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- Aguilar, Helena, et al.
(författare)
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VAV3 mediates resistance to breast cancer endocrine therapy
- 2014
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Ingår i: Breast Cancer Research. - : BioMed Central. - 1465-5411 .- 1465-542X. ; 16:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Endocrine therapies targeting cell proliferation and survival mediated by estrogen receptor alpha (ERalpha) are among the most effective systemic treatments for ERalpha-positive breast cancer. However, most tumors initially responsive to these therapies acquire resistance through mechanisms that involve ERalpha transcriptional regulatory plasticity. Here, we identify VAV3 as a critical component in this process.METHODS: A cell-based chemical compound screen was carried out to identify therapeutic strategies against resistance to endocrine therapy. Binding to ERalpha was evaluated by molecular docking analyses, an agonist fluoligand assay, and short-hairpin (sh) RNA-mediated protein depletion. Microarray analyses were performed to identify altered gene expression. Western blot of signaling and proliferation markers and shRNA-mediated protein depletion in viability and clonogenic assays were performed to delineate the role of VAV3. Genetic variation in VAV3 was assessed for association with the response to tamoxifen. Immunohistochemical analyses of VAV3 were carried out to determine the association with therapy response and different tumor markers. An analysis of gene expression association with drug sensitivity was carried out to identify a potential therapeutic approach based on differential VAV3 expression.RESULTS: The compound YC-1 was found to comparatively reduce the viability of cell models of acquired resistance. This effect was probably not due to activation of its canonical target (soluble guanylyl cyclase) but instead a result of binding to ERalpha. VAV3 was selectively reduced upon exposure to YC-1 or ERalpha depletion and, accordingly, VAV3 depletion comparatively reduced the viability of cell models of acquired resistance. In the clinical scenario, germline variation in VAV3 was associated with response to tamoxifen in Japanese breast cancer patients (rs10494071 combined P value = 8.4 x 10-4). The allele association combined with gene expression analyses indicated that low VAV3 expression predicts better clinical outcome. Conversely, high nuclear VAV3 expression in tumor cells was associated with poorer endocrine therapy response. Based on VAV3 expression levels and the response to erlotinib in cancer cell lines, targeting EGFR signaling may be a promising therapeutic strategy.CONCLUSIONS: This study proposes VAV3 as a biomarker and rationale signaling target to prevent and/or overcome resistance to endocrine therapy in breast cancer.
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| 2. |
- Asiimwe, Savina, et al.
(författare)
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Ethnobotanical study of nutri-medicinal plants used for the management of HIV/AIDS opportunistic ailments among the local communities of western Uganda
- 2013
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Ingår i: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741 .- 1872-7573. ; 150:2, s. 639-648
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Tidskriftsartikel (refereegranskat)abstract
- Ethnopharmacological relevance: Herbal remedies are a source of therapeutics for nearly 80% of the population in Uganda. Poor health facilities and limited access to antiretroviral drugs have perpetuated and increased the use of traditional medicine especially in rural areas for the treatment of opportunistic ailments of HIV/AIDS. To document the traditional uses of nutri-medicinal plants in the management of immunocompromised ailments associated with HIV/AIDS. To document the parts and growth forms of plants used, methods of preparation and administration of the herbal remedies. Materials and methods: The study was conducted in Mbarara and Isingiro districts of western Uganda between December 2010 and May 2011. Ethnobotanical information was collected from 64 respondents who were sampled based on recommendations of local elders and administrators. Ethnobotanical data on the use of nutri-medicinal plants for traditional treatment of HIV/AIDS opportunistic ailments were collected by employing semi-structured interviews with selected respondents, house hold visits and field observations as described by (Martin, 1995a). The respondents were mainly traditional medical practitioners who treat patients who are already receiving antiretroviral drugs. Fidelity levels of plant species and informant consensus factor were determined to show the percentage of informants claiming the use of certain plant species for the same major purpose and to analyse people's knowledge of plant use. Results: The study revealed 81 plant species most of which were herbs (49%). Leaves (71%) were the most frequently used parts in remedy preparations which were mainly administered orally (85%). The majority of plants (54%) were harvested from wild populations. Hibiscus sabdariffa L, Plumeria obtusa L, and Abutilon guineense (Shumach.) Baker. F and Exell were the nutri-medicinal plants that scored the highest Fidelity level values. The informant's consensus about usages of plants ranged from 0.75 to 0.80. Plants that are presumed to be effective in treating a certain disease have higher informant consensus factor (ICF) values. Family Asteraceae accounted for 18% of the total species recorded. Thirteen species (16%) of the plants are edible and provide nutritional support. Conclusion: The study recorded plant species with potential to treat ailments associated with immunocompromised people living with HIV/AIDS in western Uganda. Such studies can help stimulate confidence in traditional medicine and enhance appreciation of herbal medicine among the people and to appreciate the value of the plant resources and therefore enhance conservation efforts of the plant species. The high consensus means the majority of informants agree on the use of plant species and this reflects the intercultural relevance and the agreement in the use of the nutri-medicinal plants to the people. We recommend the documented plants for further Ethnopharmacological studies.
