15 research outputs found

    Hypoxic Adaptation and Arsenic Trioxide Treatment in Small Cell Lung Carcinoma

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    Small cell lung carcinoma (SCLC) is a very aggressive solid tumor and is often widely metastasized by the time of diagnosis. Despite good response to the initial chemotherapy, SCLC cells often develop multidrug resistance to conventionally used chemotherapeutic drugs, which cause almost all SCLC tumors to relapse. The 5-year survival rate for patients with limited disease is around 20% while it is only a few percent for patients with a disseminating disease. Arsenic trioxide (As2O3) is one of the oldest medicines used for treatment of different diseases and it is today used as first-line treatment for patients with relapsed or refractory acute promyelocytic leukemia. Here, we demonstrate that As2O3 is cytotoxic to SCLC cells and xenotransplanted SCLC tumors at clinically relevant concentrations and the effect is also sustained at hypoxic conditions. Areas of low oxygen tensions, hypoxia, are a common characteristic in solid tumors and are associated with aggressive tumor behavior, treatment resistance and poor outcome in several tumor forms. In response to hypoxia, tumor cells induce a transcriptional shift which is mainly regulated by the transcription factors hypoxia-inducible factor (HIF)-1 and HIF-2. HIF proteins consist of two subunits, an oxygen-regulated α-subunit and a constitutively expressed ÎČ-subunit. Previous reports have shown that the transcription factors are differentially regulated over time; HIF-1 primarily mediates the acute hypoxic response, whereas HIF-2 dominates during more chronic phases of hypoxia. We found that SCLC tumor specimens and cells lack expression of HIF-2α protein while HIF-1α is expressed at both acute and prolonged hypoxia. In addition, SCLC cells have a high adaptive capacity to hypoxia including a high proliferation rate and low cell death, even though we demonstrated a modest induction of well-known hypoxia-driven genes. We further show that knockdown of HIF1A using siRNA or shRNA, is not significantly affecting the cell viability of cultured SCLC cells at moderate and severe hypoxia or tumor take and tumor growth in SCLC xenografts. We found that SCLC cells are dependent on glutamine metabolism for cell viability and proliferation, in a HIF-independent fashion. The SCLC cells used here are MYC and MYCL amplified and MYC overexpression is known to stimulate glutaminolysis and lipogenesis. In HIF1A repressed cells that overexpress MYC, genes involved in these pathways are further up-regulated at hypoxic conditions. Taken together, our data indicate that the adaptive capacity to hypoxia is partially HIF-independent in MYC amplified SCLC cells

    Differential regulation of HIF-1α and HIF-2α in neuroblastoma: Estrogen-related receptor alpha (ERRα) regulates HIF2A transcription and correlates to poor outcome

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    AbstractHypoxia-inducible factors (HIFs) are differentially regulated in tumor cells. While the current paradigm supports post-translational regulation of the HIF-α subunits, we recently showed that hypoxic HIF-2α is also transcriptionally regulated via insulin-like growth factor (IGF)-II in the childhood tumor neuroblastoma. Here, we demonstrate that transcriptional regulation of HIF-2α seems to be restricted to neural cell-derived tumors, while HIF-1α is canonically regulated at the post-translational level uniformly across different tumor forms. Enhanced expression of HIF2A mRNA at hypoxia is due to de novo transcription rather than increased mRNA stability, and chemical stabilization of the HIF-α proteins at oxygen-rich conditions unexpectedly leads to increased HIF2A transcription. The enhanced HIF2A levels do not seem to be dependent on active HIF-1. Using a transcriptome array approach, we identified members of the Peroxisome proliferator-activated receptor gamma coactivator (PGC)/Estrogen-related receptor (ERR) complex families as potential regulators of HIF2A. Knockdown or inhibition of one of the members, ERRα, leads to decreased expression of HIF2A, and high expression of the ERRα gene ESRRA correlates with poor overall and progression-free survival in a clinical neuroblastoma material consisting of 88 tumors. Thus, targeting of ERRα and pathways regulating transcriptional HIF-2α are promising therapeutic avenues in neuroblastoma

    LĂ€gger strandskyddet en död hand över Lysekil? – om mottagandet av det utökade strandskyddet och dess förvĂ€ntade effekter pĂ„ kommunens utveckling

