Mitotic regulation by Polo-like kinase 1 and the Chromosomal Passenger Complex

During mitosis, the duplicated genome must be accurately divided between two daughter cells. Polo-like kinase 1 (Plk1) and Aurora B kinase, together with its binding partners Incenp, Survivin and Borealin (chromosomal passenger complex, CPC), have key roles in coordinating mitotic events. The accuracy of cell division is safeguarded by a signaling cascade termed the mitotic spindle checkpoint (SC), which ensures that chromosomes are not physically separated before correct bipolar attachments have been formed between kinetochores and spindle microtubules (MT). An inhibitory “wait anaphase” signal, which delays chromosome separation (anaphase onset), is created at individual kinetochores and broadcasted throughout the cell in response to lack of kinetochore-microtubule (kMT) attachment or proper interkinetochore tension. It is believed that the fast turnover of SC molecules at kinetochores contributes to the cell’s ability to produce this signal and enables rapid responses to changing cellular conditions. Kinetochores that lack MT attachment and tension express a certain phosphoepitope called the 3F3/2 phosphoepitope, which has been linked to SC signaling. In the experimental part, we investigated the regulation of the 3F3/2 phosphoepitope, analyzed whether CPC molecules turn over at centromeres, and dissected the mitotic roles of the CPC using a microinjection technique that allowed precise temporal control over its function. We found that the kinetochore 3F3/2 phosphoepitope is created by Plk1, and that CPC proteins exhibit constant exchange at centromeres. Moreover, we found that CPC function is necessary in the regulation of chromatid movements and spindle morphology in anaphase. In summary, we identified new functions of key mitotic regulators Plk1 and CPC, and provided insighs into the coordination of mitotic events.

Functional characterization of proteins required for mitotic progression and the spindle assembly checkpoint

During mitotic cell division, the genetic material packed into chromosomes is divided equally between two daughter cells. Before the separation of the two copies of a chromosome (sister chromatids), each chromosome has to be properly connected with microtubules of the mitotic spindle apparatus and aligned to the centre of the cell. The spindle assembly checkpoint (SAC) monitors connections between microtubules and chromosomes as well as tension applied across the centromere. Microtubules connect to a chromosome via kinetochores, which are proteinaceous organelles assembled onto the centromeric region of the sister chromatids. Improper kinetochore-microtubule attachments activate the SAC and block chromosome segregation until errors are corrected and all chromosomes are connected to the mitotic spindle in a bipolar manner. The purpose of this surveillance mechanism is to prevent loss or gain of chromosomes in daughter cells that according to current understanding contributes to cancer formation. Numerous proteins participate in the regulation of mitotic progression. In this thesis, the mitotic tasks of three kinetochore proteins, Shugoshin 1 (Sgo1), INCENP, and p38 MAP kinase (p38 MAPK), were investigated. Sgo1 is a protector of centromeric cohesion. It is also described in the tension-sensing mechanism of the SAC and in the regulation of kinetochore-microtubule connections. Our results revealed a central role for Sgo1 in a novel branch of kinetochore assembly. INCENP constitutes part of the chromosomal passenger complex (CPC). The other members of the core complex are the Aurora B kinase, Survivin and Borealin. CPC is an important regulatory element of cell division having several roles at various stages of mitosis. Our results indicated that INCENP and Aurora B are highly dynamic proteins at the mitotic centromeres and suggested a new role for CPC in regulation of chromosome movements and spindle structure during late mitosis. The p38 MAPK has been implicated in G1 and G2 checkpoints during the cell cycle. However, its role in mitotic progression and control of SAC signaling has been controversial. In this thesis, we discovered a novel function for p38γ MAPK in chromosome orientation and spindle structure as well as in promotion of viability of mitotic cells.

