Steroid sulfatase

Steroid sulfatase (STS), also known as arylsulfatase C, is an enzyme that plays a crucial role in the metabolism of steroids. It is involved in the desulfation of steroid sulfates, a process that converts these inactive steroid precursors into their active forms. This enzyme is encoded by the STS gene located on the X chromosome. Its activity is essential for the regulation of various physiological processes, including hormone synthesis and metabolism, and it has implications in several diseases.

Function

Steroid sulfatase catalyzes the hydrolysis of sulfate esters from steroid sulfates, such as dehydroepiandrosterone sulfate (DHEAS) and estrone sulfate, which are precursors for the synthesis of active androgens and estrogens, respectively. This enzymatic activity is critical for maintaining the balance of steroid hormones in the body and plays a significant role in the peripheral conversion of these hormones.

Clinical Significance

The activity of steroid sulfatase has been linked to various clinical conditions. Abnormal levels of STS activity can lead to disorders such as X-linked ichthyosis, a genetic condition characterized by scaly skin due to the accumulation of cholesterol sulfate. This is caused by mutations in the STS gene leading to a deficiency in STS enzyme activity.

In addition to its role in genetic disorders, steroid sulfatase is also implicated in hormone-dependent cancers, such as breast and prostate cancer. The enzyme's activity in peripheral tissues can increase the local production of active estrogens and androgens, which can stimulate the growth of hormone-dependent tumors. Consequently, STS inhibitors are being explored as potential therapeutic agents for treating these types of cancers.

Genetics

The STS gene is located on the X chromosome (Xp22.3). Mutations in this gene can lead to a deficiency in steroid sulfatase activity, resulting in clinical conditions such as X-linked ichthyosis. The genetic basis of these conditions provides insight into the critical role of steroid sulfatase in human physiology and disease.

Treatment and Research

Research into steroid sulfatase inhibitors has gained interest for their potential use in treating hormone-dependent cancers. By inhibiting the activity of STS, it is possible to reduce the local production of active hormones in peripheral tissues, thereby potentially slowing the growth of tumors. Additionally, understanding the genetic and molecular mechanisms underlying STS deficiency can lead to improved treatments for conditions like X-linked ichthyosis.

See Also

• Steroid
• Sulfatase
• Hormone synthesis
• X-linked ichthyosis
• Breast cancer
• Prostate cancer