mouse-mammary-epithelial-cells-form-mammospheres-during-lactogenic

Mouse Mammary Epithelial Cells form Mammospheres During Lactogenic Differentiation

A phenotypic measure commonly used to determine the degree of lactogenic differentiation in mouse mammary epithelial cell cultures is the formation of ...

HC11 Maus Milch-Epithelzellen unterscheiden als Reaktion auf lactogenic Hormon, was Ausdruck der Milchproteine einschlie&szlig;lich Beta-Kasein. Fr&uuml;here Studien haben gezeigt, dass epidermale Wachstumsfaktor (EGF) blockt Differenzierung nicht nur durch die Aktivierung des Ras/Mek/Erk Signalweges aber auch verwickelt, Phosphatidylinositol-3-Kinase (PI-3-Kinase) signalisieren. Die aktuelle Studie analysiert den Mechanismus der die PI-3-Kinase-Signalweg in einem EGF-induzierte Block der HC11 lactogenic Differenzierung.

EGF-induzierte Aktivierung der Akt mTOR-abh&auml;ngige p70S6 Kinase Phosphorylierung und Hemmung der HC11 lactogenic Zelldifferenzierung f&uuml;hrt.

HC11 mouse mammary epithelial cells differentiate in response to lactogenic hormone resulting in expression of milk proteins including beta-casein. Previous studies have shown that epidermal growth factor (EGF) blocks differentiation not only through activation of the Ras/Mek/Erk pathway but also implicated phosphatidylinositol-3-kinase (PI-3-kinase) signaling. The current study analyzes the mechanism of the PI-3-kinase pathway in an EGF-induced block of HC11 lactogenic differentiation.

EGF-induced activation of Akt results in mTOR-dependent p70S6 kinase phosphorylation and inhibition of HC11 cell lactogenic differentiation.

Previous studies demonstrated that the Ras suppressor, RSU-1, localizes to human chromosome 10p13, a region frequently deleted in high grade gliomas, and that RSU-1 expression inhibited the tumorigenesis of a glioblastoma cell line. We have now examined RNA from human glial tumors for RSU-1 expression by RT-PCR using primers for the 5' and 3' ends of the RSU-1 open reading frame. Analysis of the amplified RSU-1 cDNA demonstrated that in addition to the entire 858 bp RSU-1 open reading frame, a shorter 725 bp RSU-1 fragment was amplified as well. Sequencing of this product revealed that it encoded a RSU-1 cDNA product which was missing a single 133 bp internal exon. This exon-deleted product was found in 30% of the high grade gliomas studied and 2/3 oligodendrogliomas, but not in other CNS tumors, bladder or colon tumors or normal tissue. The exon-deleted RSU-1 product was infrequently detected in RNA from human tumor cell lines. Expression of an HA-tagged form of the deleted RSU-1 protein in transfected Cos 1 cells revealed that the protein was unstable, with a half life of less than 1 h, in contrast to the full length HA-tagged Rsu-1 protein which was stable for more than 4 h. These results suggest that the alternative splicing of the RSU-1 RNA to produce the exon-deleted form constitutes a mechanism for reduction or loss of functional Rsu-1. Because the expression of Rsu-1 can inhibit malignant growth of glioblastoma cells, the depletion of Rsu-1, via the production of the alternatively spliced form of RSU-1, may inhibit growth regulation in tumors.

Identification of an alternatively spliced RNA for the Ras suppressor RSU-1 in human gliomas.

Identifizierung einer alternativ gesplei&#xDF;ten RNA f&#xFC;r das Ras-Suppressor RSU-1 in humanen Gliomen.