Nuclear Matrix in Apoptotic Cell Death and Cell Proliferation. The role of Nuclear Mitotic Apparatus (NuMA) Protein

The nucleus is a membrane enclosed organelle containing most of the genetic information of the cell in the form of chromatin. The nucleus, which can be divided into many sub-organelles such as the nucleoli, the Cajal bodies and the nuclear lamina, is the site for several essential cellular functions such as the DNA replication and its regulation and most of the RNA synthesis and processing. The nucleus is often affected in disease: the size and the shape of the nucleus, the chromatin distribution and the size of the nucleoli have remained the basis for the grading of several cancers. The maintenance of the vertebrate body shape depends on the skeleton. Similarly, in a smaller context, the shape of the cell and the nucleus are mainly regulated by the cytoskeletal and nucleoskeletal elements. The nuclear matrix, which by definition is a detergent, DNase and salt resistant proteinaceous nuclear structure, has been suggested to form the nucleoskeleton responsible for the nuclear integrity. Nuclear mitotic apparatus protein, NuMA, a component of the nuclear matrix, is better known for its mitotic spindle organizing function. NuMA is one of the nuclear matrix proteins suggested to participate in the maintenance of the nuclear integrity during interphase but its interphase function has not been solved to date. This thesis study concentrated on the role of NuMA and the nuclear matrix as structural and functional components of the interphase nucleus. The first two studies clarified the essential role of caspase-3 in the disintegration of the nuclear structures during apoptosis. The second study also showed NuMA and chromatin to co-elute from cells in significant amounts and the apoptotic cleavage of NuMA was clarified to have an important role in the dissociation of NuMA from the chromatin. The third study concentrated on the interphase function of NuMA showing NuMA depletion to result in cell cycle arrest and the cytoplasmic relocalization of NuMA interaction partner GAS41. We suggest that the relocalization of the transcription factor GAS41 may mediate the cell cycle arrest. Thus, this study has given new aspects in the interactions of NuMA, chromatin and the nuclear matrix.

Nuclear morphometry, apoptotic and mitotic indices, and tubular differentiation in Libyan breast cancer

Aims of this study were to evaluate the relations of nuclear morphometry, mitotic and apoptotic indices, and tubular differentiation with clinicopathological features and survival rate in Libyan women. The data were compared with corresponding results on Finnish, and Nigerian female breast cancer patients. Histological samples of breast cancer (BC) from 131 patients were retrospectively studied. Mitotic activity indices (MAI and SMI), apoptotic index (AI), and fraction of fields with tubular differentiation (FTD) were estimated. Samples were also studied by computerized nuclear morphometry, such as mean nuclear area (MNA). Demographic and clinicopathological features were analyzed from 234 patients. The Libyan BC was dominantly premenopausal, and aggressive in behavior. There were statistically significant correlations between the mean nuclear area, fraction of fields with tubular differentiation, apoptotic index and proliferative indices, and most clinicopathological features. The highest significances were shown between lymph node status and the proliferative and apoptotic indices (p=0.003 with SMI, and p=0.005 with AI). There were significant associations between clinical stage and SMI and AI (p=0.002 and 0.009, respectively). The most significant associations with grade were observed with MNA and FTD (p<0.0001 and 0.001, respectively). The proliferative differences between Libyan, Nigerian and Finnish populations were prominent. These indices in Libyan were lower than in Nigerian, but higher than in Finnish patients. The Libyan patients’ AI is slightly higher than in Nigeria, but much higher than in Finland. The differences between countries may be associated with the known variation in the distribution of genetic markers in these populations. The results also indicated that morphometric factors can be reliable prognostic indicators in Libyan BC patients.

Yrityksen sijaintipaikkapäätökseen vaikuttavat tekijät ja alueiden kilpailukyky Suomessa

Tämän diplomityön tavoite on luoda viitekehys kahdesta työn pääteorioista, jotka ovat: "liiketoiminnan ulkoiset menestystekijät" ja "alueiden kilpailukyky". Kummatkin teoriat sisältävät tekijöitä, joilla on vaikutusta yrityksen sijaintipaikkapäätökseen. Viitekehyksen pohjalta tarkastellaan kahta tutkimusaluetta: Landen seutua ja Kuuma-aluetta. Työn tuloksena syntyy kuva kummastakin tutkimusalueesta ja analyysi viitekehyksestä. Työn ensimmäisessä osassa käydään läpi aihealueen tutkimuksen taustaa ja mitä ongelmia tutkimuksissa on tullut esille. Senjälkeen esitellään kaikki liiketoiminnan ulkoiset menestystekijät. Alueiden kilpailukyvyn teoriaosuus täydentää viitekehyksen tekijät. Työn jälkimmäinen empiirinen osa perustuu lähdemateriaaliin, joka on kerätty haastatteluista, lehtiartikkeleista ja seminaareista koskien tutkimusalueita. Tutkimustuloksista selviää, että kummatkin tutkimusalueet ovat erilaisia ja niillä on omat avainklusterinsa ja menestyvät toimialansa. Viitekehys luotiin melko onnistuneesti. Lopulta selvisi, että se sopii hyvin aihealueen tutkimuksen laajentamiseen, mutta heikosti yksittäisenyrityksen sijaintipaikkapäätökseen.

