Beyond epithelial circulating tumour cells (CTCs) : establishing important methods for CTC isolation and analysis

This thesis has demonstrated the various applications for antibody-based CTC capture, extending beyond conventional methods. We reported the inclusion of EMT-markers for detection and characterisation of EMT-CTCs in the ovarian cancer setting. This methodological advancement may prove a critical step in understanding the role EMT plays in CTC formation, metastasis and potentially therapeutic resistance. In addition, we explored integration of electron microscopy methods into CTC sample processing, allowing for ultrastructure analysis of CTCs and improving the tools to help understand CTC biology. Finally, we explored antibody-based CTC isolation methods in the melanoma setting with additional biomarker PD-L1 detection, enabling real-time monitoring of therapy response to PD-1 inhibitors. Overall, the knowledge gained from this thesis will aid the CTC research field from three different perspectives: (1) The clinical perspective: capitalize on CTC detection by adding important biomarker detection that may indicate response to therapy; (2) The technical perspective: demonstrating feasibility of integrating electron microscopy sample preparation into CTC analyses; (3) The biological perspective: establishing EMT detection in a range of cancers

Importance and Detection of Epithelial-to-Mesenchymal Transition (EMT) Phenotype in CTCs

The current dogma is that epithelial-to-mesenchymal transition (EMT) promotes circulating tumour cell (CTC) formation and is ultimately a driver of metastasis. There is also accumulating evidence that EMT-phenotype changes are commonly associated with therapy resistance. Thus, capturing EMT-phenotype CTCs is expected to yield important clinical information in regard to prognosis and response to therapy as well as allowing the study of metastatic processes. However, the isolation and identification of EMT-phenotype CTCs with commonly used isolation/detection methods are suboptimal, and current efforts on improving the isolation of EMT-phenotype CTCs are associated with pitfalls that need to be overcome. This chapter explores the significance of EMT in CTC formation and the role of EMT in cancer metastasis and resistance to therapy. We also comprehensively review the past and current limitations of evaluating EMT phenotypes in CTC isolation and analysis and discuss how CTCs can be seen in a more holistic fashion as important biomarkers for clinical management

Evidence of general economic principles of bargaining and trade from 2,000 classroom experiments

Standardized classroom experiments provide evidence about how well scientific results reproduce when nearly identical methods are used. We use a sample of around 20,000 observations to test reproducibility of behaviour in trading and ultimatum bargaining. Double-auction results are highly reproducible and are close to equilibrium predictions about prices and quantities from economic theory. Our sample also shows robust correlations between individual surplus and trading order, and autocorrelation of successive price changes, which test different theories of price dynamics. In ultimatum bargaining, the large dataset provides sufficient power to identify that equal-split offers are accepted more often and more quickly than slightly unequal offers. Our results imply a general consistency of results across a variety of different countries and cultures in two of the most commonly used designs in experimental economics

The genomic landscape of thyroid cancer tumourigenesis and implications for immunotherapy

Thyroid cancer is the most prevalent endocrine malignancy that comprises mostly indolent differentiated cancers (DTCs) and less frequently aggressive poorly differentiated (PDTC) or anaplastic cancers (ATCs) with high mortality. Utilisation of next-generation sequencing (NGS) and advanced sequencing data analysis can aid in understanding the multi-step progression model in the development of thyroid cancers and their metastatic potential at a molecular level, promoting a targeted approach to further research and development of targeted treatment options including immunotherapy, especially for the aggressive variants. Tumour initiation and progression in thyroid cancer occurs through constitutional activation of the mitogen-activated protein kinase (MAPK) pathway through mutations in BRAF, RAS, mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway and/or receptor tyrosine kinase fusions/translocations, and other genetic aberrations acquired in a stepwise manner. This review provides a summary of the recent genetic aberrations implicated in the development and progression of thyroid cancer and implications for immunotherapy

Isolation of circulating tumor cells from glioblastoma patients by direct immunomagnetic targeting

Glioblastoma (GBM) is the most common form of primary brain cancer in adults and tissue biopsies for diagnostic purposes are often inaccessible. The postulated idea that brain cancer cells cannot pass the blood-brain barrier to form circulating tumor cells (CTCs) has recently been overthrown and CTCs have been detected in the blood of GBM patients albeit in low numbers. Given the potential of CTCs to be analyzed for GBM biomarkers that may guide therapy decisions it is important to define methods to better isolate these cells. Here, we determined markers for immunomagnetic targeting and isolation of GBM-CTCs and confirmed their utility for CTC isolation from GBM patient blood samples. Further, we identified a new marker to distinguish isolated GBM-CTCs from residual lymphocytes

Isolation of circulating tumor cells from glioblastoma patients by direct immunomagnetic targeting

Glioblastoma (GBM) is the most common form of primary brain cancer in adults and tissue biopsies for diagnostic purposes are often inaccessible. The postulated idea that brain cancer cells cannot pass the blood-brain barrier to form circulating tumor cells (CTCs) has recently been overthrown and CTCs have been detected in the blood of GBM patients albeit in low numbers. Given the potential of CTCs to be analyzed for GBM biomarkers that may guide therapy decisions it is important to define methods to better isolate these cells. Here, we determined markers for immunomagnetic targeting and isolation of GBM-CTCs and confirmed their utility for CTC isolation from GBM patient blood samples. Further, we identified a new marker to distinguish isolated GBM-CTCs from residual lymphocytes

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology