DEVELOPMENT AND CHARACTERIZATION OF EXTRACELLULAR AND INTRACELLULAR TARGETS IN TUMOR-INDUCED ENDOTHELIAL JUNCTION REGULATIONS
Open Access
- Author:
- Yunkunis, Tara Marie
- Area of Honors:
- Bioengineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Cheng Dong, Thesis Supervisor
Cheng Dong, Thesis Supervisor
Dr. William O Hancock, Thesis Honors Advisor - Keywords:
- signaling
VE-cadherin
calcium - Abstract:
- Tumor metastasis is characterized by disassembly of endothelial junctions, which allows for tumor extravasation and migration through the endothelium. The goal of this study was to characterize extracellular stimuli and intracellular targets that induce signaling for VE- cadherin disassembly. A2058 tumor cells, anti VCAM-1, and A2058 tumor conditioned medium, containing cytokines IL-6, IL-8, IL1β, and GRO-α, were all found to induce gap formation in endothelial cells. Each cytokine was added in recombinant and neutralized forms to test for individual effect; all gave results that indicate that they in part mediate junction breakdown. As for investigation of intracellular targets involved in VE-cadherin disassembly, p38 in the MAPK pathway and intracellular Ca2+, PKC, and MLCK in the Ca2+ pathway were investigated. Each was tested to determine its role in mediating gap formation in endothelial cells. All data was collected using Human Umbilical Vein Endothelial Cells (HUVECs) and A2058 melanoma cells. Experimental techniques include cell staining, fluorescence microscopy, and Ca2+ measurement. Finally, experimental data along with information from literature/databases was incorporated into an integrated signaling map. The graphical map was translated into two kinetic models (Ca2+ individually and combined Ca2+-p38 MAPK) via ordinary differential equation formation. Global sensitivity analysis was performed to predict influential parameters in VE-cadherin: β-catenin disassembly. In the Ca2+ pathway model, components CaM and Ca2+store and reactions involving Ca2+ext, Rac-RhoGDI and MLC are the most influential; in the combined pathway model the most sensitive targets are components MKK6, p38, and Hsp27 and reactions including MK2 and p38P, all of which fall into the p38 MAPK pathway.