Skip directly to content

Coming dissertations at MedFak

  • Role of MYCN in retinoblastoma : From carcinogenesis to tumor progression Author: Hanzhao Zhang Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-523595 Publication date: 2024-03-19 08:37

    Retinoblastoma, a pediatric malignancy of the retina, is primarily driven by the bi-allelic inactivation of the RB1gene. However, a subset of cases are characterized by proficient RB1 functions but with MYCN copy number mutations, suggesting an alternative oncogenic mechanism in the absence of RB1 mutations. The aim of this thesis is to investigate the intricate molecular and cellular pathways implicated in retinoblastoma, with a particular focus on the role of MYCN expression and its interplay with the cell cycle and apoptotic pathways.

    In Paper I, we explored the regulatory mechanisms underpinning MYCN-induced retinoblastoma using aRB1-proficient MYCN-overexpressing in vivo model in embryonic chicken retina and MYCN-transformed cells in culture. Our findings revealed that MYCN overexpression led to a significant upregulation of E2F levels, thereby dysregulating the cell cycle and mimicking the mechanistic phenotype of RB1-deficient tumors. Inhibition on E2f DNA-binding activity efficiently normalized growth and apoptosis in MYCN-transformed cells in culture. Despite RB1 proficiency, the elevated E2F levels induced a neoplastic behavior in retinal cells, indicating a novel mechanism of retinoblastoma carcinogenesis independent of RB1 inactivation.

    Paper II employed single-cell RNA sequencing to dissect the cellular composition of MYCN-driven retinoblastoma in chicken in vivo model, revealing a predominant origin in cone photoreceptor progenitors. This finding suggested a cell-type-specific vulnerability to MYCN-induced transformation. The research further identifies a notable heterogeneity within the MYCN-transformed cells, with a subset of cells exhibiting non-cone photoreceptor features but features of other neurons like ganglion cells. A cluster was also identified withelevated expression of genes related to malignancy and tumor progression, including UBE2C and TOP2A. This suggested a link between MYCN overexpression and tumor development, potentially mediated through the E2F pathway.

    In Paper III, the focus shifted to the interplay between MYCN expression, E2f activity, and the p53 pathway in human retinoblastoma cell lines exhibiting both RB1 deficiency and MYCN amplification. By modulating E2f and p53 pathway activities using chemical inhibitors, we demonstrated the essential role of MYCN expression level in mediating p53-driven growth inhibition and highlighted the independent effects of E2f inhibition and p53 activation by a Mdm2 inhibitor.

    Together, these studies illuminate the intricate molecular pathways involved in MYCN-amplified retinoblastoma, emphasizing the pivotal role of MYCN in disrupting cell cycle regulation and promoting tumorigenesis. These insights not only advance our understanding of retinoblastoma pathogenesis but also provide potential therapeutic targets within the MYCN-E2F axis, offering novel treatment strategies in MYCN-amplified retinoblastoma.

  • Patients’ Access to Their Mental Health Records : Understanding Policy, Access, and Patient Experiences Author: Annika Bärkås Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-522720 Publication date: 2024-03-15 14:21

    ORA is the concept of patients' access to clinical information, which has become more widespread worldwide. When patients are provided online record access (ORA) to their health records, concerns have been raised by healthcare professionals, especially when it comes to patients with mental health diagnoses. In the general population, positive aspects appear to outweigh the negative, yet limited research has so far explored the impact of ORA in mental healthcare. 

    The overall aim of this thesis was to explore how patients experience ORA in mental healthcare through four studies: 1) a literature review aimed to explore the current literature on the experiences of ORA among mental healthcare patients, care partners, and healthcare professionals, 2) a document analysis combined with key stakeholder email interviews that aimed to explore to what extent ORA in mental healthcare has been implemented in Sweden including national and local policy regulations, 3) an online patient survey study aimed to understand mental healthcare patients' experiences with ORA in Sweden, Estonia, Finland, and Norway, and 4) an online patient survey study aimed to understand if and how patients with mental health conditions experiences of ORA differs from patients in other healthcare settings. 

    More patients reported positive experiences with ORA in mental healthcare than negative experiences. Common benefits of ORA included, among others, a greater sense of control over their care, improved understanding of their mental health diagnosis, and better adherence to appointments. Despite patients' predominant positive experiences, only 17 out of 21 regions in Sweden offered ORA in mental healthcare in 2021. Additionally, many patients experienced errors and omissions and felt offended by the content of their health records. Mental healthcare patients experienced this at a higher rate than patients in other healthcare settings.

    In conclusion, mental healthcare patients have higher rates of negative experiences of ORA compared to patients in other healthcare settings. However, patients' experiences of ORA are still predominantly positive among both patient groups. Yet, in 2021, only 17 regions offered patients ORA in mental healthcare. Denying mental healthcare patients ORA to protect them from negative experiences could instead increase stigma in this patient group.

  • Advanced molecular tools for diagnostic analyses of RNA and antibodies in situ and in solution Author: Mengqi Wang Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-522118 Publication date: 2024-02-29 11:31

    Advanced molecular diagnostics uses in vitro biological assays to detect nucleic acids or proteins even in low concentrations across samples, allowing for the identification of biomarkers, monitoring the course of the disease over time, and selection of appropriate therapy. In this thesis, I focus on development and early applications of several molecular tools of expected value in research, and eventually also clinically. 

    In papers I and II, proximity extension assay (PEA) was for the first time modified to measure specific antibody responses, rather than protein levels as in the standard PEA. We call the method AbPEA and the technique was used to sensitively measure antibody responses to the spike protein or the nucleocapsid of SARS-CoV-2. We demonstrated that AbPEA has high specificity, sensitivity, and broad dynamic range, along with multiplexing potential, offering performance similar to that of other methods for antibody measurements. We demonstrated utilization of blood and saliva samples in paper I and paper II, respectively, which further establish that our approach has great potential for large-scale screening and biobanking. 

    In paper III, we aimed to investigate how the protein composition of extracellular vesicles (EVs) differed among blood samples collected from healthy individual or ones with either mild or severe COVID-19. Proximity barcoding assay was applied to obtain a comprehensive overview of the protein composition of large numbers of individual EVs, demonstrating interesting differences. 

    In paper IV, we enhanced padlock-RCA-based RNA genotyping in situ by using another newly developed technology for highly selective detection of DNA or RNA sequence variants, referred to as super RCA (sRCA). Our analysis showed that this approach can improve the selectivity for sequence variants during in situ detection of mutant or wild-type transcripts, and the signals representing superRCA reaction products are prominent and easily distinguished from any background.

Pages