940 resultados para Tumors.


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OBJECTIVE: Endostatin is a potent endogenous inhibitor of angiogenesis. It is derived from the proteolytic cleavage of collagen XVIII, which is encoded by the COL18A1 gene. A polymorphic COL18A1 allele encoding the functional polymorphism p.D104N impairs the activity of endostatin, resulting in a decreased ability to inhibit angiogenesis. This polymorphism has been previously analyzed in many types of cancer and has been considered a phenotype modulator in some benign and malignant tumors. However, these data are controversial, and different results have been reported for the same tumor types, such as prostate and breast cancer. The purpose of this study was to genotype the p.D104N variant in a cohort of pediatric and adult patients with adrenocortical tumors and to determine its possible association with the biological behavior of adrenocortical tumors. METHODS: DNA samples were obtained from 38 pediatric and 56 adult patients (0.6-75 yrs) with adrenocortical tumors. The DNA samples were obtained from peripheral blood, frozen tissue or paraffin-embedded tumor blocks when blood samples or fresh frozen tissue samples were unavailable. Restriction fragment length polymorphism analysis was used to genotype the patients and 150 controls. The potential associations of the p.D104N polymorphism with clinical and histopathological features and oncologic outcome (age of onset, tumor size, malignant tumor behavior, and clinical syndrome) were analyzed. RESULTS: Both the patient group and the control group were in Hardy-Weinberg equilibrium. The frequencies of the p.D104N polymorphism in the patient group were 81.9% (DD), 15.9% (DN) and 2.2% (NN). In the controls, these frequencies were 80.6%, 17.3% and 2.0%, respectively. We did not observe any association of this variant with clinical or histopathological features or oncologic outcome in our cohort of pediatric and adult patients with adrenocortical tumors.

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Objective. The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs). Study Design. The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT). Results. KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1. Conclusions. MMP-9, TIMP-2, EGF and transforming growth factor alpha act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:487-496)

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Objective: Partial nephrectomy for small kidney tumors has increased in the last decades, and the approach to non-palpable endophytic tumors became a challenge, with larger chances of positive margins or complications. The aim of this study is to describe an alternative nephron-sparing approach for small endophytic kidney tumors through anatrophic nephrotomy. Patients and Methods: A retrospective analysis of patients undergoing partial nephrectomy at our institution was performed and the subjects with endophytic tumors treated with anatrophic nephrotomy were identified. Patient demographics, perioperative outcomes and oncological results were evaluated. Results: Among the partial nephrectomies performed for intraparenchymal tumors between 06/2006 and 06/2010, ten patients were submitted to anatrophic nephrotomy. The mean patient age was 42 yrs, and the mean tumor size was 2.3 cm. Mean warm ischemia time was 22.4 min and the histopathological analysis showed 80% of clear cell carcinomas. At a mean follow-up of 36 months, no significant creatinine changes or local or systemic recurrences were observed. Conclusion: The operative technique described is a safe and effective nephron-sparing option for complete removal of endophytic renal tumors.

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Background: A recent microarray study identified a set of genes whose combined expression patterns were predictive of poor outcome in a cohort of adult adrenocortical tumors (ACTs). The difference between the expression values measured by qRT-PCR of DLGAP5 and PINK1 genes was the best molecular predictor of recurrence and malignancy. Among the adrenocortical carcinomas, the combined expression of BUB1B and PINK1 genes was the most reliable predictor of overall survival. The prognostic and molecular heterogeneity of ACTs raises the need to study the applicability of these molecular markers in other cohorts. Objective: To validate the combined expression of BUB1B, DLGAP5, and PINK1 as outcome predictor in ACTs from a Brazilian cohort of adult and pediatric patients. Patients and methods: BUB1B, DLGAP5, and PINK1 expression was assessed by quantitative PCR in 53 ACTs from 52 patients - 24 pediatric and 28 adults (one pediatric patient presented a bilateral asynchronous ACT). Results: DLGAP5 PINK1 and BUB1B PINK1 were strong predictors of disease-free survival and overall survival, respectively, among adult patients with ACT. In the pediatric cohort, these molecular predictors were only marginally associated with disease-free survival but not with overall survival. Conclusion: This study confirms the prognostic value of the combined expression of BUB1B, DLGAP5, and PINK1 genes in a Brazilian group of adult ACTs. Among pediatric ACTs, other molecular predictors of outcome are required.

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Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.

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Abstract Objective To evaluate the functionality of the auditory system in patients who underwent radiotherapy and chemotherapy treatment with cisplatin to treat head and neck tumors. Study Design Case series with planned data collection. Setting From May 2007 to May 2008 by the Department of Otorhinolaryngology and the Department of Oncology/Radiotherapy at Faculdade de Medicina de Marília. Subjects and Methods Audiological evaluation (Pure Tone Audiometry (air and bone conduction), Speech Audiometry, Tympanometry, Acoustic Reflex testing and Distortion Product Otoacoustic Emissions) was performed in 17 patients diagnosed with head and neck neoplasia and treated with chemotherapy, using cisplatin, and radiotherapy. Results 12 left ears (70.5%) and 11 right ears (64.7%) presented bilateral decreased hearing soon after the treatment for the frequency 1 kHz (mild auditory damage) and for the frequency 8 kHz (more significant auditory damage). Conclusion Patients with head and neck cancer submitted to the conventional radiotherapy treatment, combined with the chemotherapy with cisplatin, presented a high incidence of decreased hearing by the end of treatment. Strong evidence was observed linking auditory alteration to the amount of radiotherapy treatment.

