Meet one of our early-career scientists at Sanford Burnham Prebys Medical Discovery Institute: Rouven Arnold, PhD, a postdoctoral researcher in the lab of Peter Adams, PhD. Rouven is a geneticist studying how aging affects the identity of individual cells. His goal is to protect people from common age-related diseases such as heart disease, cancer and dementia.

What are the key areas of research you focus on?
I’m interested in cell identity and how cell identity changes during aging. In our bodies, we have about 30 trillion cells, all with the same genetic information. So how does a liver cell know that it’s a liver cell and not a brain cell?

The answer is epigenetics, a layer of control governing the expression of genes in our DNA. With aging, we see a loss of cell identity or, in other words, epigenetic erosion. And that can eventually contribute to age-related diseases.

I’m particularly interested in a protein called HIRA, a histone chaperone. I study how this protein tries to maintain the cell’s identity as we age and prevents the onset of age-related diseases. The goal is to help people age healthier.

This is an important point to emphasize whenever we talk about aging research. The goal is not to live forever. We are trying to help people live healthier for longer.

When and how did you become interested in science?
For me, it clicked when I was in high school and we covered genetics in biology class. I found it incredibly fascinating to learn how traits are passed on and how mutations lead to diseases.

I also realized that even small discoveries can make a huge impact. This gives every biomedical scientist a sense of purpose in advancing knowledge and improving health.

What did you imagine you would be doing professionally, and how did it evolve?
I have always been connected to the research world because my parents are both biologists. I did not grow up knowing I would become a scientist. My fascination began in high school and didn’t fully solidify until college. At that point, genetics became my main focus and something I truly enjoyed pursuing.

What brought you to the Adams lab at Sanford Burnham Prebys? 
Before starting graduate school, I worked in several labs in Germany. I gained experience in cancer and heart research. When I started my PhD, I realized that much of my previous research was connected to aging.

As we age, many age-related diseases tend to pop up, such as cancer. After my PhD, I was looking for a postdoctoral research position in aging research and I found an opening in the Adams lab. I was already familiar with his work because he’s well-known in the field, so I was very excited to apply.

I haven’t regretted it at all as I’ve had a wonderful experience with this team.

What motivates you about your research?
Sometimes, research can be very challenging. But there are other times where everything falls into place. And then you get this perfect moment, which is incredibly rewarding.

In those moments, you can reflect on the entire process, from generating your hypothesis and designing your experiment to executing it and seeing an exciting result, and everything just aligns. When you have one of these experiences, you remember why you are in science, and you reap the rewards of learning something completely new. That’s a pretty amazing feeling.

Being a scientist also means you share the same passion and curiosity with all the people around you. And that’s motivating you to do even better science, because you are inspired by the collective enthusiasm.

What do you like about working here?
Sanford Burnham Prebys stands out for its collaborative environment. Everyone here is friendly and always eager to help you. Whenever I have a problem in the lab, I can walk down the hallway, talk to someone, and we come up with solutions.

I also think that the core facilities here are exceptional. They provide a tremendous boost to my research.

What are your hopes for the next stage in your career?
My wife and I are both German, so we do plan to return to Europe. I want to take everything I have learned here and continue working as a scientist.

There are several places in Europe, such as Germany, Switzerland and Portugal, with emerging aging research institutes, and more and more universities are starting departments focused on aging research. I’m hopeful that I will be able to continue contributing to this field after my postdoctoral training.

Have you had an influential mentor?
Peter (Adams) has been an incredible mentor. He is very supportive and always eager to connect me with people I can learn from or collaborate with to advance my project and grow as a scientist.

What do you enjoy doing when you’re not in the lab?
I enjoy rock climbing and being out in nature. Also, I feel like when you live in Southern California, you have to try surfing. It’s really challenging, but it’s also a lot of fun so I’m still working on getting better at it.

Postdocs at Sanford Burnham Prebys are pushing the boundaries of science every day through curiosity, collaboration, and innovation. This series highlights their unique journeys, what inspires their work, and the impact they’re making across our labs.

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Meet one of our early-career scientists at Sanford Burnham Prebys: Tsunghan Hsieh, PhD, a postdoctoral researcher in the lab of Xiao Tian, PhD. Hsieh studies stem cell biology and regenerative medicine to learn how to protect brain health during aging.

When and how did you become interested in science?
When I was in high school, I became interested in biology. I started to study biology more and more so that I could go to university and advance to fields such as molecular biology and immunology.

Then I totally changed my track to focus on immunology because I found it so fascinating.

How has your scientific career evolved?
After I completed my master’s degree in Taiwan, I wanted to see how people use biology in the business world. I went to industry for a few years, and there I was exposed to different companies and distinct products in a variety of fields.

I learned that I needed a PhD to get access to the most exciting technology in this field, so I started to apply for PhD programs around the world. Eventually I received funding from the Okinawa Institute of Science and Technology Graduate University and went to Japan to complete doctoral studies in immunology.

What brought you to the Tian lab at Sanford Burnham Prebys?
I was torn about staying in academia or going back to industry after earning my PhD. I decided that academia gave me the best chance to do something truly new and innovative.

After three years working in different roles in Japan and the Netherlands, I realized that I was most interested in the latest biotechnology. I needed to go to the country with the best biotechnology in the world.

Xiao and I connected on LinkedIn and began discussing his lab’s research on healthy aging. After one conversation, I decided to move to San Diego and join his lab.

What are the key areas of research you focus on? 
My major project is to study how to reverse the aging process of neurons and other cells. During the aging process, neurons and other cells gain a very different phenotype.