Capturing Weak Signals for Foresight Building

Tulevaisuuden hahmottamisen merkitys heikkojen signaalien avulla on korostunut viime vuosien aikana merkittävästi,koska yrityksen liiketoimintaympäristössä tapahtuvia muutoksia on ollut yhä vaikeampaa ennustaa historian perusteella. Liiketoimintaympäristössä monien muutoksien merkkejä on ollut nähtävissä, mutta niitä on ollut vaikea havaita. Heikkoja signaaleja tunnistamalla ja keräämällä sekä reagoimalla tilanteeseen riittävän ajoissa, on mahdollista saavuttaa ylivoimaista kilpailuetua. Kirjallisuustutkimus keskittyy heikkojen signaalien tunnistamisen haasteisiin liiketoimintaympäristöstä, signaalien ja informaation kehittymiseen sekä informaation hallintaan organisaatiossa. Kiinnostus näihin perustuu tarpeeseen määritellä heikkojen signaalien tunnistamiseen vaadittava prosessi, jonka avulla heikot signaalit voidaan huomioida M-real Oyj:n päätöksenteossa. Kirjallisuustutkimus osoittaa selvästi sen, että heikkoja signaaleita on olemassa ja niitä pystytään tunnistamaan liiketoimintaympäristöstä. Signaaleja voidaan rikastuttaa yrityksessä olevalla tietämyksellä ja hyödyntää edelleen päätöksenteossa. Vertailtaessa sekä kirjallisuustutkimusta että empiiristä tutkimusta tuli ilmi selkeästi tiedon moninaisuus; määrä,laatu ja tiedonsaannin oikea-aikaisuus päätöksenteossa. Tutkimuksen aikana kehittyi prosessimalli tiedon suodattamiselle, luokittelulle ja heikkojen signaalien tunnistamiselle. Työn edetessä prosessimalli kehittyi osaksi tässä työssä kehitettyä kokonaisuutta 'Weak Signal Capturing' -työkalua. Monistamalla työkalua voidaan kerätä heikkoja signaaleja eri M-realin liiketoiminnan osa-alueilta. Tietoja systemaattisesti kokoamalla voidaan kartoittaa tulevaisuutta koko M-realille.

Putkilämmönsiirtimien mitoitustyökalujen kehittäminen

Diplomityön tarkoituksena on kehittää tietokoneohjelma putkilämmönsiirtimen vaippapuolen painehäviön laskemiseksi. Ohjelmalla voidaan varmistaa lämmönsiirtimen mitoitusvaiheessa, että vaippapuolen painehäviö ei ylitä sallittuja rajoja. Ohjelmatäydentää olemassa olevia mitoitusohjelmia. Tässä diplomityössä käsitellään ainoastaan höyryvoimalaitosprosesseissa käytettäviä putkilämmönsiirtimiä. Työn kirjallisessa osassa on selvitetty periaate höyryvoimalaitosprosessista ja siinä käytettävistä putkilämmönsiirtimistä sekä esitetty putkilämmönsiirtimien rakenne, yleinen suunnittelu ja lämpö- ja virtaustekninen mitoitus. Painehäviön laskennassa käytetyt ja lämpö- ja virtausteknistä mitoitusta käsittelevässä kappaleessa esitetyt yhtälöt perustuvat Bell-Delawaren menetelmään. Painehäviönlaskentaohjelma on toteutettu hyväksikäyttäen Microsoft Excel taulukkolaskentaa ja Visual Basic -ohjelmointikieltä. Painehäviön laskenta perustuu segmenttivälilevyillä varustetun putkilämmönsiirtimen vaippapuolen yksifaasivirtaukseen. Lämmönsiirtimen lauhdutinosan painehäviö oletetaan merkityksettömäksi, joten kokonaispainehäviö muodostuu höyryn- ja lauhteenjäähdyttimessä. Kehitetty ohjelma on suunniteltu erityisesti lauhteenjäähdyttimessä muodostuvan painehäviön laskentaan. Ohjelmalla laskettuja painehäviön arvoja on verrattu todellisesta lämmönsiirtimestä mitattuihin arvoihin. Lasketut arvotvastaavat hyvin mittaamalla saatuja, eikä tuloksissa ilmene mitään systemaattista virhettä. Ohjelma on valmis käytettäväksi putkilämmönsiirtimien mitoitustyökaluna. Diplomityön pohjalta on tehty ehdotukset ohjelman edelleen kehittämiseksi.