Epidermal growth factor (EGF) and Ras mitogenic signal transduction pathways are frequently activated in breast carcinoma and inhibit mammary differentiation and apoptosis. HC11 mouse mammary epithelial cells, which differentiate and synthesize beta-casein following growth to confluency and stimulation with lactogenic hormones, were used to study EGF-dependent signaling during differentiation. Blocking Mek-Erk or phosphotidylinositol-3-kinase (PI-3 kinase) signaling with specific chemical inhibitors enhanced beta-casein promotor-driven luciferase activity. Because EGF stimulation of HC11 cells resulted in the activation of Ras, the effect of activated Ras (RasV12) or dominant negative (DNRasN17) on lactogen induced differentiation was examined. HC11 cell lines expressing RasV12 or DNRasN17 under the control of a tetracycline (tet)-responsive promotor were constructed. Activated RasV12 expression resulted in reduced tyrosine phosphorylation of Stat5 and a delay in beta-casein expression in response to prolactin. However, the expression of tet-regulated DNRasN17 and adenovirus-encoded DNRasN17 enhanced Stat5 tyrosine phosphorylation, Stat5 DNA binding, and beta-casein transcription. The expression of DNRasN17 blocked the activation of the Mek-Erk pathway by EGF but did not prevent the phosphorylation of AKT, a measure of activation of the PI-3-kinase pathway. Moreover, the expression of DNRasN17 prevented the block to lactogenic differentiation induced by EGF. Stimulation of HC11 cells with prolactin resulted in the association of the SHP2 phosphatase with Stat5, and this association was prevented by DNRasN17 expression. These results demonstrate that in HC11 cells DNRas inhibits the Mek-Erk pathway and enhances lactogenic hormone-induced differentiation. This occurs, in part, by inhibiting the association of the SHP2 phosphatase with Stat5.

Dominant negative Ras enhances lactogenic hormone-induced differentiation by blocking activation of the Raf-Mek-Erk signal transduction pathway.

Dominant negatives Ras erh&#xF6;ht laktogene Hormon-induzierte Differenzierung durch die Blockierung der Aktivierung des Raf-Mek-Erk-Signaltransduktionsweg.

Rsu-1 is a highly conserved leucine rich repeat (LRR) protein that is expressed ubiquitously in mammalian cells. Rsu-1 was identified based on its ability to inhibit transformation by Ras, and previous studies demonstrated that ectopic expression of Rsu-1 inhibited anchorage-independent growth of Ras-transformed cells and human tumor cell lines. Using GAL4-based yeast two-hybrid screening, the LIM domain protein, PINCH1, was identified as the binding partner of Rsu-1. PINCH1 is an adaptor protein that localizes to focal adhesions and it has been implicated in the regulation of adhesion functions. Subdomain mapping in yeast revealed that Rsu-1 binds to the LIM 5 domain of PINCH1, a region not previously identified as a specific binding domain for any other protein. Additional testing demonstrated that PINCH2, which is highly homologous to PINCH1, except in the LIM 5 domain, does not interact with Rsu-1. Glutathione transferase fusion protein binding studies determined that the LRR region of Rsu-1 interacts with PINCH1. Transient expression studies using epitope-tagged Rsu-1 and PINCH1 revealed that Rsu-1 co-immunoprecipitated with PINCH1 and colocalized with vinculin at sites of focal adhesions in mammalian cells. In addition, endogenous P33 Rsu-1 from 293T cells co-immunoprecipitated with transiently expressed myc-tagged PINCH1. Furthermore, RNAi-induced reduction in Rsu-1 RNA and protein inhibited cell attachment, and while previous studies demonstrated that ectopic expression of Rsu-1 inhibited Jun kinase activation, the depletion of Rsu-1 resulted in activation of Jun and p38 stress kinases. These studies demonstrate that Rsu-1 interacts with PINCH1 in mammalian cells and functions, in part, by altering cell adhesion.

The Ras suppressor Rsu-1 binds to the LIM 5 domain of the adaptor protein PINCH1 and participates in adhesion-related functions.

Das Ras-Suppressor-RSU-1 bindet an die LIM 5 Dom&#xE4;ne des Adapter-Protein PINCH1 und beteiligt sich an Adh&#xE4;sion-bezogenen Funktionen.

Chromosome instability and aneuploidy are hallmarks of cancer, but it is not clear how changes in the chromosomal content of a cell contribute to the malignant phenotype. Previously we have shown that we can readily isolate highly proliferative tumor cells and their revertants from highly invasive tumor cell populations, indicating how phenotypic shifting can contribute to malignant progression. Here we show that chromosome instability and changes in chromosome content occur with phenotypic switching. Further, we show that changes in the copy number of each chromosome quantitatively impose a proportional change in the chromosome transcriptome ratio. This correlation also applies to subchromosomal regions of derivative chromosomes. Importantly, we show that the changes in chromosome content and the transcriptome favor the expression of a large number of genes appropriate for the specific tumor phenotype. We conclude that chromosome instability generates the necessary chromosome diversity in the tumor cell populations and, therefore, the transcriptome diversity to allow for environment-facilitated clonal expansion and clonal evolution of tumor cell populations.

