Engineered Nanoparticles Show Promise For Targeted Cancer Therapy
Outside Kathryn Whitehead’s office at Carnegie Mellon University is a nametag with the words “Nanoparticle Queen” written in black marker. She said a student made it for her at the Department of Chemical Engineering’s weekly happy hour, and she liked it enough to slap it on the wall.
Her official title is Assistant Professor of Chemical Engineering and Biomedical Engineering and she does indeed spend a lot of time working with nanoparticles.
“We make nanoparticles made up of lipids, which almost resemble the materials found in soaps,” she said. “We package up a type of drug inside these nanoparticles called siRNA. Sounds fancy, but it’s a drug that can turn off certain proteins present in the cancer that help the cancer to grow.”
Unlike traditional therapies, these particles will only affect cancer cells. Each nanoparticle has an antibody attached to it that is attracted only to particular molecules expressed by cancer cells, but not by healthy cells.
Once the nanoparticle is picked up by the cancer cell the siRNA can get to work. The name stands for short interfering RNA. RNA is ribonucleic acid, which carries messages from the DNA to the rest of the cell, and siRNA silences the messages that promote growth.
The drug was discovered in the late 1990s, and the scientists responsible were awarded the Nobel Prize in 2006. But Whitehead said figuring out how to get the drug into the targeted cells has been a challenge.
“If you just inject this drug by itself, into the body, it gets cleared very rapidly from the kidney and it doesn’t do anything inside the body,” she said. “So it really was up to the drug delivery scientists to figure out how do we package up this drug so that it can actually be used for all these wonderful therapeutic purposes that were envisioned?”
Whitehead said both siRNA and nanoparticles can potentially be used to treat a wide variety of illnesses, from cancer to HIV to hereditary disorders. But her work is focused specifically on a rare and deadly type of blood cancer called mantle cell lymphoma.
Four years ago, she met a hematologist from Allegheny Health Network’s Western Pennsylvania Hospital named John Lister, who was working to learn more about the cell biology of mantle cell lymphoma in his lab.
Lister said targeted therapies, like the one Whitehead is working on, are the future of cancer treatment. Current therapies, such as radiation and chemotherapy, can often make patients feel even sicker and diminish quality of life by damaging healthy tissues as well as cancerous cells. But drugs like Whitehead’s would essentially ignore healthy cells altogether.
“I think that that’s where the whole field is going,” he said. “Therapy will be targeted specifically to the tumor itself or to the organs in which the tumor finds itself the majority of the time. Also these agents will be chosen on the basis of what genetic mutations are present in the cancer itself.”
I think that that is where the whole field is going. Therapy will be targeted specifically to the tumor itself.
The prognosis for patients with mantle cell lymphoma is not great. Whitehead said the cancer will often go into remission for a year or two, then come back stronger than before. The current life expectancy after a mantle cell lymphoma diagnosis is five to seven years.
“It’s a very lofty goal when you talk about cancer, to talk about curing it. It’s not necessarily a realistic expectation,” she said. “For these patients and for their families who are suffering alongside of them, if we could elongate that to eight to 10 years, a few years can make a big difference in a person’s life and I’d be delighted if we could have that kind of impact.”
Whitehead is currently doing animal trials with the technology, and said she anticipates that human clinical trials are least five to 10 years away.
In this week's Tech Headlines:
- It seems we aren’t getting much smarter when it comes to falling for Internet phishing scams. A recent study out of Carnegie Mellon's CyLab Security and Privacy Institute found just how likely we are to take the bait. On average, study participants were only able to correctly identify about half of the phishing emails presented to them. Researchers said that number could number could be overly optimistic given the high number of non-phishing emails that were rejected as scams by the participants. However, it seems there is still some hope because only about a quarter phishing links imbedded in the emails were clicked.
- As Yahoo's embattled email service suffers through a slew of bad news, some users are finding it hard to leave. The site has disabled automatic email forwarding. According to the Associated Press, while those who've set up forwarding in the past are unaffected, some who want to leave over recent hacking and surveillance revelations are struggling to switch to rival services. Yahoo Inc. declined to comment on the recent change beyond pointing to a three-line notice on Yahoo's help site, which said that that the company temporarily disabled the feature "while we work to improve it."