6 resultados para PROLIFERATIVE CELL NUCLEAR ANTIGEN
em Repositório da Produção Científica e Intelectual da Unicamp
Resumo:
The mechanism underlying castration-induced prostate regression, which is a classical physiological concept translated into the therapeutic treatment of advanced prostate cancer, involves epithelial cell apoptosis. In searching for events and mechanisms contributing to prostate regression in response to androgen modulation, we have frequently observed the collective deletion of epithelial cells. This work was undertaken to characterize this phenomenon hereafter named desquamation and to verify its presence after 17β-estradiol (E2) administration. Electron microscopy revealed that the desquamating cells had preserved cell-cell junctions and collapsed nuclear contents. The TUNEL reaction was negative for these cells, which were also negative for cleaved caspases-8, -9, -3 and nuclear apoptosis-inducing factor. Detailed analyses revealed that the condensed chromatin was first affected detaching from the nuclear lamina, which was observable after lamin A immunohistochemistry, suggesting the lack of lamin A degradation. A search in animals treated with supraphysiological E2 employed as an alternative anti-androgen treatment revealed no desquamation. The combined treatment (Cas + E2 group) caused changes particular to each treatment, including desquamation. In conclusion, desquamation appeared as a novel phenomenon contributing to collective prostate epithelial cell deletion, distinct from the classical castration-induced apoptosis and particular to the androgen deprivation resulting from surgical castration, and should be considered as part of the mechanisms promoting organ regression.
Resumo:
Squamous cell carcinoma is the most common neoplasm of the larynx and glottis, and its prognosis depends on the size of the lesion, level of local invasion, cervical lymphatic spread, and presence of distant metastases. Ki-67 (MKI67) is a protein present in the core, whose function is related to cell proliferation. To evaluate the expression of marker Ki-67 in squamous cell carcinoma of the larynx and glottis and its correlation to pathological findings. Experimental study with immunohistochemistry analysis of Ki-67, calculating the percentage of the cell proliferation index in glottic squamous cell carcinomas. Sixteen cases were analyzed, with six well-differentiated and 10 poorly/moderately differentiated tumors. There was a correlation between cell proliferation index and degree of cell differentiation, with higher proliferation in poorly/moderately differentiated tumors. The cell proliferation index, as measured by Ki-67, may be useful in the characterization of histological degree in glottic squamous cell tumors.
Resumo:
Simvastatin, a competitive inhibitor of HMG-CoA reductase widely used in the treatment and prevention of hyperlipidemia-related diseases, has recently been associated to in vitro anticancer stem cell (CSC) actions. However, these effects have not been confirmed in vivo. To assess in vivo anti-CSC effects of simvastatin, female Sprague-Dawley rats with 7,12-dimethyl-benz(a)anthracene (DMBA)-induced mammary cancer and control animals were treated for 14 days with either simvastatin (20 or 40 mg/kg/day) or soybean oil (N = 60). Tumors and normal breast tissues were removed for pathologic examination and immunodetection of CSC markers. At 40 mg/kg/day, simvastatin significantly reduced tumor growth and the expression of most CSC markers. The reduction in tumor growth (80%) could not be explained solely by the decrease in CSCs, since the latter accounted for less than 10% of the neoplasia (differentiated cancer cells were also affected). Stem cells in normal, nonneoplastic breast tissues were not affected by simvastatin. Simvastatin was also associated with a significant decrease in proliferative activity but no increase in cell death. In conclusion, this is the first study to confirm simvastatin anti-CSC actions in vivo, further demonstrating that this effect is specific for neoplastic cells, but not restricted to CSCs, and most likely due to inhibition of cell proliferation.
Resumo:
Alloimmunisation is a major complication in patients with sickle cell disease (SCD) receiving red blood cell (RBC) transfusions and despite provision of Rh phenotyped RBC units, Rh antibodies still occur. These antibodies in patients positive for the corresponding Rh antigen are considered autoantibodies in many cases but variant RH alleles found in SCD patients can also contribute to Rh alloimmunisation. In this study, we characterised variant RH alleles in 31 SCD patients who made antibodies to Rh antigens despite antigen-positive status and evaluated the clinical significance of the antibodies produced. RHD and RHCE BeadChip™ from BioArray Solutions and/or amplification and sequencing of exons were used to identify the RH variants. The serological features of all Rh antibodies in antigen-positive patients were analysed and the clinical significance of the antibodies was evaluated by retrospective analysis of the haemoglobin (Hb) levels before and after transfusion; the change from baseline pre-transfusion Hb and the percentage of HbS were also determined. We identified variant RH alleles in 31/48 (65%) of SCD patients with Rh antibodies. Molecular analyses revealed the presence of partial RHD alleles and variant RHCE alleles associated with altered C and e antigens. Five patients were compound heterozygotes for RHD and RHCE variants. Retrospective analysis showed that 42% of antibodies produced by the patients with RH variants were involved in delayed haemolytic transfusion reactions or decreased survival of transfused RBC. In this study, we found that Rh antibodies in SCD patients with RH variants can be clinically significant and, therefore, matching patients based on RH variants should be considered.
Resumo:
As hypoxia-induced inflammatory angiogenesis may contribute to sickle cell disease manifestations, we compared the angiogenic molecular profiles of plasma from sickle cell disease individuals and correlated these with in vitro endothelial cell-mediated angiogenesis-stimulating activity and in vivo neovascularization. Bioplex demonstrated that plasma from steady-state sickle cell anemia patients presented elevated concentrations of pro-angiogenic factors (Angiopoietin-1, basic fibroblast growth factor, vascular endothelial growth factor, vascular endothelial growth factor-D and placental growth factor) and displayed potent pro-angiogenic activity, significantly augmenting endothelial cell proliferation, migration and capillary-like structure formation. In vivo neovascularization of Matrigel plugs was significantly greater in sickle cell disease mice, compared with non-sickle cell disease mice, consistent with an upregulation of angiogenesis in the disease. In plasma from patients with hemoglobin SC disease without proliferative retinopathy, anti-angiogenic endostatin and thrombospondin-2 were significantly elevated. In contrast, plasma from hemoglobin SC individuals with proliferative retinopathy displayed a pro-angiogenic profile and had more significant effects on endothelial cell proliferation and capillary formation than plasma of patients without retinopathy. Hydroxyurea therapy was associated with significant reductions in plasma angiogenic factor profile, in association with an inhibition of endothelial cell-mediated angiogenic mechanisms and neovascularization. Thus, sickle cell anemia and retinopathic hemoglobin SC individuals present a highly angiogenic circulating milieu, capable of stimulating key endothelial cell-mediated angiogenic mechanisms. Combination anti-angiogenic therapy for preventing progression of unregulated neovascularization and associated manifestations in sickle cell disease, such as pulmonary hypertension, may be indicated; furthermore, the benefits and drawbacks of the potent anti-angiogenic effects of hydroxyurea should be clarified.
Resumo:
A 33-year-old woman complained of unilateral eyelid edema and blurred vision. Initial ophthalmic examination disclosed anterior chamber reaction with keratic precipitates on the cornea, without posterior abnormalities. Anterior uveitis was treated. Despite that, patient showed rapidly progressive unilateral vision loss with optic nerve swelling. Systemic workup was inconclusive, as well as cranial magnetic resonance imaging and cerebrospinal fluid examination. Based on the hypothesis of optic neuritis, intravenous methylprednisolone pulse was performed with no success. During the following days, the patient presented pericardial effusion and cardiac tamponade, progressing to death. Necropsy was performed and diagnosis of extranodal natural killers/T-cell lymphoma, nasal type with ocular involvement was confirmed by immunohistochemistry.