995 resultados para Orbital neoplasms
Resumo:
Gene expression signatures are used in the clinic as prognostic tools to determine the risk of individual patients with localized breast tumors developing distant metastasis. We lack a clear understanding, however, of whether these correlative biomarkers link to a common biological network that regulates metastasis. We find that the c-MYC oncoprotein coordinately regulates the expression of 13 different "poor-outcome" cancer signatures. In addition, functional inactivation of MYC in human breast cancer cells specifically inhibits distant metastasis in vivo and invasive behavior in vitro of these cells. These results suggest that MYC oncogene activity (as marked by "poor-prognosis" signature expression) may be necessary for the translocation of poor-outcome human breast tumors to distant sites.
Resumo:
Brooke-Spiegler syndrome, familial cylindromatosis, and familial trichoepithelioma are autosomal-dominant genetic predispositions for benign tumors of skin appendages caused by mutations in the CYLD gene localized on chromosome 16q12-q13. The encoded protein functions as ubiquitin-specific protease (UBP), which negatively regulates NF-kappaB and c-Jun N-terminal kinase (JNK) signaling. We investigated five families affected with these skin neoplasms and identified four premature stop codons and the novel missense mutation D681G in a family in which 11 of 12 investigated tumors were trichoepitheliomas. CYLD protein harboring this missense mutation had a significant reduced ability to inhibit TNF receptor-associated factor (TRAF)2- and TRAF6-mediated NF-kappaB activation, tumor necrosis factor-alpha (TNFalpha)-induced JNK signaling, and to deubiquitinate TRAF2. CYLD-D681G was coimmunoprecipitated by TRAF2, but was unable to cleave K63-linked polyubiquitin chains. Aspartic acid 681 is highly conserved in CYLD homologues and other members of the UBP family, but does not belong to the Cys and His boxes providing the CYLD catalytic triad (Cys601, His871, and Asp889). As reported previously, the homologous residue D295 of HAUSP/USP-7 forms a hydrogen bond with the C-terminal end of ubiquitin and is important for the enzymatic activity. These results underline that D681 in CYLD is required for cleavage of K63-linked polyubiquitin chains.
Resumo:
Adrenocortical carcinomas are rare and aggressive malignant tumors, with an incidence of 1 to 2 cases per million inhabitants. Their diagnosis is made in three clinical situations: during the work up of a syndrome of hormonal hypersecretion, during the work up of locoregional symptoms, or incidentally during an unrelated radiological procedure. Surgery is usually indicated except in situations of advanced metastatic disease. Adjuvant chemotherapy with mitotane is associated with a significant increase in disease-free survival when the drug is administered at adequate therapeutic dosage. Novel anti-mitotic therapies have recently been described for treating recurrent adrenocortical carcinoma under mitotane treatment, but their overall efficacy remains unsatisfactory.
Resumo:
PURPOSE: To determine the mechanisms and treatment of ocular hypertension in patients with thyroid-associated orbitopathy and to differenciate it from glaucomatous damage. DESIGN: Three case reports. METHODS: Retrospective review of clinical findings, course, and treatment of the three patients. RESULTS: Elevated intraocular pressure in thyroid-associated orbitopathy observed in the three cases may involve different physiopathological abnormalities such as disturbances of venous circulation, compression by infiltrative muscles, and long corticosteroid use. In the first two cases, defects demonstrated in the perimetry are in consistent with glaucomatous damage. In the third case, visual field abnormalities may be compatible with a glaucomatous disease, but all defects resolved after therapy. Treatement was of the greatest difficulty for the three cases, associating antiglaucomatous medication, steroids, orbital radiotherapy, orbital decompression and extraocular muscle surgery. Intraocular pressure was controlled in all cases. CONCLUSIONS: Elevated intraocular pressure in thyroid-associated orbitopathy is distinguished from glaucomatous disease by its physiopathological mechanisms, clinical course, visual field defects, and treatment. The management of this hypertension is closely related to the treatment of dysthyroid orbitopathy.
