Featured Research

from universities, journals, and other organizations

New way to stop cancer? Block their recycling system, and tumor cells die

Date:
May 8, 2012
Source:
Perelman School of Medicine at the University of Pennsylvania
Summary:
All cells have the ability to recycle unwanted or damaged proteins and reuse the building blocks as food. But cancer cells have ramped up the system, called autophagy, and rely on it to escape damage in the face of chemotherapy and other treatments. Now, researchers have developed a potent new drug that clogs up the recycling machinery and kills tumor cells in mouse models.

All cells have the ability to recycle unwanted or damaged proteins and reuse the building blocks as food. But cancer cells have ramped up the system, called autophagy, and rely on it to escape damage in the face of chemotherapy and other treatments. Now, researchers at the Perelman School of Medicine; the Abramson Cancer Center; and the School of Arts and Sciences, at the University of Pennsylvania, have developed a potent new drug that clogs up the recycling machinery and kills tumor cells in mouse models.

Related Articles


Ravi K. Amaravadi, MD, assistant professor of Medicine, and colleagues showed previously that an old malaria drug, hydroxychloroquine, reduces autophagy in cancer cells and makes them more likely to die when exposed to chemotherapy. The strategy is currently being tested in clinical trials, and preliminary results are promising. The catch, though, is that it's not always possible to give patients a high enough dose of hydroxychloroquine to have an effect on their tumor cells.

Amaravadi teamed up with Jeffrey Winkler, PhD, the Merriam Professor of Chemistry, to design a series of more potent versions of chloroquine. They describe the design, chemical synthesis, and biological evaluation of a highly effective, new compound called Lys05, in the early edition of the Proceedings of the National Academy of Sciences this week.

Unlike hydroxychloroquine, which has little impact on tumor cells when used as a single agent, the new drug, called Lys05, slows tumor growth in animal models even in the absence of other anti-tumor therapies. What's more, the Lys05 dose that is toxic to cancer cells, which are addicted to recycling and rely on it much more heavily than healthy cells, has little or no effect on healthy cells.

"We see that Lys05 has anti-tumor activity at doses that are non-toxic for the animals," Amaravadi says. "This single-agent anti-tumor activity suggests this drug, or its derivative, may be even more effective in patients than hydroxychloroquine." Remarkably, however, when the investigators increase the dose of Lys05, some animals develop symptoms that mimic a known genetic deficiency in an autophagy gene, ATG16L1, which affects some patients with Crohn's disease . That similarity -- technically called a phenocopy -- clearly shows that Lys05 works by interfering with the recycling system in cells.

Lys05, and its companion compound Lys01, aren't quite ready for testing in patients, according to Amaravadi. Before that can happen, the molecules need to be optimized and undergo more toxicity testing in animals. Amaravadi and Winkler hope to team up with an industry partner for that portion of the project.

In the meantime, though, Amaravadi says the work illustrates just how important autophagy is to cancer cells, and provides an important new step for future therapies.

Co-authors on the paper include Quentin McAfee, Zhihui Zhang, Arabinda Samanta, Samuel M. Levi, Xiao-Hong Ma, Shengfu Piao, John P. Lynch, Takeshi Uehara, and Antonia R. Sepulveda, all from Penn, and Lisa E. Davis from the University of the Sciences in Philadelphia.

The work was supported by an Abramson Cancer Center pilot award and the National Cancer Institute (1K23CA120862) and a seed grant from the Abramson Cancer Center.


Story Source:

The above story is based on materials provided by Perelman School of Medicine at the University of Pennsylvania. Note: Materials may be edited for content and length.


Journal Reference:

  1. Q. McAfee, Z. Zhang, A. Samanta, S. M. Levi, X.-H. Ma, S. Piao, J. P. Lynch, T. Uehara, A. R. Sepulveda, L. E. Davis, J. D. Winkler, R. K. Amaravadi. Autophagy inhibitor Lys05 has single-agent antitumor activity and reproduces the phenotype of a genetic autophagy deficiency. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1118193109

Cite This Page:

Perelman School of Medicine at the University of Pennsylvania. "New way to stop cancer? Block their recycling system, and tumor cells die." ScienceDaily. ScienceDaily, 8 May 2012. <www.sciencedaily.com/releases/2012/05/120508112705.htm>.
Perelman School of Medicine at the University of Pennsylvania. (2012, May 8). New way to stop cancer? Block their recycling system, and tumor cells die. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2012/05/120508112705.htm
Perelman School of Medicine at the University of Pennsylvania. "New way to stop cancer? Block their recycling system, and tumor cells die." ScienceDaily. www.sciencedaily.com/releases/2012/05/120508112705.htm (accessed October 30, 2014).

Share This



More Health & Medicine News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Reuters - Innovations Video Online (Oct. 29, 2014) A Swedish amputee who became the first person to ever receive a brain controlled prosthetic arm is able to manipulate and handle delicate objects with an unprecedented level of dexterity. The device is connected directly to his bone, nerves and muscles, giving him the ability to control it with his thoughts. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Google To Use Nanoparticles, Wearables To Detect Disease

Google To Use Nanoparticles, Wearables To Detect Disease

Newsy (Oct. 29, 2014) Google X wants to improve modern medicine with nanoparticles and a wearable device. It's all an attempt to tackle disease detection and prevention. Video provided by Newsy
Powered by NewsLook.com
Can Drinking Milk Lead To Early Death?

Can Drinking Milk Lead To Early Death?

Newsy (Oct. 29, 2014) Researchers in Sweden released a study showing heavy milk drinkers face an increased mortality risk from a variety of causes. Video provided by Newsy
Powered by NewsLook.com
Obama: The US Will Not 'run and Hide' From Ebola

Obama: The US Will Not 'run and Hide' From Ebola

AP (Oct. 29, 2014) Surrounded by health care workers in the White House East Room, President Barack Obama said the U.S. will likely see additional Ebola cases in the weeks ahead. But he said the nation can't seal itself off in the fight against the disease. (Oct. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins