Cell polarity is an important regulator of cellular processes and is vital in helping to prevent metaplasia and tumorigenesis. There are three many polarity complexes that regulate and maintain epithelial cellular polarity. The Par and Crumbs complexes locate to the apical membrane of the cell, while the Scribble complex is located basolaterally. Of the Scribble complex components, the polarity protein Hugl1, also known as Mgl1 in mice, is especially important in helping to maintain apical basolateral and planar polarity, and is lost in multiple types of cancer. When Hugl1 expression is lost in epithelial cells, it results in a mesenchymal phenotype. We now show that the loss of Hugl1 fundamentally shifts the cellular phenotype and specifically alters EGFR trafficking and signaling. Loss of Hugl1 results in the nuclear translocation of Taz and Slug, increased migration, and the mislocalization of EGFR (Epidermal Growth Factor Receptor), driving cellular growth. Hugl1 regulates the expression of multiple cell identity markers and its loss results in stem cell characteristics, including the increased expression of CD44, and a decrease of CD49f and CD24 expression. The loss of Hugl1 also results in increased growth in soft-agar and prolonged survival when transplanted into NOD-SCID mice; its loss also results in EGF-dependent migration which aids in increasing mammosphere survival. Furthermore, isolated EGFR mislocalization via a point mutation (P667A) also drives these same phenotypes, including activation of Akt and Taz nuclear translocation, indicating the importance of Hugl1 in the regulation of EGFR localization and its signaling. In mice, the loss of total Mgl1 is lethal within days of birth due to hydrocephaly and results in the formation of rosette like structures in the brain that are reminiscent of neuroectodermal tumors. We designed a targeted Mgl1 knockout in the mammary epithelial cells using the Cre/Lox system to evaluate the effects of Mgl1 loss in murine mammary gland development and tumorigenesis. The loss of Mgl1 expression in mice inhibits ductal outgrowth, increases side branching and epithelial layers, and results in the mislocalization of EGFR. While overt mammary tumors did not develop, some individuals did develop hyperplastic nodules that could progress into cancer. The knockdown of Hugl1 in vitro and Mgl1 in vivo reveal how the loss of polarity and presence of Hugl1 results in cancer stem cell characteristics, increased migration, and abnormal signaling due to the mislocalization of EGFR. While these changes result in metaplasia and a potential pre-cancerous state, the loss of Hugl1 alone is not enough to drive the cancer progression, indicating that other mutations or factors are necessary for the development of breast cancer. Because of the key role polarity plays in the prevention of breast cancer development we investigated if the addition of Hugl1 back into breast cancer cells could revert the cancerous cells to a normal epithelial phenotype. Most of the breast cancer cells transfected with Hugl1 expression did not survive, indicating that the re-expression of polarity regulators forces cancer cells to die. The small percentage of cells that did survive re-expression of Hugl1 had retarded growth in soft agar and a decrease in EGFR expression. Together, these data indicate that Hugl1 expression and EGFR activity are closely related and that Hugl1 is required for the proper localization and signaling of EGFR. When Hugl1 is lost, EGFR is mislocalized and fails to be degraded properly, promoting pre-neoplastic changes.

Les cellules épidermiques des téguments des graines d’Arabidopsis thaliana, espèce myxospermique, libèrent un halo de mucilage polysaccharidique lors de leur imbibition. Les polysaccharides du mucilage sont produits et accumulés au cours du développement de la graine, selon un processus de différenciation déjà largement décrit (Western et al. 2006). Au laboratoire, une mutation naturelle a été mise en évidence chez l’accession Djarly, dont les graines ne libèrent pas de mucilage au cours de leur imbibition. Le clonage positionnel a démontré que le locus affecté chez Djarly code pour un inhibiteur de pectine méthylestérase (PMEI6). Les PMEIs exercent un contrôle négatif sur l’activité des pectines méthylestérases (PME), enzymes qui déméthylestérifient les homogalacturonanes, par la formation d’un complexe PME-PMEI (Di Matteo et al., 2005 ; Hothorn et al., 2004). Des études génétiques, cytologiques et biochimiques ont prouvé que PMEI6 régule la méthylestérification des homogalacturonanes du mucilage et des parois cellulaires distales des cellules épidermiques de la graine retardant la libération du mucilage séminal. L’expression de PMEI6 dépend des régulateurs de transcription GLABRA2 et MUM1. L’activité PME dans les cellules épidermiques des graines est aussi modulée par la