Rachel Riley '22

2020 SOAR Profile

Inhibition of Src activity in glioma cells upon expression of Cx43 gap junctions

Major: Biochemistry
Hometown: Nazareth, PA
Project Advisor: Dr. Anastasia Thévenin

Briefly describe your project.

This project is centered around a protein called Connexin 43 (Cx43) which is very important to cells because it forms Gap Junctions (GJs). GJs are structures found in the plasma membrane of cells that allow cells to communicate with their neighbors through the passing of small molecules and ions. We are specifically interested in Cx43 because previous work has shown that it can function as a tumor suppressor in certain types of cancer cells. The proliferation of these cancer cells is driven by a protein called Src. The main goal of our project was to determine whether certain phosphorylation events (a type of post-translational modification to proteins) at certain amino acids on Cx43 result in a greater binding of Src and Cx43. A greater binding of Src as a result of phosphorylation of Cx43 would result in reduction of proliferation of Src-based cancer cells due to the tumor-suppressive capabilities of Cx43. Results from these experiments hopefully will aid in the development of new therapeutics for Src-based cancers. 

Describe the origin of your project.

I approached Dr. Thévenin last semester about joining her lab to work on this project. I picked up this research where a previous SOAR student, Irene Bonetti, left off when she graduated. 

What’s the best part about working with your faculty mentor? What valuable insights have they brought to your project?

The best part about working on this project with Dr. T. as my mentor is that she is always teaching me new things about the project. I am always learning new information about the details of the project or learning new protocols and procedures for lab work. We ran into significant difficulties this summer, but she guided me in working through these obstacles by not being afraid to try new procedures. She also trusted me to design experiments to determine the basis of the problems we were having. 

What has been your biggest obstacle so far?

The biggest obstacle we faced this summer was figuring out if the cell line we had been using was still reliable to continue gathering data. We were using C6 rat glioma cells because they do not make Cx43 GJs; this allowed us to introduce our Cx43 DNA with mutations that mimic phosphorylation events on Cx43. Our C6 cells began making their own Cx43 shortly after we began our work this summer. Much of the summer was spent trying to figure out why the cells began behaving this way, and we also spent time deciding on a new cell line that would allow us to carry out the same experiments. We have not yet determined why C6 began making endogenous Cx43, but we did select LNCaP (human prostate cancer) as our next cell line for our experiments.  

What has been your biggest takeaway from this experience?

My biggest takeaway from this experience has been that you never stop learning about your work as you carry out experiments. You’re always encountering new things in your experiments that make you want to reference the literature to learn more. This is also one of my favorite things about being a part of an ongoing research project. I learned so many things throughout my research that apply to many of the classes that I am taking now and will be taking in the future. 

What was the result of your project?

Though our research did not take us exactly where we expected this summer because we had to find a new cell line in order to continue our experiments, we ultimately expect to see that phosphorylation at one specific serine (S373) results in greater recruitment and binding of Src to the C-terminus of Cx43, which causes greater inhibition of Src tumor proliferation. Previous work in Dr. T.’s lab has shown that this is true, so we are continuing to conduct experiments to replicate these findings. 

In your own words, how do you feel about being awarded this opportunity? Why should other students take advantage of the SOAR program at Moravian?

I feel extremely lucky to have had the opportunity to conduct a SOAR project at Moravian this summer. The experience of working closely with a faculty member on an intense research project is something that all students should take advantage of, especially if they want to continue their education in graduate school. This experience allowed me to grow as a student and scientist because it helped me become more confident in myself in a laboratory setting. 

Now that SOAR is over, do you plan to expand upon your research? If so, how?

I plan to continue this research through independent studies with Dr. T. this coming academic year. We will be conducting experiments in our new cell line (LNCaP human prostate cancer) that will hopefully replicate the findings that Src binding increases when Cx43 is phosphorylated, and Src is, therefore, more strongly inhibited by phosphorylated Cx43. We are also very interested in how two other proteins, Csk and PTEN, interact with Cx43 to strengthen its abilities to function as a tumor suppressor in Src-based cancer cells. Experiments concerning the binding relationships of these four proteins will be our main focus moving forward. 

Have you, or do you plan to present this research outside the SOAR presentations? If so where? Be specific, if possible.

This summer I was a part of the Remote Supergroup for Chemistry Undergraduates (RSCU) which connected undergraduate research students and their advisors from across the country who could not carry out their research as they normally would have due to the pandemic. I was able to present my research at one of our large group meetings. I also presented at Moravian’s Scholars Day in 2020, and I plan on doing the same in 2021.