2,513 research outputs found

    Transcribed ultraconserved noncoding RNAs (T-UCR) are involved in Barrett's esophagus carcinogenesis.

    Get PDF
    Barretts esophagus (BE) involves a metaplastic replacement of native esophageal squamous epithelium (Sq) by columnar-intestinalized mucosa, and it is the main risk factor for Barrett-related adenocarcinoma (BAc). Ultra-conserved regions (UCRs) are a class non-coding sequences that are conserved in humans, mice and rats. More than 90% of UCRs are transcribed (T-UCRs) in normal tissues, and are altered at transcriptional level in tumorigenesis. To identify the T-UCR profiles that are dysregulated in Barretts mucosa transformation, microarray analysis was performed on a discovery set of 51 macro-dissected samples obtained from 14 long-segment BE patients. Results were validated in an independent series of esophageal biopsy/surgery specimens and in two murine models of Barretts esophagus (i.e. esophagogastric-duodenal anastomosis). Progression from normal to BE to adenocarcinoma was each associated with specific and mutually exclusive T-UCR signatures that included up-regulation of uc.58-, uc.202-, uc.207-, and uc.223- and down-regulation of uc.214+. A 9 T-UCR signature characterized BE versus Sq (with the down-regulation of uc.161-, uc.165-, and uc.327-, and the up-regulation of uc.153-, uc.158-, uc.206-, uc.274-, uc.472-, and uc.473-). Analogous BE-specific T-UCR profiles were shared by human and murine lesions. This study is the first demonstration of a role for T-UCRs in the transformation of Barretts mucosa

    Detection of miRNA cancer biomarkers using light activated Molecular Beacons

    Get PDF
    Early detection of cancer biomarkers can reduce cancer mortality rate. miRNAs are small non-coding RNAs whose expression changes upon the onset of various types of cancer. Biosensors that specifically detect such biomarkers can be engineered and integrated into point-of-care devices (POC) using label-free detection, high sensibility and compactness. In this paper, a new engineered Molecular Beacon (MB) construct used to detect miRNAs is presented. Such a construct is immobilized onto biosensor surfaces in a covalent and spatially oriented way using the photonic technology Light Assisted Molecular Immobilization (LAMI). The construct consists of a Cy3 labelled MB covalently attached to a light-switchable peptide. One MB construct contains a poly-A sequence in its loop region while the other contains a sequence complementary to the cancer biomarker miRNA-21. The constructs have been characterized by UV-Vis spectroscopy, mass spectrometry and HPLC. LAMI led to the successful immobilization of the engineered constructs onto thiol functionalized optically flat quartz slides and Silicon on Insulator (SOI) sensor surfaces. The immobilized Cy3 labelled MB construct has been imaged using confocal fluorescence microscopy (CFM). The bioavailability of the immobilized engineered MB biosensors was confirmed through specific hybridization with the Cy5 labelled complementary sequence and imaged by CFM and FRET. Hybridization kinetics have been monitored using steady state fluorescence spectroscopy. The label-free detection of miRNA-21 was also achieved by using integrated photonic sensing structures. The engineered light sensitive constructs can be immobilized onto thiol reactive surfaces and are currently being integrated in a POC device for the detection of cancer biomarkers

    Heterogeneity in circulating tumor cells : the relevance of the stem-cell subset

    Get PDF
    The release of circulating tumor cells (CTCs) into vasculature is an early event in the metastatic process. The analysis of CTCs in patients has recently received widespread attention because of its clinical implications, particularly for precision medicine. Accumulated evidence documents a large heterogeneity in CTCs across patients. Currently, the most accepted view is that tumor cells with an intermediate phenotype between epithelial and mesenchymal have the highest plasticity. Indeed, the existence of a meta-stable or partial epithelial⁻mesenchymal transition (EMT) cell state, with both epithelial and mesenchymal features, can be easily reconciled with the concept of a highly plastic stem-like state. A close connection between EMT and cancer stem cells (CSC) traits, with enhanced metastatic competence and drug resistance, has also been described. Accordingly, a subset of CTCs consisting of CSC, present a stemness profile, are able to survive chemotherapy, and generate metastases after xenotransplantation in immunodeficient mice. In the present review, we discuss the current evidence connecting CTCs, EMT, and stemness. An improved understanding of the CTC/EMT/CSC connections may uncover novel therapeutic targets, irrespective of the tumor type, since most cancers seem to harbor a pool of CSCs, and disclose important mechanisms underlying tumorigenicity

