeling of APC- driven tumor formation in the mouse has contributed substantially to our mechanistic understanding of the associated disease, but additional models are needed to explore therapeutic opportunities and overcome current limitations of mouse models. We report on a novel and penetrant genetic cancer model in Xenopus tropicalis, an aquatic tetrapod vertebrate with external development, diploid genome and short life cycle. Tadpoles and froglets derived from embryos injected with TAL effector nucleases targeting the apc gene rapidly developed intestinal hyperplasia and other neoplasms observed in FAP patients, including desmoid tumors and medulloblastomas. Bi-allelic apc mutations causing frame shifts were detected in the tumors, which displayed activation of the Wnt/β-catenin pathway and showed increased cellular proliferation. We further demonstrate that simultaneous double bi-allelic mutation of apc and a non-relevant gene is possible in the neoplasias, opening the door for identification and characterization of effector or modifier genes in tumors expressing truncated apc. Our results demonstrate the power of modeling human cancer in Xenopus tropicalis using mosaic TALEN-mediated bi-allelic gene disruption

Nuclear-Spin Relaxation in Molecular Solids with Reorienting Methyl and \u3ci\u3et\u3c/i\u3e-Butyl Groups: The Spectral Density and the State of the Solid

There are two solid phases which either have a large hysteresis of at least 90 K, or are both stable below 200 K. The sample melts at 262 K. We interpret the high-temperature phase R-versus-T-1 data with three models. First, we adopt a one-correlation-time model using a Davidson-Cole spectral density which suggests that there is a distribution of correlation times, or, equivalently, a distribution of activation energies for t-butyl and methyl group reorientation. In this case, the methyl and t-butyl reorientation is characterized by a cutoff activation energy of 17±1 kJ/mol which is to be compared with 18±1 kJ/mol in 1,4-DTB [P. A. Beckmann, F. A. Fusco, and A. E. O’Neill, J. Magn. Reson. 59, 63 (1984)] in which there is only the one phase. Second, we adopt two two-correlation-time models using Bloembergen-Purcell-Pound spectral densities; one based on the dynamical inequivalence of the methyl groups in each t-butyl group and one based on the dynamical inequivalence of different t-butyl groups, either because of intramolecular effects or because of intermolecular (crystal-structure) effects. In the low-temperature phase of 1,3-DTB, R(ω,T) is unusual in that it is Larmor-frequency dependent in the short-correlation-time limit (i.e., temperatures above the relaxation rate maximum). We have fit the data with a Havriliak-Negami spectral density (which reduces to a Davidson-Cole spectral density when one of the parameters becomes unity which, in turn, reduces to a Bloembergen-Purcell-Pound spectral density when an additional parameter becomes unity). The fit, with an effective activation energy of 10±3 kJ/mol, suggests that this low-temperature phase in 1,3-DTB is a glassy state. We relate the Havriliak-Negami spectral density to the Dissado-Hill spectral density which has a fundamental microscopic basis and which has been used to interpret a vast quantity of dielectric relaxation data as well as some mechanical relaxation data

Nuclear-Spin Relaxation in Molecular Solids with Reorienting Methyl and \u3ci\u3et\u3c/i\u3e-Butyl Groups: The Spectral Density and the State of the Solid

There are two solid phases which either have a large hysteresis of at least 90 K, or are both stable below 200 K. The sample melts at 262 K. We interpret the high-temperature phase R-versus-T-1 data with three models. First, we adopt a one-correlation-time model using a Davidson-Cole spectral density which suggests that there is a distribution of correlation times, or, equivalently, a distribution of activation energies for t-butyl and methyl group reorientation. In this case, the methyl and t-butyl reorientation is characterized by a cutoff activation energy of 17±1 kJ/mol which is to be compared with 18±1 kJ/mol in 1,4-DTB [P. A. Beckmann, F. A. Fusco, and A. E. O’Neill, J. Magn. Reson. 59, 63 (1984)] in which there is only the one phase. Second, we adopt two two-correlation-time models using Bloembergen-Purcell-Pound spectral densities; one based on the dynamical inequivalence of the methyl groups in each t-butyl group and one based on the dynamical inequivalence of different t-butyl groups, either because of intramolecular effects or because of intermolecular (crystal-structure) effects. In the low-temperature phase of 1,3-DTB, R(ω,T) is unusual in that it is Larmor-frequency dependent in the short-correlation-time limit (i.e., temperatures above the relaxation rate maximum). We have fit the data with a Havriliak-Negami spectral density (which reduces to a Davidson-Cole spectral density when one of the parameters becomes unity which, in turn, reduces to a Bloembergen-Purcell-Pound spectral density when an additional parameter becomes unity). The fit, with an effective activation energy of 10±3 kJ/mol, suggests that this low-temperature phase in 1,3-DTB is a glassy state. We relate the Havriliak-Negami spectral density to the Dissado-Hill spectral density which has a fundamental microscopic basis and which has been used to interpret a vast quantity of dielectric relaxation data as well as some mechanical relaxation data

Too little, too late: A longitudinal study of English corrective focus by Mandarin speakers

