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Molecular & Cell Biology & Genetics Program Meet Andrew Matamoros, MS, PhD

Andrew Matamoros, Molecular and Cell Biology and Genetics Program Alum


Hometown: Wilmington, Delaware
Undergraduate: University of Delaware, BA in Biology and Psychology
Graduate: Drexel University College of Medicine, MS in Cellular Molecular Neuroscience; PhD in Molecular & Cell Biology & Genetics (MCBG)


Can you tell me a little about yourself before you came to Drexel?

Sure. I was born and raised in Wilmington, Delaware. I'm biracial, so I'm an underrepresented minority. My father is from Mexico, and my mother is from Delaware. We didn't have a ton of money growing up, so I'm actually a first-generation everything—first-generation college student, first-generation graduate student. I was told in high school that I could only apply to in-state schools, so I actually only applied to the University of Delaware. Luckily, I got in.

When did you know that you wanted to become a research scientist?

I actually had a bit of a rough start in college because I had to hold a job throughout my education there. Financial pressures were a big deal for me. I didn't know what I wanted to do but had focused on computer science all through high school and entered into the University of Delaware as an electrical engineer. However, I very quickly realized that I was not passionate about it, so I was a little lost for the first year and my GPA suffered as a result.

Toward the end of my sophomore year, I had a class titled Brain and Behavior. My professor Dr. Jeffrey Rosen noticed that I was really engaged in the class. He pulled me aside after one of the classes and asked if I would like to visit his lab and maybe even do some undergraduate research. That was really huge to me. He opened this whole window of opportunities for me. I ended up declaring a major in this sort of pseudo-neuroscience program because they didn't have one yet—it was actually an interdepartmental major of biology and psychology. When I began taking those classes and doing rotations in labs, I knew this is what I wanted to do. However, people were telling me I wouldn't be a strong candidate for graduate school because of my earlier GPA, and I was devastated.

What did you do after graduation?

During my senior year I had an internship at a pharmaceutical company, and they offered me a full-time job starting at $40,000, which was amazing for me. During the internship, I had actually been juggling two other jobs—waiting tables and working as a pharmacy technician—and going to school. I had never worked for this kind of money before.

I spent two years rising through the ranks, and it started to dawn on me that people who I was working alongside who had their master's degrees were coming in at $60,000. I was now at their level doing the same exact things they were doing. That was when I began to realize that I might want to go back to school.

When did you decide to go back?

A woman I worked for, Dr. Susan Zondlo, was an important mentor to me, and she recommended that I should go back to school for my PhD. I took her advice, but it wasn't a direct route to Drexel. First, I got a job at the University of Delaware as a research technician working for Dr. Mark Stanton. I did that for a year and was able to take one class per semester for free. I was outperforming PhD students as a technician and then knew I really wanted to go back to school full-time.

I applied and was accepted to a bunch of schools, but I was still struggling with student loan debt from undergrad. Then, Dr. Rosen put me in touch with Dr. Melissa Harrington at Delaware State University where they had a Bridge-to-Doctorate program. They paid their students a $22,000-a-year stipend while getting a master's. The program was connected to Drexel University College of Medicine, so I did my first year of classes at Delaware State and then began my second year here, taking core classes with the incoming PhD students. Upon successful completion of that, I was able to merge right into the PhD program.

I did my master's work with Dr. Ramesh Raghupathi, who was an incredible mentor and really helped me out a lot. Then, Dr. Peter Baas offered me a position in his lab as I transitioned into the PhD program.

Can you tell me more about your experiences here and how you wound up in the Molecular & Cell Biology & Genetics (MCBG) program?

For me, the transition into the Drexel environment was really amazing in terms of, first and foremost, the students. They treated me just like I was in there with them, even though I had come through the Bridge program. We would band together, study together and visit each other's labs. It was really welcoming. I think that opened up this idea of collaboration. I started to meet other students' PIs and talk about what kind of work they were doing. There was a sense of connectedness that I found very encouraging. I knew Drexel was the right place for me.

In regards to research, I was kind of being pulled in different directions. People were trying to get me to pursue neuroscience versus Molecular & Cell Biology & Genetics. I always tell students that it feels good to be recruited. It feels good to have someone try to pull you in a direction, but always ask yourself, "Yeah, it feels good, but is that what you want to do? Is that what's best for you?" I again had to step back and ask myself, what do I want to do here?

I realized that I already had a BA in neuroscience, essentially. I had a master's now in cellular molecular neuroscience, and so rather than just neuro, neuro, neuro, I chose to do MCBG because you can build the program how you want it. It's this constructible major. For example, let's say I had microbiology leanings. I could take classes that were in the microbiology department. I knew that I lacked knowledge in advanced biochemical techniques, and I wanted to pick that up. Rather than shy away from something I wasn't good at, I was like, "Let me use this time to pick something up and better myself."