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    Lysekils kommun har en minskande och Ă„ldrande bofast befolkning samtidigt som befolkningen drastiskt ökar under sommarmĂ„naderna. UngefĂ€r hĂ€lften av bostĂ€derna stĂ„r tomma under stora delar av Ă„ret. Turister och fritidsboende utgör en tillgĂ„ng för kommunen i form av besöksnĂ€ring, samtidigt bidrar de till stigande bostadspriser. SĂ„ledes Ă€r inte fler fritidshus önskvĂ€rt utan snarare billigare bostĂ€der för Ă„retruntboende dĂ€r ett havsnĂ€ra lĂ€ge inte Ă€r prioriterat (Lysekil 2012). Strandskyddet Ă€r till för att sĂ€kra allmĂ€nhetens tillgĂ„ng till strĂ€nderna och att skydda viktiga miljöer för vĂ€xter och djur (SFS 1998:808). LĂ€nsstyrelsen i VĂ€stra Götaland har i december 2014 antagit den strandskyddsremiss i vilken det har skett en utökning av strandskyddet frĂ„n generellt 100 meter till 300 meter lĂ€ngs den bohuslĂ€nska kusten. Beslutet föregicks av en debatt dĂ€r kommunerna och andra aktörer hĂ€vdat att ett utökat strandskydd hindrar utvecklingen av kustsamhĂ€llena. Ytterligare röster hörs som menar att det Ă€r just nĂ€rheten och tillgĂ€ngligheten till naturen och strĂ€nderna som Ă€r sjĂ€lva attraktionskraften för kusten. LĂ€nsstyrelsen menar att det krĂ€vs ett utvidgat strandskydd för att sĂ€kra en hĂ„llbar utveckling av stranden (LĂ€nsstyrelsen 2014). Syftet med uppsatsen Ă€r att undersöka det utökade strandskyddets effekter och mottagande inom Lysekils kommun. Metoder som vi har anvĂ€nt oss av för att uppfylla detta syfte Ă€r samtalsintervjuer med tjĂ€nstepersoner, observationer inom kommunen samt textanalys. VĂ„ra frĂ„gestĂ€llningar Ă€r: Hur förvĂ€ntas det utökade strandskyddet pĂ„verka Lysekils kommuns utveckling? Hur mottogs beslutet om att utöka strandskyddet inom Lysekil? Resultatet visar att strandskyddet inte verkar vara den avgörande faktorn till varken utveckling eller avsaknad utveckling utan andra faktorer, arbetsmarknad, infrastruktur och attityder lyfts fram som viktigare. Det huvudsakliga missnöjet med att utvidga strandskyddet till 300 meter tycks inte vara de upp till 200 meters skillnad i strandskyddat omrĂ„de utan istĂ€llet hur processen som lett fram till beslutet har gĂ„tt till. Lysekil och de övriga berörda kommunerna i BohuslĂ€n menar att lĂ€nsstyrelsen har varit alltför generell i sin motivering bakom ett utökat strandskydd. LĂ€nsstyrelsen hĂ€vdar att de inte alls varit för generella och att översynen Ă€r vĂ€l genomarbetat och tillbakavisar kritiken. Det rĂ„der en konflikt mellan olika aktörers intressen - mellan att bevara eller exploatera och mellan olika skalnivĂ„er. De teorier vi anvĂ€nt som stöd i vĂ„r analys Ă€r relaterade till planering och förvaltning av mark och miljö i form av olika tankestrukturer – paradigm (Emmelin & Lerman 2006) och hur olika aktörer har olika kompetens om marken – skalnivĂ„er (HĂ€gerstrand 1993). Utöver dessa har vi anvĂ€nt oss av teorier som berör samhĂ€llsutveckling och platskĂ€nsla (Vallström 2014)

    "It's the key to life, everything gets easier when I have the language" : A phenomenographical study on the importance of language learning for the integration of immigrant women and men

