Exosomal glypican-1 discriminates pancreatic ductal adenocarcinoma from chronic pancreatitis.

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) diagnosis can be difficult in a chronic pancreatitis (CP) background, especially in its mass forming presentation. We aimed to assess the accuracy of glypican-1-positive circulating exosomes (GPC1+crExos) to distinguish PDAC from CP versus the state-of-the-art CA 19-9 biomarker. METHODS: This was a unicentric prospective cohort. Endoscopic ultrasound with fine-needle aspiration or biopsy and blood tests (GPC1+crExos and serum CA 19-9) were performed. RESULTS: The cohort comprised 60 PDAC and 29 CP (7 of which mass forming - MF) patients. Median levels of GPC1+crExos were significantly higher in PDAC (99.7%) versus CP (28.4%; p<0.0001) with an AUROC of 0.96 with 98.3% sensitivity and 86.2% specificity for a cut-off of 45.0% (p<0.0001); this outperforms CA 19-9 AUROC of 0.82 with 78.3% sensitivity and 65.5% specificity at a cut-off of 37 U/mL (p<0.0001). The superiority of% GPC1+crExos over CA 19-99 in differentiating PDAC from CP was observed in both early (stage I) and advanced tumors (stages II-IV). CONCLUSION: Levels of GPC1+crExos coupled to beads enable differential diagnosis between PDAC and CP including its mass-forming presentation.

Correction: CpG island hypermethylation-associated silencing of non-coding RNAs transcribed from ultraconserved regions in human cancer.

In the original article the authors have noted that the wrong image was used to illustrate the Uc.346 + Lu1-Lu2-Lu3 subpanel of Figure 5a. The correct image is now provided as Figure 1 in this article. This change does not affect the legend of the figure, the results, or conclusions reported in the manuscript. The authors apologize for the error, and regret any inconvenience this may have caused.

Avaliação dos perfis minerais séricos, urinários e sedimentares de ovinos recebendo dieta calculogênica / Evaluation of mineral profile in serum, urine and sediment of sheep receiving calculogenic diet

A urolitíase obstrutiva em pequenos ruminantes é uma doença metabólica de etiologia multifatorial com distribuição mundial. A elevação da concentração urinária de solutos, minerais ionizados (cristaloides) que formam cristais insolúveis é citada por alguns autores como o fator mais importante. Assim, o conhecimento do perfil mineral dos animais submetidos a dietas calculogênicas e a composição química dos urólitos tornam-se ferramentas eficazes na prevenção da doença. Neste estudo, foram utilizados 14 ovinos hígidos, machos (não castrados), da raça Santa Inês, com idade aproximada de 90 dias, distribuídos em dois grupos (G1 - sem vitamina C e G2 - com vitamina C) e alimentados com dieta calculogênica. A análise dos perfis minerais, séricos e urinários revelou completo desbalanceamento na relação entre concentrações de cálcio, fósforo e magnésio, havendo elevação expressiva do fósforo e do magnésio e diminuição substancial do cálcio. Com isso, a análise bioquímica dos urólitos demonstrou que o cálcio esteve presente em 50% das amostras analisadas.(AU)

Urolithiasis in small ruminants is a metabolic disease of multifactorial etiology with worldwide distribution. Increased urinary concentration of solutes, ionized minerals (crystalloid) that form insoluble crystals is cited by some authors as the most important factor. Thus, knowledge of mineral profile of the animals fed calculogenic diets and chemical composition of uroliths becomes an effective tool in preventing the disease. In this study, we used 14 healthy, male, non-neutered sheep, of the Santa Ines breed, aged approximately 90 days, divided into two groups (G1-without vitamin C and G2-with vitamin C) fed calculogenic diet. Analysis of mineral profiles in serum and urine revealed complete imbalance in the relationship between concentrations of calcium, phosphorus and magnesium, with significant increase of phosphorus and magnesium and substantial reduction of calcium. Thus, biochemical analysis of uroliths showed that calcium was present in 50% of samples.(AU)

A p53-bound enhancer region controls a long intergenic noncoding RNA required for p53 stress response.

Genome-wide chromatin studies identified the tumor suppressor p53 as both a promoter and an enhancer-binding transcription factor. As an enhancer factor, p53 can induce local production of enhancer RNAs, as well as transcriptional activation of distal neighboring genes. Beyond the regulation of protein-coding genes, p53 has the capacity to regulate long intergenic noncoding RNA molecules (lincRNAs); however, their importance to the p53 tumor suppressive function remains poorly characterized. Here, we identified and characterized a novel p53-bound intronic enhancer that controls the expression of its host, the lincRNA00475 (linc-475). We demonstrate the requirement of linc-475 for the proper induction of a p53-dependent cell cycle inhibitory response. We further confirm the functional importance of linc-475 in the maintenance of CDKN1A/p21 levels, a cell cycle inhibitor and a major p53 target gene, following p53 activation. Interestingly, loss of linc-475 reduced the binding of both p53 and RNA polymerase II (RNAPII) to the promoter of p21, attenuating its transcription rate following p53 activation. Altogether, our data suggest a direct role of p53-bound enhancer domains in the activation of lincRNAs required for an efficient p53 transcriptional response.

