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- Karlsson, Henning, 1985-
(author)
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New preclinical strategies for characterization and development of anticancer drugs
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Increased understanding of the molecular mechanisms underlying cancer development has shifted drug discovery towards target driven drug development the last decades, but the development of effective cancer drugs has been hampered by the lack of predictive preclinical models. 3-D cultures, considered to more accurately reflect solid tumors in vivo, have been proposed as one way to increase the predictability of clinical efficacy in cancer drug discovery and development.The aims of this thesis were to improve preclinical models for cancer drug development, with focus on colorectal cancer (CRC) and use of multicellular tumor spheroids (MCTS), and also to mechanistically characterize some potentially new anticancer drugs (papers I – IV). The most important technical improvement was the development of direct measurement of green fluorescent protein (GFP) marked cells in spheroids, simplifying live collection of viability data and enabling high-throughput screening (HTS) in the MCTS model (paper I). In paper III and IV, the 3-D model was adapted to enable studies on the interaction between drugs and radiation. Two potentially new anticancer drugs, VLX50 and VLX60, were mechanistically characterized. VLX60, a novel copper containing thiosemicarbazone, induced reactive oxygen species (ROS) formation, was selectively active against BRAF mutated colon cancer cells and exhibited anticancer activity in vivo (paper II). Furthermore, two potentially new anticancer drugs were found suitable for further development for use in combination with radiation (papers III and IV). In paper III, synergy with radiation in spheroids compared to monolayer cultured colon cancer cells was shown with the novel iron-chelating inhibitor of oxidative phosphorylation, VLX600. In paper IV, the antiprotozoal drug nitazoxanide was shown to sensitize quiescent clonogenic colon cancer cells to radiation.In conclusion, introduction of measurement of fluorescence of GFP marked cells in spheroids makes clinically relevant 3-D models feasible for HTS experiments and characterization of candidate drugs and radiosensitizers in early cancer drug discovery and development. VLX60 has several characteristics suitable for further development into a cancer drug, notably against BRAF mutated colorectal cancer cells. VLX600 and nitazoxanide show radiosensitizing properties making them promising for further development for use as cancer drugs in combination with radiation.
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| 2. |
- Senkowski, Wojciech
(author)
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High-throughput screening using multicellular tumor spheroids to reveal and exploit tumor-specific vulnerabilities
- 2017
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Doctoral thesis (other academic/artistic)abstract
- High-throughput drug screening (HTS) in live cells is often a vital part of the preclinical anticancer drug discovery process. So far, two-dimensional (2D) monolayer cell cultures have been the most prevalent model in HTS endeavors. However, 2D cell cultures often fail to recapitulate the complex microenvironments of in vivo tumors. Monolayer cultures are highly proliferative and generally do not contain quiescent cells, thought to be one of the main reasons for the anticancer therapy failure in clinic. Thus, there is a need for in vitro cellular models that would increase predictive value of preclinical research results. The utilization of more complex three-dimensional (3D) cell cultures, such as multicellular tumor spheroids (MCTS), which contain both proliferating and quiescent cells, has therefore been proposed. However, difficult handling and high costs still pose significant hurdles for application of MCTS for HTS.In this work, we aimed to develop novel assays to apply MCTS for HTS and drug evaluation. We also set out to identify cellular processes that could be targeted to selectively eradicate quiescent cancer cells. In Paper I, we developed a novel MCTS-based HTS assay and found that nutrient-deprived and hypoxic cancer cells are selectively vulnerable to treatment with inhibitors of mitochondrial oxidative phosphorylation (OXPHOS). We also identified nitazoxanide, an FDA-approved anthelmintic agent, to act as an OXPHOS inhibitor and to potentiate the effects of standard chemotherapy in vivo. Subsequently, in Paper II we applied the high-throughput gene-expression profiling method for MCTS-based drug screening. This led to discovery that quiescent cells up-regulate the mevalonate pathway upon OXPHOS inhibition and that the combination of OXPHOS inhibitors and mevalonate pathway inhibitors (statins) results in synergistic toxicity in this cell population. In Paper III, we developed a novel spheroid-based drug combination-screening platform and identified a set of molecules that synergize with nitazoxanide to eradicate quiescent cancer cells. Finally, in Paper IV, we applied our MCTS-based methods to evaluate the effects of phosphodiesterase (PDE) inhibitors in PDE3A-expressing cell lines.In summary, this work illustrates how MCTS-based HTS yields potential to reveal and exploit previously unrecognized tumor-specific vulnerabilities. It also underscores the importance of cell culture conditions in preclinical drug discovery endeavors.
