Co-carcinogen

Tolerable Upper Intake Level

A co-carcinogen is a substance that, while not necessarily carcinogenic on its own, can promote the effects of a carcinogen in the development of cancer. Co-carcinogens can enhance the carcinogenicity of other substances by various mechanisms, including increasing the absorption of the carcinogen, altering its metabolism, or affecting the body's immune system.

Mechanisms of Action

Co-carcinogens can act through several mechanisms:

• **Metabolic Activation**: Some co-carcinogens can increase the metabolic activation of procarcinogens into their active carcinogenic forms. For example, certain enzymes in the liver can convert procarcinogens into active carcinogens.
• **Inhibition of DNA Repair**: Co-carcinogens can inhibit the DNA repair mechanisms, making it more likely for mutations to accumulate and lead to cancer.
• **Immune Suppression**: By suppressing the immune system, co-carcinogens can reduce the body's ability to detect and destroy cancerous cells.
• **Inflammation**: Chronic inflammation caused by co-carcinogens can create an environment conducive to cancer development.

Examples of Co-carcinogens

• **Alcohol**: Alcohol is a well-known co-carcinogen that can enhance the carcinogenic effects of tobacco smoke, particularly in cancers of the oral cavity, pharynx, and esophagus.
• **Asbestos**: Asbestos fibers can act as co-carcinogens by promoting the effects of other carcinogens, such as those found in cigarette smoke, leading to lung cancer and mesothelioma.
• **Certain Chemicals**: Chemicals like arsenic and formaldehyde can act as co-carcinogens by enhancing the effects of other carcinogens.

Related Concepts

• Carcinogenesis: The process by which normal cells are transformed into cancer cells.
• Mutagen: An agent that causes genetic mutation.
• Oncogene: A gene that has the potential to cause cancer.
• Tumor Suppressor Gene: A gene that protects a cell from one step on the path to cancer.

See Also

• Carcinogen
• Mutagen
• Oncogene
• Tumor Suppressor Gene
• Cancer
• DNA Repair