CpG island hypermethylation-associated silencing of non-coding RNAs transcribed from ultraconserved regions in human cancer.

Although only 1.5% of the human genome appears to code for proteins, much effort in cancer research has been devoted to this minimal fraction of our DNA. However, the last few years have witnessed the realization that a large class of non-coding RNAs (ncRNAs), named microRNAs, contribute to cancer development and progression by acting as oncogenes or tumor suppressor genes. Recent studies have also shown that epigenetic silencing of microRNAs with tumor suppressor features by CpG island hypermethylation is a common hallmark of human tumors. Thus, we wondered whether there were other ncRNAs undergoing aberrant DNA methylation-associated silencing in transformed cells. We focused on the transcribed-ultraconserved regions (T-UCRs), a subset of DNA sequences that are absolutely conserved between orthologous regions of the human, rat and mouse genomes and that are located in both intra- and intergenic regions. We used a pharmacological and genomic approach to reveal the possible existence of an aberrant epigenetic silencing pattern of T-UCRs by treating cancer cells with a DNA-demethylating agent followed by hybridization to an expression microarray containing these sequences. We observed that DNA hypomethylation induces release of T-UCR silencing in cancer cells. Among the T-UCRs that were reactivated upon drug treatment, Uc.160+, Uc283+A and Uc.346+ were found to undergo specific CpG island hypermethylation-associated silencing in cancer cells compared with normal tissues. The analysis of a large set of primary human tumors (n=283) demonstrated that hypermethylation of the described T-UCR CpG islands was a common event among the various tumor types. Our finding that, in addition to microRNAs, another class of ncRNAs (T-UCRs) undergoes DNA methylation-associated inactivation in transformed cells supports a model in which epigenetic and genetic alterations in coding and non-coding sequences cooperate in human tumorigenesis.

Role of smooth muscle cell membrane potential in neointima formation in arteries of spontaneously hypertensive rats.

Based on observations that vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) have altered resting potentials as well as abnormal cell proliferation rates, neointima formation after controlled balloon injury was compared in arteries from SHR and Wistar Kyoto rats (WKY). SHR aortic VSMC showed hyperpolarized resting membrane potentials (-93+/-8 mV) when compared to those from WKY (-61+/-6 mV). Histomorphometric analysis of cross sections from aortic segments submitted to balloon injury showed reduced neointima formation in SHR (neointima/media ratio: 0.04+/-0.03) as compared to WKY (0.2+/-0.1). On the other hand, in injured carotid arteries, neointima formation was more extensive in SHR (neointima/media ratio 5.0+/-0.9) than in WKY (0.8+/-0.7), leading in most cases to luminal occlusion. Measurements of VSMC resting potential showed that carotid artery cells from SHR were depolarized with respect to those from WKY (-46+/-4 vs. -69+/-5 mV, respectively). The results demonstrate an inverse relationship between VSMC membrane polarization and neointima formation in SHR arteries, suggesting that genetic modifications in SHR determine a dysfunctional cellular physiology that may influence cell proliferation subsequent to injury.

Use of a selective medium with potassium tellurite to follow intestinal colonization of hospitalized patients by drug-resistant Enterobacteriaceae.

Nosocomial infections are a relevant factor in complicating the recovery of patients interned for even minor causes. In a attempt to determine their origin it is crucial to consider that their origin is of an endogenous nature. Looking for an accessible expression of intestinal colonization we analyzed fecal samples from 3 separate groups of hospital patients collected after different lengths of time. For practical reasons one group was studied prospectively and two other groups (patients hospitalized for up to 7 days and patients hospitalized for more than 7 days) were compared to one another. We looked for the emergence of tellurite resistance among Enterobacteriaceae using a selective medium, MacConkey potassium tellurite (MCPT). The frequency of prospectively studied patients with tellurite resistant strains was significantly greater after 7 days of hospitalization. For the two other groups, patients with more than 7 days of hospitalization showed a significant increase of bacterial species and of strains with new antimicrobial resistance markers. High molecular weight plasmids were detected in some of these strains. These data show that the MCPT medium is a useful tool for the investigation of bowel colonization in hospitalized patients by drug-resistant Enterobacteriaceae.