The goal of this dissertation was to improve our abilities in acquiring critical in vivo data by establishing embryo-larva zebrafish as an exemplary model to quantitatively evaluate cancer progression. The living environment that encompasses a tumor has a significant effect on how cancer develops, grows and metastasizes. In order to study cancer, we must observe it in this influential environment. Zebrafish embryo-larva provide a vertebrate anatomy that provides a window into how cancer cells behave. In this dissertation, I demonstrate how embryo-larva zebrafish can be utilized to study glioblastoma cell progression, how to capture and quantitate those aspects of progression and how they can be used to effectively evaluate potential cancer therapeutics.
Presented in this work are three chapters of original work with the second and third being published and the fourth comprising both published and soon to be published work. The second chapter of this dissertation examines laminin alpha 5’s, an extracellular matrix protein, effects on glioblastoma progression. By using embryo-larva zebrafish for xenografts, we determined laminin alpha 5 impaired glioblastoma invasion throughout the brain and encouraged microtumor formation. With this work, we were the first to demonstrate laminin alpha 5’s effect on glioblastoma in an in vivo setting, which were contrary to what was observed in vitro. Furthermore, we designed methodology for others to examine cancer invasion and progression using zebrafish and freely available image analysis software.
In the third chapter, I present commentary and methodology for quantitatively analyzing cancer cell invasion in a 4D environment. Within this chapter, I present methods for using ImageJ/Fiji software to track cancer cell movement and provide 3D time-lapse data. Additionally, I present quantifiable attributes to describe and measure cancer cell invasion that can be taken from the cell tracking data. This work was published with Microscopy and Microanalysis in conjunction with a poster that was presented at their annual 2017 conference which went on to win the top prize in its category that day.
For the fourth chapter of this dissertation, several potential cancer fighting drugs are tested on various cancer types using zebrafish xenografts. All tested drugs take advantage of the pro-survival protein, Bcl-2, where they bind and alter its conformation into a pro-death protein. The chapter is composed of three sections where the first section demonstrates a peptide’s, NuBCP-9, ability to induce apoptosis in chemotherapy resistant lung cancer cells in a Bcl-2 dependent manner. The second section establishes a nanoparticle light-based delivery system for the peptide where we successfully reduce growth on chemotherapy cancer cells in zebrafish xenografts. Lastly, in the third section, we test a number of small molecule drugs for their effectiveness in treating chemotherapy resistant lung cancer and triple negative breast cancer in zebrafish xenografts.
Finally, in my fifth chapter, I discuss some noteworthy insights gained while conducting zebrafish xenograft experiments.