Chromosome instability, chromosome transcriptome, and clonal evolution of tumor cell populations.

Chromosomen-Instabilit&auml;t und Aneuploidie sind Markenzeichen von Krebs, aber es ist nicht klar, wie &Auml;nderungen in der chromosomalen Inhalt einer Zelle zu der malignen Ph&auml;notyp beitragen. Zuvor haben wir gezeigt, dass wir leicht, stark proliferativ Tumorzellen isolieren k&ouml;nnen und ihre Revertants aus hoch invasiven Tumor Zelle Bev&ouml;lkerungen, die angibt, wie ph&auml;notypische Verlagerung malignen Progression zur k&ouml;nnen. Hier zeigen wir, dass Chromosomen-Instabilit&auml;t und Chromosom Content-&Auml;nderungen mit ph&auml;notypische Schaltung auftreten. Dar&uuml;ber hinaus zeigen wir, dass in die Exemplarnummer jedes Chromosoms quantitativ eine proportionale Ver&auml;nderung im Chromosom Transkriptom Verh&auml;ltnis aufzuzw&auml;ngen. Dieser Zusammenhang gilt auch f&uuml;r subchromosomal Regionen Derivative Chromosomen. Wichtiger ist, zeigen wir, dass die inhaltlichen &Auml;nderungen in Chromosom und die Transkriptom-Gunst der Ausdruck einer gro&szlig;en Anzahl von Genen entsprechend der spezifischen Tumor-Ph&auml;notyp. Wir schlie&szlig;en, dass Chromosomen-Instabilit&auml;t erzeugt die notwendigen Chromosom-Vielfalt in den Tumor Zelle Bev&ouml;lkerungen und damit die Transkriptom-Vielfalt Umgebung erleichtert klonalen Expansion und klonale Evolution der Tumor Zelle Bev&ouml;lkerungen erm&ouml;glichen.

Chromosomen-Instabilit&auml;t, Chromosom Transkriptom und klonale Evolution der Tumor Zelle Bev&ouml;lkerungen.

The response of mammary epithelial cells to basement membrane and stroma induced signals contributes to the degree of differentiation in this tissue. The studies reported here indicate that connective tissue growth factor (CTGF) is highly elevated during lactogenic differentiation of the HC11 mouse mammary epithelial cell line. In addition, CTGF is expressed in the mouse mammary gland during pregnancy and lactation and it is expressed in primary mammary epithelial cell cultures established from pregnant mice. In HC11 cells CTGF is transcriptionally regulated by dexamethasone, but not by estrogen or progesterone, and CTGF expression is not dependent on TGFbeta. CTGF contributes to and is required for lactogenic differentiation of HC11 cells, as demonstrated by increased differentiation following expression of plasmid-encoded CTGF and decreased differentiation following depletion of endogenous CTGF with siRNA. Moreover, HC11 mouse mammary epithelial cells infected with an adenoviral vector encoding CTGF exhibit increased lactogenic differentiation. Plasmid vector-induced elevation of CTGF levels also increased the level of beta1 integrin in HC11 cells. Because the production of stromal factors is an important component of differentiation in mammary epithelial cells, the regulation of CTGF by glucocorticoids may play a critical role in this aspect of the control of differentiation. The studies reported here provide important information on the role of CTGF in mammary epithelial cell differentiation.

Glucocorticoid induced expression of connective tissue growth factor contributes to lactogenic differentiation of mouse mammary epithelial cells.