Resumo:
The Rare Cancer Network (RCN), founded in 1993, performs research involving rare tumors that are not common enough to be the focus of prospective study. Over 55 studies have either been completed or are in progress.The aim of the paper is to present an overview of the 30 studies done through the RCN to date, organized by disease site. Five studies focus on breast pathology, including sarcoma, lymphoma, phyllodes tumor, adenoid cystic carcinoma, and ductal carcinoma in situ in young women. Three studies on prostate cancer address prostatic small cell carcinoma and adenocarcinoma of young and elderly patients. Six studies on head and neck cancers include orbital and intraocular lymphoma, mucosal melanoma, pediatric nasopharyngeal carcinoma, olfactory neuroblastoma, and mucosa-associated lymphoid tissue lymphoma of the salivary glands. There were 4 central nervous system studies on patients with cerebellar glioblastoma multiforme, atypical and malignant meningioma, spinal epidural lymphoma and myxopapillary ependymoma. Outside of these disease sites, there is a wide variety of other studies on tumors ranging from uterine leiomyosarcoma to giant cell tumors of the bone. The studies done by the RCN represent a wide range of rare pathologies that were previously only studied in small series or case reports. With further growth of the RCN and collaboration between members our ability to analyze rare tumors will increase and result in better understanding of their behavior and ultimately help direct research that may improve patient outcomes.
Resumo:
Expression of human leucocyte antigen (HLA) Class I molecules is essential for the recognition of malignant melanoma (MM) cells by CD8(+) T lymphocytes. A complete or partial loss of HLA Class I molecules is a potent strategy for MM cells to escape from immunosurveillance. In 2 out of 55 melanoma cell cultures we identified a complete phenotypic loss of HLA allospecificities. Both patients have been treated unsuccessfully with HLA-A2 peptides. To identify the reasons underlying the loss of single HLA-A allospecificities, we searched for genomic alterations at the locus for HLA Class I alpha-chain on chromosome 6 in melanoma cell cultures established from 2 selected patients with MM in advanced stage. This deficiency was associated with alterations of HLA-A2 gene sequences as determined by polymerase chain reaction-sequence specific primers (PCR-SSP). Karyotyping revealed a chromosomal loss in Patient 1, whereas melanoma cell cultures established from Patient 2 displayed 2 copies of chromosome 6. Loss of heterozygosity (LOH) using markers located around position 6p21 was detected in both cases. By applying group-specific primer-mixes spanning the 5'-flanking region of the HLA-A2 gene locus the relevant region was amplified by PCR and subsequent sequencing allowed alignment with the known HLA Class I reference sequences. Functional assays using HLA-A2-restricted cytotoxic T-cell clones were performed in HLA-A2 deficient MM cultures and revealed a drastically reduced susceptibility to CTL lysis in HLA-A2 negative cells. We could document the occurrence of selective HLA-A2 deficiencies in cultured advanced-stage melanoma metastases and identify their molecular causes as genomic alterations within the HLA-A gene locus.
Resumo:
Scanty information, limited to selected areas of the country, is available on cancer mortality in Brazil. Age-standardized (world population) mortality rates between 1980 and 2004, derived from the WHO database, were computed for all cancers and 24 major cancer sites in Brazil. Joinpoint regression analyses were used to identify the significant changes in trends and estimate annual percent change (APC) in rates. Total cancer mortality rates increased over the last decade in men (APC = 0.5) to reach 101.2/100 000, and in women (APC = 0.3) to reach 71.3/100 000. In men, upward trends were observed for cancers of the oral cavity and pharynx with a rate of 5.9/100 000 in 2000-2004, intestines (whose rate, however was low, i.e. 7.6), prostate (12.2), and leukemias (3.4). Male lung cancer increased until 1993 (APC = 1.39) and decreased thereafter (APC = -0.29), with a relatively low rate of 16.2/100 000 in 2000-2004. In women, there were steady upward trends for cancers of the lung (APC = 2.3), reaching 6.2/100 000 in 2000-2004, and leukemias (2.5). Breast cancer mortality leveled off at around 10/100 000 in the last decade, whereas declines were observed for cancers of the uterus, whose rate (8.3) however, remained comparatively high. Declines were observed for stomach cancer in both sexes, with rates of 11.1 in men and 4.6 in women. In conclusion, the key issues of cancer mortality in Brazil are the high rates of head and neck cancers in men and (cervix) uterine cancer in women, that is, in principle cancers that are largely avoidable through prevention, screening, and early diagnosis.
