224 research outputs found

    Engaging Undergraduates in Science Research: Not Just About Faculty Willingness.

    Get PDF
    Despite the many benefits of involving undergraduates in research and the growing number of undergraduate research programs, few scholars have investigated the factors that affect faculty members' decisions to involve undergraduates in their research projects. We investigated the individual factors and institutional contexts that predict faculty members' likelihood of engaging undergraduates in their research project(s). Using data from the Higher Education Research Institute's 2007-2008 Faculty Survey, we employ hierarchical generalized linear modeling to analyze data from 4,832 science, technology, engineering, and mathematics (STEM) faculty across 194 institutions to examine how organizational citizenship behavior theory and social exchange theory relate to mentoring students in research. Key findings show that faculty who work in the life sciences and those who receive government funding for their research are more likely to involve undergraduates in their research project(s). In addition, faculty at liberal arts or historically Black colleges are significantly more likely to involve undergraduate students in research. Implications for advancing undergraduate research opportunities are discussed

    Reverse mode Na+/Ca2+ exchange mediated by STIM1 contributes to Ca2+ influx in airway smooth muscle following agonist stimulation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Agonist stimulation of airway smooth muscle (ASM) results in IP<sub>3 </sub>mediated Ca<sup>2+ </sup>release from the sarcoplasmic reticulum followed by the activation of store operated and receptor operated non-selective cation channels. Activation of these non-selective channels also results in a Na<sup>+ </sup>influx. This localised increase in Na<sup>+ </sup>levels can potentially switch the Na<sup>+</sup>/Ca<sup>2+ </sup>exchanger into reverse mode and so result in a further influx of Ca<sup>2+</sup>. The aim of this study was to characterise the expression and physiological function of the Na<sup>+</sup>/Ca<sup>2+ </sup>exchanger in cultured human bronchial smooth muscle cells and determine its contribution to agonist induced Ca<sup>2+ </sup>influx into these cells.</p> <p>Methods</p> <p>The expression profile of NCX (which encodes the Na<sup>+</sup>/Ca<sup>2+ </sup>exchanger) homologues in cultured human bronchial smooth muscle cells was determined by reverse transcriptase PCR. The functional activity of reverse mode NCX was investigated using a combination of whole cell patch clamp, intracellular Ca<sup>2+ </sup>measurements and porcine airway contractile analyses. KB-R7943 (an antagonist for reverse mode NCX) and target specific siRNA were utilised as tools to inhibit NCX function.</p> <p>Results</p> <p>NCX1 protein was detected in cultured human bronchial smooth muscle cells (HBSMC) cells and NCX1.3 was the only mRNA transcript variant detected. A combination of intracellular Na<sup>+ </sup>loading and addition of extracellular Ca<sup>2+ </sup>induced an outwardly rectifying current which was augmented following stimulation with histamine. This outwardly rectifying current was inhibited by 10 μM KB-R7943 (an antagonist of reverse mode NCX1) and was reduced in cells incubated with siRNA against NCX1. Interestingly, this outwardly rectifying current was also inhibited following knockdown of STIM1, suggesting for the first time a link between store operated cation entry and NCX1 activation. In addition, 10 μM KB-R7943 inhibited agonist induced changes in cytosolic Ca<sup>2+ </sup>and induced relaxation of porcine peripheral airways.</p> <p>Conclusions</p> <p>Taken together, these data demonstrate a potentially important role for NCX1 in control of Ca<sup>2+ </sup>homeostasis and link store depletion via STIM1 directly with NCX activation.</p

    Endocrine resistance in breast cancer: new roles for ErbB3 and ErbB4

    Get PDF
    Endocrine resistance is a major limitation to the successful treatment of estrogen receptor-positive (ER+) breast cancer, and the EGFR (epidermal growth factor receptor) and ErbB-2 receptor tyrosine kinases are involved in this process. A recent study now implicates the other two ErbB family members, ErbB-3 and -4. Exposure of ER+ breast cancer cells to the pure antiestrogen, fulvestrant, increased levels of ErbB-3 or ErbB-4 and sensitivity to the growth-stimulatory effects of heregulin ݱ, a potent ligand for these receptors. Thus, the initial growth-inhibitory effects of fulvestrant appear compromised by cellular plasticity that allows rapid compensatory growth stimulation via ErbB-3/4. Further evaluation of pan-ErbB receptor inhibitors in endocrine-resistant disease appears warranted

