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Sequenciamento paralelo em larga escala de genes alvo é uma ferramenta útil no diagnótico etiológico de crianças nascidas pequenas para idade gestacional / Targeted gene panel sequencing is a useful technology for the diagnosis of children born small for gestational ageBruna Lucheze Freire 08 June 2018 (has links)
As doenças que comprometem o crescimento humano apresentam uma forte influência genética. O objetivo geral do projeto atual é desenvolver e aplicar a tecnologia de sequenciamento paralelo em larga escala para compreensão desses distúrbios de crescimento, com foco principal em crianças nascidas pequenas para idade gestacional (PIG), definida como criança com Escore-Z de comprimento e/ou peso ao nascimento menor ou igual a -2. PIG é uma condição heterogênea, que inclui como causa fatores maternos, placentários e fetal, dentre o qual, destacam-se as alterações genéticas. Crianças nascidas PIG e que não recuperaram seu déficit estatural espontaneamente nos primeiros anos de vida apresentam uma alta probabilidade de serem adultos baixos e costumam evoluir com quadros clínicos complexos, envolvendo retardo de crescimento persistente na vida pós-natal, dismorfismos, anomalias congênitas e distúrbios de desenvolvimento neuropsicomotor. Foi utilizada a tecnologia de sequenciamento Sure Select (Agilent Technologies, CA, USA) para estudar aproximadamente 390 genes escolhidos por pertencerem à via IGFs/IGF1R, principal eixo regulador hormonal do crescimento, genes sabidamente envolvidos em doenças associadas com distúrbio de crescimento, além de genes candidatos identificados em estudos prévios do laboratório, associados à regulação do crescimento, em um grande número de pacientes. Foram sequenciados 80 pacientes, obtendo uma cobertura média de 354 vezes e com mais de 99% da região alvo com cobertura > 10 reads. Nestas amostras foram identificadas 58 variantes, 18 consideradas patogênicas ou provavelmente patogênicas em 19 pacientes, 32 de significado incerto, 7 provavelmente benigna e 1 provavelmente patogênica para condição não associada a distúrbio de crescimento (\"achado acidental\"). Dentre as variantes consideradas patogênicas ou provavelmente patogênicas houve uma grande heterogeneidade entre os genes, sendo identificadas variantes nos genes PTPN11 (x3), BLM (x3), NPR2 (x2), ANKRD11 (x2), SRCAP (x2), FGFR3 (x2), IGF1R, SHOC2, SHOX, NIPBL e deleção 22q11. Podemos concluir que a técnica de sequenciamento paralelo em larga escala de genes alvo é eficiente em estabelecer o diagnóstico molecular de crianças nascidas PIG. Foi possível identificar a etiologia genética em 23,75% da casuística estudada, em sua maior parte, de pacientes com síndromes reconhecidas clinicamente. Contudo, defeitos no sistema IGFs/IGF1R não foram frequentes nesta condição / Diseases affecting human growth are most likely caused by genetic factors. The main goal of this project is to apply the technology of massive parallel sequencing to comprehend growth disturbs in children born small for gestational age (SGA), known as the children with Z-score of height and/or weight at birth less or equal -2. SGA is a heterogeneous condition, and as its causes we can find maternal, placental and fetal factors, of which, the most important are the genetic alterations. Children born SGA that do not have catch-up growth spontaneously up to the second year of life may remain with short stature when adults and they usually present other clinical features, such as dimorphisms, congenital anomalies and neuropsychomotor developmental delay. We used the Sure Select technology (Agilent Technologies, CA, USA) to study approximately 390 genes chosen by participate of the IGFs/IGF1R system, or genes already associated with growth disorders, or candidate genes found in previous studies of aCGH (Array Comparative Genomic Hybridization) or exome sequencing. We sequenced 80 patients, and had a mean coverage of 354x, with more than 99% of the target region with > 10 reads. We found 58 variants, 18 classified as pathogenic or probably pathogenic in 19 patients, 32 variants of unknown significance and 7 probably benign and 1 probably pathogenic for a condition non associated to short stature (``incidental finding``) Among the probably pathogenic and pathogenic we found a great heterogeneity in genes, with variants identified in 10 different genes PTPN11 (x3), BLM (x3), NPR2 (x2), ANKRD11 (x2), SRCAP (x2), FGFR3 (x2), IGF1R, SHOC2, SHOX, NIPBL and a 22q11 deletion. In conclusion, the technique of targeted gene panel sequencing is a useful tool to establish the molecular diagnose in children SGA. We could identify the molecular cause in 23.75% of the casuistic, mostly patients with clinically recognized syndromes. However, variants at IGFs/IGF1R system are not frequently associated with the studied condition
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Análise das repetições CA do gene IGF1, VNTR do gene da insulina e região promotora P4 do gene IGF2 em indivíduos nascidos pequenos para idade gestacional / Analysis of the CA repeats of IGF1 gene, VNTR of insulin gene polymorphism and P4 Promoter region of IGF2 gene in children born small for gestational ageRocio Riatto Della Coletta 22 February 2008 (has links)
Introdução: Polimorfismos na região promotora dos genes da insulina, IGF2 e IGF1 podem estar relacionados a uma diminuição da expressão desses genes na vida fetal que, por sua vez, pode causar restrição do crescimento intra-uterino e maior risco de hipospádia. Na vida pós-natal, perda completa ou parcial da expressão desses genes pode resultar em ausência de recuperação estatural e menores concentrações séricas de IGF1 na criança, além de um maior risco de diabetes melito tipo 2 e síndrome de resistência à insulina no adulto. Objetivos: Analisar em crianças nascidas pequenas para idade gestacional (PIG) com ou sem recuperação estatural (RE): 1) a freqüência alélica e genotípica dos polimorfismos VNTR-INS e das repetições CA do gene IGF1; 2) a região promotora P4 do gene IGF2; 3) a influência do VNTR INS e das repetições CA do gene IGF1 na sensibilidade à insulina e nas concentrações séricas de IGF1, respectivamente. Pacientes: Foram estudados 142 indivíduos nascidos PIG com (n= 66) e sem recuperação (n= 76) estatural selecionados de três diferentes centros (HC-FMUSP, Santa Casa de São Paulo e HC-UFPR) e um grupo controle constituído de 297 indivíduos nascidos adequados para idade gestacional (AIG). Métodos: Extração de DNA genômico; amplificação por PCR das regiões contendo os polimorfismos VNTR INS e repetições CA do IGF1 e da região promotora P4; digestão por enzima de restrição; software Genescan; seqüenciamento automático; avaliação bioquímica e hormonal da glicemia, insulina e IGF1, extração de RNA, PCR em tempo real e análise estatística com SPSS 13.0 (Statistical Package fo Social Sciences). Resultados: A média do Z-altura, Z-IMC (índice de massa corpórea), Z-altura paterno e ZEA (estatura alvo) foram maiores nas crianças PIG que tiveram recuperação estatural, com o Z-PC (perímetro cefálico) maior nas crianças sem recuperação estatural. O Z-IGF1 sérico foi significantemente mais elevado em crianças que apresentaram RE (p<0,05). A distribuição e genotipica das repetições CA do gene IGF1 e do VNTR INS foi semelhante estatisticamente entre os grupos AIG e PIG, e entre os PIG com e sem RE; não foi observada associação entre esse polimorfismo e as variáveis clínicas e laboratoriais do estudo. O estudo da região promotora P4 do gene IGF2 identificou um novo polimorfismo de 9-12 repetições C na posição -1982, antes do sítio de início de transcrição do exon 2, e este apresentou distribuição semelhante entre os grupos PIG e AIG. Foi identificada também uma troca C/T em heterozigose no nono nucleotídeo do alelo 11C em quatro crianças nascidas PIG. Contudo, a quantificação da expressão do gene IGF2 em duas dessas crianças não demonstrou perda da expressão desse gene. Conclusões: Não observamos influência dos polimorfismos acima descritos no crescimento pré e pós-natal, na presença de resistência à insulina, nem em concentrações séricas de IGF1 dos indivíduos nascidos PIG. Identificamos uma nova variante na região promotora P4 do gene IGF2, contudo estudos preliminares não demonstraram influência desse polimorfismo sobre o crescimento intra-uterino. / Introduction: Polymorphisms in the promoter region of insulin (INS), IGF2 and IGF1 genes may decrease their expression during fetal life and afterward could be related to intra-uterine fetal growth retardation and greater risk of hypospadia development. In post-natal life, decreased expression of these genes can result in lack of stature recovery and in lower IGF1 serum levels in children, as well as in higher risk for type 2 diabetes mellitus and metabolic syndrome in adults. Objectives: The aims of the present study were: (1) to analyze the allelic and the genotypic frequency of the insulin (INS) gene variable number of tandem repeats (VNTR) and the IGF1 gene CA repeats; (2) to analyze the P4 promoter region of IGF2 gene (3) to test the contribution of INS VNTR, IGF1 gene CA repeats on insulin sensitivity and IGF1 serum levels in children born SGA with and without catch up, respectively. Patients: We studied 142 individuals born SGA with catch up (n = 66) and without catch up (n = 76) selected from three different centers (HCFMUSP, Santa Casa de Sao Paulo and HC-UFPR). The control group consisted of 297 children born appropriate for gestational age (AGA). Methods: Extraction of genomic DNA, PCR-amplification of the VNTR of insulin gene, CA repeats of IGF1 and IGF2 gene P4 promoter region; restriction analysis; Genescan software; automatic sequencing. Blood measurements of serum level of glucose, insulin and IGF1. Statistical analysis (Statistical Package for Social Sciences software). Results: Regarding birth parameters, the average of Z-height, Z-BMI (body mass index) and Z-height paternal and Z- EA (target height) were higher in children born SGA who had catch up. Interestingly, we observed that the Z-PC was higher in children born SGA without catch up. In addition, the Z-IGF1 serum levels were significantly higher in children who had catch up (p <0.05). The molecular analysis of IGF1 gene CA repeats and of INS gene VNTR locus did not show a statistically significant difference in the allelic and genotypic distribution of these polymorphisms between adequate for gestational age (AGA) and SGA groups nor between SGA with and without catch up. Similarly, we have not found an association of these polymorphisms with clinical or laboratory variables of this study. A novel polymorphism in the P4 promoter region of the IGF2 gene was identified. It was characterized by cytosine repeats (9-12) at position -1982 before transcription initiation site of exon 2 of IGF2 gene. Yet, we have identified a heterozygous substitution of cytosine for thymine at the nucleotide position 9 in the allele 11C in four children born SGA. This change was also absent in the control population. Quantization of IGF2 gene expression in two of these children did show loss of expression of this gene in patients carrying the variant 9C/T. Conclusions: We have not observed an association of the above described polymorphisms with pre and post natal growth, or with the occurrence of insulin resistance in individuals born SGA. IGF-1 levels did not seem to be associated with the polymorphisms either. A new variant in the P4 promoter region of IGF2 gene was identified, however preliminary studies showed no influence on intra-uterine growth.
