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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

THE IMPACT OF E-CADHERIN AND PHOSPHATASE AND TENSIN HOMOLOG ABLATION IN THE UTERUS: THE PROGRESSION OF TYPE I ENDOMETRIAL CARCINOMA

Lindberg, Mallory E. 01 May 2014 (has links)
E-&ndashcadherin (CDH1) is a cell adhesion molecule that coordinates key morphogenetic processes regulating cell growth, cell proliferation and apoptosis. Loss of CDH1 is a trademark of the cellular event epithelial to mesenchymal transition (EMT), which increases the metastatic potential of malignant cells. PTEN is a tumor suppressor gene commonly mutated in many human cancers, including endometrial cancer. In the mouse uterus, ablation of Pten induces epithelial hyperplasia, leading to endometrial carcinomas. However, loss of Pten alone does not affect longevity until around 5 months. Similarly, conditional ablation of Cdh1 alone does not predispose mice to cancer. We characterized the impact of dual Cdh1 and Pten ablation using Pgr-Cre (Cdh1d/d Ptend/d) in the mouse uterus. We observed that Cdh1d/d Ptend/d mice died at postnatal day 15-&ndash19 with massive blood loss from their reproductive tract (abnormal metrorrhagia) with prevalent vascularization in both the endometrium and myometrium. Their uteri were abnormally structured with curly horns, disorganized epithelial structure, and increased cell proliferation. Co-&ndashimmunostaining of KRT8 and ACTA2 showed invasion of epithelial cells into the myometrium. Further, the uteri of Cdh1d/d Ptend/d mice had prevalent vascularization in both the endometrium and myometrium. We also observed reduced expression of estrogen and progesterone receptors, loss of cell adherens and tight junction molecules (CTNNB1 and claudin), as well as activation of AKT in the uteri of Cdh1d/d Ptend/d mice. However, complex hyperplasia was not found in the uteri of Cdh1d/d Ptend/d. Collectively, these findings suggest that ablation of Pten with Cdh1 in the uterus accelerates cellular invasiveness and angiogenesis, and causes early death. Thus, this model does not allow sufficient time for the emergence of advanced, clinically over aggressive endometrial tumorigenesis and metastasis. Additionally, we looked at a new Cre system to ablate Pten and Cdh1 only in the epithelial cells of the uterus. Sprr2f, an estrogen dependent gene that is found highly expressed in the uterus, helps with structure and barrier function of epithelial cells. Prg-Cre turns on at postnatal day 3-5 before development of the uterus; whereas, Sprr2f-Cre is active around 3 weeks which is after uterine development. We have driven the ablation of Cdh1d/d Ptend/d using the Sprr2f-Cre. The Sprr2f-Cre Cdh1d/d Ptend/d mice successfully lived to 2 months. The Sprr2f-Cre Ptend/d mice displayed hyperplastic epithelial cells, most prominently in the glandular like structures of the uterus. Lack of cellular structure was observed in the Sprr2f-Cre Cdh1d/d Ptend/d mice. We also developed a model of orthotopic tumor transplantation to study further tumor development including cell invasion, dissemination and metastasis. The uteri of control, Cdhd/d, Ptend/d and Cdhd/d Ptend/d mice were collected and dissected to approximately ~1 mm in diameter. Then, the tissue fragments were orthotopically implanted into the uterine wall (endometrium) of wild-type syngeneic host mice. We have observed successful implantation and sustainability of the tissue through this technique. The tissue viability was successfully verified by implanting donor uterine pieces under the kidney capsule of recipient wild type mice. This study has shown that the ablation of Cdh1 and Pten in the mouse uterus initiates a more aggressive form of type I endometrial carcinoma when using Pgr-Cre as well as Sprr2f-Cre. However, neither conditional ablation approaches allowed us to fully observe the progression of the carcinoma to a metastatic disease. Our intrauterine endometrial/myometrial implantation technique proved to be an incomplete method to further study the metastatic potential of the PgrCre/+ Cdh1f/f Ptenf/f mice.
2

Variantes genéticas de risco às fissuras orofaciais / Genetic risk variants for orofacial clefts

