Prostate cancer is the second most commonly diagnosed cancer in men worldwide. Because prognosis can vary depending on tumour stage, precise diagnosis is vital. Circulating tumour cells (CTC) detach from primary and secondary tumour sites into the bloodstream. Changes in three-dimensional (3D) nuclear organization are associated with different types of cancer and were examined in this study in CTCs of high-risk prostate cancer patients. CTCs were isolated from 3mL of patient blood samples of 20 high-risk prostate cancer patients before treatment; after neoadjuvant androgen deprivation therapy (ADT) but before radiotherapy (RT); and after completing RT. Telomere-specific fluorescence in situ hybridization was performed on filters containing cells, 3D images of 30 CTCs per filter were analysed. Changes in telomere organization were observed post ADT and RT; patients fell into three groups depending on the change in CTC telomeric profiles in response to ADT. These groups displayed responses characteristic to each group upon delivery of RT. 3D nuclear telomere profiles in CTCs post-ADT may indicate both ADT response and predict RT response in high-risk prostate cancer. / October 2016

The majority of women with ovarian cancer (OC) have advanced disease at diagnosis and 5-year survival rates of less than 25%. Women with stage I disease have significantly better 5-year survival rates of over 90%. Recent large studies using CA 125 and transvaginal ultrasound have failed to improve mortality in a screened population. There is therefore a pressing need for new diagnostic biomarkers in OC. The primary aim of my project, as a first step in developing a diagnostic circulating tumour DNA (ctDNA) biomarker for high grade serous ovarian cancer (HGSOC), was to investigate low-cost high-throughput next generation sequencing assays in plasma samples collected from women with newly diagnosed OC. The secondary aim was to apply these methods to other non-invasive samples including cervical liquid based cytology samples that might contribute to earlier diagnosis or screening for women with OC. ctDNA was detected in 30-49% of women with newly diagnosed OC from the UKOPS (n=54) and CTCR-OV04 (n=156) cohorts using targeted sequencing. Using the trimmed median absolute deviation (t-MAD) score, a quantitative measure of genome wide copy number aberration generated from shallow whole genome sequencing (sWGS) data, ctDNA was detected in 39-41% of the women with newly diagnosed disease. To improve sensitivity of ctDNA detection I developed an optimised method for targeted sequencing that has the potential to lower the limit of detection of ctDNA in HGSOC by 100 fold. I have also shown that the size profile of HGSOC ctDNA fragments is different to that of wildtype DNA fragments and shown that selecting for DNA fragments between 90-150 bp can increase rates of ctDNA detection in HGSOC. ctDNA detection increased to 53-67% of women with newly diagnosed OC using the size selected t-MAD score. I have evaluated the utility of cervical sampling for earlier diagnosis of OC by testing and optimising DNA extraction, library preparation and sequencing methods. I have detected tumour DNA in routine cervical cytology samples collected from women subsequently diagnosed with cervical and endometrial cancers. In summary I have developed methods for ctDNA detection in women with newly diagnosed HGSOC that can be applied and refined in larger prospective studies of women undergoing follow-up for treated HGSOC, women with symptoms suggestive of OC and women at high risk of OC.

Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2007.

Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.

Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.

Thesis (doctoral)--University of Göteborg, 1992. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (doctoral)--University of Göteborg, 1992. / Added t.p. with thesis statement inserted. Includes bibliographical references.

No description available.

Yes / Circulating tumour cells (CTCs) have significant diagnostic potential as they can reflect both the presence and recurrence of a wide range of cancers. However, this potential continues to be limited by the lack of robust and accessible isolation technologies. An alternative to isolation might be their direct detection amongst other peripheral blood cells, although this would require markers that allow them to be distinguished from an exceptionally high background signal. This review assesses the potential role of HOX genes, a family of homeodomain containing transcription factors with key roles in both embryonic development and oncogenesis, as unique and possibly disease specific markers of CTCs.

Endometriosis is a common cause of subfertility and pelvic pain, affecting up to 10% of women of reproductive age. It is characterised by the presence of endometrial-like tissue outside the uterus. The development of the disease is still poorly understood and, currently, the diagnosis relies on visualisation of typical lesions during surgery. There is great interest in identifying biomarkers to assist in diagnosis and disease management. Blood vessel development is known to be a crucial feature of endometriosis, but the mechanisms involved in angiogenesis are not well described for this disease. Most vessel development relies on the proliferation and migration of pre-existing endothelial cells. However, there may also be roles for cells derived from peripheral blood (circulating angiogenic cells) and surrounding stromal cells. In this thesis, the contribution of these different cell types to vessel development in endometriosis is assessed. In chapter 2, a robust protocol was optimised to identify circulating angiogenic cells (CACs) with flow cytometry. The reliability of the protocol was verified, and the level of these cells was found not to fluctuate with the menstrual cycle in healthy women (P=0.279, F=1.359, 3 d.f.). In chapter 3, levels of CACs in women with and without endometriosis were found to be equivalent (0.0835% ± 0.0422 compared to 0.0724% ± 0.0414), demonstrating that they have no use as a disease biomarker. In chapter 4, isolation and culture of endothelial cells from the endometrium was attempted. However, a pure culture of endometrial endothelial cells could not be obtained, which may be due to contamination by other cell types or cellular transdifferentiation. Finally, in chapter 5, the contribution of endometrial stromal cells to vessel development was considered. Stromal cells were found not to differentiate towards an endothelial cell phenotype, but were able to participate in tube formation assays. However, the presence of endometriosis did not influence this behaviour.