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Maternal diabetes affects cell proliferation in developing rat placenta

ZORN, T. M. T.; ZUNIGA, M.; MADRID, E.; TOSTES, R.; FORTES, Z.; GIACHINI, F.; MARTIN, S. San
Fonte: F HERNANDEZ Publicador: F HERNANDEZ
Tipo: Artigo de Revista Científica
Português
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65.96%
Placentation starts with the formation of a spheroidal trophoblastic shell surrounding the embryo, thus facilitating both implantation into the uterine stroma and contact with maternal blood. Although it is known that diabetes increases the placental size and weight, the mechanisms responsible for this alteration are still poorly understood. In mammals, cellular proliferation occurs in parallel to placental development and it is possible that diabetes induces abnormal uncontrolled cell proliferation in the placenta similar to that seen in other organs (e.g. retina). To test this hypothesis, the objective of this work was to determine cell proliferation in different regions of the placenta during its development in a diabetic rat model. Accordingly, diabetes was induced on day 2 of pregnancy in Wistar rats by a single injection of alloxan (40 mg/kg i.v.). Placentas were collected on days 14, 17, and 20 postcoitum. Immunoperoxidase was used to identify Ki67 nuclear antigen in placental sections. The number of proliferating cells was determined in the total placental area as well as in the labyrinth, spongiotrophoblast and giant trophoblast cell regions. During the course of pregnancy, the number of Ki67 positive cells decreased in both control and diabetic rat placentas. However...

Increased cell proliferation in experimentally induced endometriosis in rabbits

ROSA-E-SILVA, Julio Cesar; GARCIA, Sergio Britto; ROSA-E-SILVA, Ana Carolina Japur de Sa; CANDIDO-DOS-REIS, Francisco Jose; POLI-NETO, Omero Benedicto; FERRIANI, Rui Alberto; NOGUEIRA, Antonio Alberto
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.95%
Objective: To characterize the pattern of cell proliferation and apoptosis of eutopic and ectopic endometrium in rabbits after endometrium implantation for the experimental induction of endometriosis. Design: Animal experimental study. Setting: Sector of experimental surgery. Animal(s): Twenty-female New Zealand rabbits. Intervention(s): All animals underwent laparotomy for endometriosis induction by resection of one uterine horn, isolation of the endometrium, and fixation of tissue segment to the pelvic peritoneum. Two groups of 10 animals were sacrificed 4 and 8 weeks after endometriosis induction. The lesion was excised together with the opposite uterine horn for endometrial gland and stroma determination. Main Outcome Measure(s): Cell proliferation and apoptosis were determined in the eutopic and ectopic endometrium, and the cell proliferation index (CPI) and apoptotic index (AI) were calculated as the number of labeled cells per 1,000 cells. The tissue homeostasis index was the CPI/AI ratio. Glands and stroma were analyzed separately. Result(s): The CPI for ectopic tissue was increased compared with eutopic tissue, but there was no difference in the ectopic lesions between 4 and 8 weeks of induction. Considering only the AI, eutopic and ectopic endometrium did not differ after 4 weeks...

A role for COX2-derived PGE2 and PGE2-receptor subtypes in head and neck squamous carcinoma cell proliferation

ABRAHAO, Aline Correa; CASTILHO, Rogerio M.; SQUARIZE, Cristiane H.; MOLINOLO, Alfredo A.; SANTOS-PINTO JR., Decio dos; GUTKIND, J. Silvio
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
Português
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65.95%
The overexpression of cyclooxygenase (COX)-2 is a frequent event in squamous cell carcinomas of the head and neck (HNSCC), and non-steroidal anti-inflammatory drugs, which are potent inhibitors of COX-1 and COX-2, exert chemopreventive effects on HNSCC cancer development. COX-2 promotes the release of the pro-inflammatory mediator prostaglandin E2 (PGE2), which acts on its cell surface G protein-coupled receptors EP1, EP2, EP3, and EP4. Here, we investigated the role of PGE2 and its receptors in cellular proliferation in HNSCC. The expression of COX-2 and EP1-4 was examined in immortalized oral epithelial cells and in a representative panel of HNSCC cell lines, and based on these data EP1-EP3 and COX-2 expression were evaluated by immunohistochemistry in a large clinical sample collection using HNSCC tissue microarrays. The ability of selective COX-2 inhibition to block PGE2 secretion was measured by ELISA specific assays. The effects of PGE2 on cell proliferation were evaluated using PGE2, its stable analog, and EP2 and EP3-specific synthetic agonists. The results presented here show that HNSCC tumoral lesions and their derived cell lines constitutively express COX-2 and the EP1, EP2 and EP3 receptors for PGE2. HNSCC cells secrete PGE2...