Resumo:
Human cancer vaccines are often prepared with altered "analog" or "heteroclitic" antigens that have been optimized for HLA class I binding, resulting in enhanced immunogenicity. Here, we take advantage of CpG oligodeoxynucleotides as powerful vaccine adjuvants and demonstrate the induction of high T cell frequencies in melanoma patients, despite the use of natural (unmodified) tumor antigenic peptide. Compared with vaccination with analog peptide, natural peptide induced T cell frequencies that were approximately twofold lower. However, T cells showed superior tumor reactivity because of (i) increased functional avidity for natural antigen and (ii) enhancement of T cell activation and effector function. Thus, novel vaccine formulations comprising potent immune stimulators may allow to circumvent the need for modified antigens and can induce highly functional T cells with precise antigen specificity
Resumo:
An increase of urokinase-type plasminogen activator (uPA) and a decrease of tissue-type PA (tPA) have been associated with the transition from normal to adenomatous colorectal mucosa. Serial sections from 25 adenomas were used to identify PA-related caseinolytic activities by in situ zymography, blocking selectively uPA or tPA. The distribution of uPA, tPA, and type 1 PA inhibitor mRNAs was investigated by nonradioactive in situ hybridization, and the receptor for uPA was detected by immunostaining. Low- and high-grade epithelial cell dysplasia was mapped histologically. Results show that 23 of 25 adenomas expressed uPA-related lytic activity located predominantly in the periphery whereas tPA-related activity was mainly in central areas of adenomas. In 15 of 25 adenomas, uPA mRNA was expressed in stromal cells clustered in foci that coincided with areas of uPA lytic activity. The probability of finding uPA mRNA-reactive cells was significantly higher in areas with high-grade epithelial dysplasia. uPA receptor was mainly stromal and expressed at the periphery. Type 1 PA inhibitor mRNA cellular expression was diffuse in the stroma, in endothelial cells, and in a subpopulation of alpha-smooth muscle cell actin-reactive cells. These results show that a stromal up-regulation of the uPA/plasmin system is associated with foci of severe dysplasia in a subset of colorectal adenomas.
Resumo:
We describe a 77-year-old patient with a giant acquired fibrokeratoma on the heel. The size and the localization of the tumor was unusual. Simple shave excision was curative.
Resumo:
Tumour cells are known to be highly glycolytic, thus producing high amounts of lactic acid. Monocarboxylate transporters (MCTs), by promoting the efflux of the accumulating acids, constitute one of the most important mechanisms in the maintenance of tumour intracellular pH. Since data concerning MCT expression in colorectal carcinomas (CRC) are scarce and controversial, the present study aimed to assess the expressions of MCT1, 2, and 4 in a well characterized series of CRC and assess their role in CRC carcinogenesis. CRC samples (126 cases) were analyzed for MCT1, MCT2, and MCT4 immunoexpression and findings correlated with clinico-pathological parameters. Expression of all MCT isoforms in tumour cells was significantly increased when compared to adjacent normal epithelium. Remarkably, there was a significant gain of membrane expression for MCT1 and MCT4 and loss of plasma membrane expression for MCT2 in tumour cells. Plasma membrane expression of MCT1 was directly related to the presence of vascular invasion. This is the larger study on MCT expression in CRC and evaluates for the first time its clinico-pathological significance. The increased expression of these transporters suggests an important role in CRC, which might justify their use, especially MCT1 and MCT4, as targets in CRC drug therapy.