33 research outputs found
Effects of oxidative stress during human and animal reproductions: A review
Given its high ability to damage important cellular components (lipids, proteins and deoxyribonucleic acid), oxidative stress is now recognized as one of the most common mechanisms associated with development of a variety of diseases and natural events such as pregnancy. During reproduction period, there is a change in the pro-oxidant and antioxidant balance due to the body and circulation modifications that are inherent to the pregnancy process. The present paper discusses the role of oxidative stress on the reproduction process. More effective defense strategies are needed to decrease the deleterious effects of oxidative-stress-induced gestation. This approach could be achieved by antioxidant status alteration. Further clinical and experimental studies are needed for better understanding of oxidative stress mechanism and the impact of antioxidant supplementation on reproduction
DNA methylation patterns in bladder cancer and washing cell sediments: a perspective for tumor recurrence detection
<p>Abstract</p> <p>Background</p> <p>Epigenetic alterations are a hallmark of human cancer. In this study, we aimed to investigate whether aberrant DNA methylation of cancer-associated genes is related to urinary bladder cancer recurrence.</p> <p>Methods</p> <p>A set of 4 genes, including <it>CDH1 </it>(E-cadherin), <it>SFN </it>(stratifin), <it>RARB </it>(retinoic acid receptor, beta) and <it>RASSF1A </it>(Ras association (RalGDS/AF-6) domain family 1), had their methylation patterns evaluated by MSP (Methylation-Specific Polymerase Chain Reaction) analysis in 49 fresh urinary bladder carcinoma tissues (including 14 cases paired with adjacent normal bladder epithelium, 3 squamous cell carcinomas and 2 adenocarcinomas) and 24 cell sediment samples from bladder washings of patients classified as cancer-free by cytological analysis (control group). A third set of samples included 39 archived tumor fragments and 23 matched washouts from 20 urinary bladder cancer patients in post-surgical monitoring. After genomic DNA isolation and sodium bisulfite modification, methylation patterns were determined and correlated with standard clinic-histopathological parameters.</p> <p>Results</p> <p><it>CDH1 </it>and <it>SFN </it>genes were methylated at high frequencies in bladder cancer as well as in paired normal adjacent tissue and exfoliated cells from cancer-free patients. Although no statistically significant differences were found between <it>RARB </it>and <it>RASSF1A </it>methylation and the clinical and histopathological parameters in bladder cancer, a sensitivity of 95% and a specificity of 71% were observed for <it>RARB </it>methylation (Fisher's Exact test (p < 0.0001; OR = 48.89) and, 58% and 17% (p < 0.05; OR = 0.29) for <it>RASSF1A </it>gene, respectively, in relation to the control group.</p> <p>Conclusion</p> <p>Indistinct DNA hypermethylation of <it>CDH1 </it>and <it>SFN </it>genes between tumoral and normal urinary bladder samples suggests that these epigenetic features are not suitable biomarkers for urinary bladder cancer. However, <it>RARB </it>and <it>RASSF1A </it>gene methylation appears to be an initial event in urinary bladder carcinogenesis and should be considered as defining a panel of differentially methylated genes in this neoplasia in order to maximize the diagnostic coverage of epigenetic markers, especially in studies aiming at early recurrence detection.</p
Gemcitabine/cisplatin treatment induces concomitant sertad1, cdkn2b and gadd45a modulation and cellular changes in bladder cancer cells regardless of the site of TP53 mutation.