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Menschenskinder: Einfluss christlicher Sozialisation auf die Ausbildung von Einstellungen gegenüber Menschen mit geistiger BehinderungGoldbach, Anne 10 July 2014 (has links)
Menschen mit Behinderung sind ein Randgebiet der Soziologie. Untersuchungen mit dem Fokus auf Menschen mit geistiger Behinderung in der Gesellschaft sind auch in diesem Bereich selten . Dem entgegen, stehen die Inklusionsbestrebungen der Pädagogik für Menschen, die wir als geistig behindert bezeichnen, jedoch in engem Zusammenhang mit soziologischen Prozessen, welcher unter anderm am Wandel der Begrifflichkeiten zurBezeichnung des Personenkreises deutlich gemacht werden kann. Dieser Entwicklung zufolge findet eine Abkehr von rein medizinisch-psychologischen Definitionsversuchen statt. Sie erfahren eine Ergänzung durch soziale, pädagogische und subjektive Erklärungsansätze, denen zufolge geistige Behinderung immer auch aus einer sozialen Konstruktion hervorgeht (Bsp. AAMR, 2002). Wenn gleichsam davon auszugehen ist, dass die Gesellschaft selbst durch ihre gestörte (Nicht-) Interaktion mit Menschen, die wir als geistig behindert bezeichnen, Behinderung konstruiert, so scheint es notwendig, die Grundlagen der sozialen Interaktion zu erkennen und zu verändern, um die Voraussetzungen für inklusive Praxis zu schaffen. Aufgrund der aus der
Psychologie stammenden, Annahme der “self-fulfilling-prophecy” müssen Einstellungen gegenüber einem Menschen als Grundlage für das Gelingen von Interaktion mit diesem Menschen verstanden werden.
Wertvorstellungen und Einstellungen beeinflussen demnach grundlegend den Erfolg von Inklusion. Da Jugendliche immer wieder als Seismographen der gesellschaftlichen Entwicklung beschrieben werden, ist es nahe liegend die Einflussfaktoren für deren Einstellungsbildung gegenüber Menschen, die wir als geistig behindert bezeichnen, zu untersuchen. Dabei liegt der Fokus dieser Arbeit auf der Analyse des Einflusses durch
christliche Sozialisation, durch welche die Vermittlung eines bestimmten, scheinbar inklusionsfreundlichen Wertekanons einhergeht, welcher sich im Menschenbild des Jugendlichen widerspiegelt und sich auf dessen
Einstellungen auswirkt.
Die vorliegende Forschungsarbeit zeigt, dass sich verschiedene Faktoren christlicher Sozialisation positiv auf die expliziten Einstellungen gegenüber Menschen mit sogenannter geistiger Behinderung auswirken, kann jedoch keinen Zusammenhang für die Ausbildung positiverer impliziter Einstellungen feststellen.
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Die Bedeutung von VEGF-C und NRP-2 für die Strahlenresistenz im ProstatakarzinomLiebscher, Steffi 07 March 2017 (has links)
Hintergrund
Die Strahlentherapie ist neben der radikalen Prostatektomie eine Standardtherapie zur Behandlung von Prostatatumoren und führt zu sehr guten Ergebnissen für die lokale Tumorkontrolle und für das Überleben. Allerdings ist, wie bei der Operation auch, dabei das Risiko eines Rezidivs für fortgeschrittene Tumoren im Gegensatz zu Tumoren in früheren Stadien relativ hoch. Daher besteht eine hohe Dringlichkeit zur Verbesserung der Strahlentherapie vor allem bei fortgeschrittenen Tumoren. Ein Ansatz hierfür ist die Kombination der Bestrahlung mit molekularen Therapien. Ziel dabei ist es, bestimmte Zielproteine zu blockieren, um die Strahlensensibilität der Prostatakarzinomzellen zu erhöhen. Ein potentielles Target könnte hierbei die Blockade des VEGF-C/NRP-2/Akt-Signalwegs (VEGF-C – vascular endothelial growth factor C; NRP-2 – Neuropilin 2; Akt – Proteinkinase B) sein. Im Prostatakarzinom sind die Konzentrationen von VEGF-C und NRP-2 im Vergleich zu normalen Prostatazellen erhöht. Aus Untersuchungen ist bekannt, dass beide Proteine eine progressive Wirkung auf die Tumorgenese haben. In Vorarbeiten zeigen Muders et al. (2009) zudem eine Aktivierung von Akt über die VEGF-C/NRP-2-Achse und eine darüber vermittelte Resistenz gegenüber oxidativem Stress durch H2O2. Akt wirkt in verschiedenen Tumorentitäten außerdem protektiv gegenüber Bestrahlung. Es besteht die Annahme, dass dies auch für Prostatakarzinomzellen gilt.
