October 2010

A Career in Biomarker Discovery


Sheri Wilcox explains how her sister's illness led her to a research career finding protein signatures associated with disease. (Titled "Going Beyond Your Limits" in print version.)


Sheri Wilcox received her bachelor’s degree in chemistry from Vanderbilt University in 1993 and her doctorate in macromolecular and cellular structure and chemistry from The Scripps Research Institute in 1999. She conducted her postdoctoral research in the protein science unit at Pharmacia and Upjohn in Kalamazoo, Mich. Wilcox joined SomaLogic as a scientist in 2001. She is now an associate director at SomaLogic. Her group is responsible for performing the selections and qualifying the aptamers for SomaLogic’s biomarker discovery array.

I was only 2 years old, but I remember it very well. My older sister Laurie and I were playing in our basement with some friends when Laurie inexplicably passed out. The next two years were filled with trips to hospitals in Atlanta, and, eventually to St. Jude Research Hospital as my sister fought her battle with Wilms tumor, a solid tumor of the kidney that is the fourth most common type of cancer in children. She was six and I was four when she died. That was the spark that started my passion for making a difference in the fight against cancer. Since then, I’ve lost many relatives, including both of my parents, to cancer. Today, the cure rate for Wilms tumor is 85 to 90 percent, and there are effective treatments available for other cancers as well. The problem is that you can’t treat cancer as successfully if you don’t find it in its earliest stages. That’s why early diagnosis of cancer and other diseases is now my passion.

My career path to this point has been in part by design and part fortuitous. I always have been fascinated by science. I loved going to the Fernbank Science Center in Atlanta with my mother when I was a little girl. Once I got to college, I might as well have declared chemistry as my major even before I took my first class. I started doing research in analytical chemistry during my sophomore year and then moved into a biophysical chemistry lab as a junior.

An Interdisciplinary Education

During my senior year, I learned about a multidisciplinary graduate program at The Scripps Research Institute called “Macromolecular and Cellular Structure and Chemistry.” (Now, it’s simply called “Chemical and Biological Sciences.”) The intent was, and still is, to train scientists across chemistry and biology fields to contribute productively in a very collaborative environment. The emphasis was on having a broad foundation so you could really evaluate the quality of scientific research even if it wasn’t in your own field.

I decided that was the direction in which I needed to be going, even through I had not taken any biology classes in college. I’m still not sure how, but I was accepted into the program at Scripps, and I began my graduate career. The program’s seminar-style classes exposed me to many aspects of structural and molecular biology. I joined David Goodin’s lab for my thesis research. We focused on cytochrome c peroxidase, probing structure/function relationships with site-directed mutagenesis, enzymatic activity measurements, EPR spectroscopy and X-ray crystallography. The breadth of what I learned both in class and in the lab at Scripps built my confidence and showed me that I am never limited to what I’ve already learned. The belief that I always can learn new fields and take on roles in new areas has propelled me to where I am today.

Controlling My Destiny

As I finished up my doctoral research, I decided to make my first heretical move and do a postdoctoral fellowship in industry. I accepted a position in proteomics at what was then Pharmacia and Upjohn in Kalamazoo, Mich. After two years, it was time to get a real job. I started interviewing with contacts I’d made at conferences and searching for jobs through traditional means.

"In the future, I hope no one has to watch his or her parents go to the doctor with vague symptoms for months without getting an accurate diagnosis."

Then, my husband and I had a revolutionary thought— we wanted to be in control of our destiny and decide where to live rather than just letting the advertised job openings dictate our path. We chose Colorado. It’s not exactly a booming biotechnology community like the San Francisco Bay Area or Boston, but it’s not too shabby either.

Now, it was time for heretical act number two. I started cold-calling every biotech company in Colorado. I discovered that most people are quite willing to talk about what they are trying to do at their company, especially when they are passionate about it. After I described my research experience at Pharmacia, several people suggested I contact Larry Gold and talk to him about his newest company, SomaLogic. Larry was gracious and accepted my call. We decided I would host him to talk about the SomaLogic technology at Pharmacia, and he would arrange for me to interview at SomaLogic. The agreement worked well, and, within a few months, we moved to Colorado. I started out at SomaLogic knowing shamefully little about aptamers. Now, nearly 10 years later, I direct the company’s aptamer discovery group.

A Perfect Fit

I really could not have asked for a more perfect fit for what I wanted to do with my life. SomaLogic’s mission is to find protein signatures associated with disease. These protein signatures can be a hallmark of disease before symptoms are even evident. Signatures also can be used to identify patients who will or won’t respond to a particular therapy. The proteins are measured using a novel class of aptamers called SOMAmers (slow off-rate modified aptamers). We now have developed SOMAmers that recognize 1,000 human proteins, and we use them to measure protein levels out of a single 15-μL biological sample in a high-throughput manner. We can measure many hundreds of proteins in many hundreds of samples to do biomarker discovery for diagnostics and assist throughout the drug development process.

In the future, I hope no one has to watch his or her parents go to the doctor with vague symptoms for months without getting an accurate diagnosis. Instead, patients should be able to take a simple blood test that helps doctors know when follow-up testing is warranted long before there are rampant metastases.

I’m really glad I didn’t let “requirements” keep me from applying to positions that drew my interest. I love what my company is doing, and I think our approach is the best way to make it really work. I never would have had the opportunity to be a part of what I believe will be a major tool for personalized medicine in the future if I had limited myself to what made “sense.” If you’re smart, have good critical judgment and feel strongly about where you want to make a difference, nothing should stop you.

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