    Surgical management of mesh-related complications after prior pelvic floor reconstructive surgery with mesh

    Get PDF
    Contains fulltext : 96379.pdf (publisher's version ) (Closed access)INTRODUCTION AND HYPOTHESIS: The objective of this study is to evaluate the complications and anatomical and functional outcomes of the surgical treatment of mesh-related complications. METHODS: A retrospective cohort study of patients who underwent complete or partial mesh excision to treat complications after prior mesh-augmented pelvic floor reconstructive surgery was conducted. RESULTS: Seventy-three patients underwent 30 complete and 51 partial mesh excisions. Intraoperative complications occurred in 4 cases, postoperative complications in 13. Symptom relief was achieved in 92% of patients. Recurrence of pelvic organ prolapse (POP) occurred in 29% of complete and 5% of partial excisions of mesh used in POP surgery. De novo stress urinary incontinence (SUI) occurred in 36% of patients who underwent excision of a suburethral sling. CONCLUSIONS: Mesh excision relieves mesh-related complications effectively, although with a substantial risk of serious complications and recurrence of POP or SUI. More complex excisions should be performed in skilled centers

    Gut Microbiota Dysbiosis Is Associated with Inflammation and Bacterial Translocation in Mice with CCl4-Induced Fibrosis

    Get PDF
    BACKGROUND: Gut is the major source of endogenous bacteria causing infections in advanced cirrhosis. Intestinal barrier dysfunction has been described in cirrhosis and account for an increased bacterial translocation rate. HYPOTHESIS AND AIMS: We hypothesize that microbiota composition may be affected and change along with the induction of experimental cirrhosis, affecting the inflammatory response. ANIMALS AND METHODS: Progressive liver damage was induced in Balb/c mice by weight-controlled oral administration of carbon tetrachloride. Laparotomies were performed at weeks 6, 10, 13 and 16 in a subgroup of treated mice (n = 6/week) and control animals (n = 4/week). Liver tissue specimens, mesenteric lymph nodes, intestinal content and blood were collected at laparotomies. Fibrosis grade, pro-fibrogenic genes expression, gut bacterial composition, bacterial translocation, host's specific butyrate-receptor GPR-43 and serum cytokine levels were measured. RESULTS: Expression of pro-fibrogenic markers was significantly increased compared with control animals and correlated with the accumulated dose of carbon tetrachloride. Bacterial translocation episodes were less frequent in control mice than in treated animals. Gram-positive anaerobic Clostridia spp count was decreased in treated mice compared with control animals and with other gut common bacterial species, altering the aerobic/anaerobic ratio. This fact was associated with a decreased gene expression of GPR43 in neutrophils of treated mice and inversely correlated with TNF-alpha and IL-6 up-regulation in serum of treated mice along the study protocol. This pro-inflammatory scenario favoured blood bacterial translocation in treated animals, showing the highest bacterial translocation rate and aerobic/anaerobic ratio at the same weeks. CONCLUSIONS: Gut microbiota alterations are associated with the development of an inflammatory environment, fibrosis progression and bacterial translocation in carbon tetrachloride-treated mice

    Climate change and the emergence of vector-borne diseases in Europe: Case study of dengue fever

    Get PDF
    Background: Dengue fever is the most prevalent mosquito-borne viral disease worldwide. Dengue transmission is critically dependent on climatic factors and there is much concern as to whether climate change would spread the disease to areas currently unaffected. The occurrence of autochthonous infections in Croatia and France in 2010 has raised concerns about a potential re-emergence of dengue in Europe. The objective of this study is to estimate dengue risk in Europe under climate change scenarios. Methods. We used a Generalized Additive Model (GAM) to estimate dengue fever risk as a function of climatic variables (maximum temperature, minimum temperature, precipitation, humidity) and socioeconomic factors (population density, urbanisation, GDP per capita and population size), under contemporary conditions (1985-2007) in Mexico. We then used our model estimates to project dengue incidence under baseline conditions (1961-1990) and three climate change scenarios: short-term 2011-2040, medium-term 2041-2070 and long-term 2071-2100 across Europe. The model was used to calculate average number of yearly dengue cases at a spatial resolution of 10 × 10 km grid covering all land surface of the currently 27 EU member states. To our knowledge, this is the first attempt to model dengue fever risk in Europe in terms of disease occurrence rather than mosquito presence. Results: The results were presented using Geographical Information System (GIS) and allowed identification of areas at high risk. Dengue fever hot spots were clustered around the coastal areas of the Mediterranean and Adriatic seas and the Po Valley in northern Italy. Conclusions: This risk assessment study is likely to be a valuable tool assisting effective and targeted adaptation responses to reduce the likely increased burden of dengue fever in a warmer world

    Is salinity the main ecologic factor that shapes the distribution of two endemic Mediterranean plant species of the genus Gypsophila?

