Date of Graduation

Fall 2023


Master of Science in Biology



Committee Chair

Kyoungtae Kim


Metal oxide nanoparticles (MONPs) are becoming more popular in today’s environment. They contribute significantly to the technologies in agriculture and food development but there is little understanding to how MONPs, including ZnO, CuO, TiO2, and SnO2, impact human health and the environment. Our growth assay revealed that none of these negatively affects viability in the budding yeast, Saccharomyces cerevisiae. In contrast, both human thyroid cancer cells (ML-1) and rat medullary thyroid cancer cells (CA77) displayed a significant reduction in viability with the treatment of CuO and ZnO. The production of ROS in these cell lines when treated with CuO and ZnO was found to be not significantly altered. However, levels of apoptosis with ZnO and CuO were increased, which led us to conclude that the decreased cell viability is mainly caused by non-ROS-mediated cell death. Consistently, data from our RNAseq studies identified differentially regulated pathways associated with inflammation, Wnt, and cadherin signaling across both cell lines, ML-1 and CA77, after ZnO or CuO NP treatment. Results from gene studies further support non-ROS mediated apoptosis being the main factor behind decreased cell viability. Together, these findings provide unique evidence that the apoptosis in response to the treatment of CuO and ZnO in these thyroid cancer cells was not mainly due to oxidative stress but to the alteration of a range of signal cascades that promotes cell death.


ZnO, CuO, CA77 (rat medullary carcinoma), ML-1 (human thyroid cancer), cytotoxicity

Subject Categories

Cancer Biology | Cell Biology


© Alyse N. Peters

Open Access