Zielstellung
Im Rahmen dieser Arbeit wurde untersucht, ob und über welchen Mechanismus VEGF-C, NRP-2 und Akt die Strahlenresistenz in Prostatakarzinomzelllinien beeinflussen.
Methoden
Es wurden in vitro- und in vivo-Experimente in den humanen Prostatakarzinomzelllinen PC-3, DU145, LNCaP sowie in PC-3-Xenografts durchgeführt. Der Einfluss von VEGF-C und NRP-2 auf die Strahlenresistenz wurde in vitro nach Herunterregulierung der entsprechenden Gene mittels siRNA beziehungsweise nach Supplementierung mit humanem rekombinanten VEGF-C in Koloniebildungsassays untersucht. Zur Ermittlung des Einflusses von VEGF-C und von NRP-2 auf mögliche Zellüberlebensmechanismen wurden der autophagische Flux nach Blockade der Autophagie mit Bafilomycin A1 mittels Western Blot, die DNA-Doppelstrangbruch-Reparatur mittels Quantifizierung der γH2AX Foci sowie die Zellzyklusverteilung mittels Durchflusszytometrie untersucht. Die Signalweiterleitung von VEGF-C über Akt sowie, als weitere Möglichkeit, die Signalweiterleitung über ERK1/2 wurden nach siRNA-Transfektion mit und ohne Bestrahlung mittels Western Blot geprüft. Weitere Versuche zu Akt erfolgten in vitro und in vivo mit dem PI3K/Akt-Inhibitor Nelfinavir in PC-3-Zellen. Der in vitro Effekt von Nelfinavir auf die Strahlenresistenz wurde dabei mithilfe eines Koloniebildungsassays nach Behandlung der Zellen mit 10 µM Nelfinavir getestet. In vivo wurde die Wirkung von Nelfinavir ohne sowie in Kombination mit Bestrahlung in PC-3-Xenografts in Nacktmäusen untersucht. Für die Bestimmung der Tumorwachstumszeit wurden die Mäuse mit 80 mg Nelfinavir/kg Körpergewicht 30 mal innerhalb von 6 Wochen behandelt. In einem weiteren Versuch wurde die lokale Tumorkontrolle bei gleichzeitiger fraktionierter Bestrahlung mit Gesamtdosen von 30 bis 120 Gy und einer Nachbeobachtungszeit von 180 Tagen bestimmt.
Ergebnisse
Die Untersuchungen zur Strahlenresistenz über den VEGF-C/NRP-2/Akt-Signalweg haben ergeben, dass in den drei Prostatakarzinomzelllinien PC-3, DU145 und LNCaP VEGF-C signifikant Strahlenresistenz vermittelt. Für NRP-2 hingegen wurde festgestellt, dass es in Abhängigkeit von der Zelllinie entweder zur Strahlenresistenz (DU145) oder zur Strahlensensibilisierung (PC-3) führt. Weiterhin wurde nachgewiesen, dass durch VEGF-C in PC-3 und DU145 weder über Akt noch über ERK1/2 Strahlenresistenz vermittelt wird. Die Versuche zu Strahlenresistenz vermittelnden Mechanismen ergaben, dass VEGF-C in unbestrahlten PC-3-Zellen die Autophagie fördert, NRP-2 jedoch nicht. Unter Bestrahlung war ein Effekt von VEGF-C und NRP-2 auf die Autophagie nicht reproduzierbar nachweisbar. Ein weiterer Versuch hat gezeigt, dass in PC-3 Autophagie keinen Einfluss auf das klonogene Überleben nach Bestrahlung hat. Außerdem wurde festgestellt, dass VEGF-C in PC-3 die DNA-Doppelstrangbruch-Reparatur nicht beeinflusst. Darüber hinaus wurde nachgewiesen, dass eine Verminderung des VEGF-C-Gehalts in PC-3 zum G2/M-Arrest führt. In DU145 konnte jedoch kein Effekt beobachtet werden. In den Untersuchungen zum Einfluss von Akt auf die Strahlenresistenz unabhängig von VEGF-C und NRP-2 wirkte Nelfinavir inhibierend auf die Akt-Phosphorylierung am Ser473 und beeinflusste das klonogene Überleben von PC-3-Zellen minimal. In PC-3-Xenografts führte Nelfinavir zu keiner Tumorwachstumsverzögerung und wirkte in vitro und in vivo nicht strahlensensibilisierend.
