Featured Research

from universities, journals, and other organizations

Acidic microenvironments in tumors aid tumor cell survival, researchers find

Date:
September 6, 2012
Source:
H. Lee Moffitt Cancer Center & Research Institute
Summary:
Researchers have discovered that tumor cell survival relies on adaptation to acidic conditions in the tumor microenvironment. Their research investigating the effects of acidity on breast and pancreatic cancer cell lines revealed the importance of autophagy in acidic microenvironments and suggests that a successful treatment strategy might be based on this autophagic dependence.

Researchers at Moffitt Cancer Center and colleagues at the University of South Florida and Wayne State University have discovered that tumor cell survival relies on adaptation to acidic conditions in the tumor microenvironment. Their research investigating the effects of acidity on breast and pancreatic cancer cell lines revealed the importance of autophagy in acidic microenvironments and suggests that a successful treatment strategy might be based on this autophagic dependence.

The study appears as the cover story for the Aug. 15 issue of Cancer Research, a publication of the American Association for Cancer Research.

"Cancer progression is a multistep process strongly influenced by the physical properties of the tumor microenvironment," said Robert J. Gillies, Ph.D., corresponding author of the study and chair of Moffitt's Department of Cancer Imaging and Metabolism. "Both low oxygen and high acidity can be cytotoxic. Our research suggests that adaptation to these stressful conditions involves autophagy allowing cancer cells to survive, proliferate and eventually metastasize to secondary sites."

According to the authors, not much is known about cell survival mechanisms under acidic conditions, but it has been demonstrated that acidosis can alter gene expression leading to cell types that are adapted for growth and survival in low pH conditions. Identifying low pH survival mechanisms would "give further insight into tumor progression and potentially introduce novel therapeutic strategies," researchers said.

In this study, the researchers tested cancer cell lines under acidic conditions to learn more about autophagy and cellular adaptation. They noted that normal cells in the acidic environment can respond to acidic stress by increasing cell death pathways, thus introducing the need for survival and adaptive mechanisms by cancer cells.

The researchers also noted that their experiments were carried out under atmospheric oxygen levels and they found that the cell's stress response could lead to chronic autophagy even when nutrients and oxygen were in adequate supply.

"We found that cells subjected to transient and chronic low pH growth conditions demonstrate elevated markers for autophagy and are dependent on this process for prolonged survival in acidic environments," explained Jonathan W. Wojtkowiak, lead author of the study and postdoctoral fellow at Moffitt. "A hallmark of cancer is the ability of cancer cells to evade apoptosis. Autophagy supports this by playing a tumor promoter and survival role under certain circumstances during different stages of tumorogenesis."

Their study demonstrated the importance of autophagy in low pH-adapted breast and pancreatic cancer cell lines and the dependence of these cells on autophagy for survival to acidic tumor microenvironment. According to the researchers, they identified a potential therapeutic strategy of using an autophagy inhibitor, one that does not affect cells under neutral conditions.

Funding for the study came from National Institutes of Health grants R01 CA077575, U54 CA143970 and R01 CA 131990.


Story Source:

The above story is based on materials provided by H. Lee Moffitt Cancer Center & Research Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. W. Wojtkowiak, J. M. Rothberg, V. Kumar, K. J. Schramm, E. Haller, J. B. Proemsey, M. C. Lloyd, B. F. Sloane, R. J. Gillies. Chronic Autophagy Is a Cellular Adaptation to Tumor Acidic pH Microenvironments. Cancer Research, 2012; 72 (16): 3938 DOI: 10.1158/0008-5472.CAN-11-3881

Cite This Page:

H. Lee Moffitt Cancer Center & Research Institute. "Acidic microenvironments in tumors aid tumor cell survival, researchers find." ScienceDaily. ScienceDaily, 6 September 2012. <www.sciencedaily.com/releases/2012/09/120906074249.htm>.
H. Lee Moffitt Cancer Center & Research Institute. (2012, September 6). Acidic microenvironments in tumors aid tumor cell survival, researchers find. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2012/09/120906074249.htm
H. Lee Moffitt Cancer Center & Research Institute. "Acidic microenvironments in tumors aid tumor cell survival, researchers find." ScienceDaily. www.sciencedaily.com/releases/2012/09/120906074249.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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