169,948 research outputs found
mTORc1의 억제와 mTORc2 활성을 통한 BTG2/TIS21/PC3의 유방암 악성화 억제 및 세포 분열 억제 기전 연구
No full text12-O-tetradecanoyl phorbol-13-acetate (TPA)-inducible sequences 21 (TIS21)-an ortholog of B-cell translocation gene 2 (BTG2) in humans and pheochromocytoma cell-3 (PC3) in rats- is an antiproliferative and early growth response gene and belongs to a family of six proteins which includes BTG1-4 and Tob1, Tob2. All these proteins contain APRO domain at the N-terminus with highly conserved sequences termed Box A and Box B. However the C-terminus is less conserved except for the presence of PAM2 motif (Poly-A binding protein Motif 2) in Tob 1 and 2. BTG2 is induced following DNA damage in a p53-dependent and -independent manner by protein kinase C-δ. BTG2 induces cell cycle arrest by inhibiting cyclin D1 and E, as well as CDK4, depending on pRB activity, and by interacting with cyclin B1/CDK1. BTG2 is constitutively expressed in all human tissues but lost during the early stage of carcinogenesis and loss of BTG2 expression is associated with the size and grade of ER-positive breast cancers along with breast tumor progression. We previously reported that BTG2 inhibits invadopodia formation by downregulating reactive oxygen species (ROS) through targeting of the mDia genes and regulated AKT phosphorylation at S473 . We therefore tried to explore the mechanism of AKT activation by the BTG2 gene and its outcome in breast carcinogenesis. It has been reported that AKT1 inhibits cancer progression, but maintains cancer cell growth; however, here, we proposed novel mechanisms of AKT1 for inhibiting both cancer progression and cancer growth following expression of the tumor suppressor, BTG2, in triple negative breast cancer cells via differential regulation of mTORc1 and mTORc2. Expression of BTG2 inhibited the mTOR-Raptor interaction, and increased mTOR binding to Rictor. BTG2 selectively induced phosphorylation of AKT1, not AKT2, by mTORc2 and reduced expression of PHLPP2, an AKT1-specific phosphatase. BTG2-induced pAKT1S473 degraded NFAT1, which regulates transcription of cytokines, chemokine receptors and possibly PHLPP2, resulting in modification of the tumor microenvironment. In human breast cancer tissues, expression of NFAT1 and PHLPP2 was significantly higher compared to the low expression of BTG2. In tsc-null and p53-null mouse embryonic fibroblasts (MEFs), BTG2 was substituted for the tsc gene, -a negative regulator of mTORc1 activation- , and was also evident in -null mice. Constitutive expression of BTG2 in the basal cells of normal mammary ducts was maintained in ductal-carcinoma in situ (DCIS) of human breast cancer but absent in infiltrating breast cancer, as examined by immunohistochemistry. Indeed, the relative risk of lymph node invasion in BTG2+ breast cancer patients was approximately 1/10th that of BTG2- patients, and overall survival of ER-LN+ breast cancer patients was significantly higher among BTG2 high expressers than low expressers. Indeed, BTG2 expression significantly inhibited the in vitro colony forming ability of triple negative breast cancer cells. We present here the signaling pathways that regulate cancer growth and progression by expression of BTG2, which inhibits cancer growth via the BTG2-tsc1/2-mTORc1-p70S6K axis and downregulates cancer progression via the BTG2-mTORc2-AKT1-NFAT1-PHLPP2 axis. Therefore, we suggest the BTG2 gene is a promising candidate to combat intractable breast cancer.Part I 1
I. INTRODUCTION 1
II. MATERIALS AND METHODS 5
A. MATERIALS 5
B. METHODS 5
1. Cell culture 5
2. Adenoviral transduction of HeLa cells with BTG2 gene 5
3. Cloning of κB-response element (κB-RE) into pGL3 basic vector 5
4. Transfection analyses 6
5. Chromatin immunoprecipitation (ChIP) assay 6
6. Measurement of the level of reactive oxygen species 7
7. Small interfering RNAs (siRNAs) and preparation of lentivirus with IκBα mutant 7
8. RT-PCR 7
9. Immunoblot analyses 8
10. Cell synchronization and FACS analysis 8
III. RESULTS 9
A. BTG2 upregulates MnSOD expression in HeLa cells 9
B. BTG2 activates NFκB-response element of MnSOD gene in the 2nd intron 11
C. BTG2 mediatedNFκB activation is regulated by IκBα degradation 14
D. BTG2-enhanced IκBα degradation is regulated by p-Akt1 17
E. BTG2 enhances G2/M arrest along with reduction of H2O2 level 20
IV. DISCUSSION 25
V. CONCLUSION 27
Part II 28
I. INTRODUCTION 28
II. MATERIALS AND METHODS 31
A. MATERIALS 31
B. METHODS 31
1. Cell Culture, Antibodies and Reagents 31
2. Preparation of Ad-BTG2 virus and Reconstitution of BTG2 gene Expression 31
3. mTOR Kinase Assays 32
4. In vivo Analyses and Preparation of Mouse Tissues 32
5. Chromatin Immunoprecipitation Analysis (ChIP) 32
6. Immunohistochemistry and Survival Analysis 32
7. Immunoprecipitation 33
8. MTT assay 33
9. Colony Formation assay 33
10. FACS analysis 33
11. Transfections of siRNA and Plasmid DNAs 33
12. Reverse transcriptional PCR and RTqPCR 34
13. Subcellular fractionation 34
14. Live cell imaging of GFP-AKT PH localization 34
15. GEO data analysis 34
16. In-vitro Protein Purifications 35
17. Statistical analysis 35
III. RESULTS 36
A. BTG2 differentially regulates the mTOR interaction with Raptor and Rictor 36
B. Interaction of Raptor with BTG2 inhibits mTORc1 activity in breast cancer cells 42
C. BTG2 upregulates mTORc2 activity in both normal and cancer cells 49
D. Rictor activates AKT1, but not AKT2, in response to BTG2 expression 54
E. BTG2-induced pAKT1S473 downregulates NFAT1 60
F. In vivo evidence of BTG2 expression that blocks breast cancer invasion 68
IV. DISCUSSION 78
V. CONCLUSION 81
REFERENCES 83
국문요약 94Docto
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No full textNot AvailableQureshi, N.W., Krishnan, M., Wani, S.A., Ramasubramanian, V., Sivaramane, N. and Sundaramoorthy, C. (2017) Negative Externalities in Kashmir Lake Fisheries: Transformation in Species Patronage, Use Priorities and Policy, Indian Journal of Agricultural Economics, 72(1), 89-101Not Availabl
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Cu2+ uptake by Chlorococcum hemicolum - A Xeric Chlorophycean Alga
No full textBioremediation of copper by xeric chlorophycean bioremediator, Chlorococcum hemicolum was investigated. The growth rates at various concentrations of Cu2+ were assessed in terms of protein level and 8 mg L-1 (37.67 % level in growth kinetics) is the tolerance limit. Absorption/adsorption kinetics was estimated after 240 hrs of Cu2+ treatments. Absorptions were higher than adsorption with maximum accumulation factor (AF) of 1.40. The Cu2+ concentration and absorption were linearly related (r = 0.99; p>0.01). Other biochemical parameters like total sugar, chlorophyll and carotenoids were also quantified to correlate the state of metabolism and these exhibited reduction due to heavy metal stress
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
No full textAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
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