Schlussfolgerung
In den Versuchen konnte gezeigt werden, dass VEGF-C in Prostatakarzinomzellen Strahlenresistenz vermittelt. Diese Erkenntnis könnte als ein Forschungsansatz zur Entwicklung einer kombinierten Therapie aus VEGF-C-Blockade und Bestrahlung dienen. Ein potentieller Mechanismus, über den VEGF-C die Strahlenresistenz vermittelt, ist, in Abhängigkeit von der Zelllinie, die Aufhebung des G2/M-Arrests. NRP-2 wirkt in der Vermittlung von Strahlenresistenz beziehungsweise sensibilität je nach Zelllinie unterschiedlich. Hierzu sollten weitere Untersuchungen bezüglich möglicher Interaktionen innerhalb anderer Signalwege mit strahlensensibilisierendem Einfluss erfolgen. Innerhalb des untersuchten Signalwegs konnte weiterhin festgestellt werden, dass VEGF-C Strahlenresistenz nicht über Akt vermittelt. Die vorliegende Arbeit enthält die erste Studie sowohl zur Untersuchung des Einflusses von Nelfinavir in Kombination mit Bestrahlung auf das Überleben von Prostatakarzinomzellen in vitro als auch auf die Tumorwachstumszeit und die lokale Tumorkontrolle in vivo. Hierin konnte keine strahlensensibilisierende Wirkung von Nelfinavir nachgewiesen werden. Da Nelfinavir in Zellen anderer Tumorentitäten strahlensensibilisierend wirkt und außerdem bekannt ist, dass es in eine Reihe von Signalwegen eingreift, die das Zellüberleben fördern oder hemmen, sollte weiter geklärt werden, ob Tumorzellen mit einem bestimmten genetischen Profil besser auf die Behandlung mit Nelfinavir ansprechen.:Abkürzungsverzeichnis VIII
1 Einleitung und Zielstellung 1
2 Grundlagen 3
2.1 Zelluläre Auswirkungen der Bestrahlung 3
2.2 Überlebensfördernde Signalwege 6
2.3 Zellüberlebensstrategien 9
2.3.1 Autophagie 10
2.3.2 DNA-Doppelstrangbruch-Reparatur 12
2.3.3 Zellzyklusarrest 13
2.4 Reaktionen von Tumoren auf Bestrahlung 14
2.5 Nelfinavir als Akt-Inhibitor 15
3 Material und Methoden 17
3.1 Material 17
3.1.1 Zelllinien 17
3.1.2 Reagenzien und Substanzen 17
3.1.3 Kits 19
3.1.4 Primäre Antikörper 19
3.1.5 Sekundäre Antikörper 20
3.1.6 siRNA 20
3.1.7 Primer 20
3.1.8 Materialien und Hilfsmittel 20
3.1.9 Geräte 21
3.1.10 Software 22
3.2 Methoden 22
3.2.1 Zellkultur 22
3.2.2 siRNA-Transfektion 23
3.2.3 Bestrahlung 24
3.2.4 Koloniebildungsassay 24
3.2.5 Autophagischer Flux 26
3.2.6 Semiquantitative Proteinbestimmung 27
3.2.7 mRNA-Quantifizierung 29
3.2.8 γH2AX Foci-Assay 31
3.2.9 Zellzyklusanalyse 33
3.2.10 Tierversuch 34
3.2.11 Statistische Auswertung 37
4 Ergebnisse 39
4.1 Einfluss von VEGF C und NRP 2 auf die Strahlenresistenz 39
4.1.1 Betrachtung der VEGF C- und NRP 2-Gehalte in den Zelllinien PC 3, DU145 und LNCaP 39
4.1.2 Etablierung der VEGF C- und NRP 2-siRNA-Transfektionen 39
4.1.3 Einfluss von VEGF C und NRP 2 auf die Klonogenität bestrahlter Zellen 40
4.2 Einfluss von VEGF C und NRP 2 auf überlebensfördernde Signalwege unter Bestrahlung 42
4.2.1 Aktivierung des Akt-Signalwegs 43
4.2.2 Aktivierung des ERK1/2-Signalwegs 45
4.3 Untersuchungen zum Einfluss von VEGF C und NRP 2 auf die Strahlenresistenz beeinflussende zelluläre und molekulare Prozesse 46
4.3.1 Einfluss von VEGF C und NRP 2 auf die Autophagie und deren Bedeutung für die Strahlenresistenz 46
4.3.2 Einfluss von VEGF C auf die Reparatur von DNA-Doppelstrangbrüchen 48
4.3.3 Der Einfluss von VEGF C auf den Zellzyklus 50
4.4 Inhibierung der Aktivierung von Akt durch Nelfinavir 52
4.4.1 Einfluss von Nelfinavir auf die Klonogenität in vitro 53
4.4.2 Tumorwachstumsverzögerung 54
4.4.3 Lokale Tumorkontrolle 56
5 Diskussion 59
5.1 VEGF C- und NRP 2-Expression und -Herunterregulierung 59
5.2 Der Einfluss von VEGF-C auf die Strahlenresistenz 59
5.3 Die Funktion von NRP-2 als Co-Rezeptor für VEGF-C bei der Vermittlung von Strahlenresistenz 60
5.4 VEGF C-abhängige Akt- und ERK1/2-Regulierung unter Bestrahlung 62
5.5 Der Einfluss der Autophagie auf die Strahlenresistenz 62
5.6 Der Einfluss von VEGF C auf die DNA-Doppelstrangbruch-Reparatur 63
5.7 Der Einfluss von VEGF C auf den Zellzyklus 64
5.8 Der Einfluss von Nelfinavir auf das Wachstum und auf die Strahlenresistenz von PC 3-Zellen in vitro und in vivo 65
5.9 Schlussfolgerung und Ausblick 67
6 Zusammenfassung 69
7 Abstract 72
8 Literaturverzeichnis 75
9 Abbildungsverzeichnis 89
10 Tabellenverzeichnis 90
Danksagung 92
Anhang 93
Anlage 1 94
Anlage 2 96 / Background