subtilisine serine protéase AtSBT1.7, et le phénotype additif du mutant pmei6 atsbt1.7 indique que PMEI6 régule d’autres PMEs. Djarly fait partie d’un groupe de vingt accessions, dont les graines flottent à cause de modifications des propriétés du mucilage séminal. Ces accessions portent au moins dix mutations indépendantes, qui affectent au moins 4 locus différents. Cette étude nous a permis de proposer que la modification des propriétés du mucilage est impliquée dans l’adaptation à l’environnement local, permettant la dispersion à longue distance des graines par l’eau. / Upon imbibition, the myxospermous seeds of Arabidopsis thaliana, form a mucilage from hydrated polysaccharides released from the epidermal cells of the seed coat. These polysaccharides are produced and accumulated during seed development in a differentiation process that has been described in detail (Western et al. 2006). A screen of Arabidopsis accessions identified Djarly as a natural mucilage mutant affected in mucilage release on imbibition. The locus defective in Djarly was identified by map-based cloning as encoding a pectin methylesterase inhibitor (PMEI6). Theseproteinaceous inhibitors negatively control the activity of pectin methylesterases (PME), enzymes that demethylesterify HG, through the formation of a PME-PMEI complex (Di Matteo et al., 2005; Hothorn et al, 2004). Genetic, cytological and biochemical studies demonstrated that PMEI6 regulates methylesterification of homogalacturonans present in mucilage and the outer cell wall of seed coat epidermal cells. Delayed seed mucilage release in pmei6 mutants results, therefore, from the reduced level of homogalacturonan methylesterification. Expression of PMEI6 required the transcription regulators GLABRA2 and MUM1. PME activity in seed coat epidermal cells is also modulated by the subtilisin serine protease AtSBT1.7, and the additive phenotype of pmei6 atsbt1.7 mutants indicates that PMEI6 regulates different PMEs. Djarly is one of twenty accessions where seeds float due to modifications of mucilage properties. At least ten independent mutations are responsible for the mucilage modifications in these accessions, affecting at least 4 different loci. This study has led us to propose that these mucilage modifications are local adaptations that allow longdistance seed disperal on water.

L’épiderme est un tissu épithélial stratifié et kératinisé, majoritairement composé de kératinocytes. La cohésion de l’épiderme, élémentaire à la fonction-barrière et donc à la protection de l’organisme, est assurée grâce à des systèmes de jonctions intercellulaires, notamment les desmosomes. Comme l’indiquent nos résultats d’étude de la desmosealine, un protéoglycanne épidermique présent dans la partie extracellulaire des desmosomes, la composition de ces jonctions n’est pas encore entièrement élucidée. Les éléments matriciels issus des espaces extracellulaires de l’épiderme peuvent être incorporés au sein des desmosomes et participer ainsi à la régulation de la différenciation et la cohésion épidermiques. Nous avons mis au point une méthode permettant d’isoler les desmosomes épidermiques humains utilisables pour créer de nouveaux anticorps et favorisant la caractérisation biochimique de ces structures. Un nouvel anticorps monoclonal reconnaissant un antigène situé à la surface des kératinocytes, dont l’expression varie en fonction du degré de différenciation kératinocytaire, a été crée. A l’aide de cet anticorps, nous avons entrepris la caractérisation biochimique et par spectrométrie de masse de l’antigène associé. Nous avons ainsi développé de nouveaux outils biologiques et techniques utilisables pour l’étude des desmosomes et de leurs éléments issus de la matrice extracellulaire épidermique / Epidermis is a stratified, keratinized epithelial tissue, mostly composed of keratinocytes. Epidermal barrier function provided by epidermis is essential for protection of the organism and largely depends on cell cohesion. Desmosomes constitute the most prominent cell-to-cell junction system involved in this function. As indicated by our results of studies on desmosealin, an epidermal proteoglycan present in the extracellular parts of desmosomes, the composition of these junctions is not yet completely resolved. Elements of the intercellular matrix can be incorporated into desmosomes and thus participate in the regulation of the epidermal differentiation and cohesion. We established a method to isolate human epidermal desmosomes in order to create new antibodies allowing the biochemical characterization of new desmosomal components. A new monoclonal antibody has been generated. It recognizes an antigen located at the keratinocyte surface with an expression pattern depending on the level of keratinocyte differentiation. Using this antibody, we have engaged the biochemical and mass spectrometry characterization of the corresponding antigen. This work contributes to the development of new biological and technical tools useful for studies of desmosomes and of their components issued from the epidermal extracellular matrix