That's why I chose to do Molecular & Cell Biology & Genetics, because I wanted to get more genetics. I wanted to get more of the molecular and deeper cell biology. Molecular & Cell Biology & Genetics gave me the freedom to construct my own curriculum centered on my research interests, which then benefited my ability to publish, write papers and write reviews.

Were you involved with extracurricular activities while you were here?

I was a member of the Graduate Student Association (GSA), first as the PhD/MS student representative. I was really passionate about trying to get students who were master's students a more direct pipeline into their PhD so they could cut costs, and I was a big advocate for students and their mental health. From that, I then was elected GSA president.

Can you tell me about the research you did here?

Yes. I first investigated traumatic brain injury (TBI) with Dr. Raghupathi, where I was studying neonatal TBI. Specifically, we were looking at the effects of progesterone treatment on neonates. Progesterone at the time was in phase III clinical trials for adult humans. That has recently ceased because it wasn't showing any benefit, unfortunately. Since there had been clinical trials for adults, we knew it would be likely that they'd give an adjusted dose to children. There's this dogma that's definitely getting a lot of pushback where we just treat children as though they are mini-adults. However, that couldn't be further from the truth. In fact, this was a really great way to show that, because neonate mammalian animals have an increase in the amount of progesterone receptors that's transient through their development. It's also postnatal, so when these little guys are coming out, they still have a large amount of these progesterone receptors that then decrease as time goes on. What would happen if we were to dose them if they had shaken baby syndrome or some sort of fall? How would that affect them? We actually found that it made things worse.

Then, when I transitioned into the PhD program, Dr. Baas recruited me to his lab and told me that he was interested in microtubule-mediated nerve regeneration. Honestly, if you ever told me that I was going to be studying microtubules, I would have laughed, because it's just a loading control—a boring cytoskeletal protein. He really changed my views on that. I realized how paramount microtubules are for a neuron. They're one of the first things that are affected during nerve regeneration. They're paramount to whether or not an axon is going to be able to regenerate. In fact, I sort of coined this term where I talk about how they're the bottleneck to regeneration. Regardless of what your therapy is, whether you're regulating metabolism in the neuron after injury, whether you're degrading inhibitory molecules around the neuron, whether you found some target protein that you think can increase receptor expression and ignore the inhibitory molecules, all of those things at the end of the day are only going to be beneficial if they converge on the cytoskeleton, because the cytoskeleton is ultimately what's responsible for advancing and growing the axon forward. Uniquely in the Baas lab, we started to identify proteins that seemed to increase the labile microtubule mass. We had this theory that if we could increase microtubules, then we could hopefully push forward axons and even prevent their degeneration.

I started working on a protein called fidgetin, which is a microtubule-severing protein. Think of fidgetin like the pruning shears for your hedges. Let's say you have a garden and you've got to prune back the hedges. If I came along and broke your pruning shears, your hedges are going to overgrow. The same is kind of true here with the microtubules. By getting rid of a microtubule-severing protein, those microtubules are now preserved in a sense because we saved them from that severing ability. What we found is that increased microtubule mass appears to allow for these axons to grow onto inhibitory substrates. I wanted to expand on that, so I worked with Dr. Veronica Tom and adapted her in vitro assay, where we spotted seven spots of aggrecan, cultured cells on top of them, and then looked to see if our intervention of knocking down fidgetin would allow for neurons that grew on that inhibitory spot to cross off the spot, which is very similar to the in vivo environment after a spinal cord injury. We showed that was beneficial, and then I actually moved into in vivo.

I did that work in vivo with a dorsal root crush in adult rats. We took the virus that knocked down fidgetin and again saw that we were able to get these axons to regenerate into the dorsal horn. We didn't see any functional recovery, but we were able to accomplish what other researchers have shown by targeting metabolic pathways or by targeting Nogo which are receptors that adhere to inhibitory molecules. We were able to essentially recapitulate their findings, but by targeting fidgetin, a microtubule associated protein. That just compounded other research, such as Dr. Frank Bradkewho works with paclitaxel. He's also showing that when he can stabilize microtubules, he has regeneration. That we were able to show that again was really exciting for us.

What are you doing now?

Now I'm at Children's Hospital of Philadelphia (CHOP) working for Dr. Yuanquan Song investigating regeneration. We use Drosophila melanogaster (fruit flies) to screen for potential targets that can augment nerve regeneration, and then we confirm our findings using rodent injury models. I have an Institutional Research and Academic Career Development Award (IRACDA) and am in the Penn – Postdoctoral Opportunities in Research and Teaching (PennPORT) program, which is funded by the National Institutes of Health. With this award, I get to work in a lab for a full year, and then next year I will teach an introductory level course in the fall and make my own advanced elective for spring. My goal is to become a research professor, but I would like to be at an undergraduate-serving institution where I would be able to be valued as an educator as well as a researcher.

A Molecular & Cell Biology & Genetics program graduate student working in a laboratory at Drexel University College of Medicine.