In addition to radical prostatectomy, radiotherapy is a standard therapy for the treatment of prostate tumours and leads to good results for local tumour control and survival. However, as with the resection, the risk of recurrence for advanced tumours is relatively high compared to tumours in earlier stages. Therefore, there is a high urgency to improve radiotherapy especially for advanced stages. One approach is the combination of irradiation with molecular therapies. The aim is to block certain target proteins to increase the radiosensitivity of the prostate carcinoma cells. A potential target could be the blockade of the VEGF-C/NRP-2/Akt signalling pathway (VEGF-C – vascular endothelial growth factor C; NRP-2 – neuropilin 2; Akt – protein kinase B). In prostate cancer the concentrations of VEGF-C and NRP-2 are increased compared to normal prostate cells. Studies have shown that both proteins have a progressive effect on tumourigenesis. In preliminary work Muders et al. (2009) also showed the activation of Akt via the VEGF-C/NRP-2 axis and a resistance to H2O2 induced oxidative stress. Akt also has a protective effect against irradiation in various tumour entities. It is assumed that this also applies to prostate carcinoma cells.
Aim of the study
Within the framework of this thesis, it was investigated whether and via which mechanism VEGF-C, NRP-2, and Akt affect the radioresistance in prostate carcinoma cell lines.
Methods
In vitro and in vivo experiments were performed in the human prostate carcinoma cell lines PC-3, DU145, LNCaP, as well as in PC-3 xenografts. The influence of VEGF-C and NRP-2 on the radioresistance was examined in vitro after knock down of the corresponding genes using siRNA or after supplementation with human recombinant VEGF-C in colony formation assays. In order to determine the influence of VEGF-C and NRP-2 on possible cell survival mechanisms, the autophagic flux was examined after the blockade of autophagy with bafilomycin A1 using western blot, the DNA double strand break repair by quantification of the γH2AX foci, and the cell cycle distribution by flow cytometry. The signal transduction of VEGF-C via Akt as well as, as a further possibility, the signal transduction via ERK1/2 were tested after siRNA transfection with and without irradiation using western blot. Further experiments on Akt were performed in vitro and in vivo with the PI3K/Akt inhibitor nelfinavir in PC-3 cells. The in vitro effect of nelfinavir on radioresistance was tested using a colony formation assay after treatment of the cells with 10 μM nelfinavir. In vivo, the effect of nelfinavir without and in combination with irradiation in PC-3 xenografts was investigated in nude mice. For the determination of the tumour growth time, the mice were treated with 80 mg nelfinavir/kg body weight 30 times within 6 weeks. In a further experiment, the local tumour control was determined with simultaneous fractionated irradiation with total doses of 30 to 120 Gy and a follow-up time of 180 days.
Results
The investigations on radioresistance via the VEGF-C/NRP-2/Akt signalling pathway showed that in the three prostate carcinoma cell lines PC-3, DU145, and LNCaP VEGF-C significantly mediates radioresistance. For NRP-2 however, it was found that, depending on the cell line, it either leads to radioresistance (DU145) or radiosensitization (PC-3). Further, it was shown that in PC-3 and DU145 VEGF-C does not mediate radioresistance via Akt or ERK1/2. The experiments on radioresistance mediating mechanisms revealed that VEGF-C promotes autophagy in untreated PC-3 cells, but NRP-2 does not. Under irradiation, an effect of VEGF-C and NRP-2 on autophagy could not be detected reproducibly. A further experiment has shown that in PC-3 autophagy has no influence on the clonogenic survival after irradiation. In addition, it was found that VEGF-C does not affect the DNA double strand break repair in PC-3. Furthermore, it was shown that a reduction in the VEGF-C content leads to a G2/M arrest in PC-3. However, no effect could be observed in DU145. In studies regarding the influence of Akt on radioresistance independent of VEGF-C and NRP-2, nelfinavir inhibited Akt phosphorylation at Ser473 and minimally affected the clonogenic survival of PC-3 cells. In PC-3 xenografts, nelfinavir did not lead to any tumour growth delay and did not have a radiosensitizing effect in vitro or in vivo.
