MiRNA-200C expression in Fanconi anemia pathway functionally deficient lung cancers

The Fanconi Anemia (FA) pathway is essential for human cells to maintain genomic integrity following DNA damage. This pathway is involved in repairing damaged DNA through homologous recombination. Cancers with a defective FA pathway are expected to be more sensitive to cross-link based therapy or PARP inhibitors. To evaluate downstream effectors of the FA pathway, we studied the expression of 734 different micro RNAs (miRNA) using NanoString nCounter miRNA array in two FA defective lung cancer cells and matched control cells, along with two lung tumors and matched non-tumor tissue samples that were deficient in the FA pathway. Selected miRNA expression was validated with real-time PCR analysis. Among 734 different miRNAs, a cluster of microRNAs were found to be up-regulated including an important cancer related micro RNA, miR-200C. MiRNA-200C has been reported as a negative regulator of epithelial-mesenchymal transition (EMT) and inhibits cell migration and invasion by promoting the upregulation of E-cadherin through targeting ZEB1 and ZEB2 transcription factors. miRNA-200C was increased in the FA defective lung cancers as compared to controls. AmpliSeq analysis showed significant reduction in ZEB1 and ZEB2 mRNA expression. Our findings indicate the miRNA-200C potentially play a very important role in FA pathway downstream regulation

Expression of a Mutant p53 Results in an Age-Related Demographic Shift in Spontaneous Lung Tumor Formation in Transgenic Mice

BACKGROUND:Mutations in the P53 gene are among the most common genetic abnormalities in human lung cancer. Codon 273 in the sequence-specific DNA binding domain is one of the most frequently mutated sites. METHODOLOGY:To investigate the role of mutant p53 in lung tumorigenesis, a lung specific p53(273H) transgenic mouse model was developed. Rates of lung cancer formation in the transgenic animals and their littermates were evaluated by necropsy studies performed in progressive age cohorts ranging from 4 to 24 months. In order to establish the influence of other common genetic abnormalities in lung tumor formation in the animals, K-Ras gene mutation and p16INK4a (p16) promoter methylation were evaluated in a total of 281 transgenic mice and 189 non-transgenic littermates. PRINCIPAL FINDINGS:At the age extremes of 4-12 and 22-24 months no differences were observed, with very low prevalence of tumors in animals younger than 12 months, and a relatively high prevalence at age 22 months or older. However, the transgenic mice had a significant higher lung tumor rate than their non-transgenic counterparts during the age of 13-21 months, suggesting an age-related shift in lung tumor formation induced by the lung-specific expression of the human mutant p53. Histopathology suggested a more aggressive nature for the transgenic tumors. Older mice (>13 months) had a significantly higher rate of p16 promoter methylation (17% v 82%). In addition, an age related effect was observed for K-Ras codons 12 or 13 mutations, but not for codon 61 mutations. CONCLUSIONS/SIGNIFICANCE:These results would suggest that the mutant p53(273H) contributes to an acceleration in the development of spontaneous lung tumors in these mice. Combination with other genetic and epigenetic alterations occurring after the age of 13 months is intimately linked to its oncogenic potential

A new opportunity for the emerging tellurium semiconductor: making resistive switching devices

Abstract: The development of the resistive switching cross-point array as the next-generation platform for high-density storage, in-memory computing and neuromorphic computing heavily relies on the improvement of the two component devices, volatile selector and nonvolatile memory, which have distinct operating current requirements. The perennial current-volatility dilemma that has been widely faced in various device implementations remains a major bottleneck. Here, we show that the device based on electrochemically active, low-thermal conductivity and low-melting temperature semiconducting tellurium filament can solve this dilemma, being able to function as either selector or memory in respective desired current ranges. Furthermore, we demonstrate one-selector-one-resistor behavior in a tandem of two identical Te-based devices, indicating the potential of Te-based device as a universal array building block. These nonconventional phenomena can be understood from a combination of unique electrical-thermal properties in Te. Preliminary device optimization efforts also indicate large and unique design space for Te-based resistive switching devices

Germline Stem Cell Gene PIWIL2 Mediates DNA Repair through Relaxation of Chromatin

