Navegando por Palavras-chave "Ki67"

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    Comparative study of the expression of cellular cycle proteins in cervical intraepithelial lesions
    (Elsevier B.V., 2006-01-01) Queiroz, Conceicao; Silva, Tania Correia; Alves, Venancio A. F. [UNIFESP]; Villa, Luisa L.; Costa, Maria Cecilia; Travassos, Ana Gabriela; Araujo, Jose Bouzas; Studart, Eduardo; Cheto, Tatiana; Freitas, Luiz Antonio R. de; Universidade Federal da Bahia (UFBA); Fiocruz MS; Ludwig Inst Canc Res; Universidade Federal de São Paulo (UNIFESP)
    Interaction of human papilloma virus oncoproteins E6 and E7 with cell cycle proteins leads to disturbances of the cell cycle mechanism and subsequent alteration in the expression of some proteins, such as p16(INK4a), cyclin DI, p53 and KI67. in this study, we compared alterations in the expression of these proteins during several stages of intra-epitelial cervical carcinogenesis. Accordingly, an immunohistochemical study was performed on 50 cervical biopsies, including negative cases and intraepithelial neoplasias. the expression patterns of these markers were correlated with the histopathological diagnosis and infection with HPV. the p16(INK4a), followed by Ki67, showed better correlation with cancer progression than p53 and cyclin DI, which recommends their use in the evaluation of cervical carcinogenesis. These monoclonal antibodies can be applied to cervical biopsy specimens to identify lesions transformed by oncogenic HPV, separating CIN 1 (p16(INK4a) positive) and identifying high-grade lesions by an increase in the cellular proliferation index (Ki67). in this way, we propose immunomarkers that can be applied in clinical practice to separate patients who need a conservative therapeutic approach from those who require a more aggressive treatment. (c) 2006 Elsevier GmbH. All rights reserved.
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    Estrogen receptor alpha/beta ratio and estrogen receptor beta as predictors of endocrine therapy responsiveness-a randomized neoadjuvant trial comparison between anastrozole and tamoxifen for the treatment of postmenopausal breast cancer
    (Biomed Central Ltd, 2013-09-18) Madeira, Marcelo [UNIFESP]; Mattar, Andre [UNIFESP]; Logullo, Angela Flavia [UNIFESP]; Soares, Fernando Augusto; Gebrim, Luiz Henrique [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Albert Einstein Hosp; Perola Byington Hosp; AC Camargo Hosp
    Background: the role of estrogen receptor beta (ER-beta) in breast cancer (BC) remains unclear. Some studies have suggested that ER-beta may oppose the actions of estrogen receptor alpha (ER-alpha), and clinical evidence has indicated that the loss of ER-beta expression is associated with a poor prognosis and resistance to endocrine therapy. the objective of the present study was to determine the role of ER-beta and the ER-alpha/ER-beta ratio in predicting the response to endocrine therapy and whether different regimens have any effect on ER-beta expression levels.Methods: Ninety postmenopausal patients with primary BC were recruited for a short-term double-blinded randomized prospective controlled study. To determine tumor cell proliferation, we measured the expression of Ki67 in tumor biopsy samples taken before and after 26 days of treatment with anastrozole 1 mg/day (N = 25), tamoxifen 20 mg/day (N = 24) or placebo (N = 29) of 78 participants. the pre-and post-samples were placed in tissue microarray blocks and submitted for immunohistochemical assay. Biomarker statuses (ER-beta, ER-alpha and Ki67) were obtained by comparing each immunohistochemical evaluation of the pre- and post-surgery samples using the semi-quantitative Allred's method. Statistical analyses were performed using an ANOVA and Spearman's correlation coefficient tests, with significance at p <= 0.05.Results: the frequency of ER-beta expression did not change after treatment (p = 0.33). There were no significant changes in Ki67 levels in ER-beta-negative cases (p = 0.45), but in the ER-beta-positive cases, the anastrozole (p = 0.01) and tamoxifen groups (p = 0.04) presented a significant reduction in post-treatment Ki67 scores. There was a weak but positive correlation between the ER-alpha and ER-beta expression levels. Only patients with an ER-alpha/ER-beta expression ratio between 1 and 1.5 demonstrated significant differences in Ki67 levels after treatment with anastrozole (p = 0.005) and tamoxifen (p = 0.026).Conclusions: Our results provide additional data that indicate that the measurement of ER-beta in BC patients may help predict tamoxifen and anastrozole responsiveness in the neoadjuvant setting. These effects of hormonal treatment appear to be dependent on the ratio of ER-alpha/ER-beta expression.
