Featured Research

from universities, journals, and other organizations

Hard-to-treat Myc-driven cancers may be susceptible to drug already used in clinic

Date:
December 14, 2012
Source:
American Association for Cancer Research (AACR)
Summary:
Drugs that are used in the clinic to treat some forms of breast and kidney cancer and that work by inhibiting the signaling molecule mTORC1 might have utility in treating some of the more than 15 percent of human cancers driven by alterations in the Myc gene, according to data from a preclinical study.

Drugs that are used in the clinic to treat some forms of breast and kidney cancer and that work by inhibiting the signaling molecule mTORC1 might have utility in treating some of the more than 15 percent of human cancers driven by alterations in the Myc gene, according to data from a preclinical study published in Cancer Discovery, a journal of the American Association for Cancer Research.

"More than 1 million people diagnosed with cancer each year have a tumor driven by alterations in the Myc gene," said Grant A. McArthur, M.D., Ph.D., professor of translational research at the Peter MacCallum Cancer Centre in Melbourne, Australia. "However, it has proven impossible to develop drugs that effectively target Myc.

"One of Myc's functions is to regulate cell growth. Because mTORC1 is also a regulator of cell growth, we hypothesized that inhibiting mTORC1 with the drug everolimus might suppress Myc-driven tumor initiation and growth."

McArthur and his colleagues tested their hypothesis in a mouse model of Myc-driven lymphoma and found that treatment with everolimus provided strong protection against disease: only four of 33 mice treated with everolimus developed lymphoma, while 22 of 34 mice treated with placebo developed the disease.

In addition, treatment with everolimus led to tumor regression and significantly improved survival compared with placebo in mice with established lymphomas. However, all of these mice eventually relapsed as a result of the growth of lymphoma cells resistant to the effects of everolimus.

"These data confirmed our hypothesis that mTORC1 inhibition could suppress Myc-driven tumor initiation and growth," said McArthur. "The surprise was found in how mTORC1 inhibition led to tumor regression. We had expected that it would trigger cancer cells to die by a cellular process known as apoptosis, but we found that this was not the case."

Detailed analysis of the tumors indicated that everolimus caused tumor regression by inducing cellular senescence.

According to McArthur, normal cells protect themselves when cancer-driving genes are switched on is by entering a state called senescence. When cancers develop, they have found ways to overcome this safeguard. "Our data indicate that one way in which cancers bypass senescence, in particular senescence induced by Myc, is through a signaling pathway involving mTORC1," he said.

Resistance to everolimus treatment in mice with established lymphomas was associated with loss of the function of p53, a protein known to help suppress tumor formation and growth.

"The loss of effectiveness of everolimus therapy against lymphoma cells deficient in p53 function has important clinical implications," said McArthur. "Everolimus could be a useful new string to the bow for clinicians treating patients with Myc-driven cancers, in particular B cell lymphomas, but that it would be helpful only to those patients with functional p53."


Story Source:

The above story is based on materials provided by American Association for Cancer Research (AACR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Meaghan Wall, Gretchen Poortinga, Kym L. Stanley, Ralph K. Lindemann, Michael Bots, Christopher J. Chan, Megan J. Bywater, Kathryn M. Kinross, Megan V. Astle, Kelly Waldeck, Katherine M. Hannan, Jake Shortt, Mark J. Smyth, Scott W. Lowe, Ross D. Hannan, Richard B. Pearson, Ricky W. Johnstone, and Grant A. McArthur. The mTORC1 Inhibitor Everolimus Prevents and Treats Eμ-Myc Lymphoma by Restoring Oncogene-Induced Senescence. Cancer Discovery, 2012; DOI: 10.1158/2159-8290.CD-12-0404

Cite This Page:

American Association for Cancer Research (AACR). "Hard-to-treat Myc-driven cancers may be susceptible to drug already used in clinic." ScienceDaily. ScienceDaily, 14 December 2012. <www.sciencedaily.com/releases/2012/12/121214102229.htm>.
American Association for Cancer Research (AACR). (2012, December 14). Hard-to-treat Myc-driven cancers may be susceptible to drug already used in clinic. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2012/12/121214102229.htm
American Association for Cancer Research (AACR). "Hard-to-treat Myc-driven cancers may be susceptible to drug already used in clinic." ScienceDaily. www.sciencedaily.com/releases/2012/12/121214102229.htm (accessed April 17, 2014).

Share This



More Health & Medicine News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com
Formerly Conjoined Twins Released From Dallas Hospital

Formerly Conjoined Twins Released From Dallas Hospital

Newsy (Apr. 16, 2014) Conjoined twins Emmett and Owen Ezell were separated by doctors in August. Now, nearly nine months later, they're being released from the hospital. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
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:
from the past week

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