Nitric oxide is responsible for oxidative skin injury and modulation of cell proliferation after 24 hours of UVB exposures

Terra, Vania Aparecida; Souza-Neto, Fernando Pereira; Pereira, Raissa Caroline; Xavier Da Silva, Thamara Nishida; Ramalho, Leandra Naira Zambelli; Luiz, Rodrigo Cabral; Cecchini, Rubens; Cecchini, Alessandra Lourenco
Fonte: INFORMA HEALTHCARE; LONDON Publicador: INFORMA HEALTHCARE; LONDON
Tipo: Artigo de Revista Científica
Português
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65.97%
Nitric oxide (NO) is produced by various mammalian cells and plays a variety of regulatory roles in normal physiology and in pathological processes. This article provides evidence regarding the participation of NO in UVB-induced skin lesions and in the modulation of skin cell proliferation following UVB skin irradiation. Hairless mice were subjected to UVB irradiation for 3 hours and the skin evaluated immediately, 6 and 24 hours postirradiation. The skin lipid peroxidation, and NO levels evaluated by chemiluminescence and inducible nitric oxide synthase (iNOS) and nitrotyrosine immunolabelling increased significantly 24 hours after irradiation and decreased under the treatment with aminoguanidine (AG). On the other hand, cell proliferation markers, PCNA and VEGF showed a strong labelling index when AG was used. The data indicate that NO mediates, at least in part, the lipid peroxidation and protein nitration and also promotes the down regulation of factors involved in cell proliferation. This work shows that the NO plays an important role in the oxidative stress damage and on modulation of cell proliferation pathways in UVB irradiated skin.; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - CAPES

GPC3 reduces cell proliferation in renal carcinoma cell lines

Valsechi, Marina Curado; Oliveira, Ana Beatriz Bortolozo; Conceição, André Luis Giacometti; Stuqui, Bruna; Candido, Natalia Maria; Provazzi, Jocelan Scarin; Araujo, Luiza Ferreira de; Silva Junior, Wilson Araújo da; Calmon, Marilia de Freitas; Rahal,
Fonte: BMC Publicador: BMC
Tipo: Artigo de Revista Científica
Português
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Abstract Background Glypican 3 (GPC3) is a member of the family of glypican heparan sulfate proteoglycans (HSPGs). The GPC3 gene may play a role in controlling cell migration, negatively regulating cell growth and inducing apoptosis. GPC3 is downregulated in several cancers, which can result in uncontrolled cell growth and can also contribute to the malignant phenotype of some tumors. The purpose of this study was to analyze the mechanism of action of the GPC3 gene in clear cell renal cell carcinoma. Methods Five clear cell renal cell carcinoma cell lines and carcinoma samples were used to analyze GPC3 mRNA expression (qRT-PCR). Then, representative cell lines, one primary renal carcinoma (786-O) and one metastatic renal carcinoma (ACHN), were chosen to carry out functional studies. We constructed a GPC3 expression vector and transfected the renal carcinoma cell lines, 786-O and ACHN. GPC3 overexpression was analyzed using qRT-PCR and immunocytochemistry. We evaluated cell proliferation using MTT and colony formation assays. Flow cytometry was used to evaluate apoptosis and perform cell cycle analyses. Results We observed that GPC3 is downregulated in clear cell renal cell carcinoma samples and cell lines compared with normal renal samples. GPC3 mRNA expression and protein levels in 786-O and ACHN cell lines increased after transfection with the GPC3 expression construct...

Papel da interação entre padrão alimentar, corticosterona e fatores de crescimento na regulação da proliferação celular no epitélio gástrico de ratos em desenvolvimento pós-natal.; Role of the interaction among diet pattern, corticosterone, and growth factors on the regulation of cell proliferation in the gastric epithelium of developing rats.