    Estrogen-dependent dynamic profile of eNOS-DNA associations in prostate cancer

    Get PDF
    In previous work we have documented the nuclear translocation of endothelial NOS (eNOS) and its participation in combinatorial complexes with Estrogen Receptor Beta (ERβ) and Hypoxia Inducible Factors (HIFs) that determine localized chromatin remodeling in response to estrogen (E2) and hypoxia stimuli, resulting in transcriptional regulation of genes associated with adverse prognosis in prostate cancer (PCa). To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells. We found that: 1. the eNOS-bound regions (peaks) are widely distributed across the genome encompassing multiple transcription factors binding sites, including Estrogen Response Elements. 2. E2 increased the number of peaks, indicating hormone-dependent eNOS re-localization. 3. Peak distribution was similar with/without E2 with ≈ 55% of them in extragenic DNA regions and an intriguing involvement of the 5′ domain of several miRs deregulated in PCa. Numerous potentially novel eNOS-targeted genes have been identified suggesting that eNOS participates in the regulation of large gene sets. The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS. E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa

    Epigenetic regulation of microRNA expression in colorectal cancer

    Get PDF
    In the last years, microRNAs (miRNA) have emerged as new molecular players involved in carcinogenesis. Deregulation of miRNAs expression has been shown in different human cancer but the molecular mechanism underlying the alteration of miRNA expression is unknown. To identify tumor-supressor miRNAs silenced through aberrant epigenetic events in colorectal cancer (CRC), we used a sequential approach. We first identified 5 miRNAs down-regulated in colorectal cancer patient samples and located around/on a CpG island. Treatment with a DNA methyltransferase inhibitor and a HDAC inhibitor restored expression of 3 of the 5 microRNAs (hsa-miR-9, hsa-miR-129 and hsa-miR-137) in 3 CRC cell lines. Expression of hsa-miR-9 was inversely correlated with methylation of their promoter regions as measure by MSP and bisulphate sequencing. Further, methylation of the hsa-miR-9-1, hsa-miR-129-2 and hsa-miR- 137 CpG islands were frequently observed in CRC cell lines and in primary CRC tumors, but not in normal colonic mucosa. Finally, methylation of hsa-miR-9-1 was associated with the presence of lymph node metastasis. In summary, our results aid in the understanding of miRNA gene regulation showing that aberrant DNA methylation and histone modifications work together to induce silencing of miRNAs in CRC

    Loss of miR-204 expression is a key event in melanoma

    Get PDF
    Cutaneous melanoma (CM) is a malignancy with increasing occurrence. Its microRNA repertoire has been defined in a number studies, leading to candidates for biological and clinical relevance: miR-200a/b/c, miR-203, miR-205, miR-204, miR-211, miR-23b and miR-26a/b. Our work was aimed to validate the role of these candidate miRNAs in melanoma, using additional patients cohorts and in vitro cultures. miR-26a, miR-204 and miR-211 were more expressed in normal melanocytes, while miR-23b, miR-200b/c, miR-203 and miR-205 in epidermis and keratinocytes. None of the keratinocyte-related miRNAs was associated with any known mutation or with clinical covariates in melanoma. On the other hand, the loss of miR-204 was enriched in melanomas with NRAS sole mutation (Fisher exact test, P = 0.001, Log Odds = 1.67), and less frequent than expected in those harbouring CDKN2A mutations (Fisher exact test, P = 0.001, Log Odds − 1.09). Additionally, miR-204 was associated with better prognosis in two independent melanoma cohorts and its exogenous expression led to growth impairment in melanoma cell lines. Thus, miR-204 represents a relevant mechanism in melanoma, with potential prognostic value and its loss seems to act in the CDKN2A pathway, in cooperation with NRAS