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Abstract Background ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines. Results In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels. Conclusions ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells.

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FAPESP (Center for Cell-based Therapy Research), Instituto Nacional de Ciência e Tecnologia- Redoxoma and UICC-Yamagiwa Yoshida Grant.

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We thank the Department of Pathologic Anatomy and the International Center for Research, from AC Camargo Hospital for the tissue microarray assays and for the donation of cancer cell lines, respectively. We thank Dr. René Bernards (Amsterdam, The Netherlands) for the gift of PRAME and EZH2 short hairpin RNA vectors.

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Abstract Background Family history is among the few established risk factors for testicular germ cell tumor (TGCT). Approximately 1.4% of newly diagnosed TGCT patients report a positive family history of TGCT. Sons and siblings of TGCT patients have four- to six fold and eight- to tenfold increase in TGCT risk, respectively. In twins of men with TGCT the relative risk of testicular cancer is 37.5 (12.3-115.6). Nevertheless, information about the occurrence of TGCT in relatives of patients with extragonadal germ cell tumor is limited. Case report A 24 year-old male patient was diagnosed with a mediastinum tumor and was submitted to image-guided biopsy, which revealed a seminoma. Two months later, his non-identical asymptomatic twin brother was submitted to an elective ultrasound of the testes, which showed a left testicular mass of 4.2 cm. This patient underwent orchiectomy revealing a seminoma of the left testis. There are no other cases of seminoma or other types of cancers reported in first-degree relatives in this family. Conclusions Although familial aggregations of TGCT have been well described, to the best of our knowledge, no data concerning the association of gonadal and extragonadal germ cell tumor in relatives has been previously reported. Further investigation on this association is warranted and may help in improving our knowledge of familial pattern inheritance.

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We briefly review the characteristics of pituitary tumors associated with multiple endocrine neoplasia type 1. Multiple endocrine neoplasia type 1 is an autosomal-dominant disorder most commonly characterized by tumors of the pituitary, parathyroid, endocrine-gastrointestinal tract, and pancreas. A MEDLINE search for all available publications regarding multiple endocrine neoplasia type 1 and pituitary adenomas was undertaken. The prevalence of pituitary tumors in multiple endocrine neoplasia type 1 may vary from 10% to 60% depending on the studied series, and such tumors may occur as the first clinical manifestation of multiple endocrine neoplasia type 1 in 25% of sporadic and 10% of familial cases. Patients were younger and the time between initial and subsequent multiple endocrine neoplasia type 1 endocrine lesions was significantly longer when pituitary disease was the initial manifestation of multiple endocrine neoplasia type 1. Tumors were larger and more invasive and clinical manifestations related to the size of the pituitary adenoma were significantly more frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Normalization of pituitary hypersecretion was much less frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Pituitary tumors in patients with multiple endocrine neoplasia type 1 syndrome tend to be larger, invasive and more symptomatic, and they tend to occur in younger patients when they are the initial presentation of multiple endocrine neoplasia type 1.

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Surgical approaches to pancreatic endocrine tumors associated with multiple endocrine neoplasia type 1 may differ greatly from those applied to sporadic pancreatic endocrine tumors. Presurgical diagnosis of multiple endocrine neoplasia type 1 is therefore crucial to plan a proper intervention. Of note, hyperparathyroidism/multiple endocrine neoplasia type 1 should be surgically treated before pancreatic endocrine tumors/multiple endocrine neoplasia type 1 resection, apart from insulinoma. Non-functioning pancreatic endocrine tumors/multiple endocrine neoplasia type 1 >1 cm have a high risk of malignancy and should be treated by a pancreatic resection associated with lymphadenectomy. The vast majority of patients with gastrinoma/multiple endocrine neoplasia type 1 present with tumor lesions at the duodenum, so the surgery of choice is subtotal or total pancreatoduodenectomy followed by regional lymphadenectomy. The usual surgical treatment for insulinoma/multiple endocrine neoplasia type 1 is distal pancreatectomy up to the mesenteric vein with or without spleen preservation, associated with enucleation of tumor lesions in the pancreatic head. Surgical procedures for glucagonomas, somatostatinomas, and vipomas/ multiple endocrine neoplasia type 1 are similar to those applied to sporadic pancreatic endocrine tumors. Some of these surgical strategies for pancreatic endocrine tumors/multiple endocrine neoplasia type 1 still remain controversial as to their proper extension and timing. Furthermore, surgical resection of single hepatic metastasis secondary to pancreatic endocrine tumors/multiple endocrine neoplasia type 1 may be curative and even in multiple liver metastases surgical resection is possible. Hepatic trans-arterial chemo-embolization is usually associated with surgical resection. Liver transplantation may be needed for select cases. Finally, pre-surgical clinical and genetic diagnosis of multiple endocrine neoplasia type 1 syndrome and localization of multiple endocrine neoplasia type 1related tumors are crucial for determining the best surgical strategies in each individual case with pancreatic endocrine tumors.