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| 3. |
- Maxwell, Christopher A., et al.
(författare)
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Interplay between BRCA1 and RHAMM Regulates Epithelial Apicobasal Polarization and May Influence Risk of Breast Cancer
- 2011
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Ingår i: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885 .- 1544-9173. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Differentiated mammary epithelium shows apicobasal polarity, and loss of tissue organization is an early hallmark of breast carcinogenesis. In BRCA1 mutation carriers, accumulation of stem and progenitor cells in normal breast tissue and increased risk of developing tumors of basal-like type suggest that BRCA1 regulates stem/progenitor cell proliferation and differentiation. However, the function of BRCA1 in this process and its link to carcinogenesis remain unknown. Here we depict a molecular mechanism involving BRCA1 and RHAMM that regulates apicobasal polarity and, when perturbed, may increase risk of breast cancer. Starting from complementary genetic analyses across families and populations, we identified common genetic variation at the low-penetrance susceptibility HMMR locus (encoding for RHAMM) that modifies breast cancer risk among BRCA1, but probably not BRCA2, mutation carriers: n = 7,584, weighted hazard ratio ((w)HR) = 1.09 (95% CI 1.02-1.16), p(trend) = 0.017; and n = 3,965, (w)HR = 1.04 (95% CI 0.94-1.16), p(trend) = 0.43; respectively. Subsequently, studies of MCF10A apicobasal polarization revealed a central role for BRCA1 and RHAMM, together with AURKA and TPX2, in essential reorganization of microtubules. Mechanistically, reorganization is facilitated by BRCA1 and impaired by AURKA, which is regulated by negative feedback involving RHAMM and TPX2. Taken together, our data provide fundamental insight into apicobasal polarization through BRCA1 function, which may explain the expanded cell subsets and characteristic tumor type accompanying BRCA1 mutation, while also linking this process to sporadic breast cancer through perturbation of HMMR/RHAMM.
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| 4. |
- Spurdle, Amanda B., et al.
(författare)
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Common Genetic Variation at BARD1 Is Not Associated with Breast Cancer Risk in BRCA1 or BRCA2 Mutation Carriers
- 2011
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Ingår i: Cancer Epidemiology Biomarkers & Prevention. - 1538-7755 .- 1055-9965. ; 20:5, s. 1032-1038
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Tidskriftsartikel (refereegranskat)abstract
- Background: Inherited BRCA1 and BRCA2 (BRCA1/2) mutations confer elevated breast cancer risk. Knowledge of factors that can improve breast cancer risk assessment in BRCA1/2 mutation carriers may improve personalized cancer prevention strategies. Methods: A cohort of 5,546 BRCA1 and 2,865 BRCA2 mutation carriers was used to evaluate risk of breast cancer associated with BARD1 Cys557Ser. In a second nonindependent cohort of 1,537 of BRCA1 and 839 BRCA2 mutation carriers, BARD1 haplotypes were also evaluated. Results: The BARD1 Cys557Ser variant was not significantly associated with risk of breast cancer from single SNP analysis, with a pooled effect estimate of 0.90 (95% CI: 0.71-1.15) in BRCA1 carriers and 0.87 (95% CI: 0.59-1.29) in BRCA2 carriers. Further analysis of haplotypes at BARD1 also revealed no evidence that additional common genetic variation not captured by Cys557Ser was associated with breast cancer risk. Conclusion: Evidence to date does not support a role for BARD1 variation, including the Cy557Ser variant, as a modifier of risk in BRCA1/2 mutation carriers. Impact: Interactors of BRCA1/2 have been implicated as modifiers of BRCA1/2-associated cancer risk. Our finding that BARD1 does not contribute to this risk modification may focus research on other genes that do modify BRCA1/2-associated cancer risk. Cancer Epidemiol Biomarkers Prev; 20(5); 1032-38. (C) 2011 AACR.