    Skin homing of Sézary cells involves SDF-1-CXCR4 signaling and down-regulation of CD26/dipeptidylpeptidase IV

    Get PDF
    AbstractSézary syndrome (SS) is a rare form of cutaneous T-cell lymphoma (CTCL) characterized by a distinct metastatic pattern mainly involving blood and skin. Chemokines and their receptors play a critical role in cellular recruitment and homing to tissues and in the metastatic process of several tumors including non-Hodgkin T-cell lymphomas (NHLs). Here we report that SS cells express a functionally active CXCR4 and that its ligand SDF-1 is abundantly produced in the skin, which represents the main destination of SS cell spreading. SDF-1 is normally inactivated by proteolytic cleavage by the CD26/dipeptidylpeptidase IV (DPPIV). The lack of CD26 from the cell surface is a hallmark of circulating SS cells. We also show that the CD26- phenotype is maintained also in skin-infiltrating neoplastic T lymphocytes and that SS-affected individuals exhibit a reduced activity of plasma soluble CD26. Finally, we observe that the addition of soluble CD26 reduces the migratory response of SS cells to SDF-1 whereas the inhibition of the CD26 peptidase activity in Hut78, a CD26+ CTCL cell line, enhances the SDF-1-induced migration of these cells. Our findings suggest that the SDF-1-CXCR4 axis could play an important role in skin homing of SS through the regulatory activity of CD26

    The ‘health record’ of the church of Santa Maria Assunta in Pontecurone: contamination between historical knowledge and non-destructive testing results

    Get PDF
    The historical architecture of the church of Santa Maria Assunta in Pontecurone (Alessandria, Italy), of late medieval origins and with significant transformations until the 20th century, is a clear palimpsest of different construction and decorative phases. Nowadays, although used as a parish church, it shows a critical framework of alterations. The need to best rearrange the data in preparation for a wished restoration program required the involvement of a team of experts from the Politecnico di Torino – as members of a protocol agreement – to verify the current state of conservation of the building. Between 2019 and 2022, the study focused on examining rich but dispersed and fragmented historical sources, which provided important information for the knowledge of architectural components. In the meantime, an NDT diagnostic campaign to understand non-visible phenomena and structural problems was carried out. In particular, infrared thermography allowed the comprehension of the vaulted systems laying, the mapping of fissures and the reading of the stains caused by infiltration and rising dampness. Moreover, thanks to an innovative application of this technique, it was possible to evaluate the heating system's effectiveness through the survey of the distribution of hot air flows in the room context and on the surfaces. Instead, endoscopic inspections revealed the stratigraphy under the floor level, which is completely damaged, and resistograph analysis verified the quality of the antique roof trusses at some significant points. The contribution will deal in detail with the systematization of the data in the health record, a tool already tested in other contexts (such as at Chambord Castle, to which this project refers) that can be constantly implemented and easily consulted. Furthermore, it easily communicates and records the knowledge about the building, relating historical information with results obtained from the application of non-destructive testing

    Foraging Educators as Vectors of Environmental Knowledge in Europe

    Get PDF
    Unidad de excelencia María de Maeztu CEX2019-000940-MWidely accessible education on edible wild plants is increasingly in demand as more people search for ways to explore wild culinary uses. Despite this growing trend of nature exploration, few scholars have investigated the contribution of this new mode of engagement to human-nature connection and pro-environmental attitudes. Therefore, this research aims to explore the societal role of such foraging educators. Through convenience and snowball sampling, we recruited 31 foraging educators across Europe. Through semi-structured interviews, we inquired about their sources of knowledge, modalities of transmission and their roles as educators. The interviews revealed individuals who convey ethnobotanical knowledge to improve human-nature connection through experiences within nature. The educators gained their knowledge through written sources, vertical and horizontal sharing. Finally, foraging educators consider themselves social bridges of ecological knowledge, bringing scientific ethnobotanical information to a varied audience in an experiential way. Foraging stimulates the sharing of ecological knowledge, and it could be seen as a broader agroecological practice, enhancing the benefits of nature's contribution to people. There is great potential for emerging environmental education platforms and, correspondingly, for rethinking the food system
    corecore