Cancer Drives Jason Smith’s Choice of Research

By Gabriel Chen

Jason SmithSometimes people come into your life and you know right away that they were meant to be there, to serve some sort of purpose, teach you a lesson or help figure out who you are or who you want to become.Mention the word "cancer" to Jason Smith, a Ph.D. candidate in biomedical engineering at Duke, and it invariably stirs in him this aura of deep reflection. Smith’s chemistry teacher in college, mission president from the Church of Jesus Christ of Latter Day Saints at San Joaquin Valley in California, and grandfather all passed away from cancer.

And because of this personal connection to the disease, Smith, who comes from Mississippi, has targeted his research on developing more efficient methods to deliver drug therapeutics for cancer patients; specifically, the targeted delivery and controlled release of cancer therapeutics to more effectively treat cancer and cause less systemic toxicity than current methods. The focus, he said, is not in drug delivery into cancer in general, but specifically to cancers with solid tumors.

"I really looked up to my chemistry teacher," said Smith, who came to Duke immediately to pursue his Ph.D. after graduating from Mississippi State University last year with a bachelor of science in biological engineering.

"She loved to teach and it helped me have a greater passion for learning," he said. "My mission president taught me the value of standing up for something, being true to yourself, and having good morals. My grandfather was a good example of love. We went hunting, went to get ice cream at the store, and watched Dukes of Hazzards reruns. He showed love to everyone he came in contact with. He was quick to tell how much he cared about you."

Currently, active targeting methods have been developed to further improve the delivery and retention of cancer therapeutics. The most common form of targeting is affinity targeting, in which a cancer drug is bound to a molecule that has strong attraction for receptors that are expressed predominantly on cancer cells.

Smith's research focuses on using a thermally responsive polymer with affinity tags as a drug carrier to thermally target a drug to the cancerous tumor, and in so doing, allow him to find out if there is synergy in using thermal and affinity targeting together.

Affinity targeting is an attractive force between biological groups that resemble each other in structure that causes them to enter into and remain in chemical combination. An affinity tag is placed on the carrier to attract it to cell receptors on tumor cell. Active targeting methods require the use of an affinity tag. For example, cancer cells have a large number of transferrin receptors relative to normal cells. A drug carrier with an affinity tag for transferrin will be taken up by cancer cells more robustly than carriers with no tag.

Smith, whose advisor is Ashutosh Chilkoti, an associate professor of biomedical engineering at Duke, started his dissertation in the fall of 2003 and hopes to get it done by 2009.

"It is really basic science research right now, with studies going as far as in vivo studies in mice with good results," Smith said.

He said that most of the cancer drugs on the market have adverse side effects. For instance, people could lose their hair. As such, Smith hopes to create better methods to deliver the drugs.

"You want the drugs to work on the DNA of the cancer cells, and so if you encapsulate it with carriers, it’ll only be released at the tumor site," Smith said. "After that, you heat the tumor site by thermometry methods such as portable hand held microwaves to break down the carriers. And once the carriers are broken down, the drug can act on the tumor itself."

Smith, whose dream job is to do research on cancer at the Saint Jude’s Children’s Hospital in Memphis, said the chance to work with Chilkoti was an opportunity not to be missed. Chilkoti, said Smith, is one of the most intelligent people he has ever met, and it was the research that Chilkoti was doing that brought him to Duke.

"When he speaks, he is able to demonstrate verbally his broad knowledge of science," Smith said. "He helped me a lot when I was writing a proposal for a grant for my PhD research. Once I got onto campus, I realized that the atmosphere here makes it so conducive for learning. There’s also a spirit of altruism around. The interactions I have with my professors and my fellow peers are not cut throat."

Smith said that his research has not been easy, as it requires a lot of time, reading, and studying. But he is keen to take his knowledge of science and to use that to make a difference. Hence, he said research is "a good fit" for him.

"It’s like learning a new language," Smith said. "You have to teach yourself new terms. However, my wife has been a real strength to me. My daughter has also been a good motivation to work hard."