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    Att leva i ett nytt land stĂ€ller nya utmaningar. Den nyanlĂ€nda mĂ„ste anpassa sig till nya traditioner, en ny kultur och ett nytt sprĂ„k. Att lĂ€ra sig kommunicera pĂ„ ett nytt sprĂ„k Ă€r för det mesta en komplicerad och lĂ„ng process. Det finns mĂ„nga utmaningar och motivationen och drivkraften hos den nyanlĂ€nda mĂ„ste vara stark   Syftet med den hĂ€r uppsatsen Ă€r att undersöka vilken syn nyanlĂ€nda har pĂ„ sprĂ„kets betydelse för integration och vilka faktorer de upplever som centrala för sin sprĂ„kinlĂ€rning. Uppsatsen Ă€r byggd pĂ„ tidigare forskning samt det insamlade intervjumaterialet med hjĂ€lp av fenomenografisk forskningsanalys.  En kvalitativ studie med fenomenografisk analys har genomförts, dĂ€r resultatet baseras pĂ„ data frĂ„n semistrukturerade intervjuer. Fjorton respondenter deltog i undersökningen, hĂ€lften mĂ€n och hĂ€lften kvinnor. Respondenterna Ă€r alla elever pĂ„ SFI i NĂ€ssjö kommun och intervjuerna utfördes pĂ„ NĂ€ssjö LĂ€rcenter. Intervjuerna genomfördes med hjĂ€lp av en intervjuguide som gav utrymme för följdfrĂ„gor. Resultatet har sedan analyserats med hjĂ€lp av fenomenografisk forskningsanalys med utgĂ„ngspunkt frĂ„n tidigare forskning samt det insamlade intervjumaterialet för att kunna besvara uppsatsens frĂ„gestĂ€llningar. I resultatet presenteras fem kategorier som Ă€r indelade efter respondenternas instĂ€llningar som uppkom ur intervjuerna. Kategorierna fokuserar pĂ„ deras generella instĂ€llning till sprĂ„kinlĂ€rningen och dessa Ă€r: Den glada med positiv instĂ€llning, den tacksamma som vill ge tillbaka till samhĂ€llet, den överlevande och praktiska, den uppgivna och frustrerade samt den mĂ„lmedvetna och ambitiösa som törstar efter kunskap. I resultatet framkommer det att sprĂ„ket Ă€r ett viktigt verktyg för integrationen. Resultatet visar Ă€ven att för flera av respondenterna var sprĂ„ket bĂ„de det svĂ„raste och det viktigaste med att integreras. De intervjuade diskuterade i flera fall att utan sprĂ„ket kan man inte bli en del utav samhĂ€llet och att det svenska sprĂ„ket Ă€r som en nyckel in i Sverige och samhĂ€llet. Detta belyser vikten av bĂ„de institutionell sprĂ„kutbildning och informella sĂ€tt att lĂ€ra sig sprĂ„ket.Living in a new country poses new challenges. The immigrants must adapt to new traditions, a new culture and a new language. Learning to communicate in a new language is for most people a complicated and long process. They face many challenges and the immigrant’s motivation and willingness must be strong.   The purpose of this paper has been to investigate what views immigrant have on the importance of language for integration and what factors they perceive as central to their language learning. The essay is based on previous research as well as the collected interview material using a phenomenografic research analysis. A qualitative study with phenomenografical analysis has been conducted, based on data from semi-structured interviews. Fourteen participants took part in the conducted interviews, half of the participants were men and half of them were women. The participants were all students at SFI in NĂ€ssjö Municipality and the interviews were conducted at NĂ€ssjö LĂ€rcenter. The interviews were conducted using an interview guide that gave scope for follow-up questions. The result has then been analyzed by means of a phenomenographic research analysis, starting with previous research and the collected interview material in order to answer the essay questions. The result presented five categories that were sorted according to the participants conceptions that arose from the interviews. The categories focused on their general attitude towards language learning and these were: The happy one with positive attitude, the grateful one who wants to give back to society, the survivor and the practical, the stated and frustrated as well as the goal-conscious and ambitious who thirsts for knowledge. In the result, it appeared that language is a very important tool for integration. The result also showed that for many of the participants, the language was both the most difficult and the most important matter in integrating into society. The participants discussed in several cases that without the language one cannot be a part of society and that the Swedish language is a key in to Sweden and the society. This highlights the importance of both institutional language education and informal ways of learning the language

    Arsenic trioxide is highly cytotoxic to small cell lung carcinoma cells.

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    Small cell lung carcinoma (SCLC) is an extremely aggressive form of cancer and current treatment protocols are insufficient. SCLC have neuroendocrine characteristics and show phenotypical similarities to the childhood tumor neuroblastoma. As multidrug-resistant neuroblastoma cells are highly sensitive to arsenic trioxide (As2O3) in vitro and in vivo, we here studied the cytotoxic effects of As2O3 on SCLC cells. As2O3 induced pronounced cell death in SCLC cells at clinically relevant concentrations, and also at hypoxia. SCLC cells were more sensitive than non-SCLC cells to As2O3. Cell death was mainly due to necrosis, although apoptotic responses were also seen. A significant in vivo effect of As2O3 on SCLC growth was shown in a nude mice-xenograft model, although a fraction of the treated tumor-bearing animals did not respond. The nonresponding SCLC tumors differed in morphology and cell organization compared with treatment-responsive tumors, which in turn, showed decreased vascularization and higher expression of neuroendocrine markers compared with control tumors. Our results suggest a potential clinical application of As2O3 in SCLC therapy. In addition to cell death induction, antiangiogenic induction of differentiation may also be part of the in vivo effect of As2O3 on SCLC growth, as suggested by an increase in neuroendocrine markers in cultured cells
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