87 resultados para Tumor-growth


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The gene encoding TCTP (Translationally Controlled Tumour Protein) is present in all eukaryotes and its product is involved in various cellular processes. Although well characterized in mammals, there are only few works available in the literature related to the analysis of this protein in plants. In this present work, the expression of the gene encoding TCTP was analyzed in different organs/tissues of tomato plants (Solanum lycopersicum cv. Santa Clara). A quantification performed by RT-qPCR revealed the presence of TCTP transcript in all tissues/organs analyzed, with the highest expression level found in leaves. With the exception of fruits in intermediate stage of maturation, for which a small increase on the expression was detected, there was minimal variation in the relative expression of TCTP in other organ/tissues. In parallel, the effects of the constitutive expression of TCTP were investigated using transgenic tobacco lines able to overexpress this protein at different levels (T1, T2 and T3). Seedlings of these lines, and of a non-transgenic control line, were grown in MS culture medium for 21 days. At the end of this period, the length of roots and leaves was taken and the seedlings were photographed. According to Tukey's test, the analysis of the mean root length revealed a significant difference between T1 and T3 lines when compared to the control, although the same was not observed for the T2 line. For leaves, according to Kruskal-Wallis test, there was a statistical difference between the averages of leaf growth obtained for the different lines evaluated. According to these results, we can conclude that TCTP shows an ubiquitous expression in tomato plants, with the highest expression detected in leaves, and also that its overexpression promoted a higher root and leaf development in two of three transgenic tobacco lines tested

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Mammary cancer is a multifactorial disease that is believed to be caused by genetic and environmental factors. Among the environmental factors, pyrethroids appear to be able to participate in carcinogenesis through several mechanisms, and have been shown to be associated to mammary tumors in canines. In order to investigate the possible rule of pyrethroid on DNA lesion in mammary tissue we compare the comet assay results between mammary tumor bearing dogs with and without pyrethroid associated to the peri mammary adipose tissue or the tumor itself. The pyrethroids presence was assessed by High Performance Liquid Chromatography (HPLC) and the DNA damage was assessed by the comet assay as previously described. Despite of correlation between DNA damage and tumor histologic aggressiveness, association between the severity of DNA damage and different types of mammary carcinoma was not found. Although pyrethroids were present in 22% of tumors and peritumoral adipose tissue, no difference in the degree DNA damage between the exposed and non exposed cells to pyrethroids were found. As future perspectives for this work, our group will evaluate the relationship of pyrethroids presence in tumors with its angiogenic potential. Angiogenesis evaluation will be based on presence of vascular endothelial growth factor (VEGF) in the tumor cells, and microvessel counts

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background: COX-2 is one of the most important prostaglandin involved in urologic cancer and seems to be associated with tumor progression, invasion, and metastasis. In addition, several effects have been reported for VEGF, including inducing angiogenesis, promoting cell migration, and inhibiting apoptosis. COX2 and VEGF up-regulation have been reported in human prostate cancer. Due to the importance of canine natural model for prostate cancer, the aim of this study was to evaluate COX-2 and VEGF protein expression in canine carcinogenic process. Material and Methods: Seventy-four prostatic tissues from dogs were selected to be evaluated for protein expression by immunohistochemistry (IHC), including: 10 normal prostatic tissues, 20 benign prostatic hyperplasias (BPH), 25 proliferative inflammatory atrophies (PIA) and 20 prostatic carcinomas (PCa). COX-2 and VEGF were detected using the monoclonal antibody CX-294 (1:50 dilution, Dako Cytomation and sc-53463 (1:100 dilution, Santa Cruz), respectively. The immunolabelling was performed by a polymer method (Histofine, Nichirei Biosciences). All reaction included negative controls by omitting the primary antibody. The percentage of C-MYC, E-cadherin, and p63- positive cells per lesion was evaluated according to Prowatke et al. (2007). The samples were scored separately according to staining intensity and graded semi-quantitatively as negative, weakly positive (1), moderately positive, and strongly positive. The score was done in one 400 magnification field, considering only the lesion, since this was done in a TMA core of 1 mm. For statistical analyses, the immunostaining classifications were reduced to two categories: negative and positive. The negative category included negative and weakly positive staining. Chi-square or Fisher exact test was used to determine the association between the categorical variables. Results: The COX-2 protein expression was elevated in the cytoplasm of the canine PCa and PIA compared to normal prostate (p=0.002). VEGF protein expression was increased in 94.75% of the PCa and 100% of the PIA compared with to normal prostate (p = 0.001). No difference was found when compared normal prostate with BPH. Conclusions: This study has demonstrated that the carcinogenesis of canine prostatic tissue may be related to gain of COX-2 and VEGF protein expression.