Die Reaktion der Milch-Epithelzellen auf Basalmembran und Stroma induzierten Signale tr&auml;gt den Grad der Differenzierung in dieses Gewebe. Die Studien berichtet hier zeigen, dass das Bindegewebe Wachstumsfaktor (CTGF) w&auml;hrend der lactogenic Differenzierung der HC11 Maus Milch-Epithelzellen Linie hoch ist. Dar&uuml;ber hinaus CTGF dr&uuml;ckt sich in der Brustdr&uuml;se Maus w&auml;hrend der Schwangerschaft und Stillzeit und im prim&auml;ren Mamma epitheliale Zellkulturen hergestellt von schwangeren M&auml;usen ausgedr&uuml;ckt wird. In den Zellen der HC11-CTGF ist transcriptionally geregelt, von Dexamethason, aber nicht von &Ouml;strogen oder Progesteron und CTGF Expression ist nicht abh&auml;ngig von TGFbeta. CTGF tr&auml;gt zur und f&uuml;r erforderlich lactogenic Differenzierung der HC11 Zellen, wie erh&ouml;hte Differenzierung nach Ausdruck der Plasmid-kodierte CTGF und verminderte Differenzierung nach Ersch&ouml;pfung der endogenen CTGF mit SiRNA demonstriert. Dar&uuml;ber hinaus weisen HC11 Maus Milch-Epithelzellen infiziert mit einer adenoviral Vektor Codierung CTGF erh&ouml;hte lactogenic Differenzierung. Plasmid Vektor induziert H&ouml;he CTGF Ebenen erh&ouml;ht auch das Niveau der beta1-Integrin in HC11-Zellen. Da die Produktion von stromal Faktoren eine wichtige Komponente der Differenzierung in Milch-Epithelzellen ist, kann die Verordnung von CTGF durch Glukokortikoide in diesem Aspekt der Kontrolle von Differenzierung eine entscheidende Rolle spielen. Die hier berichteten Studien liefern wichtige Informationen &uuml;ber die Rolle der CTGF in Mamma epithelialer Zelldifferenzierung.

Glukokortikoid-induzierte Expression von Bindegewebe Wachstumsfaktor tr&auml;gt zu einer lactogenic Differenzierung der Maus Milch-Epithelzellen.

The link between Ras transformation and enhanced cell migration due to altered integrin signaling is well established in tumorigenesis, however there remain gaps in our understanding of its mechanism. The Ras suppressor, Rsu-1, has recently been linked to the IPP (integrin-linked kinase {ILK}, PINCH-1/LIMS1, parvin) focal adhesion complex based on its interaction with the LIM 5 domain of PINCH1. Defining the role of the Rsu1-PINCH1-ILK-parvin complex in tumorigenesis is important because both ILK and PINCH1 are elevated in certain tumors while ectopic expression of Rsu-1 blocks tumorigenesis. Our studies previously identified an alternatively spliced isoform of Rsu-1 in high-grade gliomas. We report here the detection of a truncated (p29) Rsu-1 protein, which correlates with the presence of the alternatively spliced Rsu-1 RNA. This RNA and the respective protein were detected in human tumor cell lines that contain high levels of activated Ras, and inhibitor studies demonstrate that the Mek-ERK pathway regulates expression of this truncated Rsu-1 product. We also show that Rsu-1 co-localizes with ILK at focal contacts and co-immunoprecipitates with the ILK-PINCH1 complex in non-transformed cells, but following Ras transformation the association of Rsu-1 with the PINCH1-ILK complex is greatly reduced. Using a human breast cancer cell line, our in vitro studies demonstrate that the depletion of Rsu-1 full-length protein enhances cell migration coincident with an increase in Rac-GTP while the depletion of the p29 Rsu-1 truncated protein inhibits migration. These findings indicate that Rsu-1 may inhibit cell migration by stabilizing the IPP adhesion complex and that Ras activation perturbs this inhibitory function by modulating both Rsu-1 splicing and association of full-length Rsu-1 with IPP. Hence, our findings demonstrate that Rsu-1 links the Ras pathway with the IPP complex and the perturbations of cell attachment-dependent signaling that occur in the malignant process.

The Rsu-1-PINCH1-ILK complex is regulated by Ras activation in tumor cells.

Die Verbindung zwischen Ras-Transformation und verst&auml;rkte Zelle Migration aufgrund ver&auml;nderter Integrin Signalisierung ist weit verbreitet in der Tumorentstehung, aber es bleiben L&uuml;cken im Verst&auml;ndnis seiner Mechanismus. Die Ras-Suppressor Rsu-1, hat vor kurzem im Zusammenhang mit der IPP (Integrin-linked Kinase {Sorte}, PINCH-1/LIMS1, Parvin) komplexe fokale Adh&auml;sion auf der Grundlage seiner Interaktion mit der LIM-5-Dom&auml;ne des PINCH1. Bestimmung der Rolle des Rsu1-PINCH1-ILK-Parvin Komplexes in Tumorentstehung ist wichtig, da bestimmte Tumoren w&auml;hrend ektopische Expression des Rsu-1 Bl&ouml;cke Tumorigenese ILK und PINCH1 erhoben werden. Unsere Studien identifizierten zuvor einer alternativ gesplei&szlig;ten Isoform Rsu-1 in hochgradige Gliome. Wir berichten hier die Erkennung eines abgeschnittenen (p29) Rsu-1-Proteins, die mit der Anwesenheit der alternativ gesplei&szlig;ten Rsu-1 RNA korreliert. Diese RNA und der jeweiligen Protein in menschlichen Tumor-Zelllinien, die hohe aktivierte Ras enthalten wurden erkannt und Inhibitor Studien belegen, dass die Mek-ERK-Pathway Ausdruck dieses abgeschnittene Rsu-1-Produktes regelt. Wir zeigen auch, dass die Rsu-1 co-localizes mit ILK fokale Kontakte und co-Immunoprecipitates mit der ILK-PINCH1-Komplex in nicht-transformierten Zellen, aber folgende Ras-Transformation, die die Assoziation der Rsu-1 mit der PINCH1-ILK-Komplex stark reduziert ist. Mit eine menschlichen Brust-Krebs-Zelllinie, zeigen unsere in-vitro-Studien, dass die Ersch&ouml;pfung der Rsu-1 in Protein Zellmigration zusammenfallend mit einem Anstieg der Rac-GTP, verbessert w&auml;hrend der Abbau des Proteins Rsu-1 abgeschnitten p29 Migration hemmt. Diese Befunde zeigen, dass Rsu-1 Zellmigration hemmen kann, durch Stabilisierung der IPP-Adh&auml;sion komplexe und Ras Aktivierung dieser hemmenden Funktion w&uuml;hlt durch Modulation Rsu-1 Splei&szlig;en und Verband in Rsu-1 mit IPP. Daher zeigen unsere Ergebnisse, dass Rsu-1 verbindet die Ras-Weg mit der IPP-komplex und die St&ouml;rungen von Zelle signalisieren Anlage abh&auml;ngig, die in der malignen Prozess auftreten.

Der Rsu-1-PINCH1-ILK-Komplex wird durch Ras Aktivierung in Tumorzellen geregelt.

Mammary epithelial cells go through a series of developmental changes during pregnancy and lactation including proliferation, differentiation, secretion and apoptosis. HC11 mouse mammary epithelial cells, which undergo lactogen-induced differentiation in cell culture, were used to follow the changes in gene expression during this process. The expression profiles of over 20,000 genes were compared in HC11 cells undergoing lactogenic differentiation to non-differentiated cells using DNA microarray analysis. Greater than two fold changes were detected in 998 genes in the differentiated cells versus growth controls. Several genes including CTGF/CCN2 exhibited greater than five-fold increase. Validation of the gene expression pattern for more than twenty genes was performed. The results indicate the involvement of numerous genes and pathways in the differentiation of mouse mammary epithelial cells in culture and they identify genetic pathways associated with specific transcriptional regulation. In addition, the expression of a subset of genes regulated by lactogenic differentiation in HC11 cells, including CTGF/CCN2 and osteopontin, was examined in mouse mammary glands revealing expression during pregnancy and lactation that declined during involution of the glands. To probe the mechanism by which epidermal growth factor (EGF), a known inhibitor of lactogenic differentiation in HC11 cells, blocks lactogenesis, the HC11 cells stimulated with lactogenic hormone in the presence of EGF were profiled. This data revealed EGF regulation of a specific subset of genes including important cell cycle regulators. The studies confirm the value of expression profiling in defining gene transcription associated with differentiation of mammary epithelial cells.

Global expression profiling reveals regulation of CTGF/CCN2 during lactogenic differentiation.

Mamm&auml;re Epithelzellen gehen durch eine Reihe von Entwicklungsst&ouml;rungen Ver&auml;nderungen w&auml;hrend der Schwangerschaft und Stillzeit einschlie&szlig;lich Proliferation, Differenzierung, Sekretion und Apoptose. HC11 Maus Milch-Epithelzellen, die Differenzierung in der Zellkultur Lactogen induziert werden, wurden verwendet, die &Auml;nderungen in der Genexpression w&auml;hrend dieses Prozesses zu folgen. Die Ausdruck-Profile von mehr als 20.000 Gene wurden in HC11 Zellen einer lactogenic Differenzierung nicht getrennte Zellen mit DNA-Microarray-Analyse verglichen. Mehr als zweifach-&Auml;nderungen im 998 Gene in den differenzierten Zellen gegen&uuml;ber Wachstum Kontrollen festgestellt wurden. Mehrere Gene einschlie&szlig;lich CTGF/CCN2 ausgestellt mehr als verf&uuml;nffacht. Validierung der Muster des Gen-Ausdrucks f&uuml;r mehr als zwanzig Gene wurde durchgef&uuml;hrt. Die Ergebnisse zeigen die Einbindung zahlreicher Gene und Wege bei der Differenzierung der Maus Milch-Epithelzellen in Kultur und sie identifizieren genetischen Wege bestimmte TRANSKRIPTIONSREGULATION zugeordnet. Dar&uuml;ber hinaus wurde der Ausdruck einer Teilmenge von Genen geregelt lactogenic Differenzierung der HC11 Zellen, einschlie&szlig;lich CTGF/CCN2 und Osteopontin, untersucht in Maus-Milchdr&uuml;sen offenbart Ausdruck w&auml;hrend der Schwangerschaft und Stillzeit, die w&auml;hrend der Involution der Dr&uuml;sen abgelehnt. Um den Mechanismus durch die epidermalen Wachstumsfaktor (EGF) Sonde, wurden ein bekannter Inhibitor der lactogenic Differenzierung in den HC11-Zellen stimuliert mit lactogenic Hormon in Anwesenheit von EGF, HC11 Zellen, Bl&ouml;cke Laktogenese profiliert. Diese Daten ergeben EGF-Verordnung einer bestimmten Teilmenge von Genen einschlie&szlig;lich wichtiger Zellzyklus Regulierungsbeh&ouml;rden. Die Studien best&auml;tigen den Wert des Ausdrucks, die Profilerstellung bei der Definition von Gen-Transkription, die Differenzierung der Milch-Epithelzellen zugeordnet.

Globale Expression profiling zeigt Regulierung von CTGF/CCN2 w&auml;hrend lactogenic Differenzierung.

Connective Tissue Growth Factor (CTGF/CCN2), a known matrix-associated protein, is required for the lactogenic differentiation of mouse mammary epithelial cells. An HC11 mammary epithelial cell line expressing CTGF/CCN2 was constructed to dissect the cellular responses to CTGF/CCN2 that contribute to this differentiation program.

Connective Tissue Growth Factor (CTGF/CCN2) enhances lactogenic differentiation of mammary epithelial cells via integrin-mediated cell adhesion.

Connective Tissue Growth Factor (CTGF/CCN2), einem bekannten Matrix-assoziierte Protein ist erforderlich f&uuml;r die lactogenic Differenzierung der Maus Milch-Epithelzellen. Eine HC11 Milch-Epithelzellen Linie CTGF/CCN2 wurde gebaut, um die zellul&auml;ren Reaktionen auf CTGF/CCN2 zu sezieren, die zu diesem Programm Differenzierung beitragen.

Connective Tissue Growth Factor (CTGF/CCN2) verbessert die lactogenic Differenzierung der Milch-Epithelzellen &uuml;ber Integrin-vermittelte Zelladh&auml;sion.