Brito, Luciano Abreu 12 April 2016 (has links)
As fissuras orofaciais, ou fissuras labiopalatinas, são malformações prevalentes na população mundial, presente em cerca de um a cada 700 nascimentos. Dentro das fissuras orofaciais, um grupo etiologicamente distinto é composto pelas fissuras de lábio com ou sem fissura de palato, que, em 70% dos casos, não estão associadas a nenhuma comorbidade (fissuras de lábio com ou sem palato não sindrômicas, FL/P NS). A etiologia das FL/P NS é complexa, e em muitos casos apresenta herança multifatorial. A contribuição genética para as FL/P NS, embora sabidamente relevante, ainda é pouco conhecida. Ainda, os loci de suscetibilidade consistentemente associados às FL/P NS, não conferem um risco que explique a herdabilidade total da doença. O objetivo do presente trabalho foi investigar, por meio de diferentes estratégias, variantes de risco às FL/P NS. Utilizando sequenciamento de exoma em casos familiais, verificamos que o gene codificante da caderina epitelial, CDH1, contribui importantemente com variantes raras de efeito moderado a alto na etiologia das FL/Ps. Além disso, propusemos que também podem ter relevância etiológica genes envolvidos na via de polaridade planar celular, transição epitélio-mesênquima, adesão celular, regulação de ciclo celular ou de interação com microtúbulos. Por meio de um estudo de associação com correção para estratificação populacional, caracterizamos o intervalo de associação da região 8q24, o principal locus de suscetibilidade às FL/P, e identificamos associação significativa também para a região 20q12. Por fim, combinando o estudo de associação com mapeamento de eQTLs, encontramos pela primeira vez a associação entre marcadores na região 2p13, que regulam MRPL53, em FL/P NS. Em conclusão, este trabalho contribui para o melhor entendimento da relevância de variantes raras, de efeito moderado a alto, e comuns, de efeito pequeno, na etiologia das FL/P NS / Orofacial clefts (or cleft lip/palate) are congenital malformations with high prevalence in population (∼1:700 births). Among the orofacial cleft types, an etiologically distinct group is composed by cleft lip with or without cleft palate, which, in 70% of cases, is not accompanied by other malformations (nonsyndromic cleft lip with or without cleft palate, NSCL/P). NSCL/P presents complex etiology, often with multifactorial inheritance. Although important, the genetic contribution to NSCL/P is still poorly comprehended, and the susceptibility loci that have been associated with NSCL/P do not explain the totality of the disease\'s heritability. In light of this, our aim was to investigate risk variants for NSCL/P by means of different strategies. With exome sequencing for NSCL/P familial cases, we report that the epithelial cadherin-encoding gene contributes with rare, moderate-to-high risk variants to NSCL/P etiology. In addition, we suggest an etiological contribution of genes laying in planar cell polarity pathway, or involved with epithelial-mesenchymal transition, cell adhesion, cell cycle regulation, and interaction with microtubules. Using structured association approach, we narrowed the associated interval of 8q24 region in a Brazilian population, and also validated the association for 20q12. Finally, by combining association analysis with eQTL mapping, we found association of regulatory variants of MRPL53, in 2p13, with NSCL/P. In conclusion, this study contributes with a deeper comprehension of the etiological role of rare and common variants for NSCL/P
3

Variantes genéticas de risco às fissuras orofaciais / Genetic risk variants for orofacial clefts

