Src, PKCα, and PKCδ are required for αvβ3 integrin-mediated metastatic melanoma invasion

<p>Abstract</p> <p>Background</p> <p>Integrins, cell-surface receptors that mediate adhesive interactions between cells and the extracellular matrix (ECM), play an important role in cancer progression. Expression of the vitronectin receptor αvβ3 integrin correlates with increased invasive and metastatic capacity of malignant melanomas, yet it remains unclear how expression of this integrin triggers melanoma invasion and metastasis.</p> <p>Results</p> <p>Two melanoma cell lines C8161.9 and M14 both express high levels of αvβ3 integrin and adhere to vitronectin. However, only the highly metastatic C8161.9 cells are capable of invading vitronectin-enriched Matrigel in an αvβ3-depenent manner. Elevated levels of PKCα and PKCδ, and activated Src were detected specifically in the highly metastatic melanoma cells, but not in the low metastatic M14 cells. Inhibition of Src or PKC activity suppressed αvβ3-dependent invasion. Furthermore, over expression of Src or PKCα and PKCδ was sufficient to confer αvβ3-dependent invasiveness to M14 cells. Stress fiber formation and focal adhesion formation were almost completely absent in C8161.9 cells compared to M14 cells. Inhibition of Src signaling was sufficient to restore normal actin architecture, and resulted in decreased p190RhoGAP phosphorylation and enhanced RhoA activity. Src had no effect on Rac activity. Loss of PKCα expression, but not PKCδ, by siRNA inhibited Rac and PAK activity as well as invasiveness. Loss of PKCα restored focal adhesion formation and partially restored stress fiber formation, while loss of PKCδ primarily restored stress fibers.</p> <p>Conclusion</p> <p>The misregulated expression of PKCα and PKCδ and elevated Src activity in metastatic melanoma cells is required for efficient αvβ3-mediated invasion. PKCα and Src enhance αvβ3-mediated invasion in part by increasing the GTPase activity of Rac relative to RhoA. PKCα influences focal adhesion formation, while PKCδ controls stress fibers.</p

American political affiliation, 2003–43: a cohort component projection

The recent rise and stability in American party identification has focused interest on the long-term dynamics of party bases. Liberal commentators cite immigration and youth as forces which will produce a natural Democratic advantage in the future while conservative writers highlight the importance of high Republican fertility in securing Republican growth. These concerns foreground the neglect of demography within political science. This paper addresses this omission by conducting the first ever cohort component projection of American partisan populations to 2043 based on survey and census data. A number of scenarios are modeled, but, on current trends, we predict that American partisanship will shift much less than the nation’s ethnic composition because the parties’ age structures are similar. Still, our projections find that the Democrats gain two to three percentage points from the Republicans by 2043, mainly through immigration, though Republican fertility may redress the balance in the very long term

Film as architectural theory

Publications on architectural theory have predominantly taken on the form of text-based books, monographs, and articles. With the rise of transdisciplinary and practice-based research in architecture, new opportunities are opening up for other forms of architectural theory, such as film-based mediums, which promise to expand and alter the convention of the written practice of theory. Two possible types of filmic theory are presented here. One follows the method of ethnographic documentary filmmaking inspired by Sarah Pinkfilm-based mediums, which promise to expand and alter thellows the line of art house filmmaking inspired by Kathryn Rameyyn Rameyg inspired by Sarah Pinkfilm-based mediums, which promise to expand ae to expand ad mediums, which promise to expand a convention of the written practice of theory. or constructing knowledge, new discourses on filmic theory can be opened up. It is argued here that film as architectural theory is part of this new discourse, broadening the audience’u engagement with architecture through not only “readership” but also “viewership.

