Related Experiment Videos
Carcinogenicity and mutagenicity testing, then and now
1American Health Foundation, 1 Dana Road, Valhalla, NY, USA. john_weisburger@nymc.edu
Abstract:
Cancer is a dread disease worldwide. Mortality of individuals suffering from cancer is high, despite the current improved methods of precocious detection, surgery and therapy. Prevention of cancer is the recognized goal of many activities in cancer research. This aim was recognized early to involve the bioassay of environmental chemicals or mixtures. The first such study involved application of coal tar to the ear of rabbits, and later on to the skin of mice. Subsequently, laboratory rats were introduced, and hamsters were utilized as a substitute for the unwieldy tests in rabbits. Investigators also became concerned with the mechanisms of carcinogenesis, and more definitive approaches to carcinogen bioassay in laboratory animals, as possible indicators of cancer risk in humans. These tests were expensive and lengthy, and did not serve the important purpose of accurately measuring risk of cancer to humans. Once it was realized that DNA and the genetic apparatus might be a key target, rapid bioassays in bacterial and mammalian cell systems were introduced successfully. Thus, batteries of tests are now available to detect effectively human cancer risks, and provide novel approaches to determine the underlying mechanisms, as a sound basis for cancer prevention.
Insights
Cancer prevention is a key research goal. New rapid bioassays, focusing on DNA damage, now effectively detect human cancer risks and inform prevention strategies.
Area of Science:
- Oncology
- Toxicology
- Molecular Biology
Background:
- Cancer remains a leading cause of mortality globally, necessitating advancements in prevention strategies.
- Early cancer research focused on bioassays of environmental chemicals using animal models.
- Traditional animal bioassays were lengthy, costly, and limited in accurately assessing human cancer risk.
Observation:
- Historical bioassays involved applying substances like coal tar to animals (rabbits, mice, rats, hamsters).
- Investigating the mechanisms of carcinogenesis led to more refined animal testing approaches.
- Limitations in accurately measuring human cancer risk with existing animal models were identified.
Findings:
- The realization of DNA as a critical target in carcinogenesis spurred the development of new methods.
- Rapid bioassays utilizing bacterial and mammalian cell systems were successfully introduced.
- Current test batteries effectively detect human cancer risks and elucidate underlying mechanisms.
Implications:
- These advanced bioassays provide a sound basis for effective cancer prevention.
- Novel approaches enable a deeper understanding of carcinogenesis mechanisms.
- The shift towards cell-based assays offers more efficient and accurate risk assessment.