During tissues development multipotent progenitor cells establish tissue-specific gene expression programmes, leading to differentiation into specialized cell types. It has been previously shown that the transcription factor p63, a master regulator of skin development, controls the expression of adhesion molecules and essential cytoskeleton components. It has also been shown that p63 plays an important role in establishing distinct three-dimensional conformations in the Epidermal Differentiation Complex (EDC) locus (Fessing et al., 2011). Here we show that in p63-null mice about 32% of keratinocytes showed altered nuclear morphology. Alterations in the nuclear shape were accompanied by decreased expression of nuclear lamins (Lamin A/C and Lamin B1), proteins of the LINC complex (Sun-1, nesprin-2/3) and Plectin. Plectin links components of the nuclear envelope (nesprin-3) with cytoskeleton and ChIP-qPCR assay with adult epidermal keratinocytes showed p63 binding to the consensus binding sequences on Plectin 1c, Sun-1 and Nesprin-3 promoters. As a possible consequence of the altered expression of nuclear lamins and nuclear envelope-associated proteins, changes in heterochromatin distribution as well as decrease of the expression of several polycomb proteins (Ezh2, Ring1B, Cbx4) has been observed in p63-null keratinocytes. Moreover, recent data in our lab have showed that p63 directly regulates Cbx4, a component of the polycomb PRC1 complex. Here we show that mice lacking Cbx4 displayed a skin phenotype, which partially resembles the one observed in p63-null mice with reduced epidermal thickness and keratinocyte proliferation. All together these data demonstrate that p63-regulated gene expression program in epidermal keratinocytes includes not only genes encoding adhesion molecules, cytoskeleton proteins (cytokeratins) and chromatin remodelling factors (Satb1, Brg1), but also polycomb proteins and components of the nuclear envelope, suggesting the existence of a functional link between cytoskeleton, nuclear architecture and three dimensional nuclear organization. Other proteins important for proper epidermal development and stratification, are cytokeratins. Here, we show that keratin genes play an essential role in spatial organization of other lineage-specific genes in keratinocytes during epidermal development. In fact, ablation of keratin type II locus from chromosome 15 in epidermal keratinocytes led to changes in the genomic organization with increased distance between the Loricrin gene located on chromosome 3 as well as between Satb1 gene located on chromosome 17 and keratin type II locus, resulting in a more peripheral localization of these genes in the nucleus. As a possible consequence of their peripheral localization, reduced expression of Loricrin and Satb1 has also been observed in keratins type II-deficient mice. These findings together with recent circularized chromosome conformation capture (4C) data, strongly suggest that keratin 5, Loricrin and Satb1 are part of the same interactome, which is required for the proper expression of these genes and proper epidermal development and epidermal barrier formation. Taken together these data suggest that higher order chromatin remodelling and spatial organization of genes in the nucleus are important for the establishment of lineage-specific differentiation programs in epidermal progenitor cells. These data provide an important background for further analyses of nuclear architecture in the alterations of epidermal differentiation, seen in pathological conditions, such as psoriasis and epithelial skin cancers.

Os vegetais apresentam variados mecanismos de defesa, os quais conferem tolerância a elementos considerados tóxicos, como o alumínio (Al). Em primeiro experimento, objetivou-se avaliar a tolerância diferencial ao Al em quatro plantas forrageiras do gênero Brachiaria (B. decumbens cv. Basilisk, B. brizantha cv. Marandu, B. brizantha cv. Piatã e B. brizantha cv. Xaraés), por meio da quantificação da área foliar; aspectos morfológicos do sistema radicular (comprimento total e superfície total de raízes); produção de biomassa de raízes e parte aérea; concentração, acúmulo e transporte de Al à longa distância; peroxidação lipídica em tecidos de folhas e raízes e concentração de H2O2 nas folhas. As concentrações de Al empregadas na solução nutritiva foram de 0; 0,44; 0,89 e 1,33 mmol L-1, as quais foram distribuídas conforme delineamento experimental de blocos completos ao acaso, utilizando-se esquema fatorial 4 x 4 (quatro doses de Al x quatro genótipos de Brachiaria), com quatro repetições. A atividade do Al3+ livre na solução nutritiva foi estimada utilizando o