Luciano Abreu Brito 12 April 2016 (has links)
As fissuras orofaciais, ou fissuras labiopalatinas, são malformações prevalentes na população mundial, presente em cerca de um a cada 700 nascimentos. Dentro das fissuras orofaciais, um grupo etiologicamente distinto é composto pelas fissuras de lábio com ou sem fissura de palato, que, em 70% dos casos, não estão associadas a nenhuma comorbidade (fissuras de lábio com ou sem palato não sindrômicas, FL/P NS). A etiologia das FL/P NS é complexa, e em muitos casos apresenta herança multifatorial. A contribuição genética para as FL/P NS, embora sabidamente relevante, ainda é pouco conhecida. Ainda, os loci de suscetibilidade consistentemente associados às FL/P NS, não conferem um risco que explique a herdabilidade total da doença. O objetivo do presente trabalho foi investigar, por meio de diferentes estratégias, variantes de risco às FL/P NS. Utilizando sequenciamento de exoma em casos familiais, verificamos que o gene codificante da caderina epitelial, CDH1, contribui importantemente com variantes raras de efeito moderado a alto na etiologia das FL/Ps. Além disso, propusemos que também podem ter relevância etiológica genes envolvidos na via de polaridade planar celular, transição epitélio-mesênquima, adesão celular, regulação de ciclo celular ou de interação com microtúbulos. Por meio de um estudo de associação com correção para estratificação populacional, caracterizamos o intervalo de associação da região 8q24, o principal locus de suscetibilidade às FL/P, e identificamos associação significativa também para a região 20q12. Por fim, combinando o estudo de associação com mapeamento de eQTLs, encontramos pela primeira vez a associação entre marcadores na região 2p13, que regulam MRPL53, em FL/P NS. Em conclusão, este trabalho contribui para o melhor entendimento da relevância de variantes raras, de efeito moderado a alto, e comuns, de efeito pequeno, na etiologia das FL/P NS / Orofacial clefts (or cleft lip/palate) are congenital malformations with high prevalence in population (∼1:700 births). Among the orofacial cleft types, an etiologically distinct group is composed by cleft lip with or without cleft palate, which, in 70% of cases, is not accompanied by other malformations (nonsyndromic cleft lip with or without cleft palate, NSCL/P). NSCL/P presents complex etiology, often with multifactorial inheritance. Although important, the genetic contribution to NSCL/P is still poorly comprehended, and the susceptibility loci that have been associated with NSCL/P do not explain the totality of the disease\'s heritability. In light of this, our aim was to investigate risk variants for NSCL/P by means of different strategies. With exome sequencing for NSCL/P familial cases, we report that the epithelial cadherin-encoding gene contributes with rare, moderate-to-high risk variants to NSCL/P etiology. In addition, we suggest an etiological contribution of genes laying in planar cell polarity pathway, or involved with epithelial-mesenchymal transition, cell adhesion, cell cycle regulation, and interaction with microtubules. Using structured association approach, we narrowed the associated interval of 8q24 region in a Brazilian population, and also validated the association for 20q12. Finally, by combining association analysis with eQTL mapping, we found association of regulatory variants of MRPL53, in 2p13, with NSCL/P. In conclusion, this study contributes with a deeper comprehension of the etiological role of rare and common variants for NSCL/P
4

Cell cycle

Chauhan, Anuradha 15 March 2011 (has links)
Die Zellreplikation ein kontrollierter Prozess aus sequentieller und zeitlich koordinierter Aktivierung und Abbau von Zyklinen, die einen schnellen Übergang zwischen den Zyklusphasen ermöglichen. Dabei ist der Erfolg bei der Ermittlung der wichtigsten Komponenten und Aufgliederung der Schaltmechanismen im Wesentlichen auf die gleichzeitige Anwendung von Modellsystemen wie Hefe, Frosch und Fliege zurückzuführen. Das heutige Verständnis des Zellzyklus muss erweitert werden, um zu überprüfen ob die Erkenntnisse auch auf in-vivo Modelle von Säugetieren wie der Maus zutreffen. Es existieren solche Modelle, die sich auf spezifische Kontrollpunkte oder Übergänge konzentrieren, allerdings noch kein integriertes Modell, in dem der Zellzyklus durch eine Verletzung im Säugetier induziert wird. Das Modellsystem der Leberregeneration bei Nagern wurde gewählt, da es sich durch das am höchsten verbreitete Phänomen der Synchronisation der Zellproliferation auszeichnet. Mit dem Fokus auf die Frage, wie die Zellen durch pro-inflammatorische Signale nach Verletzungen ins Priming in der G1/S Phase eintreten, gingen wir in einen durch Zytokine und Wachstumsfaktoren induzierten Säugetier-Zellzyklus über. Weiterhin wurden mitotische Ereignisse modelliert, die zum Alles-oder-Nichts G2/M Übergang und dem mitotischen Ausgang führen. Wir konzentrieren uns auf die vielversprechende Funktion von Cdh1 in der Zellzykluskontrolle, welches bekanntlich eine Schlüsselrolle in der G1 Phase spielt. Weiterhin haben wir dessen Rolle bei der Verzögerung der G2 Phase untersucht. Wir vermuten eine zentrale Rolle von Cdh1 im Zellzyklus durch die Kontrolle der Dynamik der Zykline. Das Modell ist ein Versuch, die Kernmechanismen der Zellzykluskontrolle bei Säugetieren zu verstehen. Besseres Verständnis der Mechanismen in der Säugetierzelle würde das Studium der Zellphysiologie im Hinblick auf Störungen der humanen Zellzyklusmaschinerie, welche zu Krankheiten wie Krebs führen. / Cell replication is a controlled process with sequential and timely activation and degradation of cyclins leading to swift transitions between the phases of the cell cycle. The essential achievement in identifying the key components and in dissecting the mechanisms of the cell cycle circuitry has been attributed to the simultaneous use of model systems like yeast, frogs, and flies. Present understanding of the cell cycle needs to be extended to investigate whether those findings also apply to mammalian in-vivo models like mice. We chose liver regeneration in mammals as the model system because it is the most synchronised cell proliferation phenomenon, where 95\% of the cells simultaneously enter cell cycle. The G1-S phase transition was modelled, focusing on how injury induced pro-inflammatory signals \textit{prime} the cells in G1 phase and consequently both cytokine and growth factor induced pathways lead to further cell cycle progression. The model was further extended to mitotic events leading to the all-or-none G2-M transition and mitotic exit. I focussed on the emerging role of Cdh1 in the mammalian cell cycle. Cdh1 known for its role in G1 phase was further investigated for its role G2 delay. Cdh1 was suggested to be at the core of the cell cycle machinery controlling cyclin dynamics. This model is an attempt in understanding core machinery of the mammalian cell cycle. Better understanding of the cell cycle control system in mammalian cells would enable understanding perturbations of the human cell cycle machinery which lead to diseases like cancers.
5