MANAGING STRATEGIC CHANGE:New Business Models Applying Wireless Technology as a Source of Competitive Edge

The diffusion of mobile telephony began in 1971 in Finland, when the first car phones, called ARP1 were taken to use. Technologies changed from ARP to NMT and later to GSM. The main application of the technology, however, was voice transfer. The birth of the Internet created an open public data network and easy access to other types of computer-based services over networks. Telephones had been used as modems, but the development of the cellular technologies enabled automatic access from mobile phones to Internet. Also other wireless technologies, for instance Wireless LANs, were also introduced. Telephony had developed from analog to digital in fixed networks and allowed easy integration of fixed and mobile networks. This development opened a completely new functionality to computers and mobile phones. It also initiated the merger of the information technology (IT) and telecommunication (TC) industries. Despite the arising opportunity for firms' new competition the applications based on the new functionality were rare. Furthermore, technology development combined with innovation can be disruptive to industries. This research focuses on the new technology's impact on competition in the ICT industry through understanding the strategic needs and alternative futures of the industry's customers. The change speed inthe ICT industry is high and therefore it was valuable to integrate the DynamicCapability view of the firm in this research. Dynamic capabilities are an application of the Resource-Based View (RBV) of the firm. As is stated in the literature, strategic positioning complements RBV. This theoretical framework leads theresearch to focus on three areas: customer strategic innovation and business model development, external future analysis, and process development combining these two. The theoretical contribution of the research is in the development of methodology integrating theories of the RBV, dynamic capabilities and strategic positioning. The research approach has been constructive due to the actual managerial problems initiating the study. The requirement for iterative and innovative progress in the research supported the chosen research approach. The study applies known methods in product development, for instance, innovation process in theGroup Decision Support Systems (GDSS) laboratory and Quality Function Deployment (QFD), and combines them with known strategy analysis tools like industry analysis and scenario method. As the main result, the thesis presents the strategic innovation process, where new business concepts are used to describe the alternative resource configurations and scenarios as alternative competitive environments, which can be a new way for firms to achieve competitive advantage in high-velocity markets. In addition to the strategic innovation process as a result, thestudy has also resulted in approximately 250 new innovations for the participating firms, reduced technology uncertainty and helped strategic infrastructural decisions in the firms, and produced a knowledge-bank including data from 43 ICT and 19 paper industry firms between the years 1999 - 2004. The methods presentedin this research are also applicable to other industries.

Metsäsektorin kehityksen vaikutus raaka-ainetarpeeseen ja rakenteeseen

Tutkimuksen tavoitteena on selvittää kuinka raakapuumarkkinat muodostuvat ja mitkä tekijät vaikuttavat raakapuun tarjontaan ja hankintaan. Lisäksi tarkastellaan onko tuontipuu korvaava vai täydentävä raaka-aine ja millainen rooli valtiovallalla on luodessaan yrityksille toimintaympäristöä. Työ on voimakkaasti teoreettispainotteinen. Teorian tarkoituksena on esittää se tieteellinen perusta, jolle raakapuumarkkinat sijoittuvat. Lisäksi on hyväksikäytetty aiemmin tehtyjä tutkimuksia, joiden tarkoituksena on valaista asiaa hieman käytännönläheisemmin. Työn tuloksena saadaan vastaukset tutkimuksen tavoitteisiin. Tulosten perusteella on ilmeistä, että keskeisin tarjontaan vaikuttava tekijä on puun hinta ja etenkin siihen liittyvät hintaodotukset. Kysyntään on puolestaan vaikuttanut teollisuuden kapasiteetin kehitys, tuotteiden menekki ja tuontipuun saatavuus. Tuotu koivukuitu on pikemminkin täydentänyt kuin korvannut kotimaan koivukuitua teollisuuden puun hankinnassa. Tuotu mäntykuitu toimii korvaavana tuotteena, mutta kuusikuidun kohdalla kotimaan hinnalla ei ole vaikutusta tuonnin määrään, ainoastaan tuontipuun omalla hinnalla näyttää olevan vaikutus tuontimäärään.