Conclusion
In the experiments, it was shown that VEGF-C mediates radioresistance in prostate cancer cells. This finding could serve as a research approach for the development of a combined therapy of a VEGF-C blockade and irradiation. A potential mechanism by which VEGF-C mediates radioresistance is the reverse of the G2/M arrest, depending on the cell line. NRP-2 acts differently in the mediation of radioresistance or radiosensitivity, depending on the cell line. On this, further investigations should be carried out with regard to possible interactions within other signalling pathways with a radiosensitizing influence. Within the investigated signalling pathway, it was further shown that VEGF-C does not mediate radioresistance via Akt. The present work contains the first study examining the effect of nelfinavir in combination with irradiation on prostate cancer cell survival in vitro as well as on growth time and local tumour control in vivo. Herein no radiosensitizing effects of nelfinavir could be detected. Since nelfinavir radiosensitizes cells of other tumour entities and is also known to interfere with a series of signalling pathways that promote or inhibit cell survival, it should be clarified whether tumour cells with a particular genetic profile are more responsive to treatment with nelfinavir.:Abkürzungsverzeichnis VIII
1 Einleitung und Zielstellung 1
2 Grundlagen 3
2.1 Zelluläre Auswirkungen der Bestrahlung 3
2.2 Überlebensfördernde Signalwege 6
2.3 Zellüberlebensstrategien 9
2.3.1 Autophagie 10
2.3.2 DNA-Doppelstrangbruch-Reparatur 12
2.3.3 Zellzyklusarrest 13
2.4 Reaktionen von Tumoren auf Bestrahlung 14
2.5 Nelfinavir als Akt-Inhibitor 15
3 Material und Methoden 17
3.1 Material 17
3.1.1 Zelllinien 17
3.1.2 Reagenzien und Substanzen 17
3.1.3 Kits 19
3.1.4 Primäre Antikörper 19
3.1.5 Sekundäre Antikörper 20
3.1.6 siRNA 20
3.1.7 Primer 20
3.1.8 Materialien und Hilfsmittel 20
3.1.9 Geräte 21
3.1.10 Software 22
3.2 Methoden 22
3.2.1 Zellkultur 22
3.2.2 siRNA-Transfektion 23
3.2.3 Bestrahlung 24
3.2.4 Koloniebildungsassay 24
3.2.5 Autophagischer Flux 26
3.2.6 Semiquantitative Proteinbestimmung 27
3.2.7 mRNA-Quantifizierung 29
3.2.8 γH2AX Foci-Assay 31
3.2.9 Zellzyklusanalyse 33
3.2.10 Tierversuch 34
3.2.11 Statistische Auswertung 37
4 Ergebnisse 39
4.1 Einfluss von VEGF C und NRP 2 auf die Strahlenresistenz 39
4.1.1 Betrachtung der VEGF C- und NRP 2-Gehalte in den Zelllinien PC 3, DU145 und LNCaP 39
4.1.2 Etablierung der VEGF C- und NRP 2-siRNA-Transfektionen 39
4.1.3 Einfluss von VEGF C und NRP 2 auf die Klonogenität bestrahlter Zellen 40
4.2 Einfluss von VEGF C und NRP 2 auf überlebensfördernde Signalwege unter Bestrahlung 42
4.2.1 Aktivierung des Akt-Signalwegs 43
4.2.2 Aktivierung des ERK1/2-Signalwegs 45
4.3 Untersuchungen zum Einfluss von VEGF C und NRP 2 auf die Strahlenresistenz beeinflussende zelluläre und molekulare Prozesse 46
4.3.1 Einfluss von VEGF C und NRP 2 auf die Autophagie und deren Bedeutung für die Strahlenresistenz 46
4.3.2 Einfluss von VEGF C auf die Reparatur von DNA-Doppelstrangbrüchen 48
4.3.3 Der Einfluss von VEGF C auf den Zellzyklus 50
4.4 Inhibierung der Aktivierung von Akt durch Nelfinavir 52
4.4.1 Einfluss von Nelfinavir auf die Klonogenität in vitro 53
4.4.2 Tumorwachstumsverzögerung 54
4.4.3 Lokale Tumorkontrolle 56
5 Diskussion 59
5.1 VEGF C- und NRP 2-Expression und -Herunterregulierung 59
5.2 Der Einfluss von VEGF-C auf die Strahlenresistenz 59
5.3 Die Funktion von NRP-2 als Co-Rezeptor für VEGF-C bei der Vermittlung von Strahlenresistenz 60
5.4 VEGF C-abhängige Akt- und ERK1/2-Regulierung unter Bestrahlung 62
5.5 Der Einfluss der Autophagie auf die Strahlenresistenz 62
5.6 Der Einfluss von VEGF C auf die DNA-Doppelstrangbruch-Reparatur 63
5.7 Der Einfluss von VEGF C auf den Zellzyklus 64
5.8 Der Einfluss von Nelfinavir auf das Wachstum und auf die Strahlenresistenz von PC 3-Zellen in vitro und in vivo 65
5.9 Schlussfolgerung und Ausblick 67
6 Zusammenfassung 69
7 Abstract 72
8 Literaturverzeichnis 75
9 Abbildungsverzeichnis 89
10 Tabellenverzeichnis 90
Danksagung 92
Anhang 93
Anlage 1 94
Anlage 2 96
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Využití prvků montessori pedagogiky při edukaci dětí s poruchami autistického spektra v přípravném stupni základní školy speciální / The implementation of montessori education elements into the education of the children with autism spectrum disorders in the preparatory form of the special elementary schoolTěhníková, Alexandra January 2021 (has links)
The goal of the diploma work is to demonstrate the possibilities of montessori education elements implementation into the education of the children with autism spectrum disorders in the preparatory form of the special elementary school. This is performed on the basis of the theoretical knowledge gained by the specific material study and by using the methods of the inspiring practice. The theoretical part has three chapters. It deals with the subject of the persons with mental disorder and is mainly focused on the children with the autism spectrum disorders. It describes the autism spectrum disorders, their etiology, diagnosis and the intervention options for people with the autism spectrum disorders. It is dedicated also to the education of children and pupils with the autism spectrum disorders and the mental disorder within the preparatory form of the special elementary school. It introduces in great detail the montessori pedagogy and its elements. The empirical part states the definition of the research inquiry. It also describes an example of the inspiring practice how the class setting, education outline concept and education materials using the elements of the montessori pedagogy into the education of the children with the autism spectrum disorders in the preparatory form of the special...
