The aim of this thesis was to develop novel treatment strategies for different types of eye melanoma utilizing zebrafish models. We first establish orthotopic and ectopic xenograft models for uveal... Show moreThe aim of this thesis was to develop novel treatment strategies for different types of eye melanoma utilizing zebrafish models. We first establish orthotopic and ectopic xenograft models for uveal and conjunctival melanoma by engraftment of the immortalized cells derived from these tumors into zebrafish embryos. Next, we expanded these models with spheroids and zebrafish patient-derived xenografts for pre-clinical, personalized screening of anti-uveal melanoma drug responses. We demonstrated that these models can be harnessed to explore the in vivo interactions of the tumor cells with blood vessels and macrophages leading to angiogenic response. We finally apply the conjunctival melanoma model to clarify the inhibitory effects of ginsenosides and correlate their structures with potential antitumoral mechanisms. Show less
As leading cause of death worldwide, cancer is responsible for nearly 10 million deaths in 2020 according to World Health Organization (WHO). Cisplatin and its derivatives are commonly used... Show moreAs leading cause of death worldwide, cancer is responsible for nearly 10 million deaths in 2020 according to World Health Organization (WHO). Cisplatin and its derivatives are commonly used chemotherapy agents for current cancer treatment in the clinics. While such metallodrugs are urgent to be improved because they are often accompanied by severe side effects to the patients. Alternatively, ruthenium-based complex are considered as more promising candidates due to their appealing photochemistry and photophysical properties. These properties offer possibility to activate such complex by external light, which realizes a better partial targeting to tumor region and thus reduces the side effect of the metallodrugs. To further optimize the tumor selectivity of ruthenium complexes, in this thesis, a series of ruthenium(Ⅱ) polypyridine-peptide conjugates were synthesized differential in polypyridine ligand, peptide sequence, and/or chirality. Their structure, photochemistry, in vitro cellular behaviors, and in vivo antitumor efficiency, were widely studied and compared. My study confirmed that the conjugation of peptides with ruthenium complexes is one of the most promising tools for improving their potential as clinical drugs, which provides a strong basis for the design and application of more ruthenium-peptide candidates for active tumor targeting in the future. Show less
Cryogenic electron microscopy (cryo-EM) is a powerful technique used to visualize the inside of cells and to study specific protein complexes. Within this thesis, I describe the use of various cryo... Show moreCryogenic electron microscopy (cryo-EM) is a powerful technique used to visualize the inside of cells and to study specific protein complexes. Within this thesis, I describe the use of various cryo-EM techniques to gain insight into the structural changes of the human pathogen, Vibrio cholerae, as it transitions between different environments. A combination of established and novel techniques is used to prepare the individual cells for cryogenic electron tomography (cryo-ET). For example, I designed a manual plunge freezing apparatus to prepare cryo-EM samples off site and subsequently image them with cryo-ET. Furthermore, I used light microscopy and serial block face scanning EM imaging to visualize changes to the cells’ morphology and structure when transitioning from the environment, into the natural host, the zebrafish (Danio rerio), and back into the environment. In addition, this thesis demonstrates how ultraviolet-C radiation of cryo-EM samples of V. cholerae and the ICP1 bacteriophage can be used to inactivate the pathogen while retaining their ultrastructural details. Lastly, this thesis outlines current and novel methods for processing of larger, more complex samples for cryo-ET. These techniques, together with new models of host-pathogen interactions, offer new tools for exploring microbial interactions with their environments. Show less
