5 Questions for Shannon Sweeney, PhD

This question-and-answer series explores the motivations, inspirations and accomplishments of members of the St. Jude workforce. Shannon Sweeney, PhD, is an academic recruiter at the St. Jude Children’s Research Hospital Graduate School of Biomedical Sciences, where she recruits current and emerging scientists for the school’s four graduate programs. Before accepting the full-time role, she worked as a postdoctoral fellow in the Department of Developmental Neurobiology. She is also studying toward a Master of Science in Clinical Investigations at St. Jude.

1. You went from postdoctoral fellow to graduate student to academic recruiter for St. Jude. How did this all come about? 

After my maternal grandfather died of cancer, I wanted to become an oncologist. Somewhere along the way, I decided I wanted to be a pediatric oncologist, so I went through college thinking that was going to be my trajectory. I took the MCAT, applied to medical school and didn’t get in. The [faculty] said I should work in a hospital to show my “dedication to the profession.”

I got a job as an outpatient phlebotomist first, and later in the hospital inpatient pharmacy. I perused some courses at a local school and fell in love with nutrition and how lifestyle impacts cancer. I attended graduate school in nutritional sciences at the University of Texas at Austin. There, I met a new faculty member who was focused on metabolomics — looking at disease states from a metabolic point of view. I joined his lab and ultimately switched from nutritional sciences to a cell and molecular biology PhD program, where my primary project for my dissertation focused on pediatric leukemia.

That project piqued my interest in the developmental drivers of pediatric tumors. I defended my PhD in 2020 and joined St. Jude later that year as a postdoctoral fellow. The decision to then switch gears and pursue a master’s at St. Jude was a product of my natural proclivity to change things up and pivot. My research was moving in a clinical direction, and my postdoc advisor wanted to lay the foundation to get St. Jude, and eventually the federal government, behind a novel clinical drug that could have important impacts for retinoblastoma, a childhood eye cancer. I mentioned the clinical investigations program and thought he would say, “Nah, you’ll learn on the job.” Instead, he said, “That’s a great idea.” 

When I heard the graduate school was looking for a new recruiter, and that they wanted to bring in a career scientist instead of a Human Resources professional, I was intrigued. I am currently in the clinical investigations program; I've mentored several PhD students; and my strength has always been people. I’m a relationship builder. I applied, interviewed, and, when they offered me the job, I took it.

2. What do you think differentiates St. Jude?

The bench-to-bedside approach is real here. You get to see the impact every day. Doing clinical investigations helped me see the possibilities of where I could take a career, so that I could exist at the intersection of basic research and clinical impact.

Ultimately, though, the reason I ended up at St. Jude is that I visited the campus. When I was still in graduate school, I was accepted into the Future Fellows Research Conference where I had the opportunity to visit Memphis for a long weekend. The integration of clinical and basic research, and the wealth of data you have access to — there really is no place like it.

There are a lot of excellent institutions, but none of them have the institutional support that St. Jude has. You can do more with less because there are more hands — more staff working in laboratories and in the core facilities than anywhere else that I’m aware of. It felt like coming here was an opportunity to maximize the impact of my work, so once I did, I was sold. I didn’t apply anywhere else.  

I’m also very belief-oriented, so working for an institution that has a mission that I can get behind is important for me. The mission of St. Jude is what drives everyone who shows up here and works hard every single day, and that’s very motivating.

3. What research questions did you explore during your postdoc? 

Part of the reason I chose the lab of Michael Dyer, PhD, Department of Developmental Neurobiology chair, is because it is somewhat evenly divided between developmental neurobiology and solid tumor research. The model he uses is the retina. The project I worked on primarily was retinoblastoma, which bridged the gap between retinal development and cancer biology.

Retinoblastoma is almost exclusively a pediatric cancer — two-thirds of patients are diagnosed before age 2, and 95% before age 5. We know this is a tumor that initiates in utero. It’s also relatively simple from a mutation standpoint, which makes it easier to untangle mechanistically. The main driver is loss of a gene called RB1, a tumor suppressor. The downside is that mice don’t get this tumor, so you can’t use a genetically engineered mouse model to understand how it starts.

My project looked at two things: the developmental origin of retinoblastoma and the role of cellular heterogeneity within the tumor. We used retinal organoids as a model to look at the earlier stages of tumor development and understand where we might be able to stop it. Retinoblastoma tumors are composed of a population trying to become photoreceptors and another that is much more undifferentiated. We found these cells are related, arising from the same mutations, and that the more differentiated cells responded better to chemotherapy. 

4. Tell me about a mentor or mentors who guided you and how they made a difference.

A faculty member at UT Austin who had nothing to do with any of my research gave me solid advice during a big moment of transition. I was looking to graduate at the beginning of a global pandemic, and my PhD advisor at the time did not want me to leave. He wanted me to postpone graduation because there were too many unknowns. But I had been in graduate school for a long time, and I was ready to be done. 

The faculty member’s office was near my cubicle. Before we all got sent home due to COVID-19 restrictions, we had a few conversations about how to push back with my advisor and how to set boundaries. I appreciated his guidance because at that time he was the only person that I was actively talking to whose only investment was in me. There was no ulterior motive for him to want me to leave sooner or later.  
 
Those conversations gave me the courage to stand my ground with my advisor.

When I look back, I think every graduate student would benefit from having a faculty member mentor who is completely unattached to their research. Getting a PhD is a long-term commitment. It’s hard, and it’s stressful. Having someone in your corner who understands your world would be helpful for a lot of students.

5. What one piece of advice would you give other scientists considering making a professional leap?

Be brave. Don’t be afraid to make big changes. If you’re interested in something or there’s someone you want to work for, even if it feels like a big pivot, go for it, especially at the stage of being a PhD student or a postdoc. You’re still technically a scientist in training. You’re expected to be learning and growing and expanding into your area of expertise. 

I took a huge pivot from my PhD to my postdoc. I changed diseases and approaches. The only consistent thing was pediatric cancer. Your postdoc is an opportunity for you to think big and do what excites and interests you before you’re locked into your niche. Very few doors slam behind you. There’s almost always a path back if you need to take it.