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 31, 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 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. 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