po 154 progesterone through progesterone receptor b inhibits invasion of human breast cancer cells by targeting cytoplasmic cyclin d1

Introduction Progesterone Receptor (PR) positivity is associated with a good prognosis and better response to breast cancer treatment. Conversely, cyclin D1 (CD1) is retained a marker of poor outcome since it has been associated with breast cancer metastasis in clinical studies. Material and methods 17-Hydroxyprogesterone (OHPg) was from Sigma-Aldrich. Antibodies and Protein A/GPLUS-Agarose were from Santa Cruz Biotechnology. T47-D, MCF-7 and MDA-MB-231 human breast cancer cells from the American Type Culture Collection; Total real-time RT-PCR assay; Western blotting and immunoprecipitation; Transfections and luciferase assays; Lipid-Mediated Transfection of siRNA Duplexes; Chromatin immunoprecipitation (ChIP) assays and realtime ChIP; Wound-healing assays; Transmigration assays; Cell invasion assay; Phalloidin staining. Results and discussions Herein we provide evidences that OHPg through PR-B isoform, reduces motility and invasion of T47-D and MCF-7 breast cancer cells, by targeting the cytoplasmic CD1. Specifically, OHPg reduces CD1 expression through a transcriptional mechanism due to the occupancy of CD1 promoter at a canonical half progesterone responsive element by PR-B. This allows the recruitment of HDAC1 influencing a less permissive chromatin conformation for gene transcription and the release of RNA Pol II. CD1 has an active role in the control of cell migration and metastasis through the interaction with key components of focal adhesion such as Paxillin (Pxn). In untreated T47-D and MCF-7 cells a specific co-immunoprecipitation of endogenous cytoplasmic CD1 with Pxn was detected. Interestingly, OHPg exposure reduced the interaction between these proteins although total Pxn expression was substantially unaffected. Moreover a concomitant reduction of p-Pxn levels was observed and these effects were required for OHPg/PR-B dependent delay in cell invasion, as evidenced by assays carried out with the phoshomimetic mutants of Pxn. Conclusion Collectively these findings support the importance of PR-B expression in breast cancer cells behaviour, suggesting potentiating of PR-B signalling as a prospective useful strategy to restrict breast tumour cells invasion and metastasis

New Insights into the Apoptotic Process in Mollusks: Characterization of Caspase Genes in Mytilus galloprovincialis

Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes’ tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs) and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature

Geochemical properties of airborne particulate matter (PM10) collected by automatic device and biomonitors in a Mediterranean urban environment

The mineralogy and geochemistry (major and trace elements) of particulate matter collected from 14 April to 29 May 2003 by automatic device (PM 10) and entrapped by moss and lichen exposed in bags in a monitoring site of Naples urban area were studied with the aim to obtain useful information for risk assessment and control measures feasibility. PM10 concentrations were generally above the threshold values fixed by the 1999/30/EC directive. Constant and low intensity winds enhanced re-suspension of fine particles and dispersion of gaseous pollutants. PM10 samples contained trace elements in relatively lower amounts compared to literature reports from other Mediterranean monitoring sites. Significant correlations between Al, Ca, Cu, Fe, K, Mg and Mn indicated that soil dust largely contributed to the accumulation of fine particles on filters and exposed mosses and lichens. Highly significant correlations were also found between Ni and V, indicative of oil combustion processes, Fe, Cu and Cr, indicative of vehicle emissions and mechanical components abrasion, and Na. and Mg, indicative of marine aerosols. Lead and Hg did not correlate significantly with any other element. Comparison of element EFs, calculated with respect to the composition of Naples surface soils, indicated higher contribution of soil dust to PM and moss chemical composition compared with lichens, which in turn, according with their better preserved vitality, intercepted/absorbed more efficiently anthropogenic particles and elements of metabolic interest. Crystalline and amorphous detrital components (quartz, calcite, feldspars, volcanic glass, mica, kaolinite and smectite) and sea-bearing salts phases (halite, gypsum, Mg-K sulphates, Mg-Ca carbonates) were the main minerals in PM10, along with silica fibers and tuff particles. (c) 2007 Elsevier Ltd. All rights reserved