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An assessment of needs of the mentally retarded in the community of district 22 (sub-district 222) KwaZulu-NatalWebster, Joyce 30 November 2003 (has links)
The system of care for persons suffering from mental retardation is in a state of upheaval. Considering the mentally handicapped as holistic beings, this study explored and assessed the needs of those residing in the community of District 22 (sub-district 222), KwaZulu-Natal, thus facilitating the planning of care and care facilities for these individuals to enable them to function optimally in the community. To accomplish this purpose, specific objectives were formulated.
A quantitative, exploratory and descriptive study based on Maslow's hierarchy of needs theory was carried out, using 167 respondents. The study revealed that despite being mentally retarded, they were still regarded as valuable members of the community, their needs did not differ from the needs of others in the rest of the world and that mental retardation is still rated low in the prioritization of health problems, hence the lack of resources and support needed for the rehabilitation of such persons. / Health Studies / M.A. (Health Studies)
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Autismus - Použití systémů alternativní a augmentativní komunikace u jedinců s poruchou autistického spektra / Autism - Application alternative and augmentative communication systems at the individuals with pervasive development disordersVošická, Edita January 2012 (has links)
This diploma thesis deals with alternative and augmentative communication systems using at the individuals with pervasive development disorders. Thesis is divided the theoretical and the experimental part. Theoretical part contains mainly informations about communication disability, speech development, diagnosis of communication abilities, alternative and augmentative communication systems and possibilities of aid to the families with child with pervasive development disorder. Experimental part presents research using questionnaire, which was send to the parents or legal representatives with child with pervasive development disorder. The research prepares base for next extensive researchs.
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An assessment of needs of the mentally retarded in the community of district 22 (sub-district 222) KwaZulu-NatalWebster, Joyce 30 November 2003 (has links)
The system of care for persons suffering from mental retardation is in a state of upheaval. Considering the mentally handicapped as holistic beings, this study explored and assessed the needs of those residing in the community of District 22 (sub-district 222), KwaZulu-Natal, thus facilitating the planning of care and care facilities for these individuals to enable them to function optimally in the community. To accomplish this purpose, specific objectives were formulated.
A quantitative, exploratory and descriptive study based on Maslow's hierarchy of needs theory was carried out, using 167 respondents. The study revealed that despite being mentally retarded, they were still regarded as valuable members of the community, their needs did not differ from the needs of others in the rest of the world and that mental retardation is still rated low in the prioritization of health problems, hence the lack of resources and support needed for the rehabilitation of such persons. / Health Studies / M.A. (Health Studies)
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Identifisering van komponente in 'n ondersteuningsprogram vir ouers van kinders met spesiale onderwysbehoeftesStopforth, Charlotte 30 June 2009 (has links)
Text in Afrikaans / The aim of this study was to identify and describe the components of a parent
support program for the parent of children with mental retardation in the ELSENunits
of Parow Preparatory School. This study is the first step in compiling a
parent support program for full service schools, since it can be utilise in the
establishment of such a program. This study does not address composition of
such a parent support program. A qualitative approach was used. Empirical
data was gathered through the use of focus groups consisting of 28 parents of
children in the ELSEN-unit of Parow Preparatory school. An interview scedule
consisting of semi-structured questions were used during the focus groups.
Themes were identified and dealt with in accordance with relevant existing
literature and literature control. Conclusions and recommendations were
made in connection with the components of a parent support program for the
parent of children in the ELSEN-units of Parow Preparatory School . / Social Work / M.Ed. (Kurrikulumstudies)
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Identifisering van komponente in 'n ondersteuningsprogram vir ouers van kinders met spesiale onderwysbehoeftesStopforth, Charlotte 30 June 2009 (has links)
Text in Afrikaans / The aim of this study was to identify and describe the components of a parent
support program for the parent of children with mental retardation in the ELSENunits
of Parow Preparatory School. This study is the first step in compiling a
parent support program for full service schools, since it can be utilise in the
establishment of such a program. This study does not address composition of
such a parent support program. A qualitative approach was used. Empirical
data was gathered through the use of focus groups consisting of 28 parents of
children in the ELSEN-unit of Parow Preparatory school. An interview scedule
consisting of semi-structured questions were used during the focus groups.
Themes were identified and dealt with in accordance with relevant existing
literature and literature control. Conclusions and recommendations were
made in connection with the components of a parent support program for the
parent of children in the ELSEN-units of Parow Preparatory School . / Social Work / M.Ed. (Kurrikulumstudies)
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