Molecular signatures of progression and chemoresistance in epithelial ovarian carcinoma

Epithelial ovarian carcinoma (EOC) is a heterogeneous disease generally classified into five histopathological subtypes; low- and high-grade serous, endometrioid, clear cell and mucinous carcinomas. Although each subtype has distinct clinical and molecular characteristics, they are all treated with surgery and platinum/ taxane chemotherapy. Despite initial responsiveness a majority of patients relapse into platinum-resistant and disseminated disease. This, together with often late diagnosis, makes EOC the most lethal gynecological cancer. Dissemination is mainly abdominal, via exfoliated tumor cells in peritoneal ascitic fluid. The origin and phenotype of cells in malignant ascites is poorly understood. Tumor progression of carcinomas towards metastasis includes epithelial-to-mesenchymal-transition (EMT), where epithelial cells gain a mesenchymal morphology to facilitate invasion. Progression and chemoresistance have also been attributed to a small population of highly tumorigenic and chemoresistant cancer stem cells, or tumor-initiating cells (TICs). In addition, altered cellular energetics is a hallmark of cancer wherefore tumor-specific metabolic features are potential targets for overcoming chemoresistance. In Paper I cell populations in malignant ascites were found to differ significantly with respect to protein expression levels of EMT and TIC markers. We identified two potential TIC profiles, highlighting a biological heterogeneity in ascitic tumor cell populations. The indicated presence of cancer-associated fibroblasts (CAFs) may further contribute to malignant properties. We found that CAF marker α-SMA expression was increased in clinical stage IV, compared to stage IIIC. Paper II reveals that long-term repeated cisplatin treatment can select for and/or induce a multiresistant cell population with EMT and TIC features. Resistance could be linked to upregulation of VDAC and HK-II, which form an anti-apoptotic complex on mitochondria. Multiresistant cells were sensitive to the lactate/ pyruvate analogue 3-BP that dissociates this complex, and particularly sensitive to 3-BP when combined with cisplatin in low doses. In Paper III expression of mitochondrial regulators PGC1α and TFAM was found to vary between EOC subtypes. For clear cell carcinomas (CCC) a profile consisting of low or undetectable levels of PGC1α, TFAM, ERα and low Ki-67 index was identified. This CCC profile, and also glycogen accumulation, was further linked to chemoresistance development in vitro. In Paper IV we used 1H NMR-based metabolomics to identify significant differences in the intracellular polar metabolome of parental and multiresistant EOC cell lines. Furthermore, we developed a tailored and reliable protocol for metabolic profiling of adherent cells, suitable for further characterization of metabolic alterations in EOC and other pathological conditions. Taken together, this thesis identifies signatures of progression and chemoresistance in EOC and highlights the need for subtype-specific treatment

Symmetric Strategy Improvement

Symmetry is inherent in the definition of most of the two-player zero-sum games, including parity, mean-payoff, and discounted-payoff games. It is therefore quite surprising that no symmetric analysis techniques for these games exist. We develop a novel symmetric strategy improvement algorithm where, in each iteration, the strategies of both players are improved simultaneously. We show that symmetric strategy improvement defies Friedmann's traps, which shook the belief in the potential of classic strategy improvement to be polynomial

“It´s not all about the food!” : Experiences among dietitians about dietary treatment with focus on lifestyle changes

Bakgrund Livsstilsrelaterade sjukdomar är idag den största dödsorsaken i Sverige, men stora möjligheter till både primär och sekundär prevention finns. För att åstadkomma detta är förändringar av kostvanor och livsstil centrala delar. Här har dietisten en viktig roll då dessa förändringar visat sig vara mycket svåra att klara av på egen hand. Men hur upplever dietister arbetet med denna patientgrupp? Ibland kan de känna sig otillräckliga i sin yrkesroll, men de upplever ändå sitt arbete som viktigt. Vidare skulle det vara intressant att undersöka vilka andra tankar och känslor som kan uppkomma hos dietister.Syfte Syftet med studien var att undersöka hur dietister upplever och hanterar att arbeta med patienter som ordineras behandling vilken innefattar en livsstilsförändring där kostomläggning ingår som en central del.Metod Fyra kvalitativa intervjuer genomfördes med dietister som arbetade med livsstilspatienter. Som stöd vid intervjuerna användes en semistrukturerad frågeguide. Intervjuerna spelades in och transkriberades sedan ordagrant. Transkriberat material analyserades med kvalitativ innehållsanalys.Resultat Dietistens arbete med denna patientgrupp upplevdes som väldigt komplext. Det var inte bara dietisternas eget arbetssätt och egenskaper som påverkade upplevelsen av att behandla dessa patienter. Även patientens beteende och hinder samt de behandlingstekniker som behärskades av dietisten hade en betydande roll. Dietisterna upplevde också att det fanns vissa begränsningar som kunde påverka deras förmåga att ge bästa behandling. Motivation hos patienten upplevdes vara av stor betydelse för att lyckas med en livsstilsförändring.Slutsats Dietister upplever att arbetet med patienter som ska genomgå en livsstilsförändring inbegriper mer än att förmedla kunskaper om kost. Motivationsfrämjande insatser betraktas som dietistens viktigaste redskap vid behandling av denna patientgrupp. Ökad kunskap om sådana behandlingsstrategier skulle därför kunna gynna både dietister och patienter.Background Lifestylerelated diseases are the most common causes of death in Sweden, but there are great options for both primary and secondary prevention. To achieve this, changes in diet and lifestyle are both central elements. Here dietitians play an important role as these changes proved to be very difficult for patients to cope with on their own. How do dietitians experience the work with these patients? Although they may feel inadequate they still feel that their work is important. Furthermore it would be interesting to examine other thoughts and feelings that may arise among dietitians.Objective The objective of this study was to examine how dietitians perceive and manage to work with patients who are prescribed treatment that involves lifestyle changes where changes in diet are central parts.Method Four qualitative interviews were conducted with dietitians working with patients undergoing lifestyle change. A semi structured topic guide was used to broadly shape the interviews. All interviews were digitaly recorded and transcribed verbatim. The transcripts were analysed with qualitative content analysis.Result Dietitians experienced work with patients undergoing lifestyle changes as very complex. Not only the dietitian’s own practice and qualities influenced the experience of treating these patients. Patientbehavior and barriers along with different treatment strategies mastered by the dietitian were also important. Dietitians experienced that there were certain limitations that could affect their ability to provide best treatment. The patients motivation was thought of as very important to achieve lifestyle changes.Conclusion This study suggests that dietitians’ work experience with patients undergoing lifestyle change includes more than just thorough knowledge about food. Promoting motivation is an important tool in treatment of these patients. Increased knowledge about different behavior modification strategies could therefore favour both patients and dietitians