DNA damage response (DDR) is an intrinsic barrier of cell to tumorigenesis initiated by genotoxic agents. However, the mechanisms underlying the DDR are not completely understood despite of extensive investigation. Recently, we have reported that ectopic expression of germline stem cell gene PIWIL2 is associated with tumor stem cell development, although the underlying mechanisms are largely unknown. Here we show that PIWIL2 is required for the repair of DNA-damage induced by various types of genotoxic agents. Upon ultraviolet (UV) irradiation, silenced PIWIL2 gene in normal human fibroblasts was transiently activated after treatment with UV light. This activation was associated with DNA repair, because Piwil2-deficienct mouse embryonic fibroblasts (mili-/- MEFs) were defective in cyclobutane pyrimidine dimers (CPD) repair after UV treatment. As a result, the UV-treated mili-/- MEFs were more susceptible to apoptosis, as characterized by increased levels of DNA damage-associated apoptotic proteins, such as active caspase-3, cleaved Poly (ADP-ribose) polymerase (PARP) and Bik. The impaired DNA repair in the mili-/- MEFs was associated with the reductions of histone H3 acetylation and chromatin relaxation, although the DDR pathway downstream chromatin relaxation appeared not to be directly affected by Piwil2. Moreover, guanine–guanine (Pt-[GG]) and double strand break (DSB) repair were also defective in the mili-/- MEFs treated by genotoxic chemicals Cisplatin and ionizing radiation (IR), respectively. The results indicate that Piwil2 can mediate DNA repair through an axis of Piwil2 → histone acetylation → chromatin relaxation upstream DDR pathways. The findings reveal a new role for Piwil2 in DNA repair and suggest that Piwil2 may act as a gatekeeper against DNA damage-mediated tumorigenesis

Notch3-dependent β-catenin signaling mediates EGFR TKI drug persistence in EGFR mutant NSCLC

EGFR tyrosine kinase inhibitors cause dramatic responses in EGFR-mutant lung cancer, but resistance universally develops. The involvement of β-catenin in EGFR TKI resistance has been previously reported, however, the precise mechanism by which β-catenin activation contributes to EGFR TKI resistance is not clear. Here, we show that EGFR inhibition results in the activation of β-catenin signaling in a Notch3-dependent manner, which facilitates the survival of a subset of cells that we call “adaptive persisters”. We previously reported that EGFR-TKI treatment rapidly activates Notch3, and here we describe the physical association of Notch3 with β-catenin, leading to increased stability and activation of β-catenin. We demonstrate that the combination of EGFR-TKI and a β-catenin inhibitor inhibits the development of these adaptive persisters, decreases tumor burden, improves recurrence free survival, and overall survival in xenograft models. These results supports combined EGFR-TKI and β-catenin inhibition in patients with EGFR mutant lung cancer

25.当院における内視鏡的乳頭切開術の臨床的検討(第617回千葉医学会例会・第1内科教室同門会例会)

Primer sequences and amplicon sizes. (DOCX 15 kb

Precancerous Stem Cells Have the Potential for both Benign and Malignant Differentiation

Cancer stem cells (CSCs) have been identified in hematopoietic and solid tumors. However, their precursors—namely, precancerous stem cells (pCSCs) —have not been characterized. Here we experimentally define the pCSCs that have the potential for both benign and malignant differentiation, depending on environmental cues. While clonal pCSCs can develop into various types of tissue cells in immunocompetent mice without developing into cancer, they often develop, however, into leukemic or solid cancers composed of various types of cancer cells in immunodeficient mice. The progress of the pCSCs to cancers is associated with the up-regulation of c-kit and Sca-1, as well as with lineage markers. Mechanistically, the pCSCs are regulated by the PIWI/AGO family gene called piwil2. Our results provide clear evidence that a single clone of pCSCs has the potential for both benign and malignant differentiation, depending on the environmental cues. We anticipate pCSCs to be a novel target for the early detection, prevention, and therapy of cancers

Teaching French pronunciation to Chinese adult learners in communicative language classrooms: examining the effectiveness of explicit phonetic instruction