Figueiredo, Priscila Moreira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/02/2011 Português
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O leite materno constitui uma rica fonte de nutrientes e peptídeos. O desmame precoce (DP) induz o aumento da proliferação e da diferenciação celular, e pode ser uma condição estressante capaz de elevar a corticosterona (CORT). Neste estudo, investigamos a interação entre padrão alimentar, CORT, TGFa e TGFb na regulação da proliferação celular na mucosa gástrica de ratos em desenvolvimento pós-natal. Utilizamos ratos Wistar em DP a partir do 15ºd, e observamos o aumento de CORT aos 16, 17 e 18d (p<0,05). No 17ºd, encontramos nível alto de TGFa e baixo de TGFb1 na mucosa gástrica (p<0,05). Para avaliarmos a ação da CORT, usamos o RU486, que ao reduzir a ação hormonal, estimulou a proliferação celular nos animais amamentados e DP (p<0,05), sem alterar os níveis de TGFa e TGFb. A sinalização para esses fatores foi estudada, e RU486 reduziu a ativação de ERK1/2 (p<0,05) no DP. Concluímos que a corticosterona circulante possui efeito antiproliferativo sobre a mucosa gástrica de ratos, e sua ação parece direta sem depender da regulação dos níveis de TGFa e TGFb.; Milk is a source of nutrients and active peptides. Early weaning (EW) leads to the increase of cell proliferation and differentiation...

Avaliação de marcadores de proliferação celular e apoptose em tecido endometrial eutópico e ectópico em modelo experimental de endometriose em coelhas; Evaluation of cell proliferation and apoptosis markers on eutopic and ectopic endometrium in a rabbit experimental model

Silva, Julio Cesar Rosa e
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/12/2007 Português
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Objetivo:Caracterizar o padrão de homeostase (proliferação celular e apoptose) de tecido endometrial eutópico e ectópico de coelhas submetidas à indução de lesões de endometriose por modelo experimental já conhecido, quatro e oito semanas após o procedimento de implantação endometrial. Material e Métodos:Estudo experimental animal sendo utilizado 20 coelhas adultas Nova Zelândia, fêmeas e virgens, submetidas à laparotomia para indução da lesão de endometriose, através da ressecção de um corno uterino e fixação no peritônio pélvico de fragmento de 5mm. As coelhas foram divididas em dois grupos de 10 animais, sendo os animais do grupo 1, sacrificados após 4 semanas da indução da lesão endometrial ectópica e os do grupo 2 após 8 semanas. A lesão foi excisada para análise histológica juntamentecom o corno uterino contralateral, comprovando a presença de tecido endometrial glandular e estromal. Reações de imunohistoquímica foram realizadas, no tecido endometrial eutópico e ectópico, para proliferação celular através do PCNA e para apoptose através do fas, na glândula e estroma, sendo obtido o índice de proliferação celular (IPC) e de apoptose (IA) através do número de células marcadas por 1000 contadas...

DETECTION OF CELL-PROLIFERATION IN TISSUE-SECTIONS

Bacchi, C. E.; Gown, A. M.
Fonte: Associação Brasileira de Divulgação Científica (ABRADIC) Publicador: Associação Brasileira de Divulgação Científica (ABRADIC)
Tipo: Artigo de Revista Científica Formato: 677-687
Português
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1. Cell proliferation is of interest since abnormal cell proliferation appears to be a precursor of tumorigenesis and also because the quantitative description of cell proliferation in tumors can be used to predict the biological behavior of a particular neoplasia.2. Them am several reliable methods of studying cell proliferation in tissues. One of the most important is the detection of the Ki67 defined antigen in frozen sections. The number of cells expressing Ki67 correlates with histological grades of tumors and can also be predictive of clinical outcome. The Ki67 can be localized in tissue sections using monoclonal antibodies in association with the immunoperoxidase technique.3. Proliferating cell nuclear antigen (PCNA) is a component of DNA polymerase-delta and is another important cell proliferation marker manifesting a striking increase in concentration during the S phase of the cell cycle. 19A2 and PC10 are two different monoclonal antibodies which can be employed to detect PCNA in paraffin-embedded tissues.4. Molecular biology has also been making a great contribution to the study of cell proliferation. The most recent innovation in tissue identification of proliferating cells is the use of in situ hybridization for the localization of histone H3 and/or H4 mRNA. H3 mRNA-positive cells appear to be present in basal cells of the skin and in crypt cells of the intestine which are sites with high proliferation rate.