The mammary gland undergoes hormonally controlled cycles of pubertal maturation, pregnancy, lactation, and involution, and these processes rely on complex signaling mechanisms, many of which are controlled by cell-cell and cell-matrix adhesion. The adhesion of epithelial cells to the extracellular matrix initiates signaling mechanisms that have an impact on cell proliferation, survival, and differentiation throughout lactation. The control of integrin expression on the mammary epithelial cells, the composition of the extracellular matrix and the presence of secreted matricellular proteins all contribute to essential adhesion signaling during lactogenesis. In vitro and in vivo studies, including the results from genetically engineered mice, have shed light on the regulation of these processes at the cell and tissue level and have led to increased understanding of the essential signaling components that are regulated in temporal and cell specific manner during lactogenesis. Recent studies suggest that a secreted matricellular protein, CTGF/CCN2, may play a role in lactogenic differentiation through binding to Î²1 integrin complexes, enhancing the production of extracellular matrix components and contributions to cell adhesion signaling.

The contribution of adhesion signaling to lactogenesis.

Der Brustdr&uuml;se durchl&auml;uft hormonell gesteuerte Zyklen der pubert&auml;re Reifung, Schwangerschaft, Stillzeit und Involution, und diese Prozesse ben&ouml;tigen komplexe Signalisierungsmechanismen, von die viele von Zell-Zell und Zelle-Matrix-Haftung gesteuert werden. Die Haftung der Epithelzellen an der extrazellul&auml;ren Matrix initiiert Signalisierungsmechanismen, die sich auf die Zellproliferation, &Uuml;berleben und Differenzierung in der gesamten Stillzeit auswirken. Die Kontrolle der Integrin-Ausdruck auf den Milch-Epithelzellen, die Zusammensetzung der extrazellul&auml;ren Matrix und das Vorhandensein von sezernierte Matricellular Proteine, die alle wesentlichen Adh&auml;sion Signalisierung w&auml;hrend Laktogenese beizutragen. In vitro und in-vivo-Studien, einschlie&szlig;lich der Ergebnisse von gentechnisch ver&auml;nderte M&auml;use haben Aufschluss &uuml;ber die Regulierung dieser Prozesse auf der Ebene von Zellen und Gewebe und f&uuml;hrten zu erh&ouml;hten Verst&auml;ndnis signalisierende Bestandteile, die in zeitlichen geregelt sind und Handy-spezifische Art und Weise w&auml;hrend Laktogenese. Neuere Studien legen nahe, dass ein Protein sezernierte Matricellular CTGF/CCN2, kann eine Rolle in lactogenic Differenzierung durch Bindung an &beta;1-Integrin-komplexe, Verbesserung der Herstellung von Komponenten der extrazellul&auml;ren Matrix und Beitr&auml;ge zur Zelle Adh&auml;sion signalisieren.

Der Beitrag der Adh&auml;sion Laktogenese Signalisierung.

Host determinants of HIV-1 viral tropism include factors from producer cells that affect the efficiency of productive infection and factors in target cells that block infection after viral entry. TRIM5Î± restricts HIV-1 infection at an early post-entry step through a mechanism associated with rapid disassembly of the retroviral capsid. Topoisomerase I (TOP1) appears to play a role in HIV-1 viral tropism by incorporating into or otherwise modulating virions affecting the efficiency of a post-entry step, as the expression of human TOP1 in African Green Monkey (AGM) virion-producing cells increased the infectivity of progeny virions by five-fold. This infectivity enhancement required human TOP1 residues 236 and 237 as their replacement with the AGM counterpart residues abolished the infectivity enhancement. Our previous studies showed that TOP1 interacts with BTBD1 and BTBD2, two proteins which co-localize with the TRIM5Î± splice variant TRIM5Î´ in cytoplasmic bodies. Because BTBD1 and BTBD2 interact with one HIV-1 viral tropism factor, TOP1, and co-localize with a splice variant of another, we investigated the potential involvement of BTBD1 and BTBD2 in HIV-1 restriction.

Human TOP1 residues implicated in species specificity of HIV-1 infection are required for interaction with BTBD2, and RNAi of BTBD2 in old world monkey and human cells increases permissiveness to HIV-1 infection.