Explicit instruction (EI) on pronunciation integrated into form-focused instruction has proven effective in second language (L2) speech development (Saito, 2013). However, most studies examined L2 segmental targets (e.g., Lee & Lyster, 2016). Accordingly, building on previous studies, this study investigates the extent to which Chinese learners of French benefit from EI on their acquisition of three different French prosody patterns: declarative sentences, yes/no questions, and information questions.Thirty-four Chinese learners of French were assigned to either a treatment group (n = 20) or a control group (n = 14). Each group attended four 1.5-hours instructional sessions that included exposure to both structured input and typographically enhanced input as well as participation in focused production tasks. In addition, the treatment group (but not the control group) received metalinguistic explanations regarding the three different prosody types as well as explicit correction of their nontargetlike prosody patterns. A pretest and a posttest were conducted in a researcher-participant dyadic setting in which the participants completed sentence-reading tasks composed of trained and untrained sentences. The audio-recorded speech samples were filtered to avoid segmental influences, and then rated by three native speakers of French for analyses. Results revealed that the treatment group overall significantly outperformed the control group at the posttest in both trained and untrained sentences. In particular, the participants benefited most from the EI on declarative sentences and information questions in the untrained sentences. This thesis concludes, therefore, by highlighting the effectiveness of EI on L2 suprasegmental targets.L'enseignement explicite de la prononciation intégré dans l'enseignement centré sur la forme s'est avéré efficace pour le développement d'une langue seconde (Saito, 2013). Cependant, la plupart des études ont examiné les prononciations segmentales (ex. : Lee & Lyster, 2016). En conséquence, s'appuyant sur les études précédentes, cette étude enquête sur le degré auquel les apprenants chinois du français profitent de l'enseignement explicite de la prononciation sur leur acquisition de trois différents types de prosodies de la langue française : les phrases déclaratives, les questions totales et les questions partielles.Trente-quatre apprenants chinois du français ont été attribués soit au groupe expérimental (n = 20) soit au groupe témoin (n = 14). Chaque groupe a assisté à quatre sessions d'enseignement d'une durée d'une heure et demie chaque et comprenant l'exposition aux intrants structurés et à la mise en évidence textuelle.En plus, le groupe expérimental (mais pas le groupe témoin) a reçu des explications métalinguistiques à propos des trois différents types de prosodie française ainsi que la correction explicite visant leurs productions non conformes à la normeUn prétest et un posttest ont été effectués dans un cadre dyadique (chercheur-participant). Les participants ont lu à haute voix des phrases dont certaines ont fait l'objet de l'enseignement et d'autres non. Les échantillons de discours ont été d'abord enregistrés et ensuite filtrés afin d'éviter les influences des prononciations segmentales. Les productions ont été enfin évaluées par les évaluateurs francophones pour les analyses. L'analyse des résultats a démontré que le groupe expérimental a nettement surclassé le groupe témoin au posttest dans les phrases ciblées par l'enseignement ainsi que dans celles qui ne l'étaient pas. En particulier, les participants ont profité le plus de l'enseignement explicite de la prononciation sur les phrases déclaratives et sur les questions partielles dans les phrases non ciblées par l'enseignement. Enfin, ce mémoire conclut à l'efficacité de l'enseignement explicite de la prononciation sur L2 prononciation au niveau suprasegmental

HOME RANGE AND HABITAT USE BY ISOLATION-REARED SANDHILL CRANES

We isolation-reared, placed radio transmitters on, and released 38 greater sandhill cranes (Grus canadensis tabida) on Seney National Wildlife Refuge (Seney) in 1988-90 to develop procedures for initiating new populations of cranes. Here we report on habitat selection by breeding birds with functional radio transmitters. Home ranges established by 6 cranes in 1992, when they were 2 to 4 years old, averaged 199±50.8 (SE) ha (harmonic mean method, 75 % utilization) and were of 2 types: feeding grounds separated from nesting habitat and feeding grounds adjacent to nesting habitat. Home ranges consisted of 36% emergent palustrine wetlands, 28% forested upland, 11 % open upland, and 11 % forested palustrine; the remainder was scrub-shrub, upland shrub, bog, or open water. Four of 5 cranes monitored in 1993 nested-all in emergent palustrine wetlands, also the nesting habitat of wild sandhill cranes at Seney. Open field and mudflat were the major feeding habitats, as they were for wild cranes. Five of the 6 cranes did not use habitats in proportion to availability in the home range (X2 , P \u3c 0.05). Three cranes significantly selected emergent palustrine wetlands and no crane avoided this habitat type; 2 cranes selected open upland, and no crane avoided this type; and 4 cranes avoided forested palustrine, and no crane preferentially selected this habitat type. The nesting areas of the 4 cranes in 1993 were the same areas they used in 1992, when they were paired but were not known to have nested. Feeding grounds changed according to their availability in the 2 years