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Perfusion CT imaging of the liver has potential to improve evaluation of tumour angiogenesis. Quantitative parameters can be obtained applying mathematical models to Time Attenuation Curve (TAC). However, there are still some difficulties for an accurate quantification of perfusion parameters due, for example, to algorithms employed, to mathematical model, to patient’s weight and cardiac output and to the acquisition system. In this thesis, new parameters and alternative methodologies about liver perfusion CT are presented in order to investigate the cause of variability of this technique. Firstly analysis were made to assess the variability related to the mathematical model used to compute arterial Blood Flow (BFa) values. Results were obtained implementing algorithms based on “ maximum slope method” and “Dual input one compartment model” . Statistical analysis on simulated data demonstrated that the two methods are not interchangeable. Anyway slope method is always applicable in clinical context. Then variability related to TAC processing in the application of slope method is analyzed. Results compared with manual selection allow to identify the best automatic algorithm to compute BFa. The consistency of a Standardized Perfusion Index (SPV) was evaluated and a simplified calibration procedure was proposed. At the end the quantitative value of perfusion map was analyzed. ROI approach and map approach provide related values of BFa and this means that pixel by pixel algorithm give reliable quantitative results. Also in pixel by pixel approach slope method give better results. In conclusion the development of new automatic algorithms for a consistent computation of BFa and the analysis and definition of simplified technique to compute SPV parameter, represent an improvement in the field of liver perfusion CT analysis.

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Folic acid, also known as vitamin B9, is the oxidized form of 5,6,7,8-tetrahydrofolate, which serves as methyl- or methylene donor (C1-building blocks) during DNA synthesis. Under physiological conditions the required amount of 5,6,7,8-tetrahydrofolate for survival of the cell is accomplished through the reduced folate carrier (RFC). In contrast, the supply of 5,6,7,8-tetrahydrofolate is insufficient under pathophysiological conditions of tumors due to an increased proliferation rate. Consequently, many tumor cells exhibit an (over)expression of the folate receptor. This phenomenon has been applied to diagnostics (PET, SPECT, MR) to image FR-positive tumors and on the other hand to treat malignancies related to a FR (over)expression. Based on this concept, a new 18F-labeled folate for PET imaging has been developed and was evaluated in vivo using tumor-bearing mice. The incorporation of oligoethylene spacers into the molecular structure led to a significant enhancement of the pharmacokinetics in comparison to previously developed 18F-folates. The liver uptake could be reduced by one sixth by remaining a tumor uptake of 3%ID/g leading to better contrast ratios. Encouraged by these results, a clickable 18F-labeled serine-based prosthetic group has been synthesized, again with the idea to improve the metabolic and pharmacokinetic profile of hydrophilic radiotracers. Therefore, an alkyne-carrying azido-functionalized serine derivative for coupling to biomolecules was synthesized and a chlorine leaving group for 18F-labeling, which could be accomplished using a microwave-assisted synthesis, a [K⊂2.2.2]+/carbonate system in DMSO. Radiochemical yields of 77±6% could be achieved.rnThe promising results obtained from the FR-targeting concept in the diagnostic field have been transferred to the boron neutron capture therapy. Therefore, a folate derivative was coupled to different boron clusters and cell uptake studies were conducted. The synthesis of the folate-boron clusters was straightforward. At first, a linker molecule based on maleic acid was synthesized, which was coupled to the boron cluster via Michael Addition of a thiol and alkene and subsequently coupled to the targeting moiety using CuAAC. The new conjugates of folate and boron clusters led to a significant increase of boron concentration in the cell of about 5-times compared to currently used and approved boron pharmaceuticals. rnMoreover, azido-folate derivatives were coupled to macromolecular carrier systems (pHPMA), which showed an enhanced and specific accumulation at target sites (up to 2.5-times) during in vivo experiments. A specific blockade could be observed up to 30% indicating an efficient targeting effect. A new kind of nanoparticles consisting of a PDLLA core and p((HPMA)-b-LMA)) as surfactants were developed and successfully radiolabeled via 18F-click chemistry in good RCYs of 8±3%rnThe nanoparticles were obtained via the miniemulsion technique in combination with solvent evaporation. The 18F-labeled nanoparticles were applied to in vivo testing using a mouse model. PET imaging showed a “mixed” biodistribution of low molecular weight as well as high molecular weight systems, indicating a partial loss of the 18F-labeled surfactant.rnIn conclusion, the presented work successfully utilized the FR-targeting concept in both, the diagnostic field (PET imaging) and for therapeutic approaches (BNCT, drug delivery systems). As a result, the high potential of FR-targeting in oncological applications has been shown and was confirmed by small animal PET imaging.rn