Hankintalain mukaiset yhteistyömahdollisuudet korkeakoulujen kanssa– case Liikennevirasto

The aim of this Master’s thesis is to examine the Finnish Transport Agency's cooperation possibilities with learning institutions. This thesis complements earlier studies made by the Finnish Transport Agency. The sources used in this research are law literature and earlier studies made by the Finnish Transport Agency. The contribution of the study is to present how to organize the cooperation rationally and legally. The study also assesses how cooperation can support the Finnish Transport Agency's strategy.

The Integrin Tail: A Tale of Cell Motility and Division

Integrin transmembrane receptor functions are regulated by adaptor molecules binding to their alpha and beta subunit intracellular domains, or tails, thus affecting integrin traffic and adhesion during e.g. cell motility. Interestingly, many cellular proteins function in both cell motility and cell division, thus raising the possibility that integrins might be involved in regulating the cell cycle. A thorough understanding of cell division is essential in cell biology and in human malignancies. It is well established that failures to complete cell cycle can give rise to genetically unstable cells with tumorigenic properties. Transformed cells promote the disruption of intercellular adhesions such as tight junctions, and this correlates with the onset of cell motility, invasion and unfavorable prognosis in cancer. In this study, we analyzed integrin regulation, mediated by adaptor binding to the  subunit tail, during cell motility and cell division. We revealed a novel molecular mechanism by which Rab21, through association with the integrin alpha subunits, drives integrin endosomal traffic during mitotic phases. In addition, we found indications for this finding in vivo, as RAB21 gene deletions were mapped in ovarian and prostate cancer samples. Importantly, the multinucleated phenotype of cultured ovarian cancer cells could be reverted by Rab21 overexpression. In this thesis work, we also show how the tight junction protein ZO-1 unexpectedly interacts with the 5 integrin cytoplasmic domain in the lamellipodia to promote cell motility and at the cleavage furrow to support separation of the daughter cells. The alpha5-ZO-1 complex formation was dependent on PKC which regulates ZO-1 phosphorylation and its subcellular localization. In addition, by an in situ detection method, we showed that a subset of metastatic human lung cancers expressed the alpha5beta-ZO-1 complex. Taken together, we were able to identify new molecular pathways that regulate integrin functions in an alpha tail-mediated fashion. These findings firmly suggest that genetic alterations in integrin traffic may lead to progression of tumorigenesis as a result of failed cell division. Also, the interplay of integrins and ZO-1 in forming spatially regulated adhesive structures broadens our view of crosstalk between pathways and distinct adhesive structures that can be involved in cancer cell biology.

Analysis on firm innovation boundaries

Innovation has been widely recognized as an important driver of firm competitiveness, and the firm’s internal research and development (R&D) activities are often considered to have a critical role in innovation activities. Internal R&D is, however, not the source of innovation as firms may tap into knowledge necessary for innovation also through various types of sourcing agreements or by collaborating with other organizations. The objective of this study is to analyze the way firms go about organizing efficiently their innovation boundaries. Within this context, the analysis is focused, firstly, on the relation between innovation boundaries and firm innovation performance and, secondly, on the factors explaining innovation boundary organization. The innovation literature recognizes that the sources of innovation depend on the nature of technology but does not offer a sufficient tool for analyzing innovation boundary options and their efficiency. Thus, this study suggests incorporating insights from transaction cost economics (TCE) complemented with dynamic governance costs and benefits into the analysis. The thesis consists of two parts. The first part introduces the background of the study, research objectives, an overview of the empirical studies, and the general conclusions of the study. The second part is formed of five publications. The overall results firstly indicate that although the relation between firm innovation boundary options is partly industry sector-specific, the firm level search strategies and knowledge transfer capabilities are important for innovation performance independently of the sector. Secondly, the results show that the attributes suggested by TCE alone do not offer a sufficient explanation of innovation boundary selection, especially under conditions of high levels of (radical) uncertainty. Based on the results, the dynamic governance cost and benefit framework complements the static TCE when firm innovation boundaries are scrutinized.