Doxazosin reduces cell proliferation and increases collagen fibers in rat prostatic lobes

Justulin Jr., Luis A.; Delella, Flavia K.; Felisbino, Sérgio L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 171-183
Português
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We investigated the effects of doxazosin (Dox), an alpha-adrenoceptor antagonist used clinically for the treatment of benign prostatic hyperplasia (BPH), on the rat prostatic complex by assessing structural parameters, collagen fiber content, cell proliferation, and apoptosis. Adult Wistar rats were treated with Dox (25 mg/kg per day), and the ventral (VP), dorsolateral, and anterior prostate (AP) regions of the prostate complex were excised at 3, 7, and 30 days after treatment. At 24 h before being killed, the rats were injected once with 5-bromodeoxyuridine (BrdU; thymidine analog) to label mitotically active cells. The prostates were weighed and processed for histochemistry, morphometry-stereology, immunohistochemistry for BrdU, Western blotting for proliferating cell nuclear antigen (PCNA), and the TUNEL reaction for apoptosis. Dox-treated prostate lobes at day 3 presented increased weight, an enlarged ductal lumen, low cubical epithelial cells, reduced epithelial folds, and stretched smooth muscle cells. However, at day 30, the prostates exhibited a weight reduction of ∼20% and an increased area of collagen and reticular fibers in the stromal space. Dox also reduced epithelial cell proliferation and increased apoptosis in the three prostatic lobes. Western blotting for PCNA confirmed the reduction of cell proliferation by Dox...

An Integrative Genomic and Transcriptomic Analysis Reveals Potential Targets Associated with Cell Proliferation in Uterine Leiomyomas

Da Cirilo, Priscilaniele Ramos; Marchi, Fábio Albuquerque; de Barros Filho, Mateus Camargo; Rocha, Rafael Malagoli; Domingues, Maria Aparecida Custódio; Jurisica, Igor; Pontes, Anagloria; Rogatto, Silvia Regina
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.96%
Background: Uterine Leiomyomas (ULs) are the most common benign tumours affecting women of reproductive age. ULs represent a major problem in public health, as they are the main indication for hysterectomy. Approximately 40-50% of ULs have non-random cytogenetic abnormalities, and half of ULs may have copy number alterations (CNAs). Gene expression microarrays studies have demonstrated that cell proliferation genes act in response to growth factors and steroids. However, only a few genes mapping to CNAs regions were found to be associated with ULs. Methodology: We applied an integrative analysis using genomic and transcriptomic data to identify the pathways and molecular markers associated with ULs. Fifty-one fresh frozen specimens were evaluated by array CGH (JISTIC) and gene expression microarrays (SAM). The CONEXIC algorithm was applied to integrate the data. Principal Findings: The integrated analysis identified the top 30 significant genes (P<0.01), which comprised genes associated with cancer, whereas the protein-protein interaction analysis indicated a strong association between FANCA and BRCA1. Functional in silico analysis revealed target molecules for drugs involved in cell proliferation, including FGFR1 and IGFBP5. Transcriptional and protein analyses showed that FGFR1 (P = 0.006 and P<0.01...