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| 3. |
- Godskesen, Tove
(author)
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Patients in Clinical Cancer Trials : Understanding, Motivation and Hope
- 2015
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Doctoral thesis (other academic/artistic)abstract
- The overall aim of this thesis was to study participants' understanding of clinical cancer trials, and their motivation for participation. Of particular interest was the question of whether the patients hoped for a cure resulting from the trial. The thesis was based on four studies and used three methods: interviews, a questionnaire, and empirical bioethics. The results of Study I indicated that the participants in phase 1 trials understood most of the information provided, but were unaware of both the very small potential for treatment benefit, and the risk of harm. Patients in phase 3 trials had a good understanding of the trial, except regarding side effects and their right to withdraw. Some found it hard to ask questions and felt they needed more information (Study III). The participants in phase 1 trials were strongly motivated by the generally unrealistic hope for therapeutic benefit (Study I). When the chances of a cure are minuscule, as for participants with end-stage cancer in phase 1 trials, hope can play an important, positive role and offer meaning to one’s remaining life. However, hope for an unrealistic outcome could also deprive patients of an opportunity to spend their remaining lives, as they would otherwise choose (Study II). The participants in phase 3 trials indicated that their motivation for participation was multifaceted; the most common motivations included hope of therapeutic benefit, altruism, access to extra clinical examinations or better care, and a wish to repay society for the help they had received (Study III). After stratifying and analysing the motivation data by gender, age, education and previous experience of trial participation, males and those aged ≥65 years were significantly more motivated to participate out of a desire to reciprocate the help they had received, either because of a sense of duty or because their families or friends considered that they should attend (Study IV). In conclusion, the informed consent process seems to work relatively well, with good results within most subgroups. However, patients with end-stage cancer who are participating in phase 1 trials are a vulnerable group as they have very little potential for treatment benefit coupled with a tangible risk of harm.
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| 4. |
- Jakobsson Larsson, Birgitta, 1965-
(author)
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Quality of life, Coping and need for Support during the ALS disease trajectory
- 2016
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Doctoral thesis (other academic/artistic)abstract
- The overall aim of this thesis was to investigate quality of life, coping and emotional distress (i.e. anxiety and depression) among newly diagnosed ALS patients. An additional aim was also to investigate relatives’ experiences of the care for the patient and the support they received for themselves during the disease progression.The most nominated areas of importance for the patient’s overall QoL were family, friends and own physical health. Most patients rated their QoL as good, which did not change at subsequent measurement, despite their physical function having changed for the worse during disease progression. Some patients had symptoms of clinical anxiety and depression during the first year after diagnosis. The total quality of life score did not correlate with physical function but with depression early on after diagnosis. Most patients used support and independence as strategies to cope with the disease during the first six months after diagnosis. There were few changes early on after the diagnosis, and the patients used several different strategies. The results show that the use of coping strategies remained stable over time. Both physical function and emotional distress correlated significant with different coping strategies, with some variation during the disease progression. Relatives experienced the care of their loved one as positive and based on the patient’s needs and desires. The treatment, knowledge, support and help from the staff were important for the relatives’ feeling of security. Different factors influence the use of support for themselves. The relatives did not think of their own needs, but their focus was rather on the patient.The results of the thesis highlight the importance of providing support both to patients and their relatives during the disease progression. With early and regular evaluation on quality of life, coping and emotional well-being among the patients, the health professionals may be able to support the patients based on their specific needs, which probably will increase their quality of life.
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| 5. |
- Nygren, Christer, et al.
(author)
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Dilemmas in service transformation : a service strategy implementation case
- 2018
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In: The 28th International RESER Conference – Services in the age of contested globalization RESER2018.
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Conference paper (peer-reviewed)abstract
- This paper study a service strategy implementation case using an inductive method to catch informant-centric perspectives and create theory-centric categories leading to the findings of three dilemmas: not really service but only services, waste of potential value and no one owns services. These dilemmas can be used in servitization implementation work from a practical viewpoint and can be of value for the discussion around service strategy implementation within an industrial organisation, working with software development apart from more traditional manufacturing.
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