Simultaneous use of cisplatin (CIS) and
gemcitabine (GEN) for treating bladder cancer has increased
because of their complementary effects. However, the molecular
mechanisms underlying the activities of these two antineoplastic
drugs are not fully known. Here, molecular biology
techniques and microscopy were used to investigate
transcriptomic and morphological changes in low and highgrade
urinary bladder transitional carcinoma cell lines [RT4 -
wild type TP53; 5637 - two TP53 mutations, one in codon 72
(Arg-Pro) and other in codon 280 (Arg-Thr) and T24 - inframe
deletion of tyrosine 126 in the TP53 allele] simultaneously
treated with CIS/GEN. Gene expression profile was
evaluated by PCR arrays; cell morphology by scanning and
transmission electron microscopy, and apoptosis was analyzed
using fluorescent dye. Results showed concomitantly upregulation
of CDKN2B (G1/S transition), GADD45A (DNA repair
and apoptosis) and SERTAD1 (regulation of transcription)
gene, increased number of nuclear chamfers and apoptotic
cells, and reduced number of microfilaments, organelles and
in the size of the nucleus in 5637 and T24 cells after
simultaneous treatment with CIS/GEN. In conclusion, independently
of the TP53 mutation status and tumor grade, CIS/
GEN induced gene modulation accompanied by changes in
cell morphologies, which confirm the antiproliferative activity
of the treatment protocol. These findings help to understand
the pathways modulated by these antineoplastic agents and
may provide insights for anti-cancer chemotherapy
Cell adhesion and growth on surfaces modified by plasma and ion implantation
In this study, we show and discuss the results of the interaction of living CHO (Chinese Hamster Ovary) cells, in terms of adhesion and growth on glass, SU-8 (epoxi photoresist), PDMS (polydimethylsiloxane), and DLC (hydrogen free diamond-like carbon) surfaces. Glass, SU-8, and DLC but not PDMS showed to be good surfaces for cell growth. DLC surfaces were treated by oxygen plasma (DLC-O) and sulfur hexafluoride plasma (DLC-F). After 24 h of cell culture, the number of cells on DLC-O was higher than on DLC-F surface. SU-8 with silver implanted, creating nanoparticles 12 nm below the surface, increased significantly the number of cells per unit area. (C) 2014 AIP Publishing LLC.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq
Portal de Contratação Utilities
Num mundo cada vez mais competitivo e não alheio a crises económicas, a margem de erro é mÃnima para as entidades empresariais. Deste modo, têm estas instituições que estar dotadas de mecanismos de resposta focadas nas linhas da inovação e criatividade, não podendo os seus lÃderes descurar a prossecução da estabilidade económico-financeira. A tais circunstancialismos, alia-se a ideia da globalização o que tudo somado, leva à obrigatoriedade das empresas em adotarem os valores de eficácia, eficiência e competitividade nas áreas de angariação de novos clientes e da sua manutenção, devendo os seus métodos organizacionais ser sinónimo destes ideais chaves. No que respeita aos serviços de utilidade pública, a competitividade na aquisição e expansão da clientela, não deixa de ser uma realidade inegável, pelo que as empresas têm o dever de investir na melhoria e desenvolvimento dos instrumentos tecnológicos de gestão, captação e cativação de novos consumidores, para que tais organizações possam conhecer um desenvolvimento sustentável e harmonioso.In an increasingly competitve world and not unrelated to economic crises, the margin for error is minimal for business entities. Therefore, these institutions have to be equipped with response mechanisms focused on innovation and creativity, and their leaders must not neglect the pursuit of economic and financial stability. In fact, the impositions of the market, the demands of clients, the pressure from investors, the competition from other peers, generate ferocity in the fight for competitiveness and control of public utility markets. In addition to these circumstances, the idea of globalisation, which all adds up, leads companies to adopt the values of effectiveness, efficiency and competitiveness in the areas of attracking new clients and maintaining them, and their organisational methods should be synonymous with these key ideals. As far as public utility services are concerned, competitiveness in acquiring and expanding customers is an undeniable reality, and companies have a duty to invest in the improvement and development of technological instruments for managing, attracting and captivating new consumers, so that such organizations can experience a sustainable and harmonious development
MRE11A and SKP2 genes are associated with the increased cytotoxicity induced by the synergistic effects of cisplatin and gemcitabine in bladder cancer cells.
The combination of gemcitabine and cisplatin
has been shown previously to elicit a synergistic therapeutic
effect on bladder cancer cell lines and result in
reduced cell survival. However, the precise mechanism by
which cells die has not been elucidated. Cell cycle-related
genes are the predominant targets of chemotherapeutic
protocols. Therefore, molecular biomarkers that are predictive
of therapeutic outcomes associated with tumor
sensitivity might be important for optimal treatment protocol
selection. The aim of this study was to investigate the
changes in gene expression in cell cycle-related genes that
were induced by cisplatin, gemcitabine or a combined
treatment using both agents in a low-grade urinary bladder
transitional carcinoma cell line (RT4). The following three
treatment protocols were used: 1.0 lM cisplatin, 1.56 lM
gemcitabine and a combination of 1.0 lM cisplatin and
1.56 lM gemcitabine. Cytometry and morphology analysis
(by phase-contrast photomicrography) were performed in
addition to pathway-specific gene expression analysis using
quantitative RT-PCR gene arrays. The following results
were observed after 1.0 lM cisplatin treatment: (1) a
decrease in cell number, (2) an increased percentage of
scattered cells and (3) downregulated expression of genes
related to cell cycle arrest, G1/S-to-mitotic cell cycle
transition, DNA repair, apoptosis, transcription and mitosis.
