The role of antioxidants in cancer has been controversial for a long time. Although the public’s belief is that antioxidants prevent and/or inhibit cancer, there is increasing evidence to suggest the opposite: that cancer cells require antioxidants to survive. We wanted to interrogate the role of antioxidants in cancer by investigating both upstream regulators and downstream effectors of antioxidant signaling. We have identified protein tyrosine phosphatase non-receptor type 12 (PTPN12) as a novel regulator of antioxidant signaling in cancer. PTPN12 reduces reactive oxygen species (ROS) levels by promoting activity of the forkhead box O (FOXO) family of antioxidant transcription factors. We have also elucidated the impact of glutathione (GSH), the most abundant antioxidant in the cell, on tumorigenesis. We have found that GSH is required for cancer initiation, yet dispensable once transformation has occurred due to compensation provided by the thioredoxin (TXN) antioxidant pathway. Together, these studies expand our knowledge of the role of antioxidants in cancer and provide numerous avenues of research for the future.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/65497 |
| Date | 20 June 2014 |
| Creators | Harris, Isaac Spencer |
| Contributors | Mak, Tak W. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0016 seconds