    Full text link
    The final publication is available at Springer via http://dx.doi.org/10.1007/s11104-014-2218-2Aims Responses to salt stress of two Gypsophila species that share territory, but with different ecological optima and distribution ranges, were analysed. G. struthium is a regionally dominant Iberian endemic gypsophyte, whereas G. tomentosa is a narrow endemic reported as halophyte. Theworking hypothesis is that salt tolerance shapes the presence of these species in their specific habitats. Methods Taking a multidisciplinary approach, we assessed the soil characteristics and vegetation structure at the sampling site, seed germination and seedling development, growth and flowering, synthesis of proline and cation accumulation under artificial conditions of increasing salt stress and effect of PEG on germination and seedling development. Results Soil salinity was low at the all sampling points where the two species grow, but moisture was higher in the area of G. tomentosa. Differences were found in the species salt and drought tolerance. The different parameters tested did not show a clear pattern indicating the main role of salt tolerance in plant distribution. Conclusions G. tomentosa cannot be considered a true halophyte as previously reported because it is unable to complete its life cycle under salinity. The presence of G. tomentosa in habitats bordering salt marshes is a strategy to avoid plant competition and extreme water stressSoriano, P.; Moruno Manchón, JF.; Boscaiu Neagu, MT.; Vicente Meana, Ó.; Hurtado, A.; Llinares Palacios, JV.; Estrelles, E. (2014). Is salinity the main ecologic factor that shapes the distribution of two endemic Mediterranean plant species of the genus Gypsophila?. Plant and Soil. 384(1-2):363-379. doi:10.1007/s11104-014-2218-2S3633793841-2Alonso MA (1996) Flora y vegetación del Valle de Villena (Alicante). Instituto de Cultura Juan Gil-Albert, AlicanteAlvarado JJ, Ruiz JM, López-Cantarero I, Molero J, Romero L (2000) Nitrogen metabolism in five plant species characteristic of gypsiferous soils. Plant Physiol 156:612–616Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot 59:206–216Ashraf MY (2009) Salt tolerance mechanisms in some halophytes from Saudi Arabia and Egypt. Res J Agric Biol Sci 5:191–206Bates LS, Waldren RP, Tear LD (1973) Rapid determination of free proline for water-stress studies. Plant Soil 39:205–207Ben-Gal A, Neori-Borochov H, Yermiyahu U, Shani U (2009) Is osmotic potential a more appropriate property than electrical conductivity for evaluating whole plant response to salinity? Environ Exp Bot 65:232–237Biondi E (2011) Phytosociology today: Methodological and conceptual evolution. Plant Biosyst 145:19–29Boscaiu M, Bautista I, Lidón A, Llinares J, Lull C, Donat P, Mayoral O, Vicente O (2013a) Environmental-dependent proline accumulation in plants living on gypsum soils. Acta Physiol Plant 35:2193–2204Boscaiu M, Llul C, Llinares J, Vicente O, Boira H (2013b) Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species. J Plant Ecol 6:177–186Bradford KJ (1990) A water relations analysis of seed germination rates. Plant Physiol 94:840–849Breckle SW (1999) Halophytic and gypsophytic vegetation of the Ebro-Basin at Los Monegros. In: Melic A, Blasco-Zumeta J (eds) Manifiesto científico por Los Monegros, vol 24, Bol. SEA., pp 101–104Brenchley JL, Probert RJ (1998) Seed germination responses to some environmental factors in the sea grass Zoostera capricorni from eastern Australia. Aquat Bot 62:177–188Cañadas EM, Ballesteros M, Valle F, Lorite J (2013) Does gypsum influence seed germination? Turk J Bot 38:141–147Chen Z, Cuin TA, Zhou M et al (2007) Compatible solute accumulation and stress-mitigating effects in barley genotypes contrasting in their salt tolerance. J Exp Bot 58:4245–4255Chutipaijit S, Cha-Um S, Sompornailin K (2009) Differential accumulation of proline and flavonoids in Indica rice varieties against salinity. Pak J Bot 41:2497–2506Cushman JC (2001) Osmoregulation in plants: implications for agriculture. Am Zool 41:758–769Debussche M, Thompson JD (2003) Habitat differentiation between two closely related Mediterranean plant species, the endemic Cyclamen balearicum and the widespread C. repandum. Acta Oecol 24:35–45Eskandari H, Kazemi K (2011) Germination and seedling properties of different wheat cultivars under salinity conditions. Not Sci Biol 3:130–134FAO (2006) Guidelines for soil descriptions, 5th edn. Food and Agricultural Organization of United Nation, RomeFerrandis P, Herranz JM, Copete MA (2005) Caracterización florística y edáfica de las estepas yesosas de Castilla-La Mancha. Invest Agrar Sist Recur For 14:195–216Flowers TJ, Hall JL (1978) Salt tolerance in Suaeda maritima (L.) Dum. The effect of sodium chloride on growth and soluble enzymes in a comparative study with Pisum sativum L. J Exp Bot 23:310–321Flowers TJ, Colmer TD (2008) Salinity tolerance in halophytes. New Phytol 179:945–963Flowers TJ, Hajibagheri MA, Clipson NJW (1986) Halophytes. Q Rev Biol 61:313–335García-Fuentes A, Salazar C, Torres JA, Cano E, Valle F (2001) Review of communities of Lygeum spartum L. in the south-eastern Iberian Peninsula (western Mediterranean). J Arid Environ 48:323–339Géhu JM (2006) Dictionnaire de Sociologie et Synécologie Végétales. J. Cramer, Berlin-Stuttgart, p 899Géhu JM (2011) On the opportunity to celebrate the centenary of modern phytosociology in 2010. Plant Biosyst 145(suppl):4–8Ghassemi F, Jakeman AJ, Nix HA (1995) Salinisation of land and water resources: human causes, extent, management and case studies. Canberra, Australia. CAB International, The Australian National University, WallingfordGrigore MN, Boscaiu M, Vicente O (2011) Assessment of the relevance of osmolyte biosynthesis for salt tolerance of halophytes under natural conditions. Eur J Plant Sci Biotech 5:12–19Grigore MN, Villanueva M, Boscaiu M, Vicente O (2012a) Do halophytes really require salts for their growth and development? An experimental approach mitigation of salt stress-induced inhibition of Plantago