Treatment with 1.56 lM gemcitabine, or with both
drugs simultaneously, induced the following effects: (1) a
decrease in cell number, (2) an increased percentage of
scattered and elongated cells, (3) the modulation of genes
that are predominantly involved in DNA repair and (4) a
significant upregulation of genes related to cell cycle arrest.
Reduced cell density was observed after the combined
treatment compared to the two other single-agent protocols.
The downregulation of MRE11A and SKP2 was observed
only in cells subjected to the combined treatment. In conclusion,
cisplatin, gemcitabine and the combination of both
drugs elicited distinct toxicogenomic effects in the RT4
bladder transitional carcinoma cell line, although disruptions
in the expression of cell cycle control-related genes
and other pathways responsible for cell survival were
observed for all of the protocols. MRE11A and SKP2
downregulation appeared to be responsible for the synergistic
therapeutic effects elicited by cisplatin and
gemcitabine
Cell growth on 3D microstructured surfaces.
Chinese Hamster Ovary (CHO) cell cultures were grown on surfaces lithographed with periodic 3D hexagonal microcavity array morphology. The range of microcavity size (inscribed circle diameter) was from 12 ?m to 560 ?m. CHO cells were grown also on flat surfaces. The characterization was performed with respect to cell growth density (number of nuclei per unit area) by fluorescence opticalmicroscopy and evaluated by correlation function analysis. We found that optimum microcavity radius was 80 ?m, concerning to the maximum cell growth density, being even greater than the growth density on a flat (unstructured) substrate of the same material. This finding can be important for optimization of biotechnological processes and devices
Effects of lycopene, synbiotic and their association on early biomarkers of rat colon carcinogenesis
This study evaluated whether a synergy exists for the combined treatment with lycopene and synbiotic on early biomarkers; of colon carcinogenesis. Male Wistar rats received a diet containing 300 mg/kg of lycopene and/or synbiotic (Bifidobacterium lactis plus oligofructose/inulin) or their combination 2 weeks before and during carcinogen treatment with 1.2-dimethylhydrazine (DMH). Twenty-four hours after the last DMH application, the colons were processed for immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), p53 protein, hematoxylin-eosin staining for apoptosis analysis and genotoxicity of fecal water by comet assay. Eight weeks after the last DMH application, the colons were analyzed for development of classical aberrant crypt foci (ACF) and mucin-negative ACF. Treatment with lycopene, synbiotic or their combination significantly increased apoptosis, reduced the PCNA and p53 labeling indexes and the development of classical ACF and mucin-negative ACF. Furthermore, a lower genotoxicity of fecal water was also detected in the groups treated with the chemopreventive agents. An additive/synergistic effect of the combined treatment with lycopene/synbiotic was observed only for the fecal water genotoxicity and mucin-negative ACF parameters. These results indicate that an additive/synergistic of the combination of chemopreventive agents on the initiation phase of colon carcinogenesis can be detected using selective early biomarkers. (C) 2009 Elsevier Ltd. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Cigarette smoke affects apoptosis in rat tongue mucosa: Role of bcl-2 gene family
While it has been clearly demonstrated that smoking is the most significant exogenous factor involved in oral carcinogenesis, little is known about the global molecular and cellular changes that occur prior to the appearance of clinically detectable symptoms. Thus, the aim of this study was to investigate the expressivity of bcl-2, bax and PCNA in the rat tongue mucosa exposed to cigarette smoke by means of immunohistochemistry. A total of twelve male Wistar rats were distributed into 2 groups: negative control and experimental group exposed to cigarette smoke during 75 days. After experimental period, no histopathological changes in the tongue mucosa were detected in the negative control and the experimental group. on the other hand, an overexpression of bcl-2 was detected (p 0.05). Also, the labeling index for bcl-2 and bax showed an increase 75 days after cigarette exposure (p < 0.01). PCNA-labeling index did not show remarkable changes between groups. Taken together, our results show that bcl-2 is overexpressed in the rat tongue keratinocytes after cigarette smoke exposure