Ovarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of OC are limited and... Show moreOvarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of OC are limited and hard to establish. We present a protocol that enables efficient derivation and long-term expansion of OC organoids. Utilizing this protocol, we have established 56 organoid lines from 32 patients, representing all main subtypes of OC. OC organoids recapitulate histological and genomic features of the pertinent lesion from which they were derived, illustrating intra-and interpatient heterogeneity, and can be genetically modified. We show that OC organoids can be used for drug-screening assays and capture different tumor subtype responses to the gold standard platinum-based chemotherapy, including acquisition of chemoresistance in recurrent disease. Finally, OC organoids can be xenografted, enabling in vivo drug-sensitivity assays. Taken together, this demonstrates their potential application for research and personalized medicine. Show less
Cells respond to extracellular cues via receptor signaling. In this manner, cellular behavior is under strict control of hormones, growth factors or neurotransmitters. Binding of a ligand to its... Show moreCells respond to extracellular cues via receptor signaling. In this manner, cellular behavior is under strict control of hormones, growth factors or neurotransmitters. Binding of a ligand to its cognate receptor triggers a cascade of intracellular signaling events leading to, for instance, activation of transcription factors, regulation of metabolic processes or changes in cell morphology. To regulate such __organized complexity__, molecular interactions in the cell are specific and regulated. Furthermore, these signaling pathways are strictly compartmentalized. This means that spatial restriction facilitates the coupling of a signaling component to its effectors, while it leaves other signaling compartments unaffected. Thus, compartmentalization adds to the specificity of signaling cascades. Signaling complexes are dynamically regulated, i.e. they can be assembled in response to extracellular signals. The dynamic targeting of a signaling molecule to a specialized compartment becomes manifest as a stimulus-induced translocation. In this thesis, we revealed and studied the translocations of two proteins: those of chloride intracellular channel 4 (CLIC4) and exchange protein directly activated by cAMP 1 (Epac1). Central in these studies were the microscopical techniques that allowed visualization of these translocations with maximal spatiotemporal resolution, most prominently via confocal imaging and measurement of FRET. Show less