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The purpose of this study was to review the literature regarding the action of the cytokines interleukin 10 (IL-10) and tumor necrosis factor-alpha (TNF-α) in pregnancy and to emphasize the factors that are of interest to clinical obstetrics. The literature highlights several actions of IL-10 and TNF-α during pregnancy. The actions of these cytokines seem to be antagonistic and dependent on the balance between them, which is orchestrated by the specific immunosuppressive action of IL-10. TNF-α has a characteristic inflammatory action, and it is an additional diabetogenic factor in pregnancy. The loss of the control of the production of these cytokines, with increase of TNF-α, is related to the risk for developing obstetric complications, particularly recurrent fetal loss, gestational diabetes mellitus, hypertensive syndromes, and fetal growth restriction. However, study results are controversial and are not clearly defined. These issues are attributed to the heterogeneity of the studies, particularly regarding their sample sizes and sources, the evaluation methods, and the multiplicity of factors and conditions that influence cytokine production. These questions are fundamental and should be addressed in future investigations to obtain more consistent results that can be applied to obstetric practice.

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Though benign, giant cell tumor of bone (GCTB) can become aggressive and can exhibit a high mitotic rate, necrosis and rarely vascular invasion and metastasis. GCTB has unique histologic characteristics, a high rate of multinucleated cells, a variable and unpredictable growth potential and uncertain biological behavior. In this study, we sought to identify genes differentially expressed in GCTB, thus building a molecular profile of this tumor. We performed quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry and analyses of methylation to identify genes that are putatively associated with GCTB. The expression of the ADAM23 and CDKN2A genes was decreased in GCTB samples compared to normal bone tissue, measured by qPCR. Additionally, a high hypermethylation frequency of the promoter regions of ADAM23 and CDKN2A in GCTB was observed. The expression of the MAP2K3, MMP14, TIMP2 and VIM genes was significantly higher in GCTB than in normal bone tissue, a fact that was confirmed by qPCR and immunohistochemistry. The set of genes identified here furthers our understanding of the molecular basis of GCTB.

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The odontogenic keratocyst is called keratocyst odontogenic tumor (TOQ), due to its features compatible with neoplasms, such as its high recurrence rate and mechanism of growth. Although its etiology has unknown, the origin seems to be connected with dental lamina remaining. This entity is generally benign, with slow progression, asymptomatic, and among the odontogenic tumors, its prevalence is high. It affects mainly males, with predilection for the posterior mandible, while in most cases associated with an impacted tooth. Radiographically, this lesion is unilocular. Histological features are stratified epithelial basal cells with hyperchromatic paraqueratinizado. Treatment ranges from conservative to radical interventions. As a result of the controversy as TOQ tumor entity, the present work is a literature review of current findings, emphasizing its intrinsic features to contribute to developments in the study of this new entity.

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In order to refine the solution given by the classical logistic equation and extend its range of applications in the study of tumor dynamics, we propose and solve a generalization of this equation, using the so-called Fractional Calculus, i.e., we replace the ordinary derivative of order 1, in one version of the usual equation, by a non-integer derivative of order 0 < α < 1, and recover the classical solution as a particular case. Finally, we analyze the applicability of this model to describe the growth of cancer tumors.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)