crassifolia reproductive development by supplemental calcium or magnesium. Not Sci Biol 4:23–29Grigore MN, Boscaiu M, Llinares J, Vicente O (2012b) Mitigation of salt stressed-induced Inhibition of Plantago crassifolia reproductive development by supplemental calcium or magnesium. Not Bot Horti Agrobo 40:58–66Hare PD, Cress WA (1997) Metabolic implications of stress-induced proline accumulation in plants. Plant Growth Regul 21:79–102Ishikawa SI, Kachi N (2000) Differential salt tolerance of two Artemisia species growing in contrasting coastal habitats. Ecol Res 15:241–247Kebreab E, Murdoch AJ (1999) Modelling the effects of water stress and temperature on germination rate of Orobanche aegyptiaca seeds. J Exp Bot 50:655–664Khan MA (2002) Halophyte seed germination: Success and Pitfalls. In: Hegazi AM, El-Shaer HM, El-Demerdashe S et al (eds) International symposium on optimum resource utilization in salt affected ecosystems in arid and semi arid regions. Desert Research Centre, Cairo, pp 346–358Khan MA, Gul B, Weber DJ (2000) Germination responses of Salicornia rubra to temperature and salinity. J Arid Environ 45:207–214Khan A, Rayner GD (2003) Robustness to non-normality of common tests for the many-sample location problem. J Appl Math Decis Sci 7:187–206Lidón A, Boscaiu M, Collado F, Vicente O (2009) Soil requirements of three salt tolerant, endemic species from south-east Spain. Not Bot Horti Agrobo 37:64–70López González G (1990) Gypsohila L. In: Castroviejo S, Laínz M, López G et al (eds) Flora Ibérica 2. Real Jardín Botánico, Madrid, pp 408–415Lutts S, Kinet JM, Bouharmont J (1996) Effects of salt stress on growth, mineral nutrition and proline accumulation in relation to osmotic adjustment in rice (Oryza sativa L.) cultivars differing in salinity resistance. Plant Growth Regul 19:207–218Madidi S, Baroudi B, Ameur FB (2004) Effects of salinity on germination and early growth of barley (Hordeum vulgare L.) cultivars. Int J Agric Biol 6:767–770Marchal FM, Lendínez ML, Salazar C, Torres JA (2008) Aportaciones al conocimiento de la vegetación gispsícola en el occidente de la provincia de Granada (sur de España). Lazaroa 29:95–100Médail F, Verlaque R (1997) Ecological characteristics and rarity of endemic plants from southern France and Corsica: implications for biodiversity conservation. Biol Conserv 80:269–281Meyer SE (1986) The ecology of gypsophile endemism in the Eastern Mojave desert. Ecology 67:1303–1313Moruno F, Soriano P, Oscar V, Boscaiu M, Estrelles E (2011) Opportunistic germination behaviour of Gypsophila (Caryophyllaceae) in two priority habitats from semi-arid Mediterranean steppes. Not Bot Horti Agrobo 9:18–23Mota JF, Sánchez Gómez P, Merlo Calvente ME, Catalán Rodríguez P, Laguna Lumbreras E, de la Cruz RM, Navarro Reyes FB, Marchal Gallardo F, Bartolomé Esteban C, Martínez Labarga JM, Sainz Ollero H, Valle Tendero F, Serra Laliga L, Martínez Hernández F, Garrido Becerra JA, Pérez García FJ (2009) Aproximación a la checklist de los gipsófitos ibéricos. An Biol 31:71–80Mota JF, Sola AJ, Jiménez-Sánchez ML, Pérez-García F, Merlo ME (2004) Gypsicolous flora, conservation and restoration of quarries in the southeast of the Iberian Peninsula. Biodivers Conserv 13:1797–1808Munns R (2002) Comparative physiology of salt and water stress. Plant Cell Environ 25:239–250Palacio S, Escudero A, Montserrat-Martí G, Maestro M, Milla R, Albert M (2007) Plants living on gypsum: beyond the specialist model. Ann Bot 99:333–343Peinado M, Martínez-Parras JM (1982) Sobre la posición fitosociológica de Gypsophila tomentosa L. Lazaroa 4:129–140Pueyo Y, Alados CL, Maestro M, Komac B (2007) Gypsophile vegetation patterns under a range of soil properties induced by topographical position. Plant Ecol 189:301–311Rasband WS (1997–2012) ImageJ. U S National Institutes of Health. http://rsb.info.nih.gov/ij/ , Bethesda, MarylandRivas-Martínez S (2005) Notions on dynamic-catenal phytosociology as a basis of landscape science. Plant Biosyst 139:135–144Rivas-Martínez S, Rivas-Saenz S (1996–2009) Worldwide bioclimatic classification system, Phytosociological Research Center, Spain. http://www.globalbioclimatics.org . Accessed 1 July 2013Rivas-Martínez S, Fernández-González F, Loidi J, Lousã M, Penas A (2001) Syntaxonomical checklist of vascular plant communities of Spain and Portugal to association level. Itinera Geobot 14:5–341Salmerón-Sánchez E, Martínez-Nieto MI, Martínez-Hernández F, Garrido-Becerra JA, Mendoza-Fernández AJ, Gil de Carrasco C, Ramos-Miras JJ, Lozano R, Merlo ME, Mota JF (2014) Ecology, genetic diversity and phylogeography of the Iberian endemic plant Jurinea pinnata (Lag.) DC. (Compositae) on two special edaphic substrates: dolomite and gypsum. Plant Soil 374:233–250Saradhi P, Alia P, Arora S, Prasad KV (1995) Proline accumulates in plants exposed to UV radiation and protects them against UV induced peroxidation. Biochem Biophys Res Commun 209:1–5Sekmen AH, Turkan I, Tanyolac ZO, Ozfidan C, Dinc A (2012) Different antioxidant defense responses to salt stress during germination and vegetative stages of endemic halophyte Gypsophila oblanceolata Bark. Environ Exp Bot 77:63–76Tipirdamaz R, Gagneul D, Duhaze C, Ainouche A, Monnier C, Ozkum D, Larher F (2006) Clustering of halophytes from an inland salt marsh in Turkey according to their ability to accumulate sodium and nitrogenous osmolytes. Environ Exp Bot 57:139–153Ungar IA (1996) Effect of salinity on seed germination, growth, and ion accumulation of Atriplex patula (Chenopodiaceae). Am J Bot 83:604–607USDA-ARS (2008) Research databases. Bibliography on salt tolerance. George E. Brown, Jr. Salinity Lab. US Dep. Agric., Agric. Res. Serv. Riverside, CA. http://www.ars.usda.gov/Services/docs.htm?docid=8908USSL Staff (1954) Diagnosis and improvement of saline and alkali soils. US Department of Agriculture Handbook no. 60, 160 ppVicente O, Boscaiu M, Naranjo M, Estrelles E, Bellés JM, Soriano P (2004) Responses to salt stress in the halophyte Plantago crassifolia (Plantaginaceae). J Arid Environ 58:463–48