Socially Competent Leadership - predictors, impacts and skilling in engineering

Earlier management studies have found a relationship between managerial qualities and subordinate impacts, but the effect of managers‘ social competence on leader perceptions has not been solidly established. To fill the related research gap, the present work embarks on a quantitative empirical effort to identify predictors of successful leadership. In particular, this study investigates relationships between perceived leader behavior and three selfreport instruments used to measure managerial capability: 1) the WOPI Work Personality Inventory, 2) Raven‘s general intelligence scale, and 3) the Emotive Communication Scale (ECS). This work complements previous research by resorting to both self-reports and other-reports: the results acquired from the managerial sample are compared to subordinate perceptions as measured through the ECS other-report and the WOPI360 multi-source appraisal. The quantitative research is comprised of a sample of 8o superiors and 354 subordinates operating in eight Finnish organizations. The strongest predictive value emerged from the ECS self- and other-reports and certain personality dimensions. In contrast, supervisors‘ logical intelligence did not correlate with leadership perceived as socially competent by subordinates. 16 of the superiors rated as most socially competent by their subordinates were selected for case analysis. Their qualitative narratives evidence the role of life history and post-traumatic growth in developing managerial skills. The results contribute to leadership theory in four ways. First, the ECS self-report devised for this research offers a reliable scale for predicting socially competent leader ability. Second, the work identifies dimensions of personality and emotive skills that can be considered predictors of managerial ability and benefited from in leader recruitment and career planning. Third, the Emotive Communication Model delineated on the basis of the empirical data allows for a systematic design and planning of communication and leadership education. Fourth, this workfurthers understanding of personal growth strategies and the role of life history in leader development and training. Finally, this research advances educational leadership by conceptualizing and operationalizing effective managerial communications. The Emotive Communication Model devised directs the pedagogic attention in engineering to assertion, emotional availability and inspiration skills. The proposed methodology addresses classroom management strategies drawing from problem-based learning, student empowerment, collaborative learning, and so-called socially competent teachership founded on teacher immediacy and perceived caring, all constituting strategies moving away from student compliance and teacher modelling. The ultimate educational objective embraces the development of individual engineers and organizational leaders that not only possess traditional analytical and technical expertise and substantive knowledge but are intelligent also creatively, practically, and socially.

The spindle assembly checkpoint as a drug target - Novel small-molecule inhibitors of Aurora kinases

Cell division (mitosis) is a fundamental process in the life cycle of a cell. Equal distribution of chromosomes between the daughter cells is essential for the viability and well-being of an organism: loss of fidelity of cell division is a contributing factor in human cancer and also gives rise to miscarriages and genetic birth defects. For maintaining the proper chromosome number, a cell must carefully monitor cell division in order to detect and correct mistakes before they are translated into chromosomal imbalance. For this purpose an evolutionarily conserved mechanism termed the spindle assembly checkpoint (SAC) has evolved. The SAC comprises a complex network of proteins that relay and amplify mitosis-regulating signals created by assemblages called kinetochores (KTs). Importantly, minor defects in SAC signaling can cause loss or gain of individual chromosomes (aneuploidy) which promotes tumorigenesis while complete failure of SAC results in cell death. The latter event has raised interest in discovery of low molecular weight (LMW) compounds targeting the SAC that could be developed into new anti-cancer therapeutics. In this study, we performed a cell-based, phenotypic high-throughput screen (HTS) to identify novel LMW compounds that inhibit SAC function and result in loss of cancer cell viability. Altogether, we screened 65 000 compounds and identified eight that forced the cells prematurely out of mitosis. The flavonoids fisetin and eupatorin, as well as the synthetic compounds termed SACi2 and SACi4, were characterized in more detail utilizing versatile cell-based and biochemical assays. To identify the molecular targets of these SAC-suppressing compounds, we investigated the conditions in which SAC activity became abrogated. Eupatorin, SACi2 and SACi4 preferentially abolished the tensionsensitive arm of the SAC, whereas fisetin lowered also the SAC activity evoked by lack of attachments between microtubules (MTs) and KTs. Consistent with the abrogation of SAC in response to low tension, our data indicate that all four compounds inhibited the activity of Aurora B kinase. This essential mitotic protein is required for correction of erratic MT-KT attachments, normal SAC signaling and execution of cytokinesis. Furthermore, eupatorin, SACi2 and SACi4 also inhibited Aurora A kinase that controls the centrosome maturation and separation and formation of the mitotic spindle apparatus. In line with the established profound mitotic roles of Aurora kinases, these small compounds perturbed SAC function, caused spindle abnormalities, such as multi- and monopolarity and fragmentation of centrosomes, and resulted in polyploidy due to defects in cytokinesis. Moreover, the compounds dramatically reduced viability of cancer cells. Taken together, using a cell-based HTS we were able to identify new LMW compounds targeting the SAC. We demonstrated for the first time a novel function for flavonoids as cellular inhibitors of Aurora kinases. Collectively, our data support the concept that loss of mitotic fidelity due to a non-functional SAC can reduce the viability of cancer cells, a phenomenon that may possess therapeutic value and fuel development of new anti-cancer drugs.