software GeoChem-EZ®, o qual evidenciou que cerca de 81% do Al estava disponível, considerando a variação nos valores de pH de 3,0 a 4,0. A adição de Al na solução nutritiva resultou na redução de parâmetros produtivos da parte aérea e do sistema radicular, além de aumentar a concentração e o acúmulo do metal nas raízes. Por intermédio de tais parâmetros, permitiu-se a seguinte classificação, quanto à tolerância diferencial ao Al: B. brizantha cv. Xaraés > B. decumbens cv. Basilisk >= B. brizantha cv. Piatã > B. brizantha cv. Marandu. No segundo experimento a B. brizantha cv. Marandu (menor tolerância) e a B. brizantha cv. Xaraés (maior tolerância) foram cultivadas em solução nutritiva e, em seguida, foram efetuadas avaliações referentes à morfologia e anatomia do sistema radicular (pêlos radiculares), por meio de microscopia de luz e microscopia eletrônica de varredura, determinação do Al no apoplasto e simplasto das raízes, bem como a quantificação da atividade de enzimas antioxidantes catalase (CAT), ascorbato peroxidase (APX), guaiacol peroxidase (GPOX) e glutationa redutase (GR), em folhas e raízes. Utilizaram-se as concentrações de Al na solução de 0 e 1,33 mmol L-1, as quais foram distribuídas conforme delineamento experimental de blocos completos ao acaso, utilizando-se esquema fatorial 2 x 2 (duas concentrações de Al x dois genótipos de Brachiaria), com oito repetições. As atividades das enzimas CAT, APX, GPOX e GR foram mais expressas em tecidos radiculares. O excesso de Al reduziu a atividade da CAT e da GPOX nas raízes de B. brizantha cv. Xaraés e da APX e GR nas raízes de B. brizantha cv. Marandu. Quanto à compartimentação do Al no sistema radicular, constatou-se que a maior parte do metal concentrou-se no simplasto radicular, para ambos os genótipos. Por sua vez, na condição de excesso do metal, a maior concentração de Al trocável no apoplasto radicular foi verificada no cultivar Xaraés, sendo 49% superior ao cultivar Marandu. Foram verificadas maiores injúrias na epiderme radicular, como microfissuras e descamação, no cultivar Marandu. Os resultados fornecem evidências de que os genótipos de Brachiaria apresentam distintas respostas ao excesso de Al, com maior ou menor eficiência, caracterizando a tolerância diferencial / A variety of plant defense mechanisms have been shown, which confer tolerance to elements considered toxics, such as aluminum (Al). The aim of the first experiment was to evaluate the differential aluminum tolerance in four forage plants of Brachiaria genus (B. decumbens cv. Basilisk, B. brizantha cv. Marandu, B. brizantha cv. Piatã and B. brizantha cv. Xaraés), by measuring leaf area; root system morphology (total root length and total root surface); quantifying roots and plant top biomass yield; the Al-concentration, uptake and Al-long distance transport; evaluating lipid peroxidation in roots and leaves tissues, as well as the H2O2 content in leaves. Aluminum rates used were 0; 0.44; 0.89 and 1.33 mmol L-1, which were distributed as randomized block design, using a factorial 4 x 4 (four Al rates x four Brachiaria genotypes), with four replications. The free Al3+ activity in the nutrient solution was estimated using the software GeoChem-EZ®, reveling that around 81% of Al was available, considering the pH range between 3.0 and 4.0. Al addition in the nutrient solution decreased the plant top and root dry matter yield, increased Al-concentration and uptake in the roots. Though all these parameters, this following rank - as related to differential Al tolerance - was done: B. brizantha cv. Xaraés > B. decumbens cv. Basilisk >= B. brizantha cv. Piatã > B. brizantha cv. Marandu. In the second experiment, B. brizantha cv. Marandu (lower Al tolerance) and B. brizantha cv. Xaraés (higher Al tolerance) were grown in nutrient solution, with 0 and 1.33 mmol L-1 Al-concentrations, which were distributed as randomized block design, using a factorial 2 x 2 (two Al rates x two Brachiaria genotypes), with eight replications. Root system morphology and anatomy (root hairs) evaluations by using light and scanning electron microscopy, the Al concentration in the apoplast and symplast of roots, as well as the antioxidant enzymes activities such as catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPOX) and glutathione reductase (GR) were taken in the leaves and roots tissues. The CAT, APX, GPOX and GR activities were more expressed in root tissues than leaves tissues. Al toxicity decreased CAT and GPOX activities in roots of B. brizantha cv. Xaraés on the one hand; and the other the APX and GR activity in B. brizantha cv. Marandu roots. As regards to Al partition in root system compartments, it was found that most of metal was accumulated in symplast, to both genotypes. On the other hand, in metal excess condition, the highest Al concentration on the root apoplast was verified to Xaraés cultivar, being 49% higher than those quantified on the Marandu cultivar. Major injuries were found in the root epidermis, as ruptures and small clefts, which in turn have induced significant structural changes on the root surface of Marandu genotype. Taken together, the results provide evidences that Brachiaria genotypes have distinct responses to Al excess, with greater or lesser efficiency mechanism, featuring differential Al-tolerance

