• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 4
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 18
  • 18
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 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.
11

Associação entre alta expressão e atividade de metaloproteinases e presença de HPV em linhagens de carcinomas cervicais humanos / Higher expression and activity of metalloproteinases is associated with HPV presence in human cervical carcinomas cell lines

Laura Beatriz da Silva Cardeal 02 June 2006 (has links)
A ação das metaloproteinases de matriz (MMP-2, MMP-9 e MT1-MMP) é necessária para degradação da membrana basal em carcinomas da cérvice uterina. O objetivo deste trabalho consistiu na avaliação da expressão das metaloproteinases MMP -2, -9 e MT1-MMP, do gene supressor de metástase RECK e do inibidor tecidual de MMPs (TIMP-2) em modelo de células de neoplasia da cérvice-uterina cultivadas em substratos de matriz extracelular. As linhagens celulares de carcinoma de cérvice uterina SiHa, CaSki, ambas HPV 16 positivas, e C33A, HPV negativa, foram cultivadas em gel de colágeno tipo I, Matrigel e plástico. Avaliou-se o crescimento, invasão, expressão gênica, através de ensaios de real-time PCR, e atividade de metaloproteinases, através de ensaios de zimografia. Os resultados demonstraram que estas linhagens de carcinoma cervical quando cultivadas em gel de colágeno tipo I apresentaram uma diminuição no crescimento, morfologia modificada na presença de substrato de matriz extracelular, e que nas linhagens HPV positivas há um aumento da expressão de MMP-2, MT1-MMP e TIMP-2 e da atividade de pró-MMP-2 em relação à linhagem HPV negativa. Observou-se também que, RECK apresentou maior expressão gênica em CaSki associada à atividade de pró-MMP-2. MMP-9 apresentou muito baixa expressão gênica em todas as linhagens e condições estudadas. Quando analisamos as linhagens separadamente, observamos que o Matrigel influenciou a expressão gênica de MMP-2, e que o gel de colágeno tipo I aparece como indutor da atividade de pró-MMP-2 em todas as linhagens. Em conclusão, nossos resultados mostram que a expressão de MMP-2, MT1-MMP e TIMP-2 e que a atividade de pró-MMP-2 estão aumentadas nas células HPV positivas, sugerindo que o HPV está associado com a expressão de MMPs e TIMP-2. / Matrix metalloproteinases (MMPs) -2, -9, and MT1-MMP are required for basement membrane degradation in cervical carcinoma. We evaluated the expression and activity of MMPs and their inhibitors RECK and TIMP-2 in three human invasive cervical carcinoma cell lines. Two HPV-16- positive cell lines (SiHa and CaSki), HPV-negative cell line (C33A) were cultured either onto type-I collagen gel, Matrigel or plastic, in order to recreate their three-dimensional growth environment and evaluate the growth and invasion of the cells and expression of these genes using quantitative real-time PCR (Q-PCR). We also analyzed the gelatinolytic activity of MMP-2 and -9 by zymography. We found that the growth curves carcinoma cells are decreased and cells morphology are modified in ECM substrate. HPV-positive cell lines expressed higher levels of MMP-2, MT1-MMP and TIMP-2 than the HPV negative cell line. In addition, MMP-9 was expressed at very low levels in both HPV-negative and HPV-positive cell lines. We also observed that the expression of the RECK gene is higher in CaSki cells, being associated with pro-MMP-2 activity. The Matrigel substrate influence MMP-2 expression for SiHa and CaSki cells. On the other hand, we found that type-I collagen gel, but not Matrigel, can enhance pro-MMP-2 activity in all cell lines. Our results suggest that the presence of HPV is related to increased expression of MMP -2, MT1-MMP and TIMP-2 and pro-MMP-2 activity in HPV-positive cells than in HPV-negative cells.
12

Molecular Pathogenesis of Cervical Carcinoma : Analysis of Clonality, HPV16 Sequence Variations and Loss of Heterozygosity