Genetic variation and prostate cancer : population-based association studies in Sweden

Lindström, Sara January 2007 (has links)
Prostate cancer constitutes the most common malignancy and the most common cause of cancer‐related death in Swedish men. A large body of evidence suggests that inherited genetic variants contribute to both development and progression of prostate cancer. The aim of this thesis is to identify genetic variants that alter prostate cancer risk and progression. All papers included in this thesis are based on a Swedish population‐based case‐control study (CAPS) comprising 2,965 incident prostate cancer cases and 1,823 controls. In paper I, we investigated if genetic variants in the E‐cadherin gene altered prostate cancer risk. Seven haplotype tagging SNPs(tagSNPs) were selected and genotyped in CAPS and families with hereditary prostate cancer. We confirmed association of a promoter SNP rs16260 previously reported to increase risk of hereditary prostate cancer (OR: 2.6; 95% CI: 1.6‐4.3) for homozygous ‘A’ carriers. In paper II, we assessed 46 polymorphisms earlier reported to be associated with prostate cancer risk. Six polymorphisms in five different genes were replicated. Interestingly, three of these genes were involved in the androgen biosynthesis. In paper III, we followed up on the results from paper II by genotyping 23 tagSNPs located in the hormone regulating genes AR, CYP17 and SRD5A2. Multiple SNPs and haplotypes were associated with prostate cancer risk, especially in the AR gene. Combining risk alleles from all genes revealed a substantial risk increase for each additional allele carried (OR: 1.12; 95% CI: 1.1‐1.2, P=0.00009). In paper IV, we collected information about cause of death for all case patients in CAPS. At time of follow‐up 300 study subjects were deceased from prostate cancer. We assessed AR, CYP17 and SRD5A2 variants for association with lethal prostate cancer and found overall no association. However, one AR promoter SNP was associated with an increased risk of dying from prostate cancer amongst men who received palliative hormonal therapy as primary treatment. In paper V, we assessed common genetic variation at the ERG locus for association between prostate cancer risk and survival. ERG is recognized as a protooncogene frequently overexpressed in prostate cancer. A total of 21 tagSNPs in the 5’ region of ERG were genotyped. There was no correlation between ERG SNPs and prostate cancer risk but common genetic variation located approximately 100,000 basepairs upstream of ERG was significantly associated with prostate cancer specific survival. In summary, our results suggest that common genetic variation in Ecadherin alters prostate cancer risk in Swedish men with a positive family history of prostate cancer. Moreover, common genetic variation in the androgen‐related genes AR, CYP17 and SRD5A2 affects the risk of developing prostate cancer but is unlikely to alter prostate cancer progression. However, genetic variants in AR may affect hormonal therapy response. Finally, ERG polymorphisms are associated with prostate cancer‐specific death but are not likely to play a role in prostate cancer development.
6

Indolent feature of Helicobacter pylori-uninfected intramucosal signet ring cell carcinomas with CDH1 mutations / ヘリコバクターピロリ未感染胃に発生するCDH1変異粘膜内印環細胞癌は進行が遅い特徴を持つ

Nikaido, Mitsuhiro 24 September 2021 (has links)
京都大学 / 新制・論文博士 / 博士(医学) / 乙第13442号 / 論医博第2241号 / 新制||医||1054(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 羽賀 博典, 教授 藤田 恭之, 教授 伊藤 貴浩 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM
7

Paving the Way: A Grounded Theory of Discovery and Decision-Making for Persons Diagnosed with the CDH1 Marker

Hersperger, Cheryl L. 01 November 2019 (has links)
Purpose: To understand the process of discovery and decision-making for adults with the CDH1 marker for hereditary diffuse gastric cancer (HDGC) and inherited breast cancer. Participants and Setting: Purposeful sampling included 20 participants; 17 adults (11 women and 6 men, ages 23–77) recruited through the No Stomach for Cancer organization; six participants were interviewed two times; with three healthcare providers also interviewed. Nineteen interviews were by telephone; one was in person. Methodological Approach: Grounded theory with constant comparison. Findings: The person diagnosed with the genetic marker CDH1 undergoes the decision-making process of Paving the way as they address this healthcare challenge. Paving the way explains the entry points for learning the risk, discerning testing for confirmation, choosing iterative individual cycles of surveillance, surgery, and ongoing adjustments postoperatively while normalizing to live longer. Implications for Nursing: Understanding the process of Paving the way explains and describes the nine key factors for decision-making and predicts the timing for nursing interventions for both post-genetic testing and pre- and postoperative assessment and planning. Knowledge Translation: Advocacy for the self and family is key to Paving the Way. Nursing has an opportunity to develop and expand the roles for navigator and counselor in the area of genetic testing. Patients undergoing PTG have chronic healthcare needs. Family implications for genetic testing require assessment beyond the individual.
8

Alterações Genéticas e Epigenéticas dos Genes do Complexo de Destruição de β-Catenina e Perfil Transcricional dos Componentes da Via de Sinalização Wnt no Câncer de Mama / Genetics and Epigenetics Disturbances of β-Catenin Destruction Complex and Transcriptional Profile of Wnt Signaling Components in Breast Cancer