Pang Yee Man Flora. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 111-128). / Abstracts in English and Chinese. / Abstract (in English) --- p.ii / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.v / Table of Contents --- p.vii / List of Figures --- p.xii / Symbols and Abbreviations --- p.xv / Scientific Names --- p.xvii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Vitellogenesis --- p.2 / Chapter 1.2 --- Vitellogenin --- p.3 / Chapter 1.2.1 --- Structure --- p.3 / Chapter 1.2.2 --- Vitellogenin synthesis in the liver --- p.4 / Chapter 1.3 --- Regulation of vitellogenin synthesis --- p.5 / Chapter 1.3.1 --- Estradiol --- p.5 / Chapter 1.3.1.1 --- Mechanism of action --- p.6 / Chapter 1.3.1.2 --- Estradiol-stimulated vitellogenin expression --- p.7 / Chapter 1.3.1.3 --- Memory effects --- p.9 / Chapter 1.3.2 --- Testosterone --- p.10 / Chapter 1.3.3 --- Cortisol --- p.13 / Chapter 1.3.4 --- Progesterone --- p.14 / Chapter 1.3.5 --- Growth Hormone --- p.14 / Chapter 1.3.6 --- Prolactin --- p.15 / Chapter 1.3.7 --- Thyroid hormone --- p.15 / Chapter 1.4 --- Growth factors --- p.16 / Chapter 1.4.1 --- Activin --- p.16 / Chapter 1.4.1.1 --- Structure --- p.16 / Chapter 1.4.1.2 --- Functions --- p.17 / Chapter 1.4.2 --- Epidermal growth factors (EGF) --- p.18 / Chapter 1.4.2.1 --- Structure --- p.18 / Chapter 1.4.2.2 --- Functions --- p.19 / Chapter 1.5 --- Objectives of the present study --- p.20 / Chapter Chapter 2 --- Expression of Goldfish Vitellogenin in vivo and in vitro --- p.25 / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Materials and Methods --- p.26 / Chapter 2.2.1 --- Materials --- p.26 / Chapter 2.2.2 --- Sequencing --- p.27 / Chapter 2.2.3 --- Cell culture --- p.28 / Chapter 2.2.4 --- RNA extraction --- p.29 / Chapter 2.2.5 --- Northern hybridization --- p.31 / Chapter 2.2.6 --- Slot blot hybridization --- p.32 / Chapter 2.2.7 --- Data analysis --- p.33 / Chapter 2.2.8 --- SDS-PAGE analysis --- p.33 / Chapter 2.2.9 --- in situ hybridization --- p.34 / Chapter 2.3 --- Results --- p.37 / Chapter 2.3.1 --- Validation of vitellogenin mRNA detection --- p.37 / Chapter 2.3.2 --- Basal and estradiol-stimulated vitellogenin expression and production invivo --- p.38 / Chapter 2.3.3 --- Localization of vitellogenin expression in the liver --- p.39 / Chapter 2.3.4 --- Expression of vitellogenin in vitro --- p.40 / Chapter 2.4 --- Discussion --- p.54 / Chapter Chapter 3 --- Effects of Steroids on the Expression of Goldfish Vitellogenin in vitro --- p.60 / Chapter 3.1 --- Introduction --- p.60 / Chapter 3.2 --- Materials and Methods --- p.62 / Chapter 3.2.1 --- Materials --- p.62 / Chapter 3.2.2 --- Animal --- p.62 / Chapter 3.2.3 --- Primary culture of dispersed hepatic cells --- p.62 / Chapter 3.2.4 --- Drug treatment --- p.64 / Chapter 3.2.5 --- Total RNA isolation --- p.64 / Chapter 3.2.6 --- Messenger RNA isolation --- p.65 / Chapter 3.2.7 --- Slot blot analysis --- p.66 / Chapter 3.2.8 --- Data analysis --- p.68 / Chapter 3.2.9 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.68 / Chapter 3.2.10 --- Cloning of aromatase cDNA --- p.69 / Chapter 3.2.11 --- Sequencing --- p.70 / Chapter 3.3 --- Results --- p.71 / Chapter 3.3.1 --- Effect of 17-β estradiol on vitellogenin mRNA expression --- p.71 / Chapter 3.3.2 --- Effect of testosterone on vitellogenin mRNA expression --- p.71 / Chapter 3.3.3 --- Detection of aromatase mRNA expression in the liver by RT-PCR --- p.72 / Chapter 3.3.4 --- Effect of aromatase inhibitors on testosterone-stimulated vitellogenin expression --- p.73 / Chapter 3.4 --- Discussion --- p.81 / Chapter Chapter 4 --- Effects of Epidermal Growth Factor (EGF) and Activin on the Expression of Vitellogenin in the Goldfish Hepatic Cells in vitro --- p.86 / Chapter 4.1 --- Introduction --- p.86 / Chapter 4.2 --- Materials and Methods --- p.88 / Chapter 4.2.1 --- Materials --- p.88 / Chapter 4.2.2 --- Primary culture of dispersed hepatic cells --- p.89 / Chapter 4.2.3 --- Slot blot analysis --- p.91 / Chapter 4.2.4 --- Data analysis --- p.91 / Chapter 4.3 --- Results --- p.92 / Chapter 4.3.1 --- Effect of activin on vitellogenin mRNA expression --- p.92 / Chapter 4.3.2 --- Effect of EGF and TGF-α on vitellogenin mRNA expression --- p.93 / Chapter 4.4 --- Discussion --- p.99 / Chapter Chapter 5 --- General Discussion --- p.104 / Chapter 5.1 --- Overview --- p.104 / Chapter 5.2 --- Contribution of the present study --- p.106 / Chapter 5.2.1 --- Expression of goldfish vitellogenin in vivo and in vitro --- p.106 / Chapter 5.2.2 --- Effects of steroids on the expression of goldfish vitellogenin in vitro --- p.106 / Chapter 5.2.3 --- Effects of EGF and activin on the expression of vitellogenin in the goldfish hepatic cells in vitro --- p.107 / Chapter 5.3 --- Future prospects --- p.108