    Comparative proteomic profiling reveals mechanisms for early spinal cord vulnerability in CLN1 disease

    Get PDF
    CLN1 disease is a fatal inherited neurodegenerative lysosomal storage disease of early childhood, caused by mutations in the CLN1 gene, which encodes the enzyme Palmitoyl protein thioesterase-1 (PPT-1). We recently found significant spinal pathology in Ppt1-deficient (Ppt1−/−) mice and human CLN1 disease that contributes to clinical outcome and precedes the onset of brain pathology. Here, we quantified this spinal pathology at 3 and 7 months of age revealing significant and progressive glial activation and vulnerability of spinal interneurons. Tandem mass tagged proteomic analysis of the spinal cord of Ppt1−/−and control mice at these timepoints revealed a significant neuroimmune response and changes in mitochondrial function, cell-signalling pathways and developmental processes. Comparing proteomic changes in the spinal cord and cortex at 3 months revealed many similarly affected processes, except the inflammatory response. These proteomic and pathological data from this largely unexplored region of the CNS may help explain the limited success of previous brain-directed therapies. These data also fundamentally change our understanding of the progressive, site-specific nature of CLN1 disease pathogenesis, and highlight the importance of the neuroimmune response. This should greatly impact our approach to the timing and targeting of future therapeutic trials for this and similar disorders

