Website Search
ID 994

Causes, Mold: Aflatoxin action

Description:
Aflatoxin causes DNA damage and with prolonged exposure to aflatoxin, cells accumulate DNA mutations and thus are at increased risk of developing into cancer cells.
Transcript:
Aflatoxin action Aflatoxin is a byproduct of mold that can cause DNA damage. With prolonged exposure to aflatoxin, cells accumulate DNA mutations and thus are at increased risk of developing into cancer cells. Click the forward arrow below to find out more about how aflatoxin damages DNA. Thomas Kensler, Ph.D., Bloomberg School of Public Health: “A lot is known about the mechanisms of activation and action of aflatoxin. It forms a reactive epoxide intermediate, which then forms a covalent bond to the N7 atom of guanine in site-specific sequences within critical target genes leading to mutations, altered function, loss of function of those genes. p53 is a major target for aflatoxin.” “Aflatoxin is probably the best example of a carcinogen, a human carcinogen that targets p53. There are multiple hot spots in the p53 gene targeted by different types of carcinogens. Aflatoxin targets a guanine in codon 249 in the p53 gene.” Thomas Kensler, Ph.D. is a professor at John Hopkins Bloomberg School of Public Health. His research focuses on the molecular mechanisms involved in the development of cancers linked to exposure to environmental carcinogens. This research has led to potential chemopreventative strategies for liver cancer in populations at high risk for aflatoxin exposure. “I believe the importance of aflatoxin and the causation of liver cancer results from a life long series of exposures. Intermittent sort of random exposures are not likely to sort of tip the balance and create the cancer cells; our defense mechanisms are pretty good for those very low levels and intermittent levels of exposure. But there is a chronic long-term exposure through the diet in many of these high-risk areas. In turn that means we need a chronic long term commitment to a preventive intervention. We need an intervention that people could take every day or at least several times a week, but not just for weeks to make the problem go away, but for the rest of their lives. For as long as the aflatoxin exposure is there, the need for the countermanding or intervention approach is also very important.”
Keywords:
critical target, p53 gene, human carcinogen, liver cancer, cancer cells, defense mechanisms, cancer results, aflatoxin, dna damage, environmental carcinogens, preventive intervention, risk areas
Creative Commons License This work by Cold Spring Harbor Laboratory is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

Related content:

988. Causes, mold
Aflatoxin, a byproduct of molds, is a potent cancer-causing agent. Long-term exposure to aflatoxin has been linked to increased incidence of liver cancer.
995. Causes, Mold: Aflatoxin action, Kensler
Professor Kensler explains that the importance of aflatoxin and the causation of liver cancer results from a life long series of exposures.
991. Causes, Mold: Aflatoxin, Kensler
Professor Kensler explains that Aflatoxin is a lipid soluble molecule that is rapidly absorbed and it goes first to the liver where there are enzymes that will chemically biotransform it into a very reactive chemical.
989. Causes, Mold: Aflatoxin
In this section learn how Aflatoxin a contaminating byproduct of mold caused liver cancer in animals and solicited strict guidelines to regulate the levels of Aflatoxin in the U.S. food supply today.
997. Causes, Mold: Prevention, Kensler clip 1
Professor Kensler explains their clinical trials in which chlorophyllin was administered as a therapy and the resultant levels of aflatoxin DNA damage products present in urine samples.
996. Causes, Mold: Prevention
In this section learn about inexpensive and safe substances being investigated that may decrease the risk of liver cancer.
998. Causes, Mold: Prevention, Kensler clip 2
Professor Kensler explains that there is a lot of interest in discovering new classes of chemopreventative agents and foods such as, fruits and vegetables appear to be a very rich source.
954. Causes, Smoking, all sections
This section explains that lung cancer is the leading cause of cancer deaths in the United States and it is almost entirely preventable, since the vast majority of cases are due to cigarette smoking.
960. Causes, Smoking: p53
This series of animations shows how mutations in the p53 gene are found in 70% of lung tumors, the highest rate for any cancer.
1025. Causes, Diet
In order to identify cancer causes and prevention strategies, researchers conduct a cohort of studies where they collect information from large groups of individuals over many years.
Cold Spring Harbor Laboratory
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving