164 resultados para Proteina p53
Resumo:
Gastric carcinogenesis is attributable to interacting environmental and genetic factors, through a sequence of events including intestinal metaplasia. Using a fluorescence in situ hybridization technique, we investigated the occurrence of ancuploidies of chromosomes 3, 7, 8, 9, and 17, TP53 gene deletion, and expression of p53 in 21 intestinal metaplasia (IM) samples from cancer-free patients and in 20 gastric adenocarcinoma samples. Aneuploidies were found in 71% (15/21) of the IM samples. Trisomy of chromosomes 7 and 9 occurred mainly in complete-type IM; in the incomplete type, trisomy of chromosomes 7 and 8 were more commonly found. The TP53 gene deletion was observed in 60% (3/5) of the IM cases, and immunohistochemistry revealed p53 overexpression in 12% (2/17) of the analyzed IM cases. All gastric adenocarcinoma cases presented higher frequencies of trisomy or tetrasomy of chromosomes 3, 7, 8, 9, and 17. The TP53 deletion was found in all three of the gastric adenocarcinoma analyzed for it, and immunohistochemistry detected overexpression of protein p53 in 80% (12/15) of the analyzed cases. Our study revealed for the first time the presence of aneuploidies of chromosomes 7, 8, 9, and 17 and of TP53 gene deletion and overexpression in IM samples from cancer-free patients. These results suggest that IM and gastric adenocarcinoma may share the same genetic alterations. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
OBJECTIVE: To analyze the role of immunochemistry in serous effusions.STUDY DESIGN: We analyzed cell blocks of 18 pleural and 18 peritoneal effusions diagnosed as malignant (18), benign (14) and suspicious (4). They were immunostained by the avidin-biotin complex method with a panel of four monoclonal antibodies-CEA, Ber-EP4, LeuM1 (CD15) and r53-and for lectins (Ulex europaeus) UEA-1, ConA and ConBr. RESULTS: Seventeen of the 18 cases of adenocarcinoma were positive for CEA (95%), 12 (66.6%)for Bev-EP4, 11 (61 %)for CD15 nild 11 (62 %)for p53. Twelve of the 18 (66.6%) were positive for UEA-1, CEA, Ber-EP4 and CD15. UEA-1 did not react with mesothelial cells. p53 Gave a positive reaction in only one case, reactive mesothelial cells. ConA and ConBr reacted indiscriminately with benign and malignant cells; thus, it was not useful in distinguishing between these cells.CONCLUSION: In this context no antibody used alone is reliable for corroborating a diagnosis, but the selective use of a small panel of three markers (CEA, Ber-EP4 and LeuM1) can be very useful in solving diagnostic difficulties in the cytodiagnosis of serous effusions.
Resumo:
Head and neck squamous cell carcinoma is a disease associated with tobacco and alcohol abuse. There is evidence that the oncogenic human papillomavirus (HPV) may also be a risk for upper aerodigestive tract cancers. High-risk HPVs encode two early proteins, E6 and E7, that can bind to p53 and pRb, respectively, and induce its degradation or inactivation. The TP53 gene has a single polymorphism at codon 72 of exon 4 that encodes either arginine (Arg) or proline (Pro). The purpose of this study was to evaluate the role of HPV infection and TP53 polymorphism in head and neck cancer. We analyzed 50 tumors, as well swabs of oral mucosa front 142 control individuals, with a polymerase chain reaction technique. The prevalence of HPV in controls was 10.6% and in cancer specimens 16%. The frequency distribution of genotypes in controls was 50% Arg/Arg, 43% Arg/ Pro and 7% Pro/Pro; in tumors, it was 52% Arg/Arg, 32% Arg/Pro, and 16% Pro/Pro. Contrary to the results of some studies on cervical cancer, no association between any TP53 genotype or allele and the development of head and neck cancer was observed, regardless of HPV status, except for the Pro/Pro genotype, which is associated with the absence of HPV. The arginine allele appears to protect against head and neck cancers. Also, the data showed that HPV infection results in no increased risk of developing head and neck tumors. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Objective: The present article presents an overview of the literature, and analyses the methods and the primary questions related to assessment of proliferation index using the Ki-67/MIB-1 labeling index in pituitary adenomas. Although atypical adenomas are characterized by their atypical morphological features by an elevated mitotic index, a Ki-67 (MIB-1) labeling index greater than 3% and extensive nuclear staining for p53, use of the proliferation index (LI) of pituitary adenomas in assessing the degree of tumor aggressiveness is a controversial topic in the literature, and there are disparate results involving many studies.Methods: A review of literature was carried out to correlate the role of Ki-67 LI and its correlation with clinical findings, tumor size, invasiveness, recurrence, adenoma subtype, adenoma doubling time, and pituitary carcinomas is addressed. Results: The prognosis cannot be predicted on the basis of the Ki-67 LI alone. Although there is no direct relation between Ki-67 LI and some of these variables and controversial data were found regarding some topics, our review justify the use of Ki-67 in the analysis of pituitary adenomas as an additional information for clinical decision.Conclusion: Although assessment of proliferative may be helpful in predicting subsequent tumor recurrence or invasiveness, there are many other important and as yet unidentified factors pituitary tumors. It is clear that further research is needed to clarify these molecular mechanisms to predict those with a potentially poor clinical outcome.
