196 research outputs found
Temporin A and Bombinin H2 Antimicrobial Peptides Exhibit Selective Cytotoxicity to Lung Cancer Cells
Temporin A and Bombinin H2 antimicrobial peptides exhibit selective cytotoxicity to lung cancer cells
Background. Recently, antimicrobial peptides (AMPs) have been investigated for their use in cancer therapy. They have been reported to selectively target and kill cancer cells whilst leaving normal healthy cells unaffected. Certain Anura AMPs have expressed selective cytotoxicity against tumour cells. Aim. To test the potential of Anura AMPs bombinin H2, bombinin H4, temporin A, and temporin L for use as therapeutic agents for non-small cell lung carcinoma (NSCLC). Methods. Cytotoxic effects on NSCLC cell lines A549 and Calu-3 and normal epithelial cell line Beas-2B were tested using the CellTox Green Cytotoxicity Assay. Their haemolytic effects on human erythrocytes were also tested for their clinical relevance. Cell membrane profiling, using MALDI-TOF, was performed to ascertain if membrane characteristics of the NSCLC and Beas-2B cell lines may contribute to the AMPs mode of action. Results. Bombinin H4 (100-1.5 ÎŒM, p<0.05) and temporin A (100-50 ÎŒM, p<0.05) showed selective cytotoxicity towards the NSCLC cell lines. Furthermore, they exhibited low levels of haemolytic activity (bombinin H4, 0.061%; temporin A, 0.874%) comparable to untreated cells. Cell membrane profiling showed the phospholipid composition of normal epithelial cell line Beas-2B to be divergent from the cancerous cell lines. However, there was an overlap in the phospholipid profiles of the NSCLC cell lines supporting the hypothesis that the AMPs may have a selective affinity via the membrane composition of cancerous cell lines. Conclusion. These results suggest that bombinin H4 and temporin A show potential for application in lung cancer therapies. Further in vitro and in vivo studies are required to develop a greater understanding of their use as anticancer agents
Broadband velocity modulation spectroscopy of HfF^+: towards a measurement of the electron electric dipole moment
Precision spectroscopy of trapped HfF^+ will be used in a search for the
permanent electric dipole moment of the electron (eEDM). While this dipole
moment has yet to be observed, various extensions to the standard model of
particle physics (such as supersymmetry) predict values that are close to the
current limit. We present extensive survey spectroscopy of 19 bands covering
nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser
velocity-modulation spectroscopy. We obtain high-precision rovibrational
constants for eight electronic states including those that will be necessary
for state preparation and readout in an actual eEDM experiment.Comment: 13 pages, 7 figures, 3 table
MSN2 and MSN4 Link Calorie Restriction and TOR to Sirtuin-Mediated Lifespan Extension in Saccharomyces cerevisiae
Calorie restriction (CR) robustly extends the lifespan of numerous species. In the yeast Saccharomyces cerevisiae, CR has been proposed to extend lifespan by boosting the activity of sirtuin deacetylases, thereby suppressing the formation of toxic repetitive ribosomal DNA (rDNA) circles. An alternative theory is that CR works by suppressing the TOR (target of rapamycin) signaling pathway, which extends lifespan via mechanisms that are unknown but thought to be independent of sirtuins. Here we show that TOR inhibition extends lifespan by the same mechanism as CR: by increasing Sir2p activity and stabilizing the rDNA locus. Further, we show that rDNA stabilization and lifespan extension by both CR and TOR signaling is due to the relocalization of the transcription factors Msn2p and Msn4p from the cytoplasm to the nucleus, where they increase expression of the nicotinamidase gene PNC1. These findings suggest that TOR and sirtuins may be part of the same longevity pathway in higher organisms, and that they may promote genomic stability during aging
Language for Specific Purposes and Corpus-based Pedagogy
This chapter describes how corpus-based pedagogies are used for teaching and learning language for specific purposes (LSP). Corpus linguistics (CL) refers to the study of large quantities of authentic language using computer-assisted methods, which form the basis for computer-assisted language learning (CALL) that uses corpora for reference, exploration, and interactive learning. The use of corpora as reference resources to create LSP materials is described. Direct student uses of corpora are illustrated by three approaches to data-driven learning (DDL) where students engage in hands-on explorations of texts. A combination of indirect and direct corpus applications is shown in an illustration of interactive CALL technologies, including an example of an inclusive corpus-based tool for genre-based writing pedagogy. The chapter concludes with potential prospects for future developments in LSP