We’re interested in a common mechanism behind this aging phenotype. As cells age, the chromosome structure and transcriptomic profiles become quite distinct from younger cells. If we can reverse this process, we may be able to help the brain stay healthier as people age, and less prone to conditions such as dementia that are more likely to afflict older individuals.

What motivates you about your research?
One thing that drives me is that I’ve found something that I truly like to do. Every day I walk into the lab with questions that I want to answer. If you have that kind of innate curiosity, science is a great outlet for it.

What do you like about working here?
I learned in my early scientific career that I was not as excited about fundamental research. Here at Sanford Burnham Prebys and in Xiao’s lab, I’m working on more translational science that fits my interests. I want to work on technology that benefits people and has the potential to be approved by regulators, commercialized and disseminated.

How would you describe the culture here?
Another one of the best things about working here is the people are friendly and open to collaboration. There are no hierarchies or traditions that get in the way of discussing potential collaborations.

What do you enjoy doing when you’re not in the lab? 
Outside of work, I’m usually taking care of my kid, getting her everywhere she needs to go and trying to enjoy some time together as a family. And I am also enjoying the region’s delicious tacos and learning Spanish!

Postdocs at Sanford Burnham Prebys are pushing the boundaries of science every day through curiosity, collaboration, and innovation. This series highlights their unique journeys, what inspires their work, and the impact they’re making across our labs.

Explore the Full Series

Meet one of our early-career scientists at Sanford Burnham Prebys: Arailym Sarsembayeva, PhD, a postdoctoral researcher in the lab of Eric Wang, PhD.

What lab are you in, and what research are you working on?
I’m currently working in Eric Wang’s lab, which specializes in chemical biology and the development of targeted protein degradation therapeutics against traditionally “undruggable” transcription factors. My project focuses on Helios, a transcription factor highly expressed in regulatory T cells and exhausted CD8+ T cells. I am investigating the effects of Helios degradation on T cell function and exhaustion phenotypes, with the aim of elucidating the underlying mechanisms that modulate tumor immune evasion. Ultimately, this work will not only clarify the role of Helios in T cells but may also guide the optimal deployment of Helios degraders in clinical settings.

When did you know you wanted to be a scientist?
I grew up around medicine—my mother is a general practitioner—and was always curious about diseases and how the body works. That early exposure sparked my interest in biomedical science, which I pursued with a presidential scholarship at Dublin Technological University. During my studies, I became increasingly fascinated by immunology and the vital role the immune system plays in health and disease. This passion led me to Kazakhstan for a master’s program and then to Austria for my PhD, where I focused on cancer immunology. Specifically, I explored how cannabinoid receptors on immune cells interact with tumors, which opened my eyes to the complex ways our body fights cancer. It’s been an incredible journey, blending my love for medicine and science.

How did you find your way to Sanford Burnham Prebys?
I discovered Eric Wang’s lab through LinkedIn. When I researched Sanford Burnham Prebys and saw the motto, ‘We translate science into health,’ I immediately felt it was the right place for me. The institute is the perfect size—not too big, not too small—and is situated in a highly collaborative environment in San Diego, which aligns perfectly with my goals and working style.

What do you like about working at the Institute?
I love the collaborative and supportive atmosphere. My colleagues and collaborators are amazing, and the Office of Education, Training & International Services (OETIS) provides postdocs with great resources—from leadership seminars and writing workshops to grant training. The scientific environment here is excellent, with top-tier core facilities and seminars featuring scientists from across the U.S., which keeps me inspired and engaged.

What’s been a challenge in your postdoc journey?
Since this is my first postdoctoral position, one of the biggest challenges has been transitioning from being a PhD student to an independent researcher. Initially, I wasn’t sure how to act or how much independence was expected. However, I’m learning as I go, and I’ve had great mentorship from Eric Wang and others. It’s a continuous process of gaining confidence and skills.

Congratulations on your fellowship! Can you tell us more about it?
Thank you! I was recently awarded a three-year postdoctoral fellowship from the American Cancer Society. It’s fully funded, which is a huge relief and allows me to focus deeply on my research. I’m especially excited about the professional development support and opportunities for collaboration that come with the fellowship. It’s a great step forward as I continue to grow as an independent cancer researcher.

For almost 80 years, the American Cancer Society has been at the forefront of funding groundbreaking research that has transformed cancer prevention, detection, and treatment. I am extremely proud to be part of an organization with such a rich legacy, committed to supporting the best science to benefit cancer patients and their families for generations to come.

What are your goals for the next stage of your career?
My goals for the next stage of my career are to deepen my research expertise while expanding my leadership and mentorship experience. I’m considering a transition into industry, particularly roles that allow me to work at the intersection of applied research and innovation. However, I still have a strong interest in leading my own research team in the future. This postdoctoral position offers an ideal opportunity to develop leadership skills through project management and interdisciplinary collaboration, while continuing to publish and refine my scientific contributions.

Have you had a mentor who made a big impact on you?
Yes, especially my master’s advisor, Dr. Eva Reithmacher. She’s a strong woman in science who supported and encouraged me every step of the way. Her mentorship had a big influence on my path.

What do you enjoy outside the lab?
Outside the lab, I really enjoy hiking, baking, horseback riding, and just walking along the beach. Being outdoors is really important to me and living in San Diego makes it easy to get outside and enjoy nature every day!

What advice would you give to aspiring scientists?
Pursue your dreams and don’t give up. Science is full of ups and downs, but if you’re passionate and curious about discovering new things, it’s worth it. Be resilient and keep going.

Postdocs at Sanford Burnham Prebys are pushing the boundaries of science every day through curiosity, collaboration, and innovation. This series highlights their unique journeys, what inspires their work, and the impact they’re making across our labs.

Explore the Full Series