GPC3 reduces cell proliferation in renal carcinoma cell lines

Valsechi, Marina Curado; Bortolozo Oliveira, Ana Beatriz; Giacometti Conceicao, Andre Luis; Stuqui, Bruna; Candido, Natalia Maria; Scarin Provazzi, Paola Jocelan; Araujo, Luiza Ferreira de; Silva, Wilson Araujo; Calmon, Marilia de Freitas; Rahal, Paula
Fonte: Biomed Central Ltd Publicador: Biomed Central Ltd
Tipo: Artigo de Revista Científica Formato: 11
Português
Relevância na Pesquisa
65.98%
Background: Glypican 3 (GPC3) is a member of the family of glypican heparan sulfate proteoglycans (HSPGs). The GPC3 gene may play a role in controlling cell migration, negatively regulating cell growth and inducing apoptosis. GPC3 is downregulated in several cancers, which can result in uncontrolled cell growth and can also contribute to the malignant phenotype of some tumors. The purpose of this study was to analyze the mechanism of action of the GPC3 gene in clear cell renal cell carcinoma.Methods: Five clear cell renal cell carcinoma cell lines and carcinoma samples were used to analyze GPC3 mRNA expression (qRT-PCR). Then, representative cell lines, one primary renal carcinoma (786-O) and one metastatic renal carcinoma (ACHN), were chosen to carry out functional studies. We constructed a GPC3 expression vector and transfected the renal carcinoma cell lines, 786-O and ACHN. GPC3 overexpression was analyzed using qRT-PCR and immunocytochemistry. We evaluated cell proliferation using MTT and colony formation assays. Flow cytometry was used to evaluate apoptosis and perform cell cycle analyses.Results: We observed that GPC3 is downregulated in clear cell renal cell carcinoma samples and cell lines compared with normal renal samples. GPC3 mRNA expression and protein levels in 786-O and ACHN cell lines increased after transfection with the GPC3 expression construct...

Cell proliferation and migration in the jejunum of suckling rats submitted to progressive fasting

Gomes,J.R.; Alvares,E.P.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/1998 Português
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65.97%
Cell proliferation and migration in the intestinal crypts, and cell migration in the villus are controlled by different mechanisms in adult rats. In the present study, weanling rats and fasting rats were used to quantitatively study the correlation of cell cycle parameters and epithelial cell migration in crypts and intestinal villi. Eighteen-day-old rats received a single injection of tritiated thymidine [3H]TdR (23:00 h); half of the pups were submitted to fasting 5 h earlier. Cell proliferation was determined in radioautographs of jejunal crypts, on the basis of the labeling indices (LI) taken 1, 8, 13 and 19 h after [3H]TdR. The results showed that the labeling index did not differ 1 h or 19 h after [3H]TdR between the fed (38.7% or 48%) and fasting groups (34.6% or 50.4%). The modified method of grain count halving indicated that cell cycle time did not differ between fed (16.5 h) and fasting rats (17.8 h); the growth fraction, however, had lower values in fasting (59%) than in fed rats (77%). Cell migration in the crypt, estimated by the LI obtained for each cell position, did not change with treatment. As for the villi, the cell migration rate was significantly retarded by 3 cell positions (8%). These results suggest that the cell migration in the villi of weanling pups does not depend directly on the cell proliferation and migration in the intestinal crypt...

Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix

Paez-Pereda,M.; Kuchenbauer,F.; Arzt,E.; Stalla,G.K.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2005 Português
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65.97%
The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that...

BC047440 antisense eukaryotic expression vectors inhibited HepG2 cell proliferation and suppressed xenograft tumorigenicity

Zheng,Lu; Liang,Ping; Zhou,JianBo; Huang,XiaoBing; Wen,Yu; Wang,Zheng; Li,Jing
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 Português
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The biological functions of the BC047440 gene highly expressed by hepatocellular carcinoma (HCC) are unknown. The objective of this study was to reconstruct antisense eukaryotic expression vectors of the gene for inhibiting HepG2 cell proliferation and suppressing their xenograft tumorigenicity. The full-length BC047440 cDNA was cloned from human primary HCC by RT-PCR. BC047440 gene fragments were ligated with pMD18-T simple vectors and subsequent pcDNA3.1(+) plasmids to construct the recombinant antisense eukaryotic vector pcDNA3.1(+)BC047440AS. The endogenous BC047440 mRNA abundance in target gene-transfected, vector-transfected and naive HepG2 cells was semiquantitatively analyzed by RT-PCR and cell proliferation was measured by the MTT assay. Cell cycle distribution and apoptosis were profiled by flow cytometry. The in vivo xenograft experiment was performed on nude mice to examine the effects of antisense vector on tumorigenicity. BC047440 cDNA fragments were reversely inserted into pcDNA3.1(+) plasmids. The antisense vector significantly reduced the endogenous BC047440 mRNA abundance by 41% in HepG2 cells and inhibited their proliferation in vitro (P < 0.01). More cells were arrested by the antisense vector at the G1 phase in an apoptosis-independent manner (P = 0.014). Additionally...