Hu, Xinrong January 2001 (has links)
<p>A previous model of morphological pathogenesis assumed that cervical carcinoma is of monoclonal origin and progresses through multiple steps from normal epithelium via CINS into invasive carcinomas. The aim of this study was to investigate the molecular mechanism of pathogenesis of cervical neoplasia. </p><p>In the clonality study, we found that 75% (6/8) of informative cases of cervical carcinoma had identical patterns of loss of heterozygosity (LOH) in the multiple synchronous lesions, while the remaining cases had different LOU patterns. In an extensively studied "golden case", the multiple carcinoma and cervical intraepithelial neoplasia (CIN) lesions could be divided into several different clonal groups by the X-chromosome inactivation patterns, HPV 16 mutations and LOH patterns. The biggest clonal family included one CIN II, one CIN III and four carcinoma samples, while four other monoclonal families of carcinoma did not include CIN lesions. These results suggested that cervical carcinoma can be either monoclonal or polygonal and contains clones developing either directly or via multiple steps. In the study of HPV types and HPV16 variations, the results confirmed that specific HPV types are the cause of cervical carcinoma but failed to support the previous opinion that HPV16 E6 variants are more malignant than the prototype. We established a novel classification called oncogene lineage of HPV16, and found that additional variations of HPV 16 oncogenes might be a weak further risk factor for cervical carcinoma. In the study of LOH, we found that interstitial deletion of two common regions of chromosome 3p, i.e., 3p2l.1-3p2l.3, and 3p22, was an early event in the development of cervical carcinoma. The results showed that the hMLH1 gene, located in 3p22 and showing LOH in 43% of the studied cases, was not involved in the development of cervical carcinoma because neither the expression level of protein nor the gene sequence was altered in these cases. </p><p>In summary, a suggested model of molecular pathogenesis of cervical carcinoma is as follows. Specific types of HPV infect one or more committed stem cells in the basal layer of the epithelium. Fully efficient LOH events turn one (monoclonal origin) or more (polyclonal origin) HPV-infected stem cells into carcinoma cells without CIN steps. Less efficient LOH events would lead to CIN steps where some other unknown factors require to be added to facilitate the formation of carcinoma. In the absence of LOH events no carcinoma develops from the HPV-infected stem cells.</p>
13

Molecular Pathogenesis of Cervical Carcinoma : Analysis of Clonality, HPV16 Sequence Variations and Loss of Heterozygosity

Hu, Xinrong January 2001 (has links)
A previous model of morphological pathogenesis assumed that cervical carcinoma is of monoclonal origin and progresses through multiple steps from normal epithelium via CINS into invasive carcinomas. The aim of this study was to investigate the molecular mechanism of pathogenesis of cervical neoplasia. In the clonality study, we found that 75% (6/8) of informative cases of cervical carcinoma had identical patterns of loss of heterozygosity (LOH) in the multiple synchronous lesions, while the remaining cases had different LOU patterns. In an extensively studied "golden case", the multiple carcinoma and cervical intraepithelial neoplasia (CIN) lesions could be divided into several different clonal groups by the X-chromosome inactivation patterns, HPV 16 mutations and LOH patterns. The biggest clonal family included one CIN II, one CIN III and four carcinoma samples, while four other monoclonal families of carcinoma did not include CIN lesions. These results suggested that cervical carcinoma can be either monoclonal or polygonal and contains clones developing either directly or via multiple steps. In the study of HPV types and HPV16 variations, the results confirmed that specific HPV types are the cause of cervical carcinoma but failed to support the previous opinion that HPV16 E6 variants are more malignant than the prototype. We established a novel classification called oncogene lineage of HPV16, and found that additional variations of HPV 16 oncogenes might be a weak further risk factor for cervical carcinoma. In the study of LOH, we found that interstitial deletion of two common regions of chromosome 3p, i.e., 3p2l.1-3p2l.3, and 3p22, was an early event in the development of cervical carcinoma. The results showed that the hMLH1 gene, located in 3p22 and showing LOH in 43% of the studied cases, was not involved in the development of cervical carcinoma because neither the expression level of protein nor the gene sequence was altered in these cases. In summary, a suggested model of molecular pathogenesis of cervical carcinoma is as follows. Specific types of HPV infect one or more committed stem cells in the basal layer of the epithelium. Fully efficient LOH events turn one (monoclonal origin) or more (polyclonal origin) HPV-infected stem cells into carcinoma cells without CIN steps. Less efficient LOH events would lead to CIN steps where some other unknown factors require to be added to facilitate the formation of carcinoma. In the absence of LOH events no carcinoma develops from the HPV-infected stem cells.
14

Genetic Risk Factors for Cervical Carcinoma <i>in situ</i>

Beskow, Anna January 2003 (has links)
<p>Oncogenic human papillomaviruses (HPVs) are implicated in 99.7 % of cervical cancer cases but require the co-operation of other factors. To investigate potential genetic risk factors we have typed the HLA class II DRB1 and DQB1 loci in 478 women diagnosed with cervical carcinoma in situ and in 608 age-matched controls. Quantitative measurements of HPV 16, HPV 18/45 and HPV 31 were obtained. The DRB1*1501 and DQB1*0602 alleles were found to increase the risk of HPV 16 infection. Carriers of DRB1*1501 and DQB1*0602 were also shown to have an increased risk of a higher viral load compared to non-carriers. The DRB1*1301 and DQB1*0603 alleles were found to protect from HPV 18/45 and 31 infections as well as resulting in a lower viral load in carriers compared to non-carriers. Women with a high HPV 16, 18/45 or 31 viral load were more prone to long-term infections and women with a low HPV 16 viral load were more prone to short-term infections. Carriers of DRB1*1501 and DQB1*0602 alleles were also shown to have an increased risk of long-term infections compared to short-term infections. We also tested if an HPV susceptibility locus found for epidermodysplasia verruciformis (EV) was also linked to HPV susceptibility in cervical cancer. We did not find any linkage to this locus in a set of 77 families, each with at least three cases diagnosed with cervical carcinoma in situ. Other potential risk factors tested were HPV 16 E6 variants together with a p53 codon 72 polymorphism and HLA class II alleles. We found an association between the E6 L83V variant and the HLA DR4-DQ3 haplotype, as well as an increased frequency of Arg homozygosity of p53 in women infected with the L83V variant. These results show that alleles at HLA class II loci represents risk factors for persistent HPV infection and thereby also contribute to the risk of development of cervical carcinoma <i>in situ</i>.</p>
15