Host Determinanten der HIV-1 virale Tropismus sind aus Hersteller-Zellen, die die Wirksamkeit der produktiven Infektion beeintr&auml;chtigen und Faktoren in Zielzellen, die Infektion nach viralen Eintrag zu blockieren. TRIM5&alpha; schr&auml;nkt HIV-1-Infektion bei einer fr&uuml;hen Nettozahlern Schritt durch einen Mechanismus, der schnelle Demontage der Retroviren Kapsid zugeordnet. Topoisomerase scheint ich (TOP1) spielen eine Rolle bei HIV-1 virale Tropismus durch Einbeziehung in oder sonst modulierenden Virionen, die Auswirkungen auf die Effizienz einer Nettozahlern Schritt, als Ausdruck der menschlichen TOP1 in African Green Monkey (AGM) Virion-produzierenden Zellen der Infektiosit&auml;t der Nachkommenschaft Virionen durch 5-fache erh&ouml;ht. Diese Erweiterung der Infektiosit&auml;t erforderlichen menschlichen TOP1 R&uuml;ckst&auml;nde 236 und 237, z. B. deren Ersetzung durch die AGM-Gegenst&uuml;ck-R&uuml;ckst&auml;nde die Infektiosit&auml;t Verbesserung abgeschafft. Unsere fr&uuml;heren Studien zeigten, dass TOP1 mit BTBD1 und BTBD2 interagiert, zwei Proteine, die mit der TRIM5&alpha; co-localize Arkane Variante TRIM5&delta; in zytoplasmatischen K&ouml;rpern. Da BTBD1 und BTBD2 mit einem HIV-1-virale Tropismus-Faktor, TOP1, interagieren und co-localize mit einer Splei&szlig;stelle-Variante eines anderen, untersuchten wir die m&ouml;gliche Beteiligung der BTBD1 und BTBD2 in HIV-1-Beschr&auml;nkung.

Menschliche TOP1 R&uuml;ckst&auml;nde Arten Spezifit&auml;t von HIV-1-Infektion in Verbindung gebracht sind in alten Cercopithecidae und menschliche Zellen erh&ouml;ht Permissivit&auml;t auf HIV-1 Infektion f&uuml;r Interaktion mit BTBD2 und RNAi des BTBD2 erforderlich.

Article	Year
EGF-induced activation of Akt results in mTOR-dependent p70S6 kinase phosphorylation and inhibition of HC11 cell lactogenic differentiation. BMC cell biology\| PubMed ID: 16984645	2006
Identification of an alternatively spliced RNA for the Ras suppressor RSU-1 in human gliomas. Journal of neuro-oncology\| PubMed ID: 12510772	2002
Dominant negative Ras enhances lactogenic hormone-induced differentiation by blocking activation of the Raf-Mek-Erk signal transduction pathway. Journal of cellular physiology\| PubMed ID: 15334659	2004
The Ras suppressor Rsu-1 binds to the LIM 5 domain of the adaptor protein PINCH1 and participates in adhesion-related functions. Experimental cell research\| PubMed ID: 15878342	2005
Chromosome instability, chromosome transcriptome, and clonal evolution of tumor cell populations. Proceedings of the National Academy of Sciences of the United States of America\| PubMed ID: 17517657	2007
Glucocorticoid induced expression of connective tissue growth factor contributes to lactogenic differentiation of mouse mammary epithelial cells. Journal of cellular physiology\| PubMed ID: 17541935	2008
The Rsu-1-PINCH1-ILK complex is regulated by Ras activation in tumor cells. European journal of cell biology\| PubMed ID: 18436335	2008
Global expression profiling reveals regulation of CTGF/CCN2 during lactogenic differentiation. Journal of cell communication and signaling\| PubMed ID: 19353304	2009
Connective Tissue Growth Factor (CTGF/CCN2) enhances lactogenic differentiation of mammary epithelial cells via integrin-mediated cell adhesion. BMC cell biology\| PubMed ID: 20497571	2010
The contribution of adhesion signaling to lactogenesis. Journal of cell communication and signaling\| PubMed ID: 21063503	2010
Human TOP1 residues implicated in species specificity of HIV-1 infection are required for interaction with BTBD2, and RNAi of BTBD2 in old world monkey and human cells increases permissivene... Virology journal\| PubMed ID: 21092135	2010

Mary Lou Cutler

Biography

JoVE Journal Publications

Other Publications