Resumo:
This paper intend to review recent advances in our understanding of programmed cell death, or apoptosis, and discuss implications of these basic science advances in the development of causes and potential treatments of a variety of diseases of the head and neck. Conclusions: apoptosis is now understood to be important in the normal development and survival of all multicellular organism. Deregulation of this normally tighly controlled process underlies a variety of disease states, including neoplasia, autoimmune disease, and disorders of the central nervous system. A better understanding of this process and regulation may help otolaryngologists better understand diseases relevant to this specialty and will lead to improved therapeutic interventions.
Resumo:
We describe affected individuals in three generations of a family and another sporadic case, all Brazilian patients, with a combination of signs that diagnose the BCD syndrome. In addition to the cardinal signs, the sporadic case has hypothyroidism and imperforate anus, which was observed previously in one patient. The broadened phenotype and the possibility of involvement of p63 and IRF6 genes in this condition are discussed. © 2003 Wiley-Liss, Inc.
Resumo:
Aim: To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TP53 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. Methods: Gastric biopsies from normal mucosa (NM, n = 10), chronic gastritis (CG, n = 38), atrophic gastritis (CAG, n = 13) and gastric ulcer (GU, n = 21) were studied using fluorescence in situ hybridization (FISH) and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect H pylori. An association of the gastric pathologies and aneuploidies with H pylori infection was assessed. Results: Aneuploidies were increasingly found from CG (21%) to CAG (31%) and to GU (62%), involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG (P = 0.0143) and GU (P = 0.0498). No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% (5/11) and 12% (2/17) of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. Conclusion: The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with H pylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa. © 2006 The WJG Press. All rights reserved.
Resumo:
The knowledge of cell-cycle control has shown that the capacity of malignant growth is acquired by the stepwise accumulation of defects in specific genes regulating cell growth. Histologic diagnosis might be improved by a quantitative evaluation of more specific diagnosis biomarkers, which could help to precisely identify pre-malignant and malignant oral lesions. The aim of the present study is to evaluate whether computer-based quantitative assessment of p53, PCNA and Ki-67 immunohistochemical expression, could be used clinically to foresee the risk of oral malignant transformation. This retrospective study was carried out in ninety-five oral biopsies, 27 were classified as fibrous inflammatory hyperplasia, 40 as leukoplakia and 28 as oral squamous cell carcinoma. Sixteen out of the 40 leukoplakia were diagnosed as non-dysplastic leukoplakia, the other 24 being dysplastic leukoplakia, of which 50.0% were classified as moderate to severe dysplasia. Comparison of the four groups of oral tissues showed significant rises in p53 and Ki-67 positivity index, which increased steadily in the order benign, pre-malignant, and malignant. In contrast, it was not possible to relate higher PCNA levels with pre-malignant and malignant oral lesions. We therefore conclude that PCNA immunohistochemistry expression is probably an inappropriate marker to identify oral carcinogenesis, whereas joint quantitative evaluation of p53 and Ki-67, appears to be useful as a tumor marker, providing a pre-diagnostic estimate of the potential for cell-cycle deregulation of the oral proliferate status.