This study tracks the production of English corrective focus by Mandarin speakers (MS) living in the US over a two-year period. We show that the MS differed from English speakers (ES) in the alignment of the corrective focus pitch accent: while ES productions typically showed a pitch peak on the stressed syllable, followed by an abrupt fall, the pitch rise and fall for MS was later and less steep. While the MS productions became more English-like over time in some respects, the failure to correctly align pitch accent persisted over time. We argue that this misalignment of pitch peak cannot be attributed to a lack of sensitivity to English stress, but rather represents a common failure to master the complex timing patterns involved in synchronizing pitch, intensity, and duration cues with segmental structure in a second language

Laparoscopic versus open liver resection: a meta‐analysis of long‐term outcome

AbstractBackgroundLaparoscopic liver resection is growing in popularity, but the long‐term outcome of patients undergoing laparoscopic liver resection for malignancy has not been established. This paper is a meta‐analysis and compares the long‐term survival of patients undergoing laparoscopic (LHep) versus open (OHep) liver resection for the treatment of malignant liver tumours.MethodsA PubMed database search identified comparative human studies analysing LHep versus OHep for malignant tumours. Clinical and survival parameters were extracted. The search was last conducted on 18 March 2012.ResultsIn total, 1002 patients in 15 studies were included (446 LHep and 556 OHep). A meta‐analysis of overall survival showed no difference [1‐year: odds ratio (OR) 0.71, 95% confidence interval (CI) 0.42 to 1.20, P = 0.202; 3‐years: OR 0.76, 95% CI 0.56 to 1.03, P = 0.076; 5‐years: OR 0.8, 95% CI 0.59 to 1.10, P = 0.173]. Subset analyses of hepatocellular carcinoma (HCC) and colorectal metastases (CRM) were performed. There was no difference in the 1‐, 3‐, and 5‐year survival for HCC or in the 1‐year survival for CRM, however, a survival advantage was found for CRM at 3 years (LHep 80% versus OHep 67.4%, P = 0.036).ConclusionsLaparoscopic surgery should be considered an acceptable alternative for the treatment of malignant liver tumours

A developmental transition in definitive erythropoiesis: erythropoietin expression is sequentially regulated by retinoic acid receptors and HNF4

The cytokine erythropoietin (Epo) promotes erythropoietic progenitor cell proliferation and is required for erythropoietic differentiation. We have found that the Epo gene is a direct transcriptional target gene of retinoic acid signaling during early erythropoiesis (prior to embryonic day E12.5) in the fetal liver. Mouse embryos lacking the retinoic acid receptor gene RXRα have a morphological and histological phenotype that is comparable with embryos in which the Epo gene itself has been mutated, and flow cytometric analysis indicates that RXRα-deficient embryos are deficient in erythroid differentiation. Epo mRNA levels are reduced substantially in the fetal livers of RXRα ^(−/−)embryos at E10.25 and E11.25, and genetic analysis shows that theRXRα and Epo genes are coupled in the same pathway. We furthermore show that the Epo gene is retinoic acid inducible in embryos, and that the Epo gene enhancer contains a DR2 sequence that represents a retinoic acid receptor-binding site and a retinoic acid receptor transcriptional response element. However, unlike Epo-deficient embryos that die from anemia, the erythropoietic deficiency in RXRα ^(−/−) embryos is transient; Epo mRNA is expressed at normal levels by E12.5, and erythropoiesis and liver morphology are normal by E14.5. We show that HNF4, like RXRα a member of the nuclear receptor family, is abundantly expressed in fetal liver hepatocytes, and is competitive with retinoic acid receptors for occupancy of the Epo gene enhancer DR2 element. We propose that Epo expression is regulated during the E9.5–E11.5 phase of fetal liver erythropoiesis by RXRα and retinoic acid, and that expression then becomes dominated by HNF_4 activity from E11.5 onward. This transition may be responsible for switching regulation of Epo expression from retinoic acid control to hypoxic control, as is found throughout the remainder of life

Critical Roles for Interleukin 1 and Tumor Necrosis Factor α in Antibody-induced Arthritis

In spontaneous inflammatory arthritis of K/BxN T cell receptor transgenic mice, the effector phase of the disease is provoked by binding of immunoglobulins (Igs) to joint surfaces. Inflammatory cytokines are known to be involved in human inflammatory arthritis, in particular rheumatoid arthritis, although, overall, the pathogenetic mechanisms of the human affliction remain unclear. To explore the analogy between the K/BxN model and human patients, we assessed the role and relative importance of inflammatory cytokines in K/BxN joint inflammation by transferring arthritogenic serum into a panel of genetically deficient recipients. Interleukin (IL)-1 proved absolutely necessary. Tumor necrosis factor (TNF)–α was also required, although seemingly less critically than IL-1, because a proportion of TNF-α–deficient mice developed robust disease. There was no evidence for an important role for IL-6. Bone destruction and reconstruction were also examined. We found that all mice with strong inflammation exhibited the bone erosion and reconstruction phenomena typical of K/BxN arthritis, with no evidence of any particular requirement for TNFα for bone destruction. The variability in the requirement for TNF-α, reminiscent of that observed in treated rheumatoid arthritis patients, did not appear genetically programmed but related instead to subtle environmental changes

A Splice Variant of NCOR2, BQ323636.1, Confers Chemoresistance in Breast Cancer by Altering the Activity of NRF2.