Liquid transportation and distribution during (re)wetting : impact on coated papers in printing

In many industrial applications, such as the printing and coatings industry, wetting of porous materials by liquids includes not only imbibition and permeation into the bulk but also surface spreading and evaporation. By understanding these phenomena, valuable information can be obtained for improved process control, runnability and printability, in which liquid penetration and subsequent drying play important quality and economic roles. Knowledge of the position of the wetting front and the distribution/degree of pore filling within the structure is crucial in describing the transport phenomena involved. Although exemplifying paper as a porous medium in this work, the generalisation to dynamic liquid transfer onto a surface, including permeation and imbibition into porous media, is of importance to many industrial and naturally occurring environmental processes. This thesis explains the phenomena in the field of heatset web offset printing but the content and the analyses are applicable in many other printing methods and also other technologies where water/moisture monitoring is crucial in order to have a stable process and achieve high quality end products. The use of near-infrared technology to study the water and moisture response of porous pigmented structures is presented. The use of sensitive surface chemical and structural analysis, as well as the internal structure investigation of a porous structure, to inspect liquid wetting and distribution, complements the information obtained by spectroscopic techniques. Strong emphasis has been put on the scale of measurement, to filter irrelevant information and to understand the relationship between interactions involved. The near-infrared spectroscopic technique, presented here, samples directly the changes in signal absorbance and its variation in the process at multiple locations in a print production line. The in-line non-contact measurements are facilitated by using several diffuse reflectance probes, giving the absolute water/moisture content from a defined position in the dynamic process in real-time. The nearinfrared measurement data illustrate the changes in moisture content as the paper is passing through the printing nips and dryer, respectively, and the analysis of the mechanisms involved highlight the roles of the contacting surfaces and the relative liquid carrier properties of both non-image and printed image areas. The thesis includes laboratory studies on wetting of porous media in the form of coated paper and compressed pigment tablets by mono-, dual-, and multi-component liquids, and paper water/moisture content analysis in both offline and online conditions, thus also enabling direct sampling of temporal water/moisture profiles from multiple locations. One main focus in this thesis was to establish a measurement system which is able to monitor rapid changes in moisture content of paper. The study suggests that near-infrared diffuse reflectance spectroscopy can be used as a moisture sensitive system and to provide accurate online qualitative indicators, but, also, when accurately calibrated, can provide quantification of water/moisture levels, its distribution and dynamic liquid transfer. Due to the high sensitivity, samples can be measured with excellent reproducibility and good signal to noise ratio. Another focus of this thesis was on the evolution of the moisture content, i.e. changes in moisture content referred to (re)wetting, and liquid distribution during printing of coated paper. The study confirmed different wetting phases together with the factors affecting each phase both for a single droplet and a liquid film applied on a porous substrate. For a single droplet, initial capillary driven imbibition is followed by equilibrium pore filling and liquid retreat by evaporation. In the case of a liquid film applied on paper, the controlling factors defining the transportation were concluded to be the applied liquid volume in relation to surface roughness, capillarity and permeability of the coating giving the liquid uptake capacity. The printing trials confirmed moisture gradients in the printed sheet depending on process parameters such as speed, fountain solution dosage and drying conditions as well as the printed layout itself. Uneven moisture distribution in the printed sheet was identified to be one of the sources for waving appearance and the magnitude of waving was influenced by the drying conditions.