AZT on telomerase activity and cell proliferation in HS 839.T melanoma cells

Souza Sobrinho,Celestino Prospero de; Gragnani,Alfredo; Santos,Ivan Dunshee Abranches Oliveira; Oliveira,Andrea Fernandes; Lipay,Monica Vanucci Nunes; Ferreira,Lydia Masako
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
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PURPOSE: To evaluate telomerase activity and proliferation of HS839.T melanoma cells, subjected to the action of AZT. METHODS: Cells were grown in triplicate, AZT at different concentrations: 50, 100 and 200μM, was added and left for 24 and 48 hours, and its effects were compared with the control group. Telomerase activity was detected by PCR and cell proliferation was evaluated by MTT. RESULTS: After 24 hours, there was no inhibition of cell proliferation or telomerase activity when compared to the control group. After 48 hours, there was a momentary decrease, suggesting that the cell lines used in this study are sensitive to AZT, but quickly recover both the enzyme activity and cell proliferation. CONCLUSION: The action of AZT on the melanoma cells studied, at the concentrations and times tested, did not inhibit telomerase activity nor affect cell proliferation.

Cell proliferation and cancer

Lopez-Saez, J.F.; De la Torre, C.; Pincheira, J.; Gimenez-Martin, G.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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The discovery that phosphorylation of selected proteins by cyclin-dependent kinases is the engine which makes the cycle run provides a new image of the control of proliferation and of its deregulation. The high conservation of this machinery in the different eukaryotic organisms emphasizes its early origin and its importance for life. It also makes the extrapolation of findings between different species feasible. The control of proliferation relies basically on accelerating and braking mechanisms which act on the engine driving the cycle. This review particularly stresses the importance of checkpoint or tumor suppressor pathways as transduction systems of negative signals which may induce a cycle braking operation. They prevent any important cycle transition, as the initiation of proliferation, that of replication, mitosis, etc., until the DNA and other cellular conditions make such a progression safe. These checkpoint pathways are able to recognize and transduce signals about the adequacy of initiating or continuing proliferation for a cell at a particular time, under a particular set of external and internal conditions. Crucial components of these pathways are proteins encoded by some of the checkpoint genes that evaluate the final balance of mitogenic and antimitogenic pathways reaching them and...

The urokinase-system - role of cell proliferation and apoptosis

Hildenbrand, Ralf; Gandhari, Mukesh; Stroebel, Philipp; Marx, Alexander; Allgayer, Heike; Arens, Norbert
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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The serine protease urokinase-type plasminogen activator (uPA) and its receptor (uPAR) are involved in the control of extracellular matrix turnover, cell migration, invasion and cell signalling leading to a variety of different responses, under both physiological and pathological conditions. The urokinase receptor, binding to the growth factor-like domain of uPA, directs membrane-associated extracellular proteolysis and signals through transmembrane proteins, thus regulating tissue regeneration, angiogenesis, cancer growth and metastasis. Since these physiological and pathophysiological processes of the uPA-system are known, less informations concerning uPA-induced cell proliferation and anti-apoptotic effects of the uPAsystem are available. Recent studies show a close relationship of the uPA-system and cell proliferation/ apoptosis. uPA is responsible for the activation and release of different growth factors and modulates the cell proliferation/apoptosis ratio through the dynamic control of cell-matrix interactions. This article focuses on the important role of the uPA/uPAR-system for cell proliferation and apoptosis.

Estudo de FEF1, uma F-box do Complexo SCF envolvida com a Proliferação Celular no Pistilo de Nicotiana tabacum L.; Study of FEF1, an SCF Complex F-box involved with Cell Proliferation in the Pistil of Nicotiana tabacum L.