Aristizábal Pachón, Andrés Felipe 22 May 2015 (has links)
O câncer de mama é a neoplasia responsável pelo maior número de mortes em mulheres no Brasil, portanto, é importante encontrar novos marcadores específicos e de diagnóstico precoce, utilizando procedimentos simples e rápidos. A via de sinalização Wnt regula importantes funções celulares como proliferação, sobrevida e adesão. Esta via está associada com os processos de iniciação e progressão em muitos tipos tumorais, como câncer de cólon familiar, melanoma e pulmão; sendo que mutações em β-Catenina (CTNNb1) explicam só 30% dos casos de sinalização aberrante encontrada no câncer de mama, indicando que existem outros componentes e/ou reguladores da via que possam estar envolvidos. O objetivo deste trabalho foi avaliar as variantes genéticas e epigenéticas nos genes do complexo de degradação de β-Catenina num grupo de pacientes com câncer de mama e num grupo controle; e determinar os perfis de transcrição dos componentes da via de sinalização Wnt e da molécula de expressão exclusiva do epitélio mamário, a Mamaglobina Humana (MGA), assim como associar estes resultados com as características clínicas, histológicas e patológicas do tumor. Para atingir este objetivo foram coletadas amostras de sangue periférico de 102 mulheres com câncer de mama e 102 mulheres sadias como grupo controle. A avaliação das variantes rs465899 do gene APC, rs2240308 e rs151279728 do gene AXIN2, rs5030625 do gene CDH1 e rs334558 do gene GSK3, foi realizada por meio de PCR-RFLPs e sequenciamento, a análise dos perfis de metilação dos promotores pela MS-PCR. A RT-qPCR foi usada para determinar os níveis de expressão dos componentes da via e a MGA. As variantes rs2240308 e rs151279728 do gene AXIN2 mostraram uma forte associação com o risco de desenvolver o câncer de mama. Um aumento significativo foi observado no nível de expressão de AXIN2 no grupo de mulheres com câncer de mama. Análises adicionais mostraram perfis de expressão diferencial dos genes APC, AXIN2, CTNNB1, GSK3 e CSNK1A1 associado ao status dos receptores hormonais e histogênese tumoral. MGA foi identificado exclusivamente em 38% dos pacientes com câncer de mama e foi associada com a progressão da doença. Este é o primeiro estudo que relaciona uma variante do gene AXIN2 com o câncer de mama na população brasileira. As variantes avaliadas do gene AXIN2 são marcadores promissores de susceptibilidade ao câncer de mama na população estudada, sendo importante, a avaliação desta variante genética na população e determinar o seu real efeito no processo de iniciação e/ou progressão do câncer de mama. / Background: Wnt/β-catenin signaling pathway is an important regulator of cellular functions such as proliferation, survival and cell adhesion. This pathway is associated with tumor initiation and progression; -catenin (CTNNB1) mutations explains only 30% of aberrant signaling found in breast cancer, indicating that other components and/or regulating of the Wnt/β-catenin pathway may be involved. Objective: The objective of the study was to evaluate the APC rs465899, AXIN2 rs2240308 and rs151279728, CDH1 rs5030625 and GSK3 rs334558 polymorphisms, APC, AXIN2, CDH1 and GSK3 promoter methylation status and expression profile of -Catenin destruction complex genes and MGA in peripheral blood of breast cancer patients. Methods: We collected peripheral blood samples from 102 breast cancer and 102 healthy subjects. The identification of the mutation was performed using PCR-RFLPs and DNA sequencing. MSP and HRM-MS was used to measure promoter methylation and RT-qPCR to determine expression profile. Results: We found significant association of AXIN2 rs2240308 polymorphism with breast cancer. Increased risk was observed even after stratification based on clinicpathological characteristics. AXIN2 rs151279728 polymorphism was found only in 9 breast cancer patients, but none in control group subject. APC and CDH1 polymorphisms were not associated with breast cancer. GSK3 polymorphism was weak associated with breast cancer and heterozygous status was associated with breast cancer protection after group stratification. APC and CDH1 promoter methylation in breast cancer patients was found. Significant increase was observed in AXIN2, CTNNB1 and GSK3 level expression in breast cancer patients. APC was down-regulated in breast cancer patients. Further analyses, showed APC, AXIN2, CTNNB1, GSK3 and CSKN1A1 gene expression associated to receptor status and histological type. MGA was found only in breast cancer patients and was associated with cancer progression. Conclusion: The present study reports, for the first time, that AXIN2 genetic defect and -catenin destruction complex expression disturbance may be found in breast cancer patients, providing additional support to the role of Wnt/-catenin pathway dysfunction in breast cancer tumorigenesis. However, the functional consequence of this genetic alteration remains to be determined. In another hand MGA was determined like a good biomarker for diagnosis and prognosis outcome.
9

Alterações Genéticas e Epigenéticas dos Genes do Complexo de Destruição de β-Catenina e Perfil Transcricional dos Componentes da Via de Sinalização Wnt no Câncer de Mama / Genetics and Epigenetics Disturbances of β-Catenin Destruction Complex and Transcriptional Profile of Wnt Signaling Components in Breast Cancer