What the disjunctivist is right about

There is a traditional conception of sensory experience on which the experiences one has looking at, say, a cat could be had by someone merely hallucinating a cat. Disjunctivists take issue with this conception on the grounds that it does not enable us to understand how perceptual knowledge is possible. In particular, they think, it does not explain how it can be that experiences gained in perception enable us to be in ‘cognitive contact’ with objects and facts. I develop this chal- lenge to the traditional conception and then show that it is possible to accommo- date an adequate account of cognitive contact in keeping with the traditional conception. One upshot of the discussion is that experiences do not bear the explanatory burden placed upon them by disjunctivists

Diversity and Evolution of Sensor Histidine Kinases in Eukaryotes

Histidine kinases (HKs) are primary sensor proteins that act in cell signaling pathways generically referred to as "two component systems" (TCSs). TCSs are among the most widely distributed transduction systems used by both prokaryotic and eukaryotic organisms to detect and respond to a broad range of environmental cues. The structure and distribution of HK proteins are now well documented in prokaryotes but information is still fragmentary for eukaryotes. Here, we have taken advantage of recent genomic resources to explore the structural diversity and the phylogenetic distribution of HKs in the prominent eukaryotic supergroups. Searches of the genomes of 67 eukaryotic species spread evenly throughout the phylogenetic tree of life identified 748 predicted HK proteins. Independent phylogenetic analyses of predicted HK proteins were carried out for each of the major eukaryotic supergroups. This allowed most of the compiled sequences to be categorised into previously described HK groups. Beyond the phylogenetic analysis of eukaryotic HKs, this study revealed some interesting findings: (i) characterisation of some previously undescribed eukaryotic HK groups with predicted functions putatively related to physiological traits; (ii) discovery of HK groups that were previously believed to be restricted to a single kingdom in additional supergroups and (iii) indications that some evolutionary paths have led to the appearance, transfer, duplication, and loss of HK genes in some phylogenetic lineages. This study provides an unprecedented overview of the structure and distribution of HKs in the Eukaryota and represents a first step towards deciphering the evolution of TCS signaling in living organisms

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Information Wars: Are the Iraqis Getting the Message?; Strategic Insights, v. 3, issue 12 (December 2004)

This article appeared in Strategic Insights, v.3, issue 12 (December 2004)Approved for public release; distribution is unlimited

Good Morning, Mr. Echo

https://digitalcommons.library.umaine.edu/mmb-vp-copyright/4776/thumbnail.jp

Thrombin Induces a Calcium Transient That Mediates an Activation of the Na\u3csup\u3e+\u3c/sup\u3e/H\u3csup\u3e+\u3c/sup\u3e Exchanger in Human Fibroblasts

The calcium dependence of growth factor-induced cytoplasmic alkalinization was determined in serum-deprived human fibroblasts (WS-1 cells). Intracellular pH (pHi) and intracellular calcium (Ca2+i) were measured using the fluorescent dyes 2\u27,7\u27-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein and fura2, respectively. Thrombin (10 nM) induced an alkalinization (0.18 +/- 0.01 pH units, n = 23) that was Na+-dependent and amiloride-sensitive, suggesting that the alkalinization was mediated by the Na+/H+ exchanger. Thrombin treatment caused a transient increase in Ca2+i (325 +/- 39 nM, n = 12) that preceded the observed increase in pHi. The increases in Ca2+i and pHi were dependent on the concentration of thrombin. The thrombin-induced increase in Ca2+i occurred in the absence of external calcium indicating that thrombin released calcium from internal stores. Inhibition of the thrombin-induced increase in Ca2+i with 8-diethylaminooctyl 3,4,5-trimethoxybenzoate hydrochloride or bis-(o-aminophenoxy)ethane-N,N,N\u27,N\u27- tetraacetic acid also inhibited the thrombin-stimulated increase in pHi. The calcium ionophore ionomycin was used to increase Ca2+i independent of growth factor stimulation. When Ca2+i was elevated with ionomycin, a concomitant increase in pHi was observed. The increase in pHi due to ionomycin was dependent on Na+ and sensitive to amiloride. The removal of external Ca2+i inhibited the ionomycin-induced elevation of both Ca2+i and pHi. The ionomycin-induced increases in Ca2+i and pHi were not inhibited by 8-diethylaminooctyl 3,4,5-trimethoxy-benzoate hydrochloride. The results suggest that thrombin treatment can activate the Na+/H+ exchanger, and this activation is mediated by an increase in Ca2+i