    Fulvestrant-induced expression of ErbB3 and ErbB4 receptors sensitizes oestrogen receptor-positive breast cancer cells to heregulin β1

    Get PDF
    Introduction We have previously reported that induction of epidermal growth factor receptor and ErbB2 in response to antihormonal agents may provide an early mechanism to allow breast cancer cells to evade the growth-inhibitory action of such therapies and ultimately drive resistant cell growth. More recently, the other two members of the ErbB receptor family, ErbB3 and ErbB4, have been implicated in antihormone resistance in breast cancer. In the present study, we have investigated whether induction of ErbB3 and/or ErbB4 may provide an alternative resistance mechanism to antihormonal action in a panel of four oestrogen receptor (ER)-positive breast cancer cell lines. Methods MCF-7, T47D, BT474 and MDAMB361 cell lines were exposed to fulvestrant (100 nM) for seven days, and effects on ErbB3/4 expression and signalling, as well as on cell growth, were assessed. Effects of heregulin β1 (HRGβ1) were also examined in the absence and presence of fulvestrant to determine the impact of ER blockade on the capacity of this ErbB3/4 ligand to promote signalling and cell proliferation. Results Fulvestrant potently reduced ER expression and transcriptional activity and significantly inhibited growth in MCF-7, T47D, BT474 and MDAMB361 cells. However, alongside this inhibitory activity, fulvestrant also consistently induced protein expression and activity of ErbB3 in MCF-7 and T47D cells and ErbB4 in BT474 and MDAMB361 cell lines. Consequently, fulvestrant treatment sensitised all cell lines to the actions of the ErbB3/4 ligand HRGβ1 with enhanced ErbB3/4-driven signalling activity, reexpression of cyclin D1 and significant increases in cell proliferation being observed when compared to untreated cells. Indeed, in T47D and MDAMB361 HRGβ1 was converted from a ligand having negligible or suppressive growth activity into one that potently promoted cell proliferation. Consequently, fulvestrant-mediated growth inhibition was completely overridden by HRGβ1 in all four cell lines. Conclusions These findings suggest that although antihormones such as fulvestrant may have potent acute growth-inhibitory activity in ER-positive breast cancer cells, their ability to induce and sensitise cells to growth factors may serve to reduce and ultimately limit their inhibitory activity
    corecore