by Chung Lung Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 149-157). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abbreviations --- p.ii / Abstracts --- p.v / List of figures --- p.ix / List of tables --- p.xii / Contents --- p.xiii / Contents / General Introduction --- p.1 / Chapter CHAPTER ONE --- CISPLATIN RESISTANCE MECHANISMS / Chapter 1.1 --- INTRODUCTION --- p.3 / Chapter 1.1.1 --- History of Cisplatin as An Anticancer Drug --- p.3 / Chapter 1.1.2 --- Active Mechanisms of Cisplatin --- p.8 / Chapter 1.1.3 --- Formation of DNA Adducts --- p.8 / Chapter 1.1.4 --- Cisplatin Resistance Mechanisms --- p.9 / Chapter 1.1.4.1 --- Intracellular Accumulation of Cisplatin --- p.11 / Chapter 1.1.4.2 --- Glutathione-S-transferase and Glutathion --- p.12 / Chapter 1.1.4.3 --- Metallothionein --- p.16 / Chapter 1.1.4.4 --- Cell Cycle Perturbation --- p.16 / Chapter 1.1.4.5 --- P-glycoprotein --- p.17 / Chapter 1.1.4.6 --- Multidrug Resistant Protein --- p.19 / Chapter 1.1.4.7 --- Topoisomerase II --- p.20 / Chapter 1.1.4.8 --- DNA Repair --- p.22 / Chapter 1.1.4.9 --- Induction of Programme Cell Death --- p.23 / Chapter 1.2 --- OBJECTIVES --- p.27 / Chapter 1.3 --- MATERIALS AND METHODS / Chapter 1.3.1 --- Materials --- p.28 / Chapter 1.3.2 --- Methods --- p.31 / Chapter 1.3.2.1 --- Cell Lines --- p.31 / Chapter 1.3.2.2 --- Drug Sensitivity Assay --- p.31 / Chapter 1.3.2.3 --- Platinum Uptake --- p.32 / Chapter 1.3.2.4 --- Cell Cycle Analysis --- p.32 / Chapter 1.3.2.5 --- Western Blot Analysis --- p.33 / Chapter 1.3.2.6 --- Glutathione Content Determination --- p.36 / Chapter 1.3.2.7 --- DNA Fragmentation --- p.36 / Chapter 1.3.2.8 --- JC-1 Staining --- p.37 / Chapter 1.3.2.9 --- HE and DCF Staining --- p.38 / Chapter 1.3.2.10 --- Quantitative RT-PCR --- p.38 / Chapter 1.4 --- RESULTS / Chapter 1.4.1 --- Cisplatin Sensitivity of A431 Cells by MTT Assay --- p.40 / Chapter 1.4.2 --- Cross-resistance to Anti-cancer Drugs --- p.40 / Chapter 1.4.3 --- Quantitation of Cisplatin Accumulation in A431 Cells by AAS --- p.44 / Chapter 1.4.4 --- Drug Detoxification Agent --- p.45 / Chapter 1.4.5 --- Detection of Cell Cycle Arrest by Flow Cytometer --- p.47 / Chapter 1.4.6 --- Expression of Drug Resistance Related Genes --- p.48 / Chapter 1.4.7 --- Detection of Apoptosis by DNA Fragmentation --- p.50 / Chapter 1.4.8 --- Role of Mitochondria and Reactive Oxygen Species by Flow Cytometer --- p.52 / Chapter 1.4.9 --- Detection of Apoptotic mRNA Level by Quantitative RT-PCR --- p.57 / Chapter 1.4.10 --- Detection of Apoptotic Protein Level by Western Blot Analysis --- p.57 / Chapter 1.5 --- DISCUSSIONS --- p.59 / Chapter CHAPTER TWO: --- THE INTERACTION BETWEEN DRUG RESISTANCE MECHANISMS AND GROWTH FACTOR SIGNALLING PATHWAY / Chapter 2.1 --- INTRODUCTION --- p.63 / Chapter 2.1.1 --- Structure of EGF and EGFR --- p.64 / Chapter 2.1.2 --- Growth Factor Signal Transduction Pathway --- p.69 / Chapter 2.1.3 --- Biological Effect of EGF --- p.69 / Chapter 2.1.3.1 --- Modification of Drug Sensitivity by EGF --- p.71 / Chapter 2.2 --- OBJECTIVES --- p.74 / Chapter 2.3 --- MATERIALS AND METHODS / Chapter 2.3.1 --- Materials --- p.75 / Chapter 2.3.2 --- Methods / Chapter 2.3.2.1 --- Cell Lines --- p.76 / Chapter 2.3.2.2 --- Drug Sensitivity Assay --- p.77 / Chapter 2.3.2.3 --- Northern Blot Analysis --- p.77 / Chapter 2.3.2.4 --- Southern Blot Analysis --- p.78 / Chapter 2.3.2.5 --- Others --- p.78 / Chapter 2.4 --- RESULTS / Chapter 2.4.1 --- Sensitivity to EGF --- p.79 / Chapter 2.4.2 --- EGFR Expression Levels --- p.80 / Chapter 2.4.3 --- EGF Induced Protein Phosphorylation Pattern --- p.84 / Chapter 2.4.4 --- Effect of EGF on A431 Cells --- p.86 / Chapter 2.4.5 --- Response of Cells to Agents Targeting on EGF Signalling Pathway --- p.91 / Chapter 2.4.6 --- Response of Cells to Other Growth Factors --- p.97 / Chapter 2.4.7 --- Sensitivity of Cells to Different Anti-cancer Drugs --- p.99 / Chapter 2.4.8 --- Drug Resistance Mechanisms --- p.103 / Chapter 2.4.9 --- 5-Fluorouracil Sensitivity in A431 Cells --- p.108 / Chapter 2.4.10 --- Cisplatin Sensitivity in A431 Cells --- p.113 / Chapter 2.5 --- DISCUSSIONS --- p.117 / Chapter CHAPTER THREE: --- IDENTIFICATION OF DIFFERENTIALLY EXPRESSED GENE IN A431 CELLS BY DIFFERENTIAL DISPLAY / Chapter 3.1 --- INTRODUCTION --- p.122 / Chapter 3.2 --- MATERIALS AND METHODS / Chapter 3.2.1 --- Materials --- p.128 / Chapter 3.2.2 --- Methods / Chapter 3.2.2.1 --- Identification of Differentially Expressed Genes by RT-PCR / Chapter 3.2.2.2 --- Cloning of a Differentially Expressed cDNAs --- p.129 / Chapter 3.2.2.3 --- Screening and Sequencing of cDNA Inserts --- p.130 / Chapter 3.2.2.4 --- Rapid Amplification of cDNA Ends (RACE) --- p.131 / Chapter 3.2.2.5 --- Amplifcation Reaction --- p.131 / Chapter 3.2.2.6 --- Cloning and Sequencing of the RACE Fragment --- p.132 / Chapter 3.3 --- RESULTS / Chapter 3.3.1 --- Identification of novel cDNA by mRNA differential display --- p.133 / Chapter 3.4 --- DISCUSSIONS --- p.145 / General Conclusion --- p.147 / References --- p.149

