4-Hydroxyestrone

4-Hydroxyestrone.svg

4-Hydroxyestrone (4-OHE1) is a metabolite of the estrogen estrone. It is one of the several hydroxylated derivatives of estrone, which include 2-Hydroxyestrone and 16α-Hydroxyestrone.

Biochemistry

4-Hydroxyestrone is formed through the hydroxylation of estrone by the enzyme cytochrome P450 1B1 (CYP1B1). This metabolic pathway is part of the estrogen metabolism process, which occurs primarily in the liver and other tissues.

Biological Activity

4-Hydroxyestrone has been studied for its potential role in carcinogenesis. It can form catechol estrogens, which may undergo further oxidation to form quinones. These quinones can react with DNA, leading to the formation of DNA adducts and potentially causing mutations that contribute to the development of cancer.

Health Implications

The balance between different estrogen metabolites, such as 2-hydroxyestrone and 4-hydroxyestrone, is thought to influence the risk of developing hormone-dependent cancers, such as breast cancer and endometrial cancer. Elevated levels of 4-hydroxyestrone have been associated with an increased risk of these cancers.

Research

Ongoing research is focused on understanding the precise mechanisms by which 4-hydroxyestrone and other estrogen metabolites contribute to cancer risk. This includes studies on the role of genetic polymorphisms in enzymes involved in estrogen metabolism and the impact of environmental factors on these metabolic pathways.

See Also

• Estrone
• Estrogen metabolism
• Catechol estrogen
• Cytochrome P450
• Breast cancer
• Endometrial cancer

References

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