Andrés Felipe Aristizábal Pachón 22 May 2015 (has links)
O câncer de mama é a neoplasia responsável pelo maior número de mortes em mulheres no Brasil, portanto, é importante encontrar novos marcadores específicos e de diagnóstico precoce, utilizando procedimentos simples e rápidos. A via de sinalização Wnt regula importantes funções celulares como proliferação, sobrevida e adesão. Esta via está associada com os processos de iniciação e progressão em muitos tipos tumorais, como câncer de cólon familiar, melanoma e pulmão; sendo que mutações em β-Catenina (CTNNb1) explicam só 30% dos casos de sinalização aberrante encontrada no câncer de mama, indicando que existem outros componentes e/ou reguladores da via que possam estar envolvidos. O objetivo deste trabalho foi avaliar as variantes genéticas e epigenéticas nos genes do complexo de degradação de β-Catenina num grupo de pacientes com câncer de mama e num grupo controle; e determinar os perfis de transcrição dos componentes da via de sinalização Wnt e da molécula de expressão exclusiva do epitélio mamário, a Mamaglobina Humana (MGA), assim como associar estes resultados com as características clínicas, histológicas e patológicas do tumor. Para atingir este objetivo foram coletadas amostras de sangue periférico de 102 mulheres com câncer de mama e 102 mulheres sadias como grupo controle. A avaliação das variantes rs465899 do gene APC, rs2240308 e rs151279728 do gene AXIN2, rs5030625 do gene CDH1 e rs334558 do gene GSK3, foi realizada por meio de PCR-RFLPs e sequenciamento, a análise dos perfis de metilação dos promotores pela MS-PCR. A RT-qPCR foi usada para determinar os níveis de expressão dos componentes da via e a MGA. As variantes rs2240308 e rs151279728 do gene AXIN2 mostraram uma forte associação com o risco de desenvolver o câncer de mama. Um aumento significativo foi observado no nível de expressão de AXIN2 no grupo de mulheres com câncer de mama. Análises adicionais mostraram perfis de expressão diferencial dos genes APC, AXIN2, CTNNB1, GSK3 e CSNK1A1 associado ao status dos receptores hormonais e histogênese tumoral. MGA foi identificado exclusivamente em 38% dos pacientes com câncer de mama e foi associada com a progressão da doença. Este é o primeiro estudo que relaciona uma variante do gene AXIN2 com o câncer de mama na população brasileira. As variantes avaliadas do gene AXIN2 são marcadores promissores de susceptibilidade ao câncer de mama na população estudada, sendo importante, a avaliação desta variante genética na população e determinar o seu real efeito no processo de iniciação e/ou progressão do câncer de mama. / Background: Wnt/β-catenin signaling pathway is an important regulator of cellular functions such as proliferation, survival and cell adhesion. This pathway is associated with tumor initiation and progression; -catenin (CTNNB1) mutations explains only 30% of aberrant signaling found in breast cancer, indicating that other components and/or regulating of the Wnt/β-catenin pathway may be involved. Objective: The objective of the study was to evaluate the APC rs465899, AXIN2 rs2240308 and rs151279728, CDH1 rs5030625 and GSK3 rs334558 polymorphisms, APC, AXIN2, CDH1 and GSK3 promoter methylation status and expression profile of -Catenin destruction complex genes and MGA in peripheral blood of breast cancer patients. Methods: We collected peripheral blood samples from 102 breast cancer and 102 healthy subjects. The identification of the mutation was performed using PCR-RFLPs and DNA sequencing. MSP and HRM-MS was used to measure promoter methylation and RT-qPCR to determine expression profile. Results: We found significant association of AXIN2 rs2240308 polymorphism with breast cancer. Increased risk was observed even after stratification based on clinicpathological characteristics. AXIN2 rs151279728 polymorphism was found only in 9 breast cancer patients, but none in control group subject. APC and CDH1 polymorphisms were not associated with breast cancer. GSK3 polymorphism was weak associated with breast cancer and heterozygous status was associated with breast cancer protection after group stratification. APC and CDH1 promoter methylation in breast cancer patients was found. Significant increase was observed in AXIN2, CTNNB1 and GSK3 level expression in breast cancer patients. APC was down-regulated in breast cancer patients. Further analyses, showed APC, AXIN2, CTNNB1, GSK3 and CSKN1A1 gene expression associated to receptor status and histological type. MGA was found only in breast cancer patients and was associated with cancer progression. Conclusion: The present study reports, for the first time, that AXIN2 genetic defect and -catenin destruction complex expression disturbance may be found in breast cancer patients, providing additional support to the role of Wnt/-catenin pathway dysfunction in breast cancer tumorigenesis. However, the functional consequence of this genetic alteration remains to be determined. In another hand MGA was determined like a good biomarker for diagnosis and prognosis outcome.
10

The Role of the E3 Ubiquitin Ligase Cdh1-APC in Axon Growth in the Mammalian Brain / Die Rolle der E3 Ubiquitin Ligase Cdh1-APC in Axon Wachstum im Gehirn von Säugetieren

Kannan, Madhuvanthi 22 August 2012 (has links)
No description available.

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