(NIH) - 4/7/2011 - Researchers at the National Institutes of Health have discovered how exposure to arsenic can turn normal stem cells into cancer stem cells and spur tumor growth. Inorganic arsenic, which affects the drinking water of millions of people worldwide, has been previously shown to be a human carcinogen. A growing body of evidence suggests that cancer is a stem-cell based disease. Normal stem cells are essential to normal tissue regeneration, and to the stability of organisms and processes. But cancer stem cells are thought to be the driving force for the formation, growth, and spread of tumors.
Michael Waalkes, Ph.D., and his team at the National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, part of NIH, had shown previously that normal cells become cancerous when they are treated with inorganic arsenic. This new study shows that when these cancer cells are placed near, but not in contact with normal stem cells, the normal stem cells very rapidly acquire the characteristics of cancer stem cells. It demonstrates that malignant cells are able to send molecular signals through a semi-permeable membrane, where cells can't normally pass, and turn the normal stem cells into cancer stem cells.
“This paper shows a different and unique way that cancers can expand by recruiting nearby normal stem cells and creating an overabundance of cancer stem cells,” Waalkes said. “The recruitment of normal stem cells into cancer stem cells could have broad implications for the carcinogenic process in general, including tumor growth and metastases.”
This reveals a potentially important aspect of arsenic carcinogenesis and may help explain observances by researchers working with arsenic that arsenic often causes multiple tumors of many types to form on the skin or inside the body. The paper is online in Environmental Health Perspectives.Waalkes' lab started working with stem cells about five years ago. The researchers used a prostate stem cell line, not embryonic stem cells.
“Using stem cells to answer questions about disease is an important new growing area of research. Stem cells help to explain a lot about carcinogenesis, and it is highly likely that stem cells are contributing factors to other chronic diseases,” Waalkes said.
Stem cells are unique in the body. They stay around for a long time and are capable of dividing and renewing themselves. “Most cancers take 30 or 40 years to develop,” said Linda Birnbaum, Ph.D., director of NIEHS and NTP. “It makes sense that stem cells may play a role in the developmental basis of adult disease. We know that exposures to toxicants during development and growth can lead to diseases later in life.”
Next, the laboratory team will look to see if this finding is unique to arsenic or if it is applicable to other organic and inorganic carcinogens.
Source:
http://www.nih.gov/
MARK TWAIN: FATHER OF AMERICAN LITERATURE -- FACT FACTS
ABOVE: Samuel Clemens, aka Mark Twain, was cemented as a premier writer of late 19th century America with his works "The Adventures of Tom Sawyer" and "Adventures of Huckleberry Finn." Find out more about his life and writing in this video.
Showing posts with label water. Show all posts
Showing posts with label water. Show all posts
EPA To Provide Millions to Clean Up Beaches
WASHINGTON – 1/31/2012 - The U.S. Environmental Protection Agency (EPA) announced on Jan. 31 that it will provide $9.8 million in grants to 38 states, territories and tribes to help protect the health of swimmers at America’s beaches. The agency also launched an improved website for beach advisories and closings, which will allow the public to more quickly and easily access the most current water quality and pollution testing information for more than 6,000 U.S. beaches.
The website, called BEACON, has the capability to update as frequently as every two hours based on new data provided by states, territories and tribes. Users will have access to mapped location data for beaches and water monitoring stations, monitoring results for various pollutants such as bacteria and algae, and data on public notification of beach water quality advisories and closures. For the first time, users can also access reports that combine notifications and water quality monitoring data. The enhanced system also uses enhanced map navigation and report display tools.
The majority of beach advisories and closures in the United States are due to water test results indicating bacterial contamination, which can make people sick. Bacterial contamination comes from a variety of sources. Some examples are sewer overflows, untreated stormwater runoff, boating wastes, wildlife and pet waste, and malfunctioning septic systems.
During each swimming season, state and local health and environmental protection agencies monitor the quality of water at the nation’s beaches. When bacteria levels in the water are too high, these agencies notify the public by posting beach warnings or closing the beach.
The grants will help local authorities monitor beach water quality and notify the public of conditions that may be unsafe for swimming. This is the 12th year that EPA is providing beach grant funds, bringing the total amount EPA has made available to nearly $111 million.
As a result, the number of monitored beaches has more than tripled to more than 3,600 in 2010. Grant applications must be received within 60 days of publication of EPA’s notice in the Federal Register. EPA expects to award the grants later this year.
View EPA’s enhanced beach advisory and closing information: http://watersgeo.epa.gov/BEACON2/
More information on the grants: http://water.epa.gov/grants_funding/beachgrants/index.cfm
The website, called BEACON, has the capability to update as frequently as every two hours based on new data provided by states, territories and tribes. Users will have access to mapped location data for beaches and water monitoring stations, monitoring results for various pollutants such as bacteria and algae, and data on public notification of beach water quality advisories and closures. For the first time, users can also access reports that combine notifications and water quality monitoring data. The enhanced system also uses enhanced map navigation and report display tools.
The majority of beach advisories and closures in the United States are due to water test results indicating bacterial contamination, which can make people sick. Bacterial contamination comes from a variety of sources. Some examples are sewer overflows, untreated stormwater runoff, boating wastes, wildlife and pet waste, and malfunctioning septic systems.
During each swimming season, state and local health and environmental protection agencies monitor the quality of water at the nation’s beaches. When bacteria levels in the water are too high, these agencies notify the public by posting beach warnings or closing the beach.
The grants will help local authorities monitor beach water quality and notify the public of conditions that may be unsafe for swimming. This is the 12th year that EPA is providing beach grant funds, bringing the total amount EPA has made available to nearly $111 million.
As a result, the number of monitored beaches has more than tripled to more than 3,600 in 2010. Grant applications must be received within 60 days of publication of EPA’s notice in the Federal Register. EPA expects to award the grants later this year.
View EPA’s enhanced beach advisory and closing information: http://watersgeo.epa.gov/BEACON2/
More information on the grants: http://water.epa.gov/grants_funding/beachgrants/index.cfm
Source: U.S. Environmental Protection Agency release
