1,720,985 research outputs found
NEW INSIGHTS OF MIR-145 FUNCTION AND REGULATION IN HUMAN BREAST CANCER.
No full textmiR-145 is down-regulated in the majority of human cancers, including breast cancer (BC).
However, its role remains largely unknown. Here, I provide evidence for miR-145 induced
anti-proliferative and pro-apoptotic effect in several BC cell lines, which was not detected in
BC cells lacking a functional TP53 gene and exhibiting an estrogen receptor alfa (ESR1)
negative status. I found that miR-145 anti-proliferative effects were dependent upon TP53
activation and that activation of TP53 could in turn stimulates miR-145 expression. I also
found that miR-145 could repress the expression of ESR1 protein by direct interaction with
two sites within its gene coding sequence. My findings support the existence of a positive
regulatory loop where miR-145 directly targets ESR1 and indirectly activates TP53, which in
turn sustains miR-145 expression and reinforces miR-145 overall effects on proliferation and
apoptosis
Anticancer activity of an adenoviral vector expressing short hairpin RNA against BK virus T-ag
No full textThe human polyomavirus BK (BKV) is oncogenic in rodents and induces malignant transformation of rodent cells in vitro. Although its role in human tumorigenesis is still debated, BKV represents an excellent model to evaluate molecularly targeted antineoplastic approaches. Here, we have tested whether stable suppression of the T antigen (T-ag) oncogene expression could inhibit the in vitro and in vivo malignant phenotype of BKV-transformed mouse cells. An adenovirus vector system that expresses small hairpin RNAs (shRNAs), which are converted into active small interfering RNAs (siRNA) molecules against the BKV T-ag, was developed. This vector was able to inhibit the expression of BKV T-ag through a highly efficient in vitro and in vivo delivery of the siRNA molecule. In addition, it allowed a stable expression of siRNA for a period of time sufficient to elicit a biological effect. Inhibition of T-ag expression results in reduction of the in vitro growth rate of BKV-transformed cells, which is, at least in part, caused by restoration of p53 activity and induction of apoptosis. In vivo studies proved that adenovirus vectors expressing anti-T-ag siRNA were able to suppress tumorigenicity of BKV-transformed cells. Moreover, adenovirus vector direct treatment of growing tumors resulted in a significant reduction of tumor growth. This study indicates that siRNAs delivery via a viral vector have a potential usefulness as in vivo anticancer tool against viral and cellular oncogenes
PROCEDIMENTO PER REALIZZARE UN SUBSTRATO PER ESEGUIRE ANALISI, SUBSTRATO E METODO DI ANALISI CONNESSO
No full text: From the spectroscopic analysis, using a portable commercial instrument, it is possible to obtain a diagnostic response for breast cancer, at different stages. The invention is constituted by these elements: 1. a nanostructured metallic substrate, made by gold or silver nanoparticles deposited on paper, used to amplify the spectroscopic signal; this type of SERS substrate is already known in literature, but ours has a better performance in terms of repeatability, with respect to those paper-based substrates already reported; it is easy to prepare, inexpensive, and can be prepared on large scale; innovation with respect to published procedures consists in modifying two parameters during the substrate synthesis, in particular in using concentrated (by centrifugation) nanoparticles and in using a paper with a 2 micrometers porosity; 2. the instrumental method of analysis, i.e. the use of paper-based SERS substrate to analyze biofluids such as serum. In fact, such substrate are not new (see above), but so far they have only been used with samples different from blood, serum of plasma. We were the first to find out their use with this type of samples (blood, serum and plasma). 3. a multivariate predictive model, built using a training set of spectral data from a group of patients and from a control group, capable of interpreting a spectrum in diagnostic terms. The algorithms used for such models (e.g. PCA-LDA) are already well known, but our model is unique in so far as it is built using our own data, and it has diagnostic performance parameters (sensitivity, specificity, accuracy) which are better than alternative methods (e.g. mammography)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Thiopurine Biotransformation and Pharmacological Effects: Contribution of Oxidative Stress
No full textThiopurine antimetabolites are important agents for the treatment of severe diseases, such as acute lymphoblastic leukemia and inflammatory bowel disease. Their pharmacological actions depend on biotransformation into active thioguanine-nucleotides; intracellular metabolism is mediated by enzymes of the salvage pathway of nucleotide synthesis and relies on polymorphic enzymes involved in thiopurines' catabolism such as thiopurine-S-methyl transferase. Given the enzymes involved in thiopurines' metabolism, it is reasonable to hypothesize that these drugs are able to induce significant oxidative stress conditions, possibly altering their pharmacological activity
SERS analysis of serum for detection of early and locally advanced breast cancer
Full text linkn this contribution, we investigated whether surface-enhanced Raman scattering (SERS) of serum can be a candidate method for detecting “luminal A” breast cancer (BC) at different stages. We selected three groups of participants aged over 50 years: 20 healthy women, 20 women with early localized small BC, and 20 women affected by BC with lymph node involvement. SERS revealed clear spectral differences between these three groups. A predictive model using principal component analysis (PCA) and linear discriminant analysis (LDA) was developed based on spectral data, and its performance was estimated with cross-validation. PCA-LDA of SERS spectra could distinguish healthy from BC subjects (sensitivity, 92 %; specificity, 85 %), as well as subjects with BC at different stages, with a promising diagnostic performance (sensitivity and specificity, ≥80 %; overall accuracy, 84 %). Our data suggest that SERS spectroscopy of serum, combined with multivariate data analysis, represents a minimally invasive, easy to use, and fast approach to discriminate healthy from BC subjects and even to distinguish BC at different clinical stages
Association between plasminogen activator inhibitor 1 gene polymorphisms and preeclampsia.
No full textIt is known that the plasminogen activator inhibitor 1 (PAI-1) protein levels are increased in placentas of preeclamptic subjects. Therefore, we assessed whether polymorphisms related to the transcriptional control of the PAI-1 gene (-675 4G/5G and -844G/A) are associated with mild preeclampsia. We compared 52 women with preeclampsia to 80 women with a normal pregnancy. None of the preeclamptic women suffered from the severe form of preeclampsia. DNA was extracted from blood, and -675 4G/5G and -844G/A genotypes of the PAI-1 gene were determined. Since it has been shown that the presence of factor V Leiden, prothrombin G20210A, and MTHFR C677T gene variants may be associated with preeclampsia, their frequency was also evaluated in our study groups. The factor V Leiden, PT G20210A, and MTHFR C677T gene variants were not associated with preeclampsia. In the case of the -675 4G/5G polymorphism, genotypes 4G/4G and 5G/5G were more prevalent in the preeclamptic and in the control group, respectively. In the case of -844 G/A polymorphism, genotypes A/A and G/G were more prevalent in the preeclamptic and in the control group, respectively. By using the χ 2 test for trend, differences for both genotypes were significant (p = 0.0141 for the -675 genotypes and p = 0.0492 for the -844 genotypes). The frequency of the 4G and 5G alleles of the -675 gene polymorphism was significantly different between preeclamptic and normal women (p = 0.032). Differently, the allelic frequency of the -844 gene polymorphism did not show significant differences between preeclamptic and normal women (p = 0.083). In conclusion, the hypofibrinolytic genotypes 4G/4G and A/A at positions -675 and -844 of the PAI-1 gene are associated with the occurrence of mild preeclampsia independently of thrombophilic mutations of the factor V, prothrombin, and MTHFR gene
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