The distribution of epidermal hairs (trichomes) is an important taxonomic character in the genus Antirrhinum. Most species in subsection Antirrhinum produce trichomes from lower internodes and leaves, then have bald stems and leaf blades after the third node and resume trichomes production again in the inflorescence (the "bald" phenotype). All species in subsection Kickxiella produce trichomes throughout development (the "hairy" phenotype). Populations of some species are polymorphic for trichome distribution-both bald and hairy individuals were observed in A. australe, A. graniticum, A. latifolium and A. meonanthum. Antirrhinum species also varied in trichome morphology. Five types were recognized according to length and the presence or absence of a secretory gland. Some types were present in all species and had similar distributions-for example short glandular trichomes were found on the adaxial midribs of all leaves in all species, and the lower leaves and internodes of all species shared longer glandular and long eglandular trichomes. However, the trichomes on leaf blades and stems at higher vegetative nodes of hairy species and in the inflorescences differed in morphology between species, suggesting that they are regulated differently from trichomes at more basal positions. Other species in the tribe Antirrhineae showed similar variation in trichome morphology and distribution to Antirrhinum, suggesting that the control of trichome development might be conserved within the tribe. To understand the genetic basis for variation in trichome distribution, a near-isogenic line (NIL) was generated by introducing regions of the genome of A. charidemi (hairy, subsection Kickxiella) into the genetic background of A. majus subsp. majus (bald, subsection Antirrhinum). One NIL segregated bald and hairy progeny, with the same trichome distributions as the parent species, in a ratio that suggested a single locus is responsible for the differences and baldness is dominant. The locus was named as Hairy and assumed to act as a suppressor of trichome formation. Progeny of the NIL were used in genome resequencing of bulked phenotype pools (Pool-seq) to map Hairy. No recombination between Hairy and a candidate gene (GRX1) from the Glutaredoxin gene family, was detected in the mapping population. In addition, RNA-seq revealed that GRX1 was expressed in bald parts of bald progeny, but not in the same parts of hairy progeny, and in situ hybridisation showed GRX1 RNA was restricted to epidermal cells, which form trichomes in the absence of Hairy activity. A virus-induced gene silencing (VIGS) method was also developed to test GRX1 function further. Reducing GRX1 activity allowed ectopic trichome formation in the bald NIL. Together, this evidence strongly supported Hairy being GRX1. To investigate evolution of Hairy and its relationship to variation in trichome distribution, the NIL was crossed to other Antirrhinum species. These allelism tests suggested that Hairy underlies variation in trichome distribution throughout the genus, with the exception of A. siculum, which has a bald phenotype but might lack activity of hairy and a gene needed for trichome formation. Hairy sequences were obtained from representative of 24 Antirrhinum species and two related species in the tribe Antirrhineae. The conserved trichome-suppressing function of the sequence from one of these species (Misopates orontium, bald phenotype) was confirmed by VIGS. Gene phylogenies combined with RNA expression analysis suggested that the ancestral Antirrhinum had a bald phenotype, that a single mutation could have given rise to the hairy alleles in the majority of Kickxiella species, that these alleles were also present in polymorphic populations in the other subsections, consistent with transfer from Kickxiella by hybridisation, and that multiple, independent mutations had been involved in parallel evolution of the hairy phenotype in a minority of Kickxiella species. Phylogenetic analysis of GRX proteins suggested that Hairy gained its trichome-repressing function relatively late in the evolutionary history of eudicots, after the Antirrhineae-Phrymoideae split, but before divergence of the lineages leading to Antirrhinum and Misopates. A yeast two-hybrid screen identified members of the TGA and HD-Zip IV transcription factors as potential substrates of the Hairy GRX.