An Evaluation of Structured Language Modeling for Automatic Speech Recognition

We evaluated probabilistic lexicalized tree-insertion grammars (PLTIGs) on a classification task relevant for automatic speech recognition. The baseline is a family of n-gram models tuned with Witten-Bell smoothing. The language models are trained on unannotated corpora, consisting of 10,000 to 50,000 sentences collected from the English section of Wikipedia. For the evaluation, an additional 150 random sentences were selected from the same source, and for each of these, approximately 3,200 variations were generated. Each variant sentence was obtained by replacing an arbitrary word by a similar word, chosen to be at most 2 character edits from the original. The evaluation task consisted of identifying the original sentence among the automatically constructed (and typically inferior) alternatives. In the experiments, the n-gram models outperformed the PLTIG model on the smaller data set, but as the size of data grew, the PLTIG model gave comparable results. While PLTIGs are more demanding to train, they have the advantage that they assign a parse structure to their input sentences. This is valuable for continued algorithmic processing, for example, for summarization or sentiment analysis

Expression of Mitochondrial Regulators PGC1α and TFAM as Putative Markers of Subtype and Chemoresistance in Epithelial Ovarian Carcinoma

<div><p>Epithelial ovarian carcinoma (EOC), the major cause of gynaecological cancer death, is a heterogeneous disease classified into five subtypes. Each subtype has distinct clinical characteristics and is associated with different genetic risk factors and molecular events, but all are treated with surgery and platinum/taxane regimes. Tumour progression and chemoresistance is generally associated with major metabolic alterations, notably altered mitochondrial function(s). Here, we report for the first time that the expression of the mitochondrial regulators PGC1α and TFAM varies between EOC subtypes; furthermore, we have identified a profile in clear-cell carcinoma consisting of undetectability of PGC1α/TFAM, and low ERα/Ki-67. By contrast, high-grade serous carcinomas were characterised by a converse state of PGC1α/TFAM, ERα positivity and a high Ki-67 index. Interestingly, loss of PGC1α/TFAM and ERα was found also in a non-clear cell EOC cell line made highly resistant to platinum in vitro. Similar to clear-cell carcinomas, these resistant cells also showed accumulation of glycogen. Altogether, our data provide mechanistic insights into the chemoresistant nature of ovarian clear-cell carcinomas. Furthermore, these findings corroborate the need to take into account the diversity of EOC and to develop subtype specific treatment strategies.</p></div

Expression status of PGC1α and TFAM in the EOC study population.

<p>Abbreviations: EOC; epithelial ovarian carcinoma, ERα; oestrogen receptor alpha, nd; not determined, ns; not significant, PR; progesterone receptor, PGC1α; Peroxisome proliferator-activated receptor gamma co-activator 1-alpha, TFAM; mitochondrial transcription factor A.</p>a<p> Across variable; tested with Fisher's exact test for subtypes, expression of ERα and PR, and Mann-Whitney U test for distribution of age and Ki-67.</p>b<p> Within variable; tested with non-parametric Chi² test.</p><p>Expression status of PGC1α and TFAM in the EOC study population.</p

Expression status of PGC1α/TFAM in EOC.

<p>Abbreviations: EOC; epithelial ovarian carcinoma, ERα; oestrogen receptor alpha, nd; not determined, ns; not significant, PR; progesterone receptor, PGC1α; Peroxisome proliferator-activated receptor gamma co-activator 1-alpha, TFAM; mitochondrial transcription factor A.</p>a<p>Across variable; tested with Fisher's exact test for subtype, expression of ERα and PR, and Kruskal-Wallis test for distribution of age and Ki-67.</p><p>Expression status of PGC1α/TFAM in EOC.</p

ERα expression and intracellular levels of glycogen in SKOV-3 and SKOV-3-R.

<p>(A) Gene expression of <i>ESR1</i> evaluated by qRT-PCR (<i>n</i> = 3). The decrease in expression in SKOV-3-R was statistically significant (<i>p</i><0.001, using independent t-test). Expression levels were normalised to <i>ACTB</i>. Error bars represent S.E.M. (B) Representative western blot showing protein expression of ERα. β-tubulin was used as a loading control. (C) Glycogen levels were evaluated using a colorimetric assay (<i>n</i> = 3). The increased level in SKOV-3-R was statistically significant (<i>p</i> = 0.027, using independent t-test). Error bars represent S.E.M.</p