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    Expressão das proteínas P53, HER2 e Ki67 em ratas submetidas à ampliação vesical com estômago, colo e íleo
    (Universidade Federal de São Paulo (UNIFESP), 2015-10-28) Miranda, Edinaldo Goncalves de [UNIFESP]; Waisberg, Jaques [UNIFESP]; http://lattes.cnpq.br/8316985163665041; Universidade Federal de São Paulo (UNIFESP)
    Introdução: Segmentos intestinais são utilizados para ampliação vesical, mas a ocorrência de neoplasias na neobexiga tem sido com freqüência. Objetivo: Estudar a expressão gênica nas cistoplastias de aumento em ratas. Método ? 60 ratas foram divididas aleatoriamente em três grupos iguais de 20 animais. Realizou-se cistoplastia de aumento com íleo (Grupo I), colo (Grupo II) e estômago (Grupo III). Coletou-se tecido de cada rata para seu próprio controle. Sacrificou-se os animais após 12 semanas, a neobexiga foi coletada, incluída em parafina e enviada para análise imunohistoquímica dos genes p53, HER2 e Ki67. Utilizou-se os testes não-paramétricos de Wilcoxon e Mann-Whitney para estudo estatístico. Resultados: Não houve alterações nos genes p53 e HER2 em nenhum dos grupos estudados. Observou-se aumento significante na expressão gênica do Ki67 em todos os grupos (p<0,0001), quando comparados com os seus respectivos controles. Quando os grupos estudos foram comparados entre houve um aumento maior da proliferação celular nas gastrocistoplastias em relação às ileocistoplastias (p=0,004) e em relação às colocistoplastias (p=0,003). Conclusão: Nas condições deste experimento observou-se aumento com significância estatística da proliferação celular marcada pelo Ki67 no segmento do trato digestório das ileocistoplastias, das colocistoplastias e das gastrocistoplastias, e que este aumento foi significativamente maior nas gastrocistoplastias.
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    Immunocytochemical expression of p16(INK4A) and Ki-67 in cytologically negative and equivocal Pap smears positive for oncogenic human papillomavirus
    (Lippincott Williams & Wilkins, 2005-04-01) Longatto, A.; Utagawa, M. L.; Shirata, N. K.; Pereira, SMM; Namiyama, G. M.; Kanamura, C. T.; Santos, G. D.; Oliveira, M. A. de; Wakamatsu, A.; Nonogaki, S.; Roteli-Martins, C.; di Loreto, C.; Ferraz, MDMD; Maeda, MYS; Alves, VAF; Syrjanen, K.; Adolfo Lutz Inst; Univ Minho; Universidade Federal de São Paulo (UNIFESP); Leonor Mendes Barros Hosp; Universidade de São Paulo (USP); Turku Univ
    This study was designed to analyze the cross-sectional comparison of the p16(INK4A) and Ki-67 immunocytochemical expression in negative and equivocal (atypical squamous cells of undetermined significance (ASC-US)) liquid-based cytology (LBQ samples testing positive for high-risk human papillomavirus (HPV) types with HC2 assay or polymerase-chain reaction (PCR). A series of 199 consecutive LBC specimens derived from the same number of women participating in the ongoing Latin American Screening Study at Leonor Mendes de Barros Hospital, São Paulo, were analyzed using immunocytochemistry for expression of p16(INK4A) and Ki-67 in negative and equivocal LBC samples testing positive for high-risk HPV types with hybrid capture 11 test (HC2) or PCR. All patients with at least one test positive (cytology, PCR, and/or HC2) were followed each 6 months for 3 years. the follow-up procedure consisted of visual examination, colposcopic inspection, cytology, and HC2 assay. Among the negative cytologic samples, 101 were HPV-positive and 55 HPV-negative. of the HPV-positive group, 59 of 101 cases (58.4%) were positive for both p16 and M67 inummostaining, and 17 of 101 (16.8%) were negative for both. the proportion of Ki-67-positivity increased almost in parallel with the increasing grade of p16-positivity (p = 0.0001 for linear trend). in the HPV-negative group, both markers were negative in 41 of 55 cases (74.5%), and no statistical relationship was observed between the two markers (Pearson, p = 0.595). HPV-positive ASC-US samples demonstrated a simultaneous positive immunoreaction for p 16 and Ki67 in 11 of 16 cases (68.7%), whereas 3 (18.7%) were concurrently negative. the relationship between the two markers was of borderline significance (Pearson, p = 0.053), but no linear relationship was found between the graded p16 and Ki-67 expression (p = 0.065 for linear trend). in the HPV-negative ASGUS group, there was no statistical association between the graded p16 and Ki-67 positivity (Pearson, p = 0.28 1). After 36 months of follow-up of the ASC-US patients, 6 women still displayed ASC-US smear, of which 4 of 6 were HPV-positive and expressed both p16 and Ki-67 markers. Two of 43 ASC-US smears had high-grade intraepithelial lesion (2.3%). All of those were positive for HPV, p16 and Ki-67. Patients with ASC-US diagnosis and positive high-risk HPV status and positive for p16(INK4A) Ki67 should be carefully observed to exclude occurrence of a squamous intraepithelial lesion. the combination of these two markers can be a useful implement for management of women with equivocal cytology.