Resumo:
Topical retinoids are used to treat photoaging; oral isotretinoin is gold standard for acne; off label indications, including photoaging, have been reported with insufficient evidence of efficacy. This is a randomized controlled phase II trial with clinical and histological assessment to evaluate efficacy and safety of oral isotretinoin for photoaging. Study population was comprised of 32 menopausal or sterilized women, aged 40-55, divided in 2 groups: A (21) received 20mg isotretinoin, 3 times per week, nightly moisturizer, and daily sunscreen, for three months; B (11) just moisturizer/sunscreen. Main outcome measures were: overall clinical assessment; profilometry, corneometer and elasticity tests in periocular regions and left forearm; before/after biopsies from left forearm in patients of B and in 10 randomly selected of A. Microscopic blinded evaluation of epidermal thickness, dermal elastosis, new collagen, p53 epidermal expression was performed by quantitative digital image analysis. All data were submitted to statistical analysis. Clinical evaluation showed slight improvement; profilometry, corneometer and skin elasticity tests presented significant difference in pre/post values (P = 0.001 to 0.028), but no differences between A/B. Histological findings and p53 expression were comparable between groups before treatment (P > 0.1); microscopic analysis showed no differences between groups for most variables, after treatment. Slight but significant difference between A/B for p53 with major reduction post isotretinoin [0.66±0.31 vs. 0.94±0.34 respectively (P = 0.04) was observed. There were minor side effects and no significant laboratory test alterations. We concluded that no significant clinical, microscopic changes but p53 epidermal expression reduction were observed. The role of ultra-violet induced p53 mutation in skin carcinogenesis reinforces retinoids chemoprevention. Oral isotretinoin seemed safe but not effective to treat photoaging. Caution should be considered for women prone to pregnancy. Further controlled studies are necessary. © 2010 The International Society of Dermatology.
Resumo:
Canine distemper virus (CDV) may induce multifocal demyelination in the central nervous system of infected dogs. The present work investigated apoptosis in white and gray matter (granular layer) in the cerebellum of naturally infected dogs by the analysis of the expression of the pro-apoptotic antigens caspase - 2 and - 3, b(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL-staining) positivity, annexin-V immunodetection, and the presence of the anti-apoptotic antigens, BCl-2 and p53. Cerebellum specimens were obtained from the Laboratory of Animal Pathology, from 1995 to 2009, and the 5-μm thick fragments were stained both with hematoxylin-eosin and Shorr. All samples were diagnosed as positive for CDV genome by reverse transcriptase polymerase chain reaction targeting the nucleocapsid gene. The anti-apoptotic pathways evidenced in this study were BCl-2 and p53 proteins that were intensively detected in cerebellum of CDV positive slides (40-80% of labeled cells/mm2). In addition, the apoptosis markers annexin-V and TUNEL are directly correlated among the same samples (80 and 40% of labeled cells, respectively). This is the first description of p53 and annexin-V expression, characterized as anti-apoptotic and apoptotic proteins, involvement in canine natural cases of CDV infections.
Resumo:
Canine transmissible venereal tumor (CTVT) is a neoplasm transmitted by the physical transfer of viable tumor cells by direct contact with injured skin and/or mucous tissue. These cells can transpose across histocompatibility barriers into unrelated hosts. This review focuses on the biology of apoptosis and the interaction of proteins involved in this process, as well as p53, p63 and the antiapoptotic protein Bcl-2. As such, this disease offer unique opportunity to study the biology of transplantable tumours and the interaction of proteins involved in apoptosis process and the prognosis of CTVT.
Resumo:
Infection of young poults with turkey coronavirus (TCoV) produces a syndrome characterized by acute enteritis, diarrhea, anorexia, ruffled feathers, decreased body weight gain and uneven flock growth. The objective of this study was to standardize an intestinal organ culture (IOC) in order to assess host-virus interaction related to apoptosis. For this purpose the Brazilian strain (TCoV/Brazil/2006 with GenBank accession number FJ188401), was used for infection. Infected IOC cells had mitochondrial dysfunction and initial nuclear activation with MTT value of 90.7 (± 2.4) and apoptotic factor 2.21 (± 2.1), considered statistically different from uninfected IOC cells (p > 0.05). The kinetics of TCoV antigens and viral RNA was directly correlated to annexin-V, caspases- 2 and -3, p53, BCl-2 antigens at 24, 72 and 96 h post-infection (p.i.). Morphological and biochemical features of apoptosis, such as in situ nuclear fragmentation (TUNEL and annexin-V) and DNA ladder formation were also detected in infected cells at all assayed p.i. intervals. Moreover, different from other coronaviruses, the expression of both effective caspase-2 and - 3 and p53 antigens were considered lower. However, at all p.i., the BCl-2 antigens were expressed quantitatively and qualitatively as viral antigen measured by immunofluorescence microscopy analysis. Because the diagnosis of TCoV infection is only performed by infecting embryonated poult eggs, the pathological characteri tics related to host-virus interaction remain unclear. This is the first report on apoptosis of TCoV infected IOC, and reveals that it may be useful immunological method to assess virus pathogenesis.