Roberto, Luis Fernando
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/04/2015 Português
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65.96%
O desenvolvimento dos órgãos vegetativos e florais das angiospermas depende da ação combinada e finamente regulada de eventos de proliferação e expansão celular. Estudar os genes envolvidos com a regulação destes processos permite ampliar nossa compreensão sobre o desenvolvimento da flor, de seus diferentes órgãos, do processo reprodutivo como um todo, além de permitir produzir modificações de interesse econômico. Um gene codificando uma proteína da família F-box foi identificado na biblioteca TOBEST de cDNAs de estigma/estilete de N. tabacum (Quiapim et al., 2009; Abbad, 2012). A maioria das proteínas F-box pertence ao complexo SCF (formado principalmente pelas proteínas SKP1, CUL1 e F-box), participando da marcação de proteínas alvo para a degradação pela via ubiquitina-proteassomo. O gene identificado no TOBEST demonstrou expressão preferencial nos órgãos florais e foi denominado FEF1 (Flower Expressed F-box 1). Plantas de silenciamento e superexpressão deste gene indicaram alterações no tamanho dos órgãos florais, incluindo o pistilo, foco principal de estudo em nosso laboratório (Abbad, 2012). O screening de duplo-híbrido de uma biblioteca de cDNAs de estigma/estilete de N. tabacum identificou a interação com uma SKP1...

Vasectomia e prostata ventral de gerbilos : proliferação celular, morte celular e interação estroma-epitelio; Vasectomy and gerbil ventral prostate: cell proliferation, apoptosis and estrom-epithelium interaction

Sergio Pereira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/02/2006 Português
Relevância na Pesquisa
65.97%
Doenças como o câncer e hiperplasia benigna de próstata estão relacionadas à falha no mecanismo de regulação do equilíbrio funcional entre os processos de proliferação celular e apoptose nas células prostáticas. O equilíbrio entre esses processos é controlado por níveis séricos de andrógenos e por fatores de crescimento. A vasectomia pode alterar tal equilíbrio por mecanismo ainda desconhecido. Durante os processos de carcinogênese da próstata, as interações parácrinas entre epitélio e estroma podem ser perturbadas, causando prejuízos tanto para epitélio quanto para musculatura lisa, e resultando em progressão para um estado anaplásico. Assim, o presente trabalho teve como objetivo avaliar a influência da vasectomia sobre os processos de proliferação e morte celular, bem como avaliar a estrutura e a ultra-estrutura da próstata ventral de gerbilo após vasectomia. Foram realizados estudos estruturais (Hematoxilina-eosina; tricrômico de Masson, reticulina de Gömöri e reação de Feulgen), ultra-estrutural (Microscopia eletrônica de transmissão) e imuno-histoquímicos (anti-Ki67, anti-PCNA e anti-Caspase-9) na próstata ventral de gerbilos. Os índices de proliferação celular prostática aumentaram nos gerbilos vasectomizados...

Chitosan and platelet-derived growth factor synergistically stimulate cell proliferation in gingival fibroblasts

Díaz Dosque, Mario Rodrigo; Acuña Rougier, C.; Tapia, C.; Arancibia, R.; Silva, D.
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo de revista
Português
Relevância na Pesquisa
66.01%
Artículo de publicación ISI; Background and Objective: Chitosan is a naturally derived polymer that may be applied in periodontal therapy for tissue-reconstruction purposes. Previous studies have shown that chitosan may stimulate tissue healing. However, reports exploring the cellular responses stimulated by chitosan are lacking. In the present study we analyzed whether chitosan may promote cell proliferation in primary cultures of human gingival fibroblasts. Material and Methods: Chitosan particles were generated, and their size, zeta potential and morphology were characterized using transmission and scanning electron microscopy and zetasizer analysis. The biocompatibility of chitosan particles was analyzed using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)- 2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell-viability assay and by detecting the release of lactate dehydrogenase into the cell-culture medium. The total number of cells was estimated by staining with crystal violet followed by measurement of the absorbance at 560 nm on a microplate reader. Cell proliferation was studied by detecting proliferating cell nuclear antigen protein levels, immunofluorescence for Ki67 and incorporation of 5′-bromo-2′-deoxyuridine. Results: The sizes of the chitosan particles generated were in the micrometer and nanometer ranges. Cell viability was increased in the presence of chitosan. Moreover...
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