Breast cancer is the most common type of female cancer. Reactive oxygen species (ROS) are vital in regulating signaling pathways that control cell survival and cell proliferation. Chemotherapeutic drugs such as anthracyclines induce cell death via ROS induction. Chemoresistance development is associated with adaptive response to oxidative stress. NRF2 is the main regulator of cytoprotective response to oxidative stress. NRF2 can enhance cell growth, antioxidant expression, and chemoresistance by providing growth advantage for malignant cells. Previously, we identified BQ323636.1 (BQ), a novel splice variant of nuclear co-repressor NCOR2, which can robustly predict tamoxifen resistance in primary breast cancer. In this study, we found that BQ was overexpressed in epirubicin-resistant cells and demonstrated that BQ overexpression could reduce the levels of epirubicin-induced ROS and confer epirubicin resistance. In vivo analysis using tissue microarray of primary breast cancer showed direct correlation between BQ expression and chemoresistance. In vitro experiments showed BQ could modulate NRF2 transcriptional activity and upregulate antioxidants. Luciferase reporter assays showed that although NCOR2 repressed the transcriptional activity of NRF2, the presence of BQ reduced this repressive activity. Co-immunoprecipitation confirmed that NCOR2 could bind to NRF2 and that this interaction was compromised by BQ overexpression, leading to increased transcriptional activity in NRF2. Our findings suggest BQ can regulate the NRF2 signaling pathway via interference with NCOR2 suppressive activity and reveals a novel role for BQ as a modulator of chemoresistance in breast cancer

Rosette-Disrupting Effect of an Anti-Plasmodial Compound for the Potential Treatment of Plasmodium falciparum Malaria Complications

The spread of artemisinin-resistant parasites could lead to higher incidence of patients with malaria complications. However, there are no current treatments that directly dislodge sequestered parasites from the microvasculature. We show that four common antiplasmodial drugs do not disperse rosettes (erythrocyte clusters formed by malaria parasites) and therefore develop a cell-based high-throughput assay to identify potential rosette-disrupting compounds. A pilot screen of 2693 compounds identified Malaria Box compound MMV006764 as a potential candidate. Although it reduced rosetting by a modest 20%, MMV006764 was validated to be similarly effective against both blood group O and A rosettes of three laboratory parasite lines. Coupled with its antiplasmodial activity and drug-likeness, MMV006764 represents the first small-molecule compound that disrupts rosetting and could potentially be used in a resource-limited setting to treat patients deteriorating rapidly from malaria complications. Such dual-action drugs that simultaneously restore microcirculation and reduce parasite load could significantly reduce malaria morbidity and mortality

Effect of Extending the Original CROSS Criteria on Tumor Response to Neoadjuvant Chemoradiotherapy in Esophageal Cancer Patients:A National Multicenter Cohort Analysis

BACKGROUND: Extending the original criteria of the Chemoradiotherapy for Oesophageal Cancer followed by Surgery Study (CROSS) in daily practice may increase the treatment outcome of esophageal cancer (EC) patients. This retrospective national cohort study assessed the impact on the pathologic complete response (pCR) rate and surgical outcome. PATIENTS AND METHODS: Data from EC patients treated between 2009 and 2017 were collected from the national Dutch Upper Gastrointestinal Cancer Audit database. Patients had locally advanced EC (cT1/N+ or cT2-4a/N0-3/M0) and were treated according to the CROSS regimen. CROSS (n = 1942) and the extended CROSS (e-CROSS; n = 1359) represent patients fulfilling the original or extended CROSS criteria, respectively. The primary outcome was total pCR (ypT0N0), while secondary outcomes were local esophageal pCR (ypT0), surgical radicality, and postoperative morbidity and mortality. RESULTS: Overall, CROSS and e-CROSS did not differ in total or local pCR rate, although a trend was observed (23.2% vs. 20.4%, p = 0.052; and 26.7% vs. 23.8%, p = 0.061). When stratifying by histology, the pCR rate was higher in the CROSS group compared with e-CROSS in squamous cell carcinomas (48.2% vs. 33.3%, p = 0.000) but not in adenocarcinomas (16.8% vs. 16.9%, p = 0.908). Surgical radicality did not differ between groups. Postoperative mortality (3.2% vs. 4.6%, p = 0.037) and morbidity (58.3% vs. 61.8%, p = 0.048) were higher in e-CROSS. CONCLUSION: Extending the CROSS inclusion criteria for neoadjuvant chemoradiotherapy in routine clinical practice of EC patients had no impact on the pCR rate and on radicality, but was associated with increased postoperative mortality and morbidity. Importantly, effects differed between histological subtypes. Hence, in future studies, we should carefully reconsider who will benefit most in the real-world setting