Genetic Risk Factors for Cervical Carcinoma in situ

Beskow, Anna January 2003 (has links)
Oncogenic human papillomaviruses (HPVs) are implicated in 99.7 % of cervical cancer cases but require the co-operation of other factors. To investigate potential genetic risk factors we have typed the HLA class II DRB1 and DQB1 loci in 478 women diagnosed with cervical carcinoma in situ and in 608 age-matched controls. Quantitative measurements of HPV 16, HPV 18/45 and HPV 31 were obtained. The DRB1*1501 and DQB1*0602 alleles were found to increase the risk of HPV 16 infection. Carriers of DRB1*1501 and DQB1*0602 were also shown to have an increased risk of a higher viral load compared to non-carriers. The DRB1*1301 and DQB1*0603 alleles were found to protect from HPV 18/45 and 31 infections as well as resulting in a lower viral load in carriers compared to non-carriers. Women with a high HPV 16, 18/45 or 31 viral load were more prone to long-term infections and women with a low HPV 16 viral load were more prone to short-term infections. Carriers of DRB1*1501 and DQB1*0602 alleles were also shown to have an increased risk of long-term infections compared to short-term infections. We also tested if an HPV susceptibility locus found for epidermodysplasia verruciformis (EV) was also linked to HPV susceptibility in cervical cancer. We did not find any linkage to this locus in a set of 77 families, each with at least three cases diagnosed with cervical carcinoma in situ. Other potential risk factors tested were HPV 16 E6 variants together with a p53 codon 72 polymorphism and HLA class II alleles. We found an association between the E6 L83V variant and the HLA DR4-DQ3 haplotype, as well as an increased frequency of Arg homozygosity of p53 in women infected with the L83V variant. These results show that alleles at HLA class II loci represents risk factors for persistent HPV infection and thereby also contribute to the risk of development of cervical carcinoma in situ.
16

Rizika a limity laparoskopie v léčbě gynekologických zhoubných nádorů / Risks and limits of laparoscopy in the treatment of gynecological cancers

Charvát, Martin January 2016 (has links)
The thesis evaluates the results of experimental protocol involving the fertility sparing treatment procedure in early stage cervical carcinoma (LAP I protocol). Sentinel lymph node detection and experimental extirpation of afferent channels using laparoscopy and its technical aspects were analysed in prospective group of 85 women. The oncologic results and early/late morbidity show that established surgical procedures can be considered safe with minimal morbidity, provided that the indication criteria are met. The second part analyses the results of 148 women with no further pregnancy plans suffering from cervical tumors less than 2 cm in size with invasion less than half of the stroma (LAP II protocol). The oncological results in our defined group are very good and comparable to 'standard' procedure of modified radical hysterectomy type B or C with lower morbidity. In the separate section the thesis analyses the possibilities of laparoscopy in endometrial cancer treatment including the potentials of use of sentinel lymph node detection and technical aspects of laparoscopy in obese women. Currently the biggest controversy is the use of laparoscopy in malignant ovarian tumors. Our oncogynaecological study group at FN Motol prefers the laparotomic approach and we chose to include the set of advanced...
17

Rizika a limity laparoskopie v léčbě gynekologických zhoubných nádorů / Risks and limits of laparoscopy in the treatment of gynecological cancers

Charvát, Martin January 2016 (has links)
The thesis evaluates the results of experimental protocol involving the fertility sparing treatment procedure in early stage cervical carcinoma (LAP I protocol). Sentinel lymph node detection and experimental extirpation of afferent channels using laparoscopy and its technical aspects were analysed in prospective group of 85 women. The oncologic results and early/late morbidity show that established surgical procedures can be considered safe with minimal morbidity, provided that the indication criteria are met. The second part analyses the results of 148 women with no further pregnancy plans suffering from cervical tumors less than 2 cm in size with invasion less than half of the stroma (LAP II protocol). The oncological results in our defined group are very good and comparable to 'standard' procedure of modified radical hysterectomy type B or C with lower morbidity. In the separate section the thesis analyses the possibilities of laparoscopy in endometrial cancer treatment including the potentials of use of sentinel lymph node detection and technical aspects of laparoscopy in obese women. Currently the biggest controversy is the use of laparoscopy in malignant ovarian tumors. Our oncogynaecological study group at FN Motol prefers the laparotomic approach and we chose to include the set of advanced...
18