A function-first approach to identifying formulaic language in academic writing
publication-status: Publishedtypes: ArticleThere is currently much interest in creating pedagogically-oriented descriptions of formulaic language. Research in this area has typically taken what we call a âform-firstâ approach, in which formulas are identified as the most frequent recur- rent forms in a relevant corpus. While this research continues to yield valuable results, the present paper argues that much can also be gained by taking a âfunction-firstâ approach, in which a corpus is first annotated for communicative functions and formulas are then identified as the recurrent patterns associated with each function. We demonstrate this approach through a comparative analysis of introductions to student essays and research articles. Focusing on one particularly com- mon communicative function, the analysis demonstrates that (1) this function is more common in student essays than in articles; (2) both the choice to use the function and the choice of linguistic forms that realize the function vary across sub- ject areas in research articles, but not in student essays; (3) research articles tend to be more formulaic in expressing the function than student essays; and (4) some parts of the forms used are highly formulaic, while others are more open. The key formulas are described and suggestions made regarding their pedagogical presentation
CUX1 transcription factor is required for optimal ATM/ATR-mediated responses to DNA damage
The p110 Cut homeobox 1 (CUX1) transcription factor regulates genes involved in DNA replication and chromosome segregation. Using a genome-wide-approach, we now demonstrate that CUX1 also modulates the constitutive expression of DNA damage response genes, including ones encoding ATM and ATR, as well as proteins involved in DNA damage-induced activation of, and signaling through, these kinases. Consistently, RNAi knockdown or genetic inactivation of CUX1 reduced ATM/ATR expression and negatively impacted hallmark protective responses mediated by ATM and ATR following exposure to ionizing radiation (IR) and UV, respectively. Specifically, abrogation of CUX1 strongly reduced ATM autophosphorylation after IR, in turn causing substantial decreases in (i) levels of phospho-Chk2 and p53, (ii) Îł-H2AX and Rad51 DNA damage foci and (iii) the efficiency of DNA strand break repair. Similarly remarkable reductions in ATR-dependent responses, including phosphorylation of Chk1 and H2AX, were observed post-UV. Finally, multiple cell cycle checkpoints and clonogenic survival were compromised in CUX1 knockdown cells. Our results indicate that CUX1 regulates a transcriptional program that is necessary to mount an efficient response to mutagenic insult. Thus, CUX1 ensures not only the proper duplication and segregation of the genetic material, but also the preservation of its integrity
Metatalk in American academic talk: The cases of "point" and "thing"
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88138/1/swales-metatalk_american_academic.pd
Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Inhibitors: Rationale and Importance to Inhibiting These Pathways in Human Health
The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Integral components of these pathways, Ras, B-Raf, PI3K, and PTEN are also activated/inactivated by mutations. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of these pathways can contribute to chemotherapeutic drug resistance, proliferation of cancer initiating cells (CICs) and premature aging. This review will evaluate more recently described potential uses of MEK, PI3K, Akt and mTOR inhibitors in the proliferation of malignant cells, suppression of CICs, cellular senescence and prevention of aging. Ras/Raf/MEK/ERK and Ras/PI3K/PTEN/Akt/mTOR pathways play key roles in the regulation of normal and malignant cell growth. Inhibitors targeting these pathways have many potential uses from suppression of cancer, proliferative diseases as well as aging
- âŠ