O cavalo Baixadeiro é encontrado na Baixada Maranhense, região caracterizada por planície, podendo permanecer alagada por até seis meses. Ainda que diante destas condições, o cavalo Baixadeiro pode viver sem apresentar doenças da úngula, tais como, a laminite. Assim, propôs-se identificar elementos morfológicos da úngula desta raça específica de cavalo com o intuito de explicar tal resistência à umidade. Foram utilizadas amostras de úngula provenientes de 4 cavalos Baixadeiros (N=16) e de 4 cavalos Puro Sangue Inglês (N=16). Todas as úngulas foram analisadas por macroscopia, morfometria e por microscopia eletrônica de varredura e de luz. Macroscopicamente, a úngula do cavalo Baixadeiro era cuneiforme, com comprimento médio de 10.22 ± 1.3 cm, largura de 9.83 ± 1.01 cm e comprimento da parede medial de 5.67 ± 0.76 cm. A úngula do cavalo Puro Sangue Inglês teve um comprimento médio de 13.47 ± 0.8 cm, largura de 12.54 ± 0.49 cm e comprimento da parede medial de 7.77 ± 0.54 cm. Na microscopia de luz da camada interna, o tecido que conecta as lamelas epidérmicas primárias às secundárias e ao estrato médio foi visualmente mais espesso no Baixadeiro. Além disso, a região distal das lamelas era mais compacta do que as da região proximal, enquanto que no Puro Sangue Inglês não foram observadas diferenças. Na microscopia eletrônica de varredura, o espaço intertubular do estrato médio foi visualmente maior. A partir desta arquitetura nós sugerimos que existe maior adesão da cápsula da úngula à falange distal no cavalo Baixadeiro, provavelmente diminuindo a incidência de rotação da falange distal e, consequentemente, diminuindo a laminite / The Baixadeiro horse is found in Baixada Maranhense, region is characterized by a flat land that can be flooded during six months per year. In this region the Baixadeiro horse can live without ungula diseases, such as, laminitis. Thus, was proposed to identify morphological elements of the ungula from this specific breed to indicate this resistance to humidity. We used ungula samples from four Baixadeiro horse (N=16) and from four Thoroughbred horse (N=16). All ungulas were analyzed macroscopically, morphometrically and by light and scanning electronic microscopy. Macroscopically, the ungula of Baixadeiro horse was cuneiform, with average length 10.22 ± 1.3 cm, width of 9.83 ± 1.01 cm and medial wall lenght of 5.67 ± 0.76 cm. While the Thoroughbred horse ungula had average length 13.47 ± 0.8 cm, width 12.54 ± 0.49 cm and medial wall length 7.77 ± 0.54 cm. Under light microscopy, in the internal layer, the tissue that connects primary to secondary epidermal lamella and to middle stratum was visually thicker in the Baixadeiro. In addition, the distal region of lamellae was more compact than the proximal region, while in Thoroughbred no differences were observed. By scanning electron microscopy, the intertubular space of the middle stratum was visually bigger. From this architecture we suggested that there are greater adhesion of ugula capsule to distal phalanx in the Baixadeiro horse, probably decreasing incidence of distal phalanx rotation and consequently diminishing laminitis

共著者あり。共著者名:Munakata Mitsuru, Sato Atsuko, Amishima Masaru, Homma Yukihiko, Kawakami Yoshikazu. / Hokkaido University (北海道大学) / 博士 / 医学