Détection moléculaire des métastases des ganglions lymphatique dans le cancer du col de l'utérus

Mechtouf, Nawel 12 1900 (has links)
Le Cancer du Col Utérin (CCU) chez la femme est provoqué par le virus oncogénique VPH. La métastase lymphatique ganglionnaire est un facteur pronostique majeur pour l’évolution de ce cancer et sa présence influence la décision thérapeutique. En général, l’envahissement ganglionnaire est diagnostiqué par histologie, mais cette méthode est laborieuse et parfois prise en défaut pour détecter les micrométastases et les cellules cancéreuses isolées et pour donner des résultats rapides en per opératoire. L’outil moléculaire que nous désirons développer pour combler cette lacune est basé sur une analyse d’ARN des gènes du VPH exprimés par les cellules du CCU. Ceci sera fait par transcription réverse de l’ARN cellulaire couplé à une réaction quantitative en chaine par polymérase en temps réel (RT-qPCR). Cette technique devrait nous permettre une détection et une évaluation rapide des micrométastases pour aider à déterminer immédiatement un pronostic fiable et la thérapie associée. C’est un test précis, sensible et rapide pour détecter un envahissement ganglionnaire dans le CCU visant à améliorer la gestion thérapeutique. Le projet est basé sur trois objectifs. En premier lieu, valider les marqueurs moléculaires E6 et E7 de VPH16 et 18 à partir des échantillons frais et des échantillons fixés dans des blocs de paraffine. En deuxième lieu, déterminer la fiabilité et la sensibilité des marqueurs pour la détection des macrométastases, des micrométastases et les cellules tumorales isolées en utilisant la technique de RT-qPCR. En troisième lieu et parallèlement au travail présenté dans ce mémoire, il est nécessaire de constituer une base de données des patientes qui ont le virus VPH16 et 18 intégré dans leur génome, qui ont été traitées et dont nous connaissons déjà le diagnostic final afin de valider la méthode (biobanque). Nous avons réussi à extraire de l’ARNm de haute qualité à partir d’échantillons complexes, à détecter les gènes E6 et E7 de VPH16 et 18 en RT-qPCR, et à déterminer précisément la limite de détection de E6 et E7 dans les échantillons frais qui est une proportion de 0,008% de cellules cancéreuses. Dans les échantillons fixés dans la paraffine, cette limite est de 0,02% et 0,05% pour E6-E7-VPH16 et E6-E7-VPH18 respectivement. Ceci comparativement à une limite de détection histologique de 1% qui est déterminée par immunohistochimie de CK19. Enfin, notre protocole est validé pour VPH18 dans les ganglions lymphatiques du CCU. / The presence of lymph nodes metastasis in uterine cervical carcinoma influences therapeutic management and patient survival. The gold standard for metastasis detection is histology. However, histology lacks sensitivity to detect micrometastasis or isolated cancer cells and is not an efficient method for immediate diagnosis during surgery. The molecular tool that we want to develop to fill this gap is based on an analysis of expressed RNA transcripts derived from the HPV genome in cells of uterine cervical carcinoma (UCC). This will be done by reverse transcription of cellular RNA coupled to a quantitative polymerase chain reaction in real-time (RT-qPCR). This technique could allow detection and rapid assessment of micrometastasis to help determine prognosis and an immediate reliable combination therapy. The proposed technique would be a specific test, sensitive and rapid to detect lymph node involvement in the UCC to improve therapy management. Our objective is to constitute a patient bank containing genetic and clinical information. This genetic information will be used to test and improve new molecular markers for UCC metastasis. These markers will be validated using comparisons to traditional histological results and evaluated for their capacity to detect lymph nodes micrometastasis. Ultimately, we wish to develop a reliable molecular diagnosis method useful during surgery and improve our knowledge about the clinical evolution of metastatic UCC. Currently, we are able to extract high quality mRNA from formalin-fixed cells mounted in paraffin blocks and to detect E6 and E7 from HPV16 and HPV18 using RT-qPCR. We have specifically determined the detection limit of E6 and E7, which is 0.008% in the fresh samples and 0.02% and 0.05% for HPV16-E6-E7 and HPV18- E6-E7 respectively in the samples fixed in paraffin blocks. Comparatively, the histological detection limit was determined to be around 1% using immunohistochemistry for CK19 expression. Finally, our protocol has been validated for HPV18 in UCC patient lymph nodes

Page generated in 0.0688 seconds