By Mallory Thompson

Faculty Mentor: Dr. Laura Sipe

Abstract

The Effect of Oxaliplatin and Methionine Restriction on Immunogenic Cell Death in Cell Lines
EO771 and 4T1.
Mallory Thompson
Advisor: Laura Sipe, PhD

The immune system’s ability to detect cancer is integral to the body’s ability to fight the disease. Some anti-cancer therapies trigger targeted cells to alter their cell membrane, like inserting proteins such as Calreticulin, which allows identification by the immune system and the initiation of an anti-tumor response.
Understanding which methods allow for this process, known as immunogenic cell death (ICD), can help to identify anti-cancer therapies that will alert the immune system, and are thus more effective than those that do not generate ICD. Whether methionine restriction, where the amino acid required to begin gene transcription is present in a small concentration in the cell culture media, leads to ICD is a main topic of interest. This study sought to determine the difference in ICD response to Oxaliplatin and methionine restriction in murine breast cancer cell lines EO771 and 4T1. One aspect of ICD is Calreticulin presence on the plasma membrane, which allows identification by the immune system and the initiation of an anti-tumor response. Each cell line was incubated with Oxaliplatin, known to initiate ICD, and then immunostained for plasma membrane Calreticulin. Plasma membrane Calreticulin was quantified by Mean fluorescent Intensity (MFI) and percent positively stained cells using a Cellometer. While there was not a significant difference in the 4T1 cells, there was a significant difference between the EO771 cells that were treated with Oxaliplatin and the control cells in both MFI and percent positive. EO771 cells treated with Oxaliplatin had an increased MFI of 1650.84 and a mean percent positive of 8.68% when compared to the control EO771 cells, which had an MFI of 871.45 and a mean percent positive of 4.40%. Thus, the EO771 cell line displayed a more intense ICD reaction, demonstrating how different cancers’ response to different anti-cancer therapies varies. This procedure was also conducted with methionine restriction media for EO771 cells to determine if this anti-cancer therapy leads to ICD. The EO771 cells treated with Oxaliplatin and Methionine restriction media showed a difference, albeit not significant, where the treated cells displayed a higher MFI and percent positive than those of the control. Thus, further studies will be needed to investigate the activation of ICD due to the combination of different anti-cancer therapies.