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| 5. |
- Ytreberg, Agnes, et al.
(författare)
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God havsmiljö 2020 : Marin strategi för Nordsjön och Östersjön Del 3: Övervakningsprogram
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Havsmiljöförordningens övergripande mål är att upprätthålla eller uppnå en god miljöstatus i de svenska förvaltningsområdena Nordsjön och Östersjön till år 2020. En av uppgifterna i den första förvaltningsperioden är att fastställa övervakningsprogram.God miljöstatus baseras på ett ramverk av så kallade deskriptorer som anges i havsmiljödirektivet, det vill säga det EU-direktiv som i Sverige genomförs genom havsmiljöförordningen. Deskriptorerna beskriver god miljöstatus på en övergripande nivå för elva temaområden. Till varje deskriptor hör en rad kriterier som anger vad som ska ingå i en bedömning av miljöstatus. Utifrån de elva deskriptorerna har Sverige fastställt 13 övervakningsprogram. Sex program utgår ifrån olika biodiversitetsteman som berörs av en upp till tre deskriptorer, medan de övriga sju programmen utgår ifrån de deskriptorer som är mer inriktade mot belastning och miljöförändring.För varje program har ett antal underprogram föreslagits baserat på den nuvarande övervakningen och/eller planerad övervakning. Övervakning som ingår i programmen ska vara pågående och data ska vara tillgängliga. I programmen ingår nationell och regional miljöövervakning inklusive verksamhetsutövares recipientkontroll. Dessutom ingår annan typ av datainsamling som till exempel inventeringar av tumlare och uppgifter om omfattningen av mänskliga aktiviteter som orsakar belastning och miljöförändringar. Enligt havsmiljödirektivet ska övervakningen fånga upp tillstånd och miljöförändringar, belastning och omfattning av aktiviteterna som orsakar belastningen samt effekter av åtgärder. Eftersom nästa steg i havsförvaltningscykeln är att fastställa åtgärdsprogram kommer övervakning för att följa upp åtgärder att läggas till övervakningsprogrammen först under nästa förvaltningscykel.I beskrivningarna av programmen framgår hur den nuvarande övervakningen motsvarar de krav som ställs på dataunderlag genom havsmiljödirektivets bilaga III samt genom deskriptorer, kriterier, indikatorer och beslutade miljökvalitetsnormer. I dagens övervakning saknas bland annat tillräcklig övervakning för uppföljning av livsmiljöers tillstånd och utbredning. För marint avfall, buller och främmande arter saknas nationellt samordnad övervakning, men det görs regionala insatser och ett antal projekt har genomförts eller påbörjats för att öka kunskapen om hur övervakning bäst ska utformas. För de program som har pågående övervakning beskrivs utvecklingsbehoven för att förbättra underlaget för de återkommande tillståndsbedömningarna.Övervakningsprogrammet som fastställs under 2014 utgör således inte ett fast program för kunskapsinhämtning. Bristerna kommer att beaktas i det fortsatta genomförandet av havsmiljöförordningen där utveckling av indikatorer och övervakning kommer att ske kontinuerligt.
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