Featured Research

from universities, journals, and other organizations

What's Feeding Cancer Cells?

Date:
February 22, 2009
Source:
Johns Hopkins Medical Institutions
Summary:
Cancer cells need a lot of nutrients to multiply and survive. While much is understood about how cancer cells use blood sugar to make energy, not much is known about how they get other nutrients. Now, researchers have discovered how the Myc cancer-promoting gene uses microRNAs to control the use of glutamine, a major energy source.

Cancer cells need a lot of nutrients to multiply and survive. While much is understood about how cancer cells use blood sugar to make energy, not much is known about how they get other nutrients. Now, researchers at the Johns Hopkins University School of Medicine have discovered how the Myc cancer-promoting gene uses microRNAs to control the use of glutamine, a major energy source. The results, which shed light on a new angle of cancer that might help scientists figure out a way to stop the disease, appear Feb. 15 online at Nature.

"While we were looking for how Myc promotes cancer growth, it was unexpected to find that Myc can increase use of glutamine by cancer cells," says Chi V. Dang, M.D., Ph.D., the Johns Hopkins Family Professor of Oncology at Johns Hopkins. "This surprising discovery only came about after scientists from several disciplines came together across Hopkins to collaborate — it was a real team effort."

In their search to learn how Myc promotes cancer, the researchers teamed up with protein experts, and using human cancer cells with Myc turned on or off, they looked for proteins in the cell's powerhouse — the mitochondria — that appeared to respond to Myc. They found eight proteins that were distinctly turned up in response to Myc.

At the top of the list of mitochondrial proteins that respond to Myc was glutaminase, or GLS, which, according to Dang, is the first enzyme that processes glutamine and feeds chemical reactions that make cellular energy. So the team then asked if removing GLS could stop or slow cancer cell growth. Compared to cancer cells with GLS, those lacking GLS grew much slower, which led the team to conclude that yes, GLS does affect cell growth stimulated by Myc.

The researchers then wanted to figure out how Myc enhances GLS protein expression. Because Myc can control and turn on genes, the team guessed that Myc might directly turn on the GLS gene, but they found that wasn't the case. "So then we thought, maybe there's an intermediary, maybe Myc controls something that in turn controls GLS," says Ping Gao, Ph.D., a research associate in hematology at Johns Hopkins.

They then built on previous work done with the McKusick-Nathans Institute of Genetic Medicine at Hopkins where they discovered that Myc turns down some microRNAs, small bits of RNA that can bind to and inhibit RNAs, which contain instructions for making proteins. The team looked more carefully at the GLS RNA and found that it could be bound and regulated by two microRNAs, called miR23a and miR23b, pointing to the microRNAs as the intermediary that links Myc to GLS expression.

"Next we want to study GLS in mice to see if removing it can slow or stop cancer growth," says Gao. "If we know how cancer cells differ from normal cells in how they make energy and use nutrients, we can identify new pathways to target for designing drugs with fewer side effects."

This study was funded by the National Institutes of Health, the National Cancer Institute, the Rita Allen Foundation, the Leukemia and Lymphoma Society and the Sol Goldman Center for Pancreatic Cancer Research.

Authors on the paper are Ping Gao, Irina Tchernyshyov, Tsung-Cheng Chang, Yun-Sil Lee, Karen Zeller, Angelo De Marzo, Jennifer Van Eyk, Joshua Mendell and Chi V. Dang, of Johns Hopkins; and Kayoko Kita and Takfumi Ochi of Teikyo University in Japan.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ping Gao, Irina Tchernyshyov, Tsung-Cheng Chang, Yun-Sil Lee, Kayoko Kita, Takafumi Ochi, Karen I. Zeller, Angelo M. De Marzo, Jennifer E. Van Eyk, Joshua T. Mendell, Chi V. Dang. c-Myc suppression of miR-23a/b enhances mitochondrial glutaminase expression and glutamine metabolism. Nature, Feb 15, 2009; DOI: 10.1038/nature07823

Cite This Page:

Johns Hopkins Medical Institutions. "What's Feeding Cancer Cells?." ScienceDaily. ScienceDaily, 22 February 2009. <www.sciencedaily.com/releases/2009/02/090217092748.htm>.
Johns Hopkins Medical Institutions. (2009, February 22). What's Feeding Cancer Cells?. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2009/02/090217092748.htm
Johns Hopkins Medical Institutions. "What's Feeding Cancer Cells?." ScienceDaily. www.sciencedaily.com/releases/2009/02/090217092748.htm (accessed September 23, 2014).

Share This



More Health & Medicine News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Liberia Pleads for Help to Fight Ebola

Liberia Pleads for Help to Fight Ebola

AP (Sep. 22, 2014) Liberia's finance minister is urging the international community to quickly follow through on pledges of cash to battle Ebola. Bodies are piling up in the capital Monrovia as the nation awaits more help. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Ebola Doctor Says Border Controls Critical

Ebola Doctor Says Border Controls Critical

AP (Sep. 22, 2014) A Florida doctor who helped fight the expanding Ebola outbreak in West Africa says the disease can be